From da142f3d373a6ddaca0119615a8db2175ddc4121 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 5 Dec 2025 15:26:55 -0800 Subject: KVM: Remove subtle "struct kvm_stats_desc" pseudo-overlay Remove KVM's internal pseudo-overlay of kvm_stats_desc, which subtly aliases the flexible name[] in the uAPI definition with a fixed-size array of the same name. The unusual embedded structure results in compiler warnings due to -Wflex-array-member-not-at-end, and also necessitates an extra level of dereferencing in KVM. To avoid the "overlay", define the uAPI structure to have a fixed-size name when building for the kernel. Opportunistically clean up the indentation for the stats macros, and replace spaces with tabs. No functional change intended. Reported-by: Gustavo A. R. Silva Closes: https://lore.kernel.org/all/aPfNKRpLfhmhYqfP@kspp Acked-by: Marc Zyngier Acked-by: Christian Borntraeger [..] Acked-by: Anup Patel Reviewed-by: Bibo Mao Acked-by: Gustavo A. R. Silva Link: https://patch.msgid.link/20251205232655.445294-1-seanjc@google.com Signed-off-by: Sean Christopherson --- include/linux/kvm_host.h | 83 ++++++++++++++++++++---------------------------- 1 file changed, 35 insertions(+), 48 deletions(-) (limited to 'include/linux') diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index d93f75b05ae2..7428d9949382 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1927,56 +1927,43 @@ enum kvm_stat_kind { struct kvm_stat_data { struct kvm *kvm; - const struct _kvm_stats_desc *desc; + const struct kvm_stats_desc *desc; enum kvm_stat_kind kind; }; -struct _kvm_stats_desc { - struct kvm_stats_desc desc; - char name[KVM_STATS_NAME_SIZE]; -}; - -#define STATS_DESC_COMMON(type, unit, base, exp, sz, bsz) \ - .flags = type | unit | base | \ - BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \ - BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \ - BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \ - .exponent = exp, \ - .size = sz, \ +#define STATS_DESC_COMMON(type, unit, base, exp, sz, bsz) \ + .flags = type | unit | base | \ + BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) | \ + BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) | \ + BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK), \ + .exponent = exp, \ + .size = sz, \ .bucket_size = bsz -#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \ - { \ - { \ - STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \ - .offset = offsetof(struct kvm_vm_stat, generic.stat) \ - }, \ - .name = #stat, \ - } -#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \ - { \ - { \ - STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \ - .offset = offsetof(struct kvm_vcpu_stat, generic.stat) \ - }, \ - .name = #stat, \ - } -#define VM_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \ - { \ - { \ - STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \ - .offset = offsetof(struct kvm_vm_stat, stat) \ - }, \ - .name = #stat, \ - } -#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \ - { \ - { \ - STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \ - .offset = offsetof(struct kvm_vcpu_stat, stat) \ - }, \ - .name = #stat, \ - } +#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \ +{ \ + STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \ + .offset = offsetof(struct kvm_vm_stat, generic.stat), \ + .name = #stat, \ +} +#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \ +{ \ + STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \ + .offset = offsetof(struct kvm_vcpu_stat, generic.stat), \ + .name = #stat, \ +} +#define VM_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \ +{ \ + STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \ + .offset = offsetof(struct kvm_vm_stat, stat), \ + .name = #stat, \ +} +#define VCPU_STATS_DESC(stat, type, unit, base, exp, sz, bsz) \ +{ \ + STATS_DESC_COMMON(type, unit, base, exp, sz, bsz), \ + .offset = offsetof(struct kvm_vcpu_stat, stat), \ + .name = #stat, \ +} /* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */ #define STATS_DESC(SCOPE, stat, type, unit, base, exp, sz, bsz) \ SCOPE##_STATS_DESC(stat, type, unit, base, exp, sz, bsz) @@ -2053,7 +2040,7 @@ struct _kvm_stats_desc { STATS_DESC_IBOOLEAN(VCPU_GENERIC, blocking) ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header, - const struct _kvm_stats_desc *desc, + const struct kvm_stats_desc *desc, void *stats, size_t size_stats, char __user *user_buffer, size_t size, loff_t *offset); @@ -2098,9 +2085,9 @@ static inline void kvm_stats_log_hist_update(u64 *data, size_t size, u64 value) extern const struct kvm_stats_header kvm_vm_stats_header; -extern const struct _kvm_stats_desc kvm_vm_stats_desc[]; +extern const struct kvm_stats_desc kvm_vm_stats_desc[]; extern const struct kvm_stats_header kvm_vcpu_stats_header; -extern const struct _kvm_stats_desc kvm_vcpu_stats_desc[]; +extern const struct kvm_stats_desc kvm_vcpu_stats_desc[]; #ifdef CONFIG_KVM_GENERIC_MMU_NOTIFIER static inline int mmu_invalidate_retry(struct kvm *kvm, unsigned long mmu_seq) -- cgit v1.2.3 From 4ced4cf5c9d172d91f181df3accdf949d3761aab Mon Sep 17 00:00:00 2001 From: Andrei Vagin Date: Tue, 17 Feb 2026 18:01:05 +0000 Subject: binfmt_elf_fdpic: fix AUXV size calculation for ELF_HWCAP3 and ELF_HWCAP4 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit 4e6e8c2b757f ("binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4") added support for AT_HWCAP3 and AT_HWCAP4, but it missed updating the AUX vector size calculation in create_elf_fdpic_tables() and AT_VECTOR_SIZE_BASE in include/linux/auxvec.h. Similar to the fix for AT_HWCAP2 in commit c6a09e342f8e ("binfmt_elf_fdpic: fix AUXV size calculation when ELF_HWCAP2 is defined"), this omission leads to a mismatch between the reserved space and the actual number of AUX entries, eventually triggering a kernel BUG_ON(csp != sp). Fix this by incrementing nitems when ELF_HWCAP3 or ELF_HWCAP4 are defined and updating AT_VECTOR_SIZE_BASE. Cc: Mark Brown Cc: Max Filippov Reviewed-by: Michal Koutný Reviewed-by: Mark Brown Reviewed-by: Cyrill Gorcunov Reviewed-by: Alexander Mikhalitsyn Fixes: 4e6e8c2b757f ("binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4") Signed-off-by: Andrei Vagin Link: https://patch.msgid.link/20260217180108.1420024-2-avagin@google.com Signed-off-by: Kees Cook --- fs/binfmt_elf_fdpic.c | 6 ++++++ include/linux/auxvec.h | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 95b1d0852135..95b65aab7daa 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -595,6 +595,12 @@ static int create_elf_fdpic_tables(struct linux_binprm *bprm, #ifdef ELF_HWCAP2 nitems++; #endif +#ifdef ELF_HWCAP3 + nitems++; +#endif +#ifdef ELF_HWCAP4 + nitems++; +#endif csp = sp; sp -= nitems * 2 * sizeof(unsigned long); diff --git a/include/linux/auxvec.h b/include/linux/auxvec.h index 407f7005e6d6..8bcb9b726262 100644 --- a/include/linux/auxvec.h +++ b/include/linux/auxvec.h @@ -4,6 +4,6 @@ #include -#define AT_VECTOR_SIZE_BASE 22 /* NEW_AUX_ENT entries in auxiliary table */ +#define AT_VECTOR_SIZE_BASE 24 /* NEW_AUX_ENT entries in auxiliary table */ /* number of "#define AT_.*" above, minus {AT_NULL, AT_IGNORE, AT_NOTELF} */ #endif /* _LINUX_AUXVEC_H */ -- cgit v1.2.3 From 2d28ed588f8d7d0d41b0a4fad7f0d05e4bbf1797 Mon Sep 17 00:00:00 2001 From: Axel Rasmussen Date: Tue, 24 Feb 2026 16:24:34 -0800 Subject: Revert "ptdesc: remove references to folios from __pagetable_ctor() and pagetable_dtor()" This change swapped out mod_node_page_state for lruvec_stat_add_folio. But, these two APIs are not interchangeable: the lruvec version also increments memcg stats, in addition to "global" pgdat stats. So after this change, the "pagetables" memcg stat in memory.stat always yields "0", which is a userspace visible regression. I tried to look for a refactor where we add a variant of lruvec_stat_mod_folio which takes a pgdat and a memcg instead of a folio, to try to adhere to the spirit of the original patch. But at the end of the day this just means we have to call folio_memcg(ptdesc_folio(ptdesc)) anyway, which doesn't really accomplish much. This regression is visible in master as well as 6.18 stable, so CC stable too. Link: https://lkml.kernel.org/r/20260225002434.2953895-1-axelrasmussen@google.com Fixes: f0c92726e89f ("ptdesc: remove references to folios from __pagetable_ctor() and pagetable_dtor()") Signed-off-by: Axel Rasmussen Acked-by: Shakeel Butt Acked-by: Johannes Weiner Reviewed-by: Vishal Moola (Oracle) Cc: David Hildenbrand Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Roman Gushchin Cc: Muchun Song Cc: Signed-off-by: Andrew Morton --- include/linux/mm.h | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mm.h b/include/linux/mm.h index 5be3d8a8f806..abb4963c1f06 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3514,26 +3514,21 @@ static inline bool ptlock_init(struct ptdesc *ptdesc) { return true; } static inline void ptlock_free(struct ptdesc *ptdesc) {} #endif /* defined(CONFIG_SPLIT_PTE_PTLOCKS) */ -static inline unsigned long ptdesc_nr_pages(const struct ptdesc *ptdesc) -{ - return compound_nr(ptdesc_page(ptdesc)); -} - static inline void __pagetable_ctor(struct ptdesc *ptdesc) { - pg_data_t *pgdat = NODE_DATA(memdesc_nid(ptdesc->pt_flags)); + struct folio *folio = ptdesc_folio(ptdesc); - __SetPageTable(ptdesc_page(ptdesc)); - mod_node_page_state(pgdat, NR_PAGETABLE, ptdesc_nr_pages(ptdesc)); + __folio_set_pgtable(folio); + lruvec_stat_add_folio(folio, NR_PAGETABLE); } static inline void pagetable_dtor(struct ptdesc *ptdesc) { - pg_data_t *pgdat = NODE_DATA(memdesc_nid(ptdesc->pt_flags)); + struct folio *folio = ptdesc_folio(ptdesc); ptlock_free(ptdesc); - __ClearPageTable(ptdesc_page(ptdesc)); - mod_node_page_state(pgdat, NR_PAGETABLE, -ptdesc_nr_pages(ptdesc)); + __folio_clear_pgtable(folio); + lruvec_stat_sub_folio(folio, NR_PAGETABLE); } static inline void pagetable_dtor_free(struct ptdesc *ptdesc) -- cgit v1.2.3 From 7392f8e4ea632622b2cd2086675ba022db238b3a Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Sun, 1 Mar 2026 16:52:29 -0800 Subject: uaccess: correct kernel-doc parameter format Use the correct kernel-doc function parameter format to avoid kernel-doc warnings: Warning: include/linux/uaccess.h:814 function parameter 'uptr' not described in 'scoped_user_rw_access_size' Warning: include/linux/uaccess.h:826 function parameter 'uptr' not described in 'scoped_user_rw_access' Link: https://lkml.kernel.org/r/20260302005229.3471955-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton --- include/linux/uaccess.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h index 1f3804245c06..001cfef21b61 100644 --- a/include/linux/uaccess.h +++ b/include/linux/uaccess.h @@ -806,7 +806,7 @@ for (bool done = false; !done; done = true) \ /** * scoped_user_rw_access_size - Start a scoped user read/write access with given size - * @uptr Pointer to the user space address to read from and write to + * @uptr: Pointer to the user space address to read from and write to * @size: Size of the access starting from @uptr * @elbl: Error label to goto when the access region is rejected * @@ -817,7 +817,7 @@ for (bool done = false; !done; done = true) \ /** * scoped_user_rw_access - Start a scoped user read/write access - * @uptr Pointer to the user space address to read from and write to + * @uptr: Pointer to the user space address to read from and write to * @elbl: Error label to goto when the access region is rejected * * The size of the access starting from @uptr is determined via sizeof(*@uptr)). -- cgit v1.2.3 From 599b4e290c8766b19378d85d4310c6ec8f90ade4 Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Sun, 1 Mar 2026 16:52:22 -0800 Subject: mm/mmu_notifier: clean up mmu_notifier.h kernel-doc Eliminate kernel-doc warnings in mmu_notifier.h: - add a missing struct short description - use the correct format for function parameters - add missing function return comment sections Warning: include/linux/mmu_notifier.h:236 missing initial short description on line: * struct mmu_interval_notifier_ops Warning: include/linux/mmu_notifier.h:325 function parameter 'interval_sub' not described in 'mmu_interval_set_seq' Warning: include/linux/mmu_notifier.h:325 function parameter 'cur_seq' not described in 'mmu_interval_set_seq' Warning: include/linux/mmu_notifier.h:346 function parameter 'interval_sub' not described in 'mmu_interval_read_retry' Warning: include/linux/mmu_notifier.h:346 function parameter 'seq' not described in 'mmu_interval_read_retry' Warning: include/linux/mmu_notifier.h:346 No description found for return value of 'mmu_interval_read_retry' Warning: include/linux/mmu_notifier.h:370 function parameter 'interval_sub' not described in 'mmu_interval_check_retry' Warning: include/linux/mmu_notifier.h:370 function parameter 'seq' not described in 'mmu_interval_check_retry' Warning: include/linux/mmu_notifier.h:370 No description found for return value of 'mmu_interval_check_retry' Link: https://lkml.kernel.org/r/20260302005222.3470783-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap Reviewed-by: Jason Gunthorpe Cc: David Hildenbrand Cc: "Liam R. Howlett" Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Randy Dunlap Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/mmu_notifier.h | 31 ++++++++++++++++--------------- 1 file changed, 16 insertions(+), 15 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 07a2bbaf86e9..8450e18a87c2 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -234,7 +234,7 @@ struct mmu_notifier { }; /** - * struct mmu_interval_notifier_ops + * struct mmu_interval_notifier_ops - callback for range notification * @invalidate: Upon return the caller must stop using any SPTEs within this * range. This function can sleep. Return false only if sleeping * was required but mmu_notifier_range_blockable(range) is false. @@ -309,8 +309,8 @@ void mmu_interval_notifier_remove(struct mmu_interval_notifier *interval_sub); /** * mmu_interval_set_seq - Save the invalidation sequence - * @interval_sub - The subscription passed to invalidate - * @cur_seq - The cur_seq passed to the invalidate() callback + * @interval_sub: The subscription passed to invalidate + * @cur_seq: The cur_seq passed to the invalidate() callback * * This must be called unconditionally from the invalidate callback of a * struct mmu_interval_notifier_ops under the same lock that is used to call @@ -329,8 +329,8 @@ mmu_interval_set_seq(struct mmu_interval_notifier *interval_sub, /** * mmu_interval_read_retry - End a read side critical section against a VA range - * interval_sub: The subscription - * seq: The return of the paired mmu_interval_read_begin() + * @interval_sub: The subscription + * @seq: The return of the paired mmu_interval_read_begin() * * This MUST be called under a user provided lock that is also held * unconditionally by op->invalidate() when it calls mmu_interval_set_seq(). @@ -338,7 +338,7 @@ mmu_interval_set_seq(struct mmu_interval_notifier *interval_sub, * Each call should be paired with a single mmu_interval_read_begin() and * should be used to conclude the read side. * - * Returns true if an invalidation collided with this critical section, and + * Returns: true if an invalidation collided with this critical section, and * the caller should retry. */ static inline bool @@ -350,20 +350,21 @@ mmu_interval_read_retry(struct mmu_interval_notifier *interval_sub, /** * mmu_interval_check_retry - Test if a collision has occurred - * interval_sub: The subscription - * seq: The return of the matching mmu_interval_read_begin() + * @interval_sub: The subscription + * @seq: The return of the matching mmu_interval_read_begin() * * This can be used in the critical section between mmu_interval_read_begin() - * and mmu_interval_read_retry(). A return of true indicates an invalidation - * has collided with this critical region and a future - * mmu_interval_read_retry() will return true. - * - * False is not reliable and only suggests a collision may not have - * occurred. It can be called many times and does not have to hold the user - * provided lock. + * and mmu_interval_read_retry(). * * This call can be used as part of loops and other expensive operations to * expedite a retry. + * It can be called many times and does not have to hold the user + * provided lock. + * + * Returns: true indicates an invalidation has collided with this critical + * region and a future mmu_interval_read_retry() will return true. + * False is not reliable and only suggests a collision may not have + * occurred. */ static inline bool mmu_interval_check_retry(struct mmu_interval_notifier *interval_sub, -- cgit v1.2.3 From 55f854dd5bdd8e19b936a00ef1f8d776ac32c7b0 Mon Sep 17 00:00:00 2001 From: Laurent Vivier Date: Wed, 4 Mar 2026 14:43:38 +0100 Subject: qmi_wwan: allow max_mtu above hard_mtu to control rx_urb_size Commit c7159e960f14 ("usbnet: limit max_mtu based on device's hard_mtu") capped net->max_mtu to the device's hard_mtu in usbnet_probe(). While this correctly prevents oversized packets on standard USB network devices, it breaks the qmi_wwan driver. qmi_wwan relies on userspace (e.g. ModemManager) setting a large MTU on the wwan0 interface to configure rx_urb_size via usbnet_change_mtu(). QMI modems negotiate USB transfer sizes of 16,383 or 32,767 bytes, and the USB receive buffers must be sized accordingly. With max_mtu capped to hard_mtu (~1500 bytes), userspace can no longer raise the MTU, the receive buffers remain small, and download speeds drop from >300 Mbps to ~0.8 Mbps. Introduce a FLAG_NOMAXMTU driver flag that allows individual usbnet drivers to opt out of the max_mtu cap. Set this flag in qmi_wwan's driver_info structures to restore the previous behavior for QMI devices, while keeping the safety fix in place for all other usbnet drivers. Fixes: c7159e960f14 ("usbnet: limit max_mtu based on device's hard_mtu") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/lkml/CAPh3n803k8JcBPV5qEzUB-oKzWkAs-D5CU7z=Vd_nLRCr5ZqQg@mail.gmail.com/ Reported-by: Koen Vandeputte Tested-by: Daniele Palmas Signed-off-by: Laurent Vivier Link: https://patch.msgid.link/20260304134338.1785002-1-lvivier@redhat.com Signed-off-by: Jakub Kicinski --- drivers/net/usb/qmi_wwan.c | 4 ++-- drivers/net/usb/usbnet.c | 7 ++++--- include/linux/usb/usbnet.h | 1 + 3 files changed, 7 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c index 3a4985b582cb..05acac10cd2b 100644 --- a/drivers/net/usb/qmi_wwan.c +++ b/drivers/net/usb/qmi_wwan.c @@ -928,7 +928,7 @@ err: static const struct driver_info qmi_wwan_info = { .description = "WWAN/QMI device", - .flags = FLAG_WWAN | FLAG_SEND_ZLP, + .flags = FLAG_WWAN | FLAG_NOMAXMTU | FLAG_SEND_ZLP, .bind = qmi_wwan_bind, .unbind = qmi_wwan_unbind, .manage_power = qmi_wwan_manage_power, @@ -937,7 +937,7 @@ static const struct driver_info qmi_wwan_info = { static const struct driver_info qmi_wwan_info_quirk_dtr = { .description = "WWAN/QMI device", - .flags = FLAG_WWAN | FLAG_SEND_ZLP, + .flags = FLAG_WWAN | FLAG_NOMAXMTU | FLAG_SEND_ZLP, .bind = qmi_wwan_bind, .unbind = qmi_wwan_unbind, .manage_power = qmi_wwan_manage_power, diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index ed86ba87ca4e..b72ba0803392 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -1829,11 +1829,12 @@ usbnet_probe(struct usb_interface *udev, const struct usb_device_id *prod) if ((dev->driver_info->flags & FLAG_NOARP) != 0) net->flags |= IFF_NOARP; - if (net->max_mtu > (dev->hard_mtu - net->hard_header_len)) + if ((dev->driver_info->flags & FLAG_NOMAXMTU) == 0 && + net->max_mtu > (dev->hard_mtu - net->hard_header_len)) net->max_mtu = dev->hard_mtu - net->hard_header_len; - if (net->mtu > net->max_mtu) - net->mtu = net->max_mtu; + if (net->mtu > (dev->hard_mtu - net->hard_header_len)) + net->mtu = dev->hard_mtu - net->hard_header_len; } else if (!info->in || !info->out) status = usbnet_get_endpoints(dev, udev); diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h index b0e84896e6ac..bbf799ccf3b3 100644 --- a/include/linux/usb/usbnet.h +++ b/include/linux/usb/usbnet.h @@ -132,6 +132,7 @@ struct driver_info { #define FLAG_MULTI_PACKET 0x2000 #define FLAG_RX_ASSEMBLE 0x4000 /* rx packets may span >1 frames */ #define FLAG_NOARP 0x8000 /* device can't do ARP */ +#define FLAG_NOMAXMTU 0x10000 /* allow max_mtu above hard_mtu */ /* init device ... can sleep, or cause probe() failure */ int (*bind)(struct usbnet *, struct usb_interface *); -- cgit v1.2.3 From 6f1a9140ecda3baba3d945b9a6155af4268aafc4 Mon Sep 17 00:00:00 2001 From: Weiming Shi Date: Sat, 7 Mar 2026 00:01:34 +0800 Subject: net: add xmit recursion limit to tunnel xmit functions Tunnel xmit functions (iptunnel_xmit, ip6tunnel_xmit) lack their own recursion limit. When a bond device in broadcast mode has GRE tap interfaces as slaves, and those GRE tunnels route back through the bond, multicast/broadcast traffic triggers infinite recursion between bond_xmit_broadcast() and ip_tunnel_xmit()/ip6_tnl_xmit(), causing kernel stack overflow. The existing XMIT_RECURSION_LIMIT (8) in the no-qdisc path is not sufficient because tunnel recursion involves route lookups and full IP output, consuming much more stack per level. Use a lower limit of 4 (IP_TUNNEL_RECURSION_LIMIT) to prevent overflow. Add recursion detection using dev_xmit_recursion helpers directly in iptunnel_xmit() and ip6tunnel_xmit() to cover all IPv4/IPv6 tunnel paths including UDP encapsulated tunnels (VXLAN, Geneve, etc.). Move dev_xmit_recursion helpers from net/core/dev.h to public header include/linux/netdevice.h so they can be used by tunnel code. BUG: KASAN: stack-out-of-bounds in blake2s.constprop.0+0xe7/0x160 Write of size 32 at addr ffff88810033fed0 by task kworker/0:1/11 Workqueue: mld mld_ifc_work Call Trace: __build_flow_key.constprop.0 (net/ipv4/route.c:515) ip_rt_update_pmtu (net/ipv4/route.c:1073) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:84) ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) ip_finish_output2 (net/ipv4/ip_output.c:237) ip_output (net/ipv4/ip_output.c:438) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) ip_finish_output2 (net/ipv4/ip_output.c:237) ip_output (net/ipv4/ip_output.c:438) iptunnel_xmit (net/ipv4/ip_tunnel_core.c:86) ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847) gre_tap_xmit (net/ipv4/ip_gre.c:779) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) bond_dev_queue_xmit (drivers/net/bonding/bond_main.c:312) bond_xmit_broadcast (drivers/net/bonding/bond_main.c:5279) bond_start_xmit (drivers/net/bonding/bond_main.c:5530) dev_hard_start_xmit (net/core/dev.c:3887) __dev_queue_xmit (net/core/dev.c:4841) mld_sendpack mld_ifc_work process_one_work worker_thread Fixes: 745e20f1b626 ("net: add a recursion limit in xmit path") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Link: https://patch.msgid.link/20260306160133.3852900-2-bestswngs@gmail.com Signed-off-by: Paolo Abeni --- include/linux/netdevice.h | 32 ++++++++++++++++++++++++++++++++ include/net/ip6_tunnel.h | 12 ++++++++++++ include/net/ip_tunnels.h | 7 +++++++ net/core/dev.h | 35 ----------------------------------- net/ipv4/ip_tunnel_core.c | 13 +++++++++++++ 5 files changed, 64 insertions(+), 35 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 67e25f6d15a4..ae269a2e7f4d 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3576,17 +3576,49 @@ struct page_pool_bh { }; DECLARE_PER_CPU(struct page_pool_bh, system_page_pool); +#define XMIT_RECURSION_LIMIT 8 + #ifndef CONFIG_PREEMPT_RT static inline int dev_recursion_level(void) { return this_cpu_read(softnet_data.xmit.recursion); } + +static inline bool dev_xmit_recursion(void) +{ + return unlikely(__this_cpu_read(softnet_data.xmit.recursion) > + XMIT_RECURSION_LIMIT); +} + +static inline void dev_xmit_recursion_inc(void) +{ + __this_cpu_inc(softnet_data.xmit.recursion); +} + +static inline void dev_xmit_recursion_dec(void) +{ + __this_cpu_dec(softnet_data.xmit.recursion); +} #else static inline int dev_recursion_level(void) { return current->net_xmit.recursion; } +static inline bool dev_xmit_recursion(void) +{ + return unlikely(current->net_xmit.recursion > XMIT_RECURSION_LIMIT); +} + +static inline void dev_xmit_recursion_inc(void) +{ + current->net_xmit.recursion++; +} + +static inline void dev_xmit_recursion_dec(void) +{ + current->net_xmit.recursion--; +} #endif void __netif_schedule(struct Qdisc *q); diff --git a/include/net/ip6_tunnel.h b/include/net/ip6_tunnel.h index 120db2865811..1253cbb4b0a4 100644 --- a/include/net/ip6_tunnel.h +++ b/include/net/ip6_tunnel.h @@ -156,6 +156,16 @@ static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb, { int pkt_len, err; + if (dev_recursion_level() > IP_TUNNEL_RECURSION_LIMIT) { + net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n", + dev->name); + DEV_STATS_INC(dev, tx_errors); + kfree_skb(skb); + return; + } + + dev_xmit_recursion_inc(); + memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); IP6CB(skb)->flags = ip6cb_flags; pkt_len = skb->len - skb_inner_network_offset(skb); @@ -166,6 +176,8 @@ static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb, pkt_len = -1; iptunnel_xmit_stats(dev, pkt_len); } + + dev_xmit_recursion_dec(); } #endif #endif diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 4021e6a73e32..80662f812080 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -27,6 +27,13 @@ #include #endif +/* Recursion limit for tunnel xmit to detect routing loops. + * Unlike XMIT_RECURSION_LIMIT (8) used in the no-qdisc path, tunnel + * recursion involves route lookups and full IP output, consuming much + * more stack per level, so a lower limit is needed. + */ +#define IP_TUNNEL_RECURSION_LIMIT 4 + /* Keep error state on tunnel for 30 sec */ #define IPTUNNEL_ERR_TIMEO (30*HZ) diff --git a/net/core/dev.h b/net/core/dev.h index 98793a738f43..781619e76b3e 100644 --- a/net/core/dev.h +++ b/net/core/dev.h @@ -366,41 +366,6 @@ static inline void napi_assert_will_not_race(const struct napi_struct *napi) void kick_defer_list_purge(unsigned int cpu); -#define XMIT_RECURSION_LIMIT 8 - -#ifndef CONFIG_PREEMPT_RT -static inline bool dev_xmit_recursion(void) -{ - return unlikely(__this_cpu_read(softnet_data.xmit.recursion) > - XMIT_RECURSION_LIMIT); -} - -static inline void dev_xmit_recursion_inc(void) -{ - __this_cpu_inc(softnet_data.xmit.recursion); -} - -static inline void dev_xmit_recursion_dec(void) -{ - __this_cpu_dec(softnet_data.xmit.recursion); -} -#else -static inline bool dev_xmit_recursion(void) -{ - return unlikely(current->net_xmit.recursion > XMIT_RECURSION_LIMIT); -} - -static inline void dev_xmit_recursion_inc(void) -{ - current->net_xmit.recursion++; -} - -static inline void dev_xmit_recursion_dec(void) -{ - current->net_xmit.recursion--; -} -#endif - int dev_set_hwtstamp_phylib(struct net_device *dev, struct kernel_hwtstamp_config *cfg, struct netlink_ext_ack *extack); diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c index 2e61ac137128..b1b6bf949f65 100644 --- a/net/ipv4/ip_tunnel_core.c +++ b/net/ipv4/ip_tunnel_core.c @@ -58,6 +58,17 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, struct iphdr *iph; int err; + if (dev_recursion_level() > IP_TUNNEL_RECURSION_LIMIT) { + net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n", + dev->name); + DEV_STATS_INC(dev, tx_errors); + ip_rt_put(rt); + kfree_skb(skb); + return; + } + + dev_xmit_recursion_inc(); + skb_scrub_packet(skb, xnet); skb_clear_hash_if_not_l4(skb); @@ -88,6 +99,8 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb, pkt_len = 0; iptunnel_xmit_stats(dev, pkt_len); } + + dev_xmit_recursion_dec(); } EXPORT_SYMBOL_GPL(iptunnel_xmit); -- cgit v1.2.3 From fa655a9ca73f7df32b8ca4d14ce11742f9578288 Mon Sep 17 00:00:00 2001 From: Thorsten Blum Date: Tue, 3 Mar 2026 22:31:01 +0100 Subject: nvme: Annotate struct nvme_dhchap_key with __counted_by Add the __counted_by() compiler attribute to the flexible array member 'key' to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE. Reviewed-by: Christoph Hellwig Signed-off-by: Thorsten Blum Signed-off-by: Keith Busch --- include/linux/nvme-auth.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/nvme-auth.h b/include/linux/nvme-auth.h index 60e069a6757f..e75c29c51464 100644 --- a/include/linux/nvme-auth.h +++ b/include/linux/nvme-auth.h @@ -11,7 +11,7 @@ struct nvme_dhchap_key { size_t len; u8 hash; - u8 key[]; + u8 key[] __counted_by(len); }; u32 nvme_auth_get_seqnum(void); -- cgit v1.2.3 From 22fd7f7fed2ae3702f90d1985c326354e86b9c75 Mon Sep 17 00:00:00 2001 From: Muhammad Amirul Asyraf Mohamad Jamian Date: Thu, 5 Mar 2026 01:31:51 -0800 Subject: firmware: stratix10-svc: Add Multi SVC clients support In the current implementation, SVC client drivers such as socfpga-hwmon, intel_fcs, stratix10-soc, stratix10-rsu each send an SMC command that triggers a single thread in the stratix10-svc driver. Upon receiving a callback, the initiating client driver sends a stratix10-svc-done signal, terminating the thread without waiting for other pending SMC commands to complete. This leads to a timeout issue in the firmware SVC mailbox service when multiple client drivers send SMC commands concurrently. To resolve this issue, a dedicated thread is now created per channel. The stratix10-svc driver will support up to the number of channels defined by SVC_NUM_CHANNEL. Thread synchronization is handled using a mutex to prevent simultaneous issuance of SMC commands by multiple threads. SVC_NUM_DATA_IN_FIFO is reduced from 32 to 8, since each channel now has its own dedicated FIFO and the SDM processes commands one at a time. 8 entries per channel is sufficient while keeping the total aggregate capacity the same (4 channels x 8 = 32 entries). Additionally, a thread task is now validated before invoking kthread_stop when the user aborts, ensuring safe termination. Timeout values have also been adjusted to accommodate the increased load from concurrent client driver activity. Fixes: 7ca5ce896524 ("firmware: add Intel Stratix10 service layer driver") Cc: stable@vger.kernel.org Signed-off-by: Ang Tien Sung Signed-off-by: Fong, Yan Kei Signed-off-by: Muhammad Amirul Asyraf Mohamad Jamian Link: https://lore.kernel.org/all/20260305093151.2678-1-muhammad.amirul.asyraf.mohamad.jamian@altera.com Signed-off-by: Dinh Nguyen --- drivers/firmware/stratix10-svc.c | 228 ++++++++++++--------- .../linux/firmware/intel/stratix10-svc-client.h | 8 +- 2 files changed, 130 insertions(+), 106 deletions(-) (limited to 'include/linux') diff --git a/drivers/firmware/stratix10-svc.c b/drivers/firmware/stratix10-svc.c index 6f5c298582ab..e9e35d67ef96 100644 --- a/drivers/firmware/stratix10-svc.c +++ b/drivers/firmware/stratix10-svc.c @@ -37,15 +37,14 @@ * service layer will return error to FPGA manager when timeout occurs, * timeout is set to 30 seconds (30 * 1000) at Intel Stratix10 SoC. */ -#define SVC_NUM_DATA_IN_FIFO 32 +#define SVC_NUM_DATA_IN_FIFO 8 #define SVC_NUM_CHANNEL 4 -#define FPGA_CONFIG_DATA_CLAIM_TIMEOUT_MS 200 +#define FPGA_CONFIG_DATA_CLAIM_TIMEOUT_MS 2000 #define FPGA_CONFIG_STATUS_TIMEOUT_SEC 30 #define BYTE_TO_WORD_SIZE 4 /* stratix10 service layer clients */ #define STRATIX10_RSU "stratix10-rsu" -#define INTEL_FCS "intel-fcs" /* Maximum number of SDM client IDs. */ #define MAX_SDM_CLIENT_IDS 16 @@ -105,11 +104,9 @@ struct stratix10_svc_chan; /** * struct stratix10_svc - svc private data * @stratix10_svc_rsu: pointer to stratix10 RSU device - * @intel_svc_fcs: pointer to the FCS device */ struct stratix10_svc { struct platform_device *stratix10_svc_rsu; - struct platform_device *intel_svc_fcs; }; /** @@ -251,12 +248,10 @@ struct stratix10_async_ctrl { * @num_active_client: number of active service client * @node: list management * @genpool: memory pool pointing to the memory region - * @task: pointer to the thread task which handles SMC or HVC call - * @svc_fifo: a queue for storing service message data * @complete_status: state for completion - * @svc_fifo_lock: protect access to service message data queue * @invoke_fn: function to issue secure monitor call or hypervisor call * @svc: manages the list of client svc drivers + * @sdm_lock: only allows a single command single response to SDM * @actrl: async control structure * * This struct is used to create communication channels for service clients, to @@ -269,12 +264,10 @@ struct stratix10_svc_controller { int num_active_client; struct list_head node; struct gen_pool *genpool; - struct task_struct *task; - struct kfifo svc_fifo; struct completion complete_status; - spinlock_t svc_fifo_lock; svc_invoke_fn *invoke_fn; struct stratix10_svc *svc; + struct mutex sdm_lock; struct stratix10_async_ctrl actrl; }; @@ -283,6 +276,9 @@ struct stratix10_svc_controller { * @ctrl: pointer to service controller which is the provider of this channel * @scl: pointer to service client which owns the channel * @name: service client name associated with the channel + * @task: pointer to the thread task which handles SMC or HVC call + * @svc_fifo: a queue for storing service message data (separate fifo for every channel) + * @svc_fifo_lock: protect access to service message data queue (locking pending fifo) * @lock: protect access to the channel * @async_chan: reference to asynchronous channel object for this channel * @@ -293,6 +289,9 @@ struct stratix10_svc_chan { struct stratix10_svc_controller *ctrl; struct stratix10_svc_client *scl; char *name; + struct task_struct *task; + struct kfifo svc_fifo; + spinlock_t svc_fifo_lock; spinlock_t lock; struct stratix10_async_chan *async_chan; }; @@ -527,10 +526,10 @@ static void svc_thread_recv_status_ok(struct stratix10_svc_data *p_data, */ static int svc_normal_to_secure_thread(void *data) { - struct stratix10_svc_controller - *ctrl = (struct stratix10_svc_controller *)data; - struct stratix10_svc_data *pdata; - struct stratix10_svc_cb_data *cbdata; + struct stratix10_svc_chan *chan = (struct stratix10_svc_chan *)data; + struct stratix10_svc_controller *ctrl = chan->ctrl; + struct stratix10_svc_data *pdata = NULL; + struct stratix10_svc_cb_data *cbdata = NULL; struct arm_smccc_res res; unsigned long a0, a1, a2, a3, a4, a5, a6, a7; int ret_fifo = 0; @@ -555,12 +554,12 @@ static int svc_normal_to_secure_thread(void *data) a6 = 0; a7 = 0; - pr_debug("smc_hvc_shm_thread is running\n"); + pr_debug("%s: %s: Thread is running!\n", __func__, chan->name); while (!kthread_should_stop()) { - ret_fifo = kfifo_out_spinlocked(&ctrl->svc_fifo, + ret_fifo = kfifo_out_spinlocked(&chan->svc_fifo, pdata, sizeof(*pdata), - &ctrl->svc_fifo_lock); + &chan->svc_fifo_lock); if (!ret_fifo) continue; @@ -569,9 +568,25 @@ static int svc_normal_to_secure_thread(void *data) (unsigned int)pdata->paddr, pdata->command, (unsigned int)pdata->size); + /* SDM can only process one command at a time */ + pr_debug("%s: %s: Thread is waiting for mutex!\n", + __func__, chan->name); + if (mutex_lock_interruptible(&ctrl->sdm_lock)) { + /* item already dequeued; notify client to unblock it */ + cbdata->status = BIT(SVC_STATUS_ERROR); + cbdata->kaddr1 = NULL; + cbdata->kaddr2 = NULL; + cbdata->kaddr3 = NULL; + if (pdata->chan->scl) + pdata->chan->scl->receive_cb(pdata->chan->scl, + cbdata); + break; + } + switch (pdata->command) { case COMMAND_RECONFIG_DATA_CLAIM: svc_thread_cmd_data_claim(ctrl, pdata, cbdata); + mutex_unlock(&ctrl->sdm_lock); continue; case COMMAND_RECONFIG: a0 = INTEL_SIP_SMC_FPGA_CONFIG_START; @@ -700,10 +715,11 @@ static int svc_normal_to_secure_thread(void *data) break; default: pr_warn("it shouldn't happen\n"); - break; + mutex_unlock(&ctrl->sdm_lock); + continue; } - pr_debug("%s: before SMC call -- a0=0x%016x a1=0x%016x", - __func__, + pr_debug("%s: %s: before SMC call -- a0=0x%016x a1=0x%016x", + __func__, chan->name, (unsigned int)a0, (unsigned int)a1); pr_debug(" a2=0x%016x\n", (unsigned int)a2); @@ -712,8 +728,8 @@ static int svc_normal_to_secure_thread(void *data) pr_debug(" a5=0x%016x\n", (unsigned int)a5); ctrl->invoke_fn(a0, a1, a2, a3, a4, a5, a6, a7, &res); - pr_debug("%s: after SMC call -- res.a0=0x%016x", - __func__, (unsigned int)res.a0); + pr_debug("%s: %s: after SMC call -- res.a0=0x%016x", + __func__, chan->name, (unsigned int)res.a0); pr_debug(" res.a1=0x%016x, res.a2=0x%016x", (unsigned int)res.a1, (unsigned int)res.a2); pr_debug(" res.a3=0x%016x\n", (unsigned int)res.a3); @@ -728,6 +744,7 @@ static int svc_normal_to_secure_thread(void *data) cbdata->kaddr2 = NULL; cbdata->kaddr3 = NULL; pdata->chan->scl->receive_cb(pdata->chan->scl, cbdata); + mutex_unlock(&ctrl->sdm_lock); continue; } @@ -801,6 +818,8 @@ static int svc_normal_to_secure_thread(void *data) break; } + + mutex_unlock(&ctrl->sdm_lock); } kfree(cbdata); @@ -1696,22 +1715,33 @@ int stratix10_svc_send(struct stratix10_svc_chan *chan, void *msg) if (!p_data) return -ENOMEM; - /* first client will create kernel thread */ - if (!chan->ctrl->task) { - chan->ctrl->task = - kthread_run_on_cpu(svc_normal_to_secure_thread, - (void *)chan->ctrl, - cpu, "svc_smc_hvc_thread"); - if (IS_ERR(chan->ctrl->task)) { + /* first caller creates the per-channel kthread */ + if (!chan->task) { + struct task_struct *task; + + task = kthread_run_on_cpu(svc_normal_to_secure_thread, + (void *)chan, + cpu, "svc_smc_hvc_thread"); + if (IS_ERR(task)) { dev_err(chan->ctrl->dev, "failed to create svc_smc_hvc_thread\n"); kfree(p_data); return -EINVAL; } + + spin_lock(&chan->lock); + if (chan->task) { + /* another caller won the race; discard our thread */ + spin_unlock(&chan->lock); + kthread_stop(task); + } else { + chan->task = task; + spin_unlock(&chan->lock); + } } - pr_debug("%s: sent P-va=%p, P-com=%x, P-size=%u\n", __func__, - p_msg->payload, p_msg->command, + pr_debug("%s: %s: sent P-va=%p, P-com=%x, P-size=%u\n", __func__, + chan->name, p_msg->payload, p_msg->command, (unsigned int)p_msg->payload_length); if (list_empty(&svc_data_mem)) { @@ -1747,12 +1777,16 @@ int stratix10_svc_send(struct stratix10_svc_chan *chan, void *msg) p_data->arg[2] = p_msg->arg[2]; p_data->size = p_msg->payload_length; p_data->chan = chan; - pr_debug("%s: put to FIFO pa=0x%016x, cmd=%x, size=%u\n", __func__, - (unsigned int)p_data->paddr, p_data->command, - (unsigned int)p_data->size); - ret = kfifo_in_spinlocked(&chan->ctrl->svc_fifo, p_data, + pr_debug("%s: %s: put to FIFO pa=0x%016x, cmd=%x, size=%u\n", + __func__, + chan->name, + (unsigned int)p_data->paddr, + p_data->command, + (unsigned int)p_data->size); + + ret = kfifo_in_spinlocked(&chan->svc_fifo, p_data, sizeof(*p_data), - &chan->ctrl->svc_fifo_lock); + &chan->svc_fifo_lock); kfree(p_data); @@ -1773,11 +1807,12 @@ EXPORT_SYMBOL_GPL(stratix10_svc_send); */ void stratix10_svc_done(struct stratix10_svc_chan *chan) { - /* stop thread when thread is running AND only one active client */ - if (chan->ctrl->task && chan->ctrl->num_active_client <= 1) { - pr_debug("svc_smc_hvc_shm_thread is stopped\n"); - kthread_stop(chan->ctrl->task); - chan->ctrl->task = NULL; + /* stop thread when thread is running */ + if (chan->task) { + pr_debug("%s: %s: svc_smc_hvc_shm_thread is stopping\n", + __func__, chan->name); + kthread_stop(chan->task); + chan->task = NULL; } } EXPORT_SYMBOL_GPL(stratix10_svc_done); @@ -1817,8 +1852,8 @@ void *stratix10_svc_allocate_memory(struct stratix10_svc_chan *chan, pmem->paddr = pa; pmem->size = s; list_add_tail(&pmem->node, &svc_data_mem); - pr_debug("%s: va=%p, pa=0x%016x\n", __func__, - pmem->vaddr, (unsigned int)pmem->paddr); + pr_debug("%s: %s: va=%p, pa=0x%016x\n", __func__, + chan->name, pmem->vaddr, (unsigned int)pmem->paddr); return (void *)va; } @@ -1855,6 +1890,13 @@ static const struct of_device_id stratix10_svc_drv_match[] = { {}, }; +static const char * const chan_names[SVC_NUM_CHANNEL] = { + SVC_CLIENT_FPGA, + SVC_CLIENT_RSU, + SVC_CLIENT_FCS, + SVC_CLIENT_HWMON +}; + static int stratix10_svc_drv_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -1862,11 +1904,11 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev) struct stratix10_svc_chan *chans; struct gen_pool *genpool; struct stratix10_svc_sh_memory *sh_memory; - struct stratix10_svc *svc; + struct stratix10_svc *svc = NULL; svc_invoke_fn *invoke_fn; size_t fifo_size; - int ret; + int ret, i = 0; /* get SMC or HVC function */ invoke_fn = get_invoke_func(dev); @@ -1905,8 +1947,8 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev) controller->num_active_client = 0; controller->chans = chans; controller->genpool = genpool; - controller->task = NULL; controller->invoke_fn = invoke_fn; + INIT_LIST_HEAD(&controller->node); init_completion(&controller->complete_status); ret = stratix10_svc_async_init(controller); @@ -1917,32 +1959,20 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev) } fifo_size = sizeof(struct stratix10_svc_data) * SVC_NUM_DATA_IN_FIFO; - ret = kfifo_alloc(&controller->svc_fifo, fifo_size, GFP_KERNEL); - if (ret) { - dev_err(dev, "failed to allocate FIFO\n"); - goto err_async_exit; - } - spin_lock_init(&controller->svc_fifo_lock); - - chans[0].scl = NULL; - chans[0].ctrl = controller; - chans[0].name = SVC_CLIENT_FPGA; - spin_lock_init(&chans[0].lock); + mutex_init(&controller->sdm_lock); - chans[1].scl = NULL; - chans[1].ctrl = controller; - chans[1].name = SVC_CLIENT_RSU; - spin_lock_init(&chans[1].lock); - - chans[2].scl = NULL; - chans[2].ctrl = controller; - chans[2].name = SVC_CLIENT_FCS; - spin_lock_init(&chans[2].lock); - - chans[3].scl = NULL; - chans[3].ctrl = controller; - chans[3].name = SVC_CLIENT_HWMON; - spin_lock_init(&chans[3].lock); + for (i = 0; i < SVC_NUM_CHANNEL; i++) { + chans[i].scl = NULL; + chans[i].ctrl = controller; + chans[i].name = (char *)chan_names[i]; + spin_lock_init(&chans[i].lock); + ret = kfifo_alloc(&chans[i].svc_fifo, fifo_size, GFP_KERNEL); + if (ret) { + dev_err(dev, "failed to allocate FIFO %d\n", i); + goto err_free_fifos; + } + spin_lock_init(&chans[i].svc_fifo_lock); + } list_add_tail(&controller->node, &svc_ctrl); platform_set_drvdata(pdev, controller); @@ -1951,7 +1981,7 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev) svc = devm_kzalloc(dev, sizeof(*svc), GFP_KERNEL); if (!svc) { ret = -ENOMEM; - goto err_free_kfifo; + goto err_free_fifos; } controller->svc = svc; @@ -1959,51 +1989,43 @@ static int stratix10_svc_drv_probe(struct platform_device *pdev) if (!svc->stratix10_svc_rsu) { dev_err(dev, "failed to allocate %s device\n", STRATIX10_RSU); ret = -ENOMEM; - goto err_free_kfifo; + goto err_free_fifos; } ret = platform_device_add(svc->stratix10_svc_rsu); - if (ret) { - platform_device_put(svc->stratix10_svc_rsu); - goto err_free_kfifo; - } - - svc->intel_svc_fcs = platform_device_alloc(INTEL_FCS, 1); - if (!svc->intel_svc_fcs) { - dev_err(dev, "failed to allocate %s device\n", INTEL_FCS); - ret = -ENOMEM; - goto err_unregister_rsu_dev; - } - - ret = platform_device_add(svc->intel_svc_fcs); - if (ret) { - platform_device_put(svc->intel_svc_fcs); - goto err_unregister_rsu_dev; - } + if (ret) + goto err_put_device; ret = of_platform_default_populate(dev_of_node(dev), NULL, dev); if (ret) - goto err_unregister_fcs_dev; + goto err_unregister_rsu_dev; pr_info("Intel Service Layer Driver Initialized\n"); return 0; -err_unregister_fcs_dev: - platform_device_unregister(svc->intel_svc_fcs); err_unregister_rsu_dev: platform_device_unregister(svc->stratix10_svc_rsu); -err_free_kfifo: - kfifo_free(&controller->svc_fifo); -err_async_exit: + goto err_free_fifos; +err_put_device: + platform_device_put(svc->stratix10_svc_rsu); +err_free_fifos: + /* only remove from list if list_add_tail() was reached */ + if (!list_empty(&controller->node)) + list_del(&controller->node); + /* free only the FIFOs that were successfully allocated */ + while (i--) + kfifo_free(&chans[i].svc_fifo); stratix10_svc_async_exit(controller); err_destroy_pool: gen_pool_destroy(genpool); + return ret; } static void stratix10_svc_drv_remove(struct platform_device *pdev) { + int i; struct stratix10_svc_controller *ctrl = platform_get_drvdata(pdev); struct stratix10_svc *svc = ctrl->svc; @@ -2011,14 +2033,16 @@ static void stratix10_svc_drv_remove(struct platform_device *pdev) of_platform_depopulate(ctrl->dev); - platform_device_unregister(svc->intel_svc_fcs); platform_device_unregister(svc->stratix10_svc_rsu); - kfifo_free(&ctrl->svc_fifo); - if (ctrl->task) { - kthread_stop(ctrl->task); - ctrl->task = NULL; + for (i = 0; i < SVC_NUM_CHANNEL; i++) { + if (ctrl->chans[i].task) { + kthread_stop(ctrl->chans[i].task); + ctrl->chans[i].task = NULL; + } + kfifo_free(&ctrl->chans[i].svc_fifo); } + if (ctrl->genpool) gen_pool_destroy(ctrl->genpool); list_del(&ctrl->node); diff --git a/include/linux/firmware/intel/stratix10-svc-client.h b/include/linux/firmware/intel/stratix10-svc-client.h index d290060f4c73..91013161e9db 100644 --- a/include/linux/firmware/intel/stratix10-svc-client.h +++ b/include/linux/firmware/intel/stratix10-svc-client.h @@ -68,12 +68,12 @@ * timeout value used in Stratix10 FPGA manager driver. * timeout value used in RSU driver */ -#define SVC_RECONFIG_REQUEST_TIMEOUT_MS 300 -#define SVC_RECONFIG_BUFFER_TIMEOUT_MS 720 -#define SVC_RSU_REQUEST_TIMEOUT_MS 300 +#define SVC_RECONFIG_REQUEST_TIMEOUT_MS 5000 +#define SVC_RECONFIG_BUFFER_TIMEOUT_MS 5000 +#define SVC_RSU_REQUEST_TIMEOUT_MS 2000 #define SVC_FCS_REQUEST_TIMEOUT_MS 2000 #define SVC_COMPLETED_TIMEOUT_MS 30000 -#define SVC_HWMON_REQUEST_TIMEOUT_MS 300 +#define SVC_HWMON_REQUEST_TIMEOUT_MS 2000 struct stratix10_svc_chan; -- cgit v1.2.3 From 6ffd853b0b10e1e292cef0bfd0997986471254de Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Sun, 1 Mar 2026 16:51:44 -0800 Subject: build_bug.h: correct function parameters names in kernel-doc Use the correct function (or macro) names to avoid kernel-doc warnings: Warning: include/linux/build_bug.h:38 function parameter 'cond' not described in 'BUILD_BUG_ON_MSG' Warning: include/linux/build_bug.h:38 function parameter 'msg' not described in 'BUILD_BUG_ON_MSG' Warning: include/linux/build_bug.h:76 function parameter 'expr' not described in 'static_assert' Link: https://lkml.kernel.org/r/20260302005144.3467019-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap Reviewed-by: SeongJae Park Signed-off-by: Andrew Morton --- include/linux/build_bug.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/build_bug.h b/include/linux/build_bug.h index 2cfbb4c65c78..d3dc5dc5f916 100644 --- a/include/linux/build_bug.h +++ b/include/linux/build_bug.h @@ -32,7 +32,8 @@ /** * BUILD_BUG_ON_MSG - break compile if a condition is true & emit supplied * error message. - * @condition: the condition which the compiler should know is false. + * @cond: the condition which the compiler should know is false. + * @msg: build-time error message * * See BUILD_BUG_ON for description. */ @@ -60,6 +61,7 @@ /** * static_assert - check integer constant expression at build time + * @expr: expression to be checked * * static_assert() is a wrapper for the C11 _Static_assert, with a * little macro magic to make the message optional (defaulting to the -- cgit v1.2.3 From b2e48c429ec54715d16fefa719dd2fbded2e65be Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 10 Mar 2026 21:28:53 +0100 Subject: sched/mmcid: Prevent CID stalls due to concurrent forks A newly forked task is accounted as MMCID user before the task is visible in the process' thread list and the global task list. This creates the following problem: CPU1 CPU2 fork() sched_mm_cid_fork(tnew1) tnew1->mm.mm_cid_users++; tnew1->mm_cid.cid = getcid() -> preemption fork() sched_mm_cid_fork(tnew2) tnew2->mm.mm_cid_users++; // Reaches the per CPU threshold mm_cid_fixup_tasks_to_cpus() for_each_other(current, p) .... As tnew1 is not visible yet, this fails to fix up the already allocated CID of tnew1. As a consequence a subsequent schedule in might fail to acquire a (transitional) CID and the machine stalls. Move the invocation of sched_mm_cid_fork() after the new task becomes visible in the thread and the task list to prevent this. This also makes it symmetrical vs. exit() where the task is removed as CID user before the task is removed from the thread and task lists. Fixes: fbd0e71dc370 ("sched/mmcid: Provide CID ownership mode fixup functions") Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Tested-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260310202525.969061974@kernel.org --- include/linux/sched.h | 2 -- kernel/fork.c | 2 -- kernel/sched/core.c | 22 +++++++++++++++------- 3 files changed, 15 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index a7b4a980eb2f..5a5d3dbc9cdf 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2354,7 +2354,6 @@ static __always_inline void alloc_tag_restore(struct alloc_tag *tag, struct allo #ifdef CONFIG_SCHED_MM_CID void sched_mm_cid_before_execve(struct task_struct *t); void sched_mm_cid_after_execve(struct task_struct *t); -void sched_mm_cid_fork(struct task_struct *t); void sched_mm_cid_exit(struct task_struct *t); static __always_inline int task_mm_cid(struct task_struct *t) { @@ -2363,7 +2362,6 @@ static __always_inline int task_mm_cid(struct task_struct *t) #else static inline void sched_mm_cid_before_execve(struct task_struct *t) { } static inline void sched_mm_cid_after_execve(struct task_struct *t) { } -static inline void sched_mm_cid_fork(struct task_struct *t) { } static inline void sched_mm_cid_exit(struct task_struct *t) { } static __always_inline int task_mm_cid(struct task_struct *t) { diff --git a/kernel/fork.c b/kernel/fork.c index 65113a304518..7febf4c2889e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1586,7 +1586,6 @@ static int copy_mm(u64 clone_flags, struct task_struct *tsk) tsk->mm = mm; tsk->active_mm = mm; - sched_mm_cid_fork(tsk); return 0; } @@ -2498,7 +2497,6 @@ bad_fork_cleanup_namespaces: exit_nsproxy_namespaces(p); bad_fork_cleanup_mm: if (p->mm) { - sched_mm_cid_exit(p); mm_clear_owner(p->mm, p); mmput(p->mm); } diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b7f77c165a6e..d25427855b5d 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -4729,8 +4729,11 @@ void sched_cancel_fork(struct task_struct *p) scx_cancel_fork(p); } +static void sched_mm_cid_fork(struct task_struct *t); + void sched_post_fork(struct task_struct *p) { + sched_mm_cid_fork(p); uclamp_post_fork(p); scx_post_fork(p); } @@ -10646,12 +10649,13 @@ static void mm_cid_do_fixup_tasks_to_cpus(struct mm_struct *mm) * possible switch back to per task mode happens either in the * deferred handler function or in the next fork()/exit(). * - * The caller has already transferred. The newly incoming task is - * already accounted for, but not yet visible. + * The caller has already transferred so remove it from the users + * count. The incoming task is already visible and has mm_cid.active, + * but has task::mm_cid::cid == UNSET. Still it needs to be accounted + * for. Concurrent fork()s might add more threads, but all of them have + * task::mm_cid::active = 0, so they don't affect the accounting here. */ - users = mm->mm_cid.users - 2; - if (!users) - return; + users = mm->mm_cid.users - 1; guard(rcu)(); for_other_threads(current, t) { @@ -10688,12 +10692,15 @@ static bool sched_mm_cid_add_user(struct task_struct *t, struct mm_struct *mm) return mm_update_max_cids(mm); } -void sched_mm_cid_fork(struct task_struct *t) +static void sched_mm_cid_fork(struct task_struct *t) { struct mm_struct *mm = t->mm; bool percpu; - WARN_ON_ONCE(!mm || t->mm_cid.cid != MM_CID_UNSET); + if (!mm) + return; + + WARN_ON_ONCE(t->mm_cid.cid != MM_CID_UNSET); guard(mutex)(&mm->mm_cid.mutex); scoped_guard(raw_spinlock_irq, &mm->mm_cid.lock) { @@ -10885,6 +10892,7 @@ void mm_init_cid(struct mm_struct *mm, struct task_struct *p) } #else /* CONFIG_SCHED_MM_CID */ static inline void mm_update_cpus_allowed(struct mm_struct *mm, const struct cpumask *affmsk) { } +static inline void sched_mm_cid_fork(struct task_struct *t) { } #endif /* !CONFIG_SCHED_MM_CID */ static DEFINE_PER_CPU(struct sched_change_ctx, sched_change_ctx); -- cgit v1.2.3 From 192d852129b1b7c4f0ddbab95d0de1efd5ee1405 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 10 Mar 2026 21:29:09 +0100 Subject: sched/mmcid: Avoid full tasklist walks Chasing vfork()'ed tasks on a CID ownership mode switch requires a full task list walk, which is obviously expensive on large systems. Avoid that by keeping a list of tasks using a mm MMCID entity in mm::mm_cid and walk this list instead. This removes the proven to be flaky counting logic and avoids a full task list walk in the case of vfork()'ed tasks. Fixes: fbd0e71dc370 ("sched/mmcid: Provide CID ownership mode fixup functions") Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Tested-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260310202526.183824481@kernel.org --- include/linux/rseq_types.h | 6 +++++- kernel/fork.c | 1 + kernel/sched/core.c | 54 +++++++++++----------------------------------- 3 files changed, 18 insertions(+), 43 deletions(-) (limited to 'include/linux') diff --git a/include/linux/rseq_types.h b/include/linux/rseq_types.h index da5fa6f40294..0b42045988db 100644 --- a/include/linux/rseq_types.h +++ b/include/linux/rseq_types.h @@ -133,10 +133,12 @@ struct rseq_data { }; * @active: MM CID is active for the task * @cid: The CID associated to the task either permanently or * borrowed from the CPU + * @node: Queued in the per MM MMCID list */ struct sched_mm_cid { unsigned int active; unsigned int cid; + struct hlist_node node; }; /** @@ -157,6 +159,7 @@ struct mm_cid_pcpu { * @work: Regular work to handle the affinity mode change case * @lock: Spinlock to protect against affinity setting which can't take @mutex * @mutex: Mutex to serialize forks and exits related to this mm + * @user_list: List of the MM CID users of a MM * @nr_cpus_allowed: The number of CPUs in the per MM allowed CPUs map. The map * is growth only. * @users: The number of tasks sharing this MM. Separate from mm::mm_users @@ -177,13 +180,14 @@ struct mm_mm_cid { raw_spinlock_t lock; struct mutex mutex; + struct hlist_head user_list; /* Low frequency modified */ unsigned int nr_cpus_allowed; unsigned int users; unsigned int pcpu_thrs; unsigned int update_deferred; -}____cacheline_aligned_in_smp; +} ____cacheline_aligned; #else /* CONFIG_SCHED_MM_CID */ struct mm_mm_cid { }; struct sched_mm_cid { }; diff --git a/kernel/fork.c b/kernel/fork.c index 7febf4c2889e..bc2bf58b93b6 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1000,6 +1000,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node) #ifdef CONFIG_SCHED_MM_CID tsk->mm_cid.cid = MM_CID_UNSET; tsk->mm_cid.active = 0; + INIT_HLIST_NODE(&tsk->mm_cid.node); #endif return tsk; diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f56156f91d08..496dff740dca 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -10620,13 +10620,10 @@ static inline void mm_cid_transit_to_cpu(struct task_struct *t, struct mm_cid_pc } } -static bool mm_cid_fixup_task_to_cpu(struct task_struct *t, struct mm_struct *mm) +static void mm_cid_fixup_task_to_cpu(struct task_struct *t, struct mm_struct *mm) { /* Remote access to mm::mm_cid::pcpu requires rq_lock */ guard(task_rq_lock)(t); - /* If the task is not active it is not in the users count */ - if (!t->mm_cid.active) - return false; if (cid_on_task(t->mm_cid.cid)) { /* If running on the CPU, put the CID in transit mode, otherwise drop it */ if (task_rq(t)->curr == t) @@ -10634,51 +10631,21 @@ static bool mm_cid_fixup_task_to_cpu(struct task_struct *t, struct mm_struct *mm else mm_unset_cid_on_task(t); } - return true; } -static void mm_cid_do_fixup_tasks_to_cpus(struct mm_struct *mm) +static void mm_cid_fixup_tasks_to_cpus(void) { - struct task_struct *p, *t; - unsigned int users; - - /* - * This can obviously race with a concurrent affinity change, which - * increases the number of allowed CPUs for this mm, but that does - * not affect the mode and only changes the CID constraints. A - * possible switch back to per task mode happens either in the - * deferred handler function or in the next fork()/exit(). - * - * The caller has already transferred so remove it from the users - * count. The incoming task is already visible and has mm_cid.active, - * but has task::mm_cid::cid == UNSET. Still it needs to be accounted - * for. Concurrent fork()s might add more threads, but all of them have - * task::mm_cid::active = 0, so they don't affect the accounting here. - */ - users = mm->mm_cid.users - 1; - - guard(rcu)(); - for_other_threads(current, t) { - if (mm_cid_fixup_task_to_cpu(t, mm)) - users--; - } + struct mm_struct *mm = current->mm; + struct task_struct *t; - if (!users) - return; + lockdep_assert_held(&mm->mm_cid.mutex); - /* Happens only for VM_CLONE processes. */ - for_each_process_thread(p, t) { - if (t == current || t->mm != mm) - continue; - mm_cid_fixup_task_to_cpu(t, mm); + hlist_for_each_entry(t, &mm->mm_cid.user_list, mm_cid.node) { + /* Current has already transferred before invoking the fixup. */ + if (t != current) + mm_cid_fixup_task_to_cpu(t, mm); } -} - -static void mm_cid_fixup_tasks_to_cpus(void) -{ - struct mm_struct *mm = current->mm; - mm_cid_do_fixup_tasks_to_cpus(mm); mm_cid_complete_transit(mm, MM_CID_ONCPU); } @@ -10687,6 +10654,7 @@ static bool sched_mm_cid_add_user(struct task_struct *t, struct mm_struct *mm) lockdep_assert_held(&mm->mm_cid.lock); t->mm_cid.active = 1; + hlist_add_head(&t->mm_cid.node, &mm->mm_cid.user_list); mm->mm_cid.users++; return mm_update_max_cids(mm); } @@ -10744,6 +10712,7 @@ static bool sched_mm_cid_remove_user(struct task_struct *t) /* Clear the transition bit */ t->mm_cid.cid = cid_from_transit_cid(t->mm_cid.cid); mm_unset_cid_on_task(t); + hlist_del_init(&t->mm_cid.node); t->mm->mm_cid.users--; return mm_update_max_cids(t->mm); } @@ -10886,6 +10855,7 @@ void mm_init_cid(struct mm_struct *mm, struct task_struct *p) mutex_init(&mm->mm_cid.mutex); mm->mm_cid.irq_work = IRQ_WORK_INIT_HARD(mm_cid_irq_work); INIT_WORK(&mm->mm_cid.work, mm_cid_work_fn); + INIT_HLIST_HEAD(&mm->mm_cid.user_list); cpumask_copy(mm_cpus_allowed(mm), &p->cpus_mask); bitmap_zero(mm_cidmask(mm), num_possible_cpus()); } -- cgit v1.2.3 From 227312b4a65c373d5d8b4683b7fc36203fedc516 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Sat, 28 Feb 2026 15:52:58 +0100 Subject: HID: input: Add HID_BATTERY_QUIRK_DYNAMIC for Elan touchscreens Elan touchscreens have a HID-battery device for the stylus which is always there even if there is no stylus. This is causing upower to report an empty battery for the stylus and some desktop-environments will show a notification about this, which is quite annoying. Because of this the HID-battery is being ignored on all Elan I2c and USB touchscreens, but this causes there to be no battery reporting for the stylus at all. This adds a new HID_BATTERY_QUIRK_DYNAMIC and uses these for the Elan touchscreens. This new quirks causes the present value of the battery to start at 0, which will make userspace ignore it and only sets present to 1 after receiving a battery input report which only happens when the stylus gets in range. Reported-by: ggrundik@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221118 Signed-off-by: Hans de Goede Reviewed-by: Sebastian Reichel Signed-off-by: Jiri Kosina --- drivers/hid/hid-input.c | 14 +++++++++++--- include/linux/hid.h | 1 + 2 files changed, 12 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 67ca1e88ce13..8fc20df99b97 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -354,6 +354,7 @@ static enum power_supply_property hidinput_battery_props[] = { #define HID_BATTERY_QUIRK_FEATURE (1 << 1) /* ask for feature report */ #define HID_BATTERY_QUIRK_IGNORE (1 << 2) /* completely ignore the battery */ #define HID_BATTERY_QUIRK_AVOID_QUERY (1 << 3) /* do not query the battery */ +#define HID_BATTERY_QUIRK_DYNAMIC (1 << 4) /* report present only after life signs */ static const struct hid_device_id hid_battery_quirks[] = { { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE, @@ -398,8 +399,8 @@ static const struct hid_device_id hid_battery_quirks[] = { * Elan HID touchscreens seem to all report a non present battery, * set HID_BATTERY_QUIRK_IGNORE for all Elan I2C and USB HID devices. */ - { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, HID_ANY_ID), HID_BATTERY_QUIRK_IGNORE }, - { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, HID_ANY_ID), HID_BATTERY_QUIRK_IGNORE }, + { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, HID_ANY_ID), HID_BATTERY_QUIRK_DYNAMIC }, + { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, HID_ANY_ID), HID_BATTERY_QUIRK_DYNAMIC }, {} }; @@ -456,11 +457,14 @@ static int hidinput_get_battery_property(struct power_supply *psy, int ret = 0; switch (prop) { - case POWER_SUPPLY_PROP_PRESENT: case POWER_SUPPLY_PROP_ONLINE: val->intval = 1; break; + case POWER_SUPPLY_PROP_PRESENT: + val->intval = dev->battery_present; + break; + case POWER_SUPPLY_PROP_CAPACITY: if (dev->battery_status != HID_BATTERY_REPORTED && !dev->battery_avoid_query) { @@ -573,6 +577,8 @@ static int hidinput_setup_battery(struct hid_device *dev, unsigned report_type, if (quirks & HID_BATTERY_QUIRK_AVOID_QUERY) dev->battery_avoid_query = true; + dev->battery_present = (quirks & HID_BATTERY_QUIRK_DYNAMIC) ? false : true; + dev->battery = power_supply_register(&dev->dev, psy_desc, &psy_cfg); if (IS_ERR(dev->battery)) { error = PTR_ERR(dev->battery); @@ -628,6 +634,7 @@ static void hidinput_update_battery(struct hid_device *dev, unsigned int usage, return; if (hidinput_update_battery_charge_status(dev, usage, value)) { + dev->battery_present = true; power_supply_changed(dev->battery); return; } @@ -643,6 +650,7 @@ static void hidinput_update_battery(struct hid_device *dev, unsigned int usage, if (dev->battery_status != HID_BATTERY_REPORTED || capacity != dev->battery_capacity || ktime_after(ktime_get_coarse(), dev->battery_ratelimit_time)) { + dev->battery_present = true; dev->battery_capacity = capacity; dev->battery_status = HID_BATTERY_REPORTED; dev->battery_ratelimit_time = diff --git a/include/linux/hid.h b/include/linux/hid.h index 2990b9f94cb5..31324609af4d 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -682,6 +682,7 @@ struct hid_device { __s32 battery_charge_status; enum hid_battery_status battery_status; bool battery_avoid_query; + bool battery_present; ktime_t battery_ratelimit_time; #endif -- cgit v1.2.3 From 416909962e7cdf29fd01ac523c953f37708df93d Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 17 Feb 2026 22:07:47 -0500 Subject: USB: usbcore: Introduce usb_bulk_msg_killable() The synchronous message API in usbcore (usb_control_msg(), usb_bulk_msg(), and so on) uses uninterruptible waits. However, drivers may call these routines in the context of a user thread, which means it ought to be possible to at least kill them. For this reason, introduce a new usb_bulk_msg_killable() function which behaves the same as usb_bulk_msg() except for using wait_for_completion_killable_timeout() instead of wait_for_completion_timeout(). The same can be done later for usb_control_msg() later on, if it turns out to be needed. Signed-off-by: Alan Stern Suggested-by: Oliver Neukum Link: https://lore.kernel.org/linux-usb/3acfe838-6334-4f6d-be7c-4bb01704b33d@rowland.harvard.edu/ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") CC: stable@vger.kernel.org Link: https://patch.msgid.link/248628b4-cc83-4e81-a620-3ce4e0376d41@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/message.c | 79 ++++++++++++++++++++++++++++++++++++++++------ include/linux/usb.h | 5 +-- 2 files changed, 72 insertions(+), 12 deletions(-) (limited to 'include/linux') diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index ea970ddf8879..d97ec7e8c280 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -42,16 +42,17 @@ static void usb_api_blocking_completion(struct urb *urb) /* - * Starts urb and waits for completion or timeout. Note that this call - * is NOT interruptible. Many device driver i/o requests should be - * interruptible and therefore these drivers should implement their - * own interruptible routines. + * Starts urb and waits for completion or timeout. + * Whether or not the wait is killable depends on the flag passed in. + * For example, compare usb_bulk_msg() and usb_bulk_msg_killable(). */ -static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length) +static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length, + bool killable) { struct api_context ctx; unsigned long expire; int retval; + long rc; init_completion(&ctx.done); urb->context = &ctx; @@ -61,12 +62,21 @@ static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length) goto out; expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT; - if (!wait_for_completion_timeout(&ctx.done, expire)) { + if (killable) + rc = wait_for_completion_killable_timeout(&ctx.done, expire); + else + rc = wait_for_completion_timeout(&ctx.done, expire); + if (rc <= 0) { usb_kill_urb(urb); - retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status); + if (ctx.status != -ENOENT) + retval = ctx.status; + else if (rc == 0) + retval = -ETIMEDOUT; + else + retval = rc; dev_dbg(&urb->dev->dev, - "%s timed out on ep%d%s len=%u/%u\n", + "%s timed out or killed on ep%d%s len=%u/%u\n", current->comm, usb_endpoint_num(&urb->ep->desc), usb_urb_dir_in(urb) ? "in" : "out", @@ -100,7 +110,7 @@ static int usb_internal_control_msg(struct usb_device *usb_dev, usb_fill_control_urb(urb, usb_dev, pipe, (unsigned char *)cmd, data, len, usb_api_blocking_completion, NULL); - retv = usb_start_wait_urb(urb, timeout, &length); + retv = usb_start_wait_urb(urb, timeout, &length, false); if (retv < 0) return retv; else @@ -385,10 +395,59 @@ int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe, usb_fill_bulk_urb(urb, usb_dev, pipe, data, len, usb_api_blocking_completion, NULL); - return usb_start_wait_urb(urb, timeout, actual_length); + return usb_start_wait_urb(urb, timeout, actual_length, false); } EXPORT_SYMBOL_GPL(usb_bulk_msg); +/** + * usb_bulk_msg_killable - Builds a bulk urb, sends it off and waits for completion in a killable state + * @usb_dev: pointer to the usb device to send the message to + * @pipe: endpoint "pipe" to send the message to + * @data: pointer to the data to send + * @len: length in bytes of the data to send + * @actual_length: pointer to a location to put the actual length transferred + * in bytes + * @timeout: time in msecs to wait for the message to complete before + * timing out (if 0 the wait is forever) + * + * Context: task context, might sleep. + * + * This function is just like usb_blk_msg() except that it waits in a + * killable state. + * + * Return: + * If successful, 0. Otherwise a negative error number. The number of actual + * bytes transferred will be stored in the @actual_length parameter. + * + */ +int usb_bulk_msg_killable(struct usb_device *usb_dev, unsigned int pipe, + void *data, int len, int *actual_length, int timeout) +{ + struct urb *urb; + struct usb_host_endpoint *ep; + + ep = usb_pipe_endpoint(usb_dev, pipe); + if (!ep || len < 0) + return -EINVAL; + + urb = usb_alloc_urb(0, GFP_KERNEL); + if (!urb) + return -ENOMEM; + + if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == + USB_ENDPOINT_XFER_INT) { + pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30); + usb_fill_int_urb(urb, usb_dev, pipe, data, len, + usb_api_blocking_completion, NULL, + ep->desc.bInterval); + } else + usb_fill_bulk_urb(urb, usb_dev, pipe, data, len, + usb_api_blocking_completion, NULL); + + return usb_start_wait_urb(urb, timeout, actual_length, true); +} +EXPORT_SYMBOL_GPL(usb_bulk_msg_killable); + /*-------------------------------------------------------------------*/ static void sg_clean(struct usb_sg_request *io) diff --git a/include/linux/usb.h b/include/linux/usb.h index fbfcc70b07fb..57ceeb02a7cb 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1868,8 +1868,9 @@ extern int usb_control_msg(struct usb_device *dev, unsigned int pipe, extern int usb_interrupt_msg(struct usb_device *usb_dev, unsigned int pipe, void *data, int len, int *actual_length, int timeout); extern int usb_bulk_msg(struct usb_device *usb_dev, unsigned int pipe, - void *data, int len, int *actual_length, - int timeout); + void *data, int len, int *actual_length, int timeout); +extern int usb_bulk_msg_killable(struct usb_device *usb_dev, unsigned int pipe, + void *data, int len, int *actual_length, int timeout); /* wrappers around usb_control_msg() for the most common standard requests */ int usb_control_msg_send(struct usb_device *dev, __u8 endpoint, __u8 request, -- cgit v1.2.3 From 1015c27a5e1a63efae2b18a9901494474b4d1dc3 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 17 Feb 2026 22:10:32 -0500 Subject: USB: core: Limit the length of unkillable synchronous timeouts The usb_control_msg(), usb_bulk_msg(), and usb_interrupt_msg() APIs in usbcore allow unlimited timeout durations. And since they use uninterruptible waits, this leaves open the possibility of hanging a task for an indefinitely long time, with no way to kill it short of unplugging the target device. To prevent this sort of problem, enforce a maximum limit on the length of these unkillable timeouts. The limit chosen here, somewhat arbitrarily, is 60 seconds. On many systems (although not all) this is short enough to avoid triggering the kernel's hung-task detector. In addition, clear up the ambiguity of negative timeout values by treating them the same as 0, i.e., using the maximum allowed timeout. Signed-off-by: Alan Stern Link: https://lore.kernel.org/linux-usb/3acfe838-6334-4f6d-be7c-4bb01704b33d@rowland.harvard.edu/ Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") CC: stable@vger.kernel.org Link: https://patch.msgid.link/15fc9773-a007-47b0-a703-df89a8cf83dd@rowland.harvard.edu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/message.c | 27 +++++++++++++-------------- include/linux/usb.h | 3 +++ 2 files changed, 16 insertions(+), 14 deletions(-) (limited to 'include/linux') diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index d97ec7e8c280..2ab120ce2fa8 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -45,6 +45,8 @@ static void usb_api_blocking_completion(struct urb *urb) * Starts urb and waits for completion or timeout. * Whether or not the wait is killable depends on the flag passed in. * For example, compare usb_bulk_msg() and usb_bulk_msg_killable(). + * + * For non-killable waits, we enforce a maximum limit on the timeout value. */ static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length, bool killable) @@ -61,7 +63,9 @@ static int usb_start_wait_urb(struct urb *urb, int timeout, int *actual_length, if (unlikely(retval)) goto out; - expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT; + if (!killable && (timeout <= 0 || timeout > USB_MAX_SYNCHRONOUS_TIMEOUT)) + timeout = USB_MAX_SYNCHRONOUS_TIMEOUT; + expire = (timeout > 0) ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT; if (killable) rc = wait_for_completion_killable_timeout(&ctx.done, expire); else @@ -127,8 +131,7 @@ static int usb_internal_control_msg(struct usb_device *usb_dev, * @index: USB message index value * @data: pointer to the data to send * @size: length in bytes of the data to send - * @timeout: time in msecs to wait for the message to complete before timing - * out (if 0 the wait is forever) + * @timeout: time in msecs to wait for the message to complete before timing out * * Context: task context, might sleep. * @@ -183,8 +186,7 @@ EXPORT_SYMBOL_GPL(usb_control_msg); * @index: USB message index value * @driver_data: pointer to the data to send * @size: length in bytes of the data to send - * @timeout: time in msecs to wait for the message to complete before timing - * out (if 0 the wait is forever) + * @timeout: time in msecs to wait for the message to complete before timing out * @memflags: the flags for memory allocation for buffers * * Context: !in_interrupt () @@ -242,8 +244,7 @@ EXPORT_SYMBOL_GPL(usb_control_msg_send); * @index: USB message index value * @driver_data: pointer to the data to be filled in by the message * @size: length in bytes of the data to be received - * @timeout: time in msecs to wait for the message to complete before timing - * out (if 0 the wait is forever) + * @timeout: time in msecs to wait for the message to complete before timing out * @memflags: the flags for memory allocation for buffers * * Context: !in_interrupt () @@ -314,8 +315,7 @@ EXPORT_SYMBOL_GPL(usb_control_msg_recv); * @len: length in bytes of the data to send * @actual_length: pointer to a location to put the actual length transferred * in bytes - * @timeout: time in msecs to wait for the message to complete before - * timing out (if 0 the wait is forever) + * @timeout: time in msecs to wait for the message to complete before timing out * * Context: task context, might sleep. * @@ -347,8 +347,7 @@ EXPORT_SYMBOL_GPL(usb_interrupt_msg); * @len: length in bytes of the data to send * @actual_length: pointer to a location to put the actual length transferred * in bytes - * @timeout: time in msecs to wait for the message to complete before - * timing out (if 0 the wait is forever) + * @timeout: time in msecs to wait for the message to complete before timing out * * Context: task context, might sleep. * @@ -408,12 +407,12 @@ EXPORT_SYMBOL_GPL(usb_bulk_msg); * @actual_length: pointer to a location to put the actual length transferred * in bytes * @timeout: time in msecs to wait for the message to complete before - * timing out (if 0 the wait is forever) + * timing out (if <= 0, the wait is as long as possible) * * Context: task context, might sleep. * - * This function is just like usb_blk_msg() except that it waits in a - * killable state. + * This function is just like usb_blk_msg(), except that it waits in a + * killable state and there is no limit on the timeout length. * * Return: * If successful, 0. Otherwise a negative error number. The number of actual diff --git a/include/linux/usb.h b/include/linux/usb.h index 57ceeb02a7cb..04277af4bb9d 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1862,6 +1862,9 @@ void usb_free_noncoherent(struct usb_device *dev, size_t size, * SYNCHRONOUS CALL SUPPORT * *-------------------------------------------------------------------*/ +/* Maximum value allowed for timeout in synchronous routines below */ +#define USB_MAX_SYNCHRONOUS_TIMEOUT 60000 /* ms */ + extern int usb_control_msg(struct usb_device *dev, unsigned int pipe, __u8 request, __u8 requesttype, __u16 value, __u16 index, void *data, __u16 size, int timeout); -- cgit v1.2.3 From 9f6a983cfa22ac662c86e60816d3a357d4b551e9 Mon Sep 17 00:00:00 2001 From: Jie Deng Date: Fri, 27 Feb 2026 16:49:31 +0800 Subject: usb: core: new quirk to handle devices with zero configurations Some USB devices incorrectly report bNumConfigurations as 0 in their device descriptor, which causes the USB core to reject them during enumeration. logs: usb 1-2: device descriptor read/64, error -71 usb 1-2: no configurations usb 1-2: can't read configurations, error -22 However, these devices actually work correctly when treated as having a single configuration. Add a new quirk USB_QUIRK_FORCE_ONE_CONFIG to handle such devices. When this quirk is set, assume the device has 1 configuration instead of failing with -EINVAL. This quirk is applied to the device with VID:PID 5131:2007 which exhibits this behavior. Signed-off-by: Jie Deng Link: https://patch.msgid.link/20260227084931.1527461-1-dengjie03@kylinos.cn Signed-off-by: Greg Kroah-Hartman --- Documentation/admin-guide/kernel-parameters.txt | 3 +++ drivers/usb/core/config.c | 6 +++++- drivers/usb/core/quirks.c | 5 +++++ include/linux/usb/quirks.h | 3 +++ 4 files changed, 16 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index cb850e5290c2..7d907efe9f49 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -8183,6 +8183,9 @@ Kernel parameters p = USB_QUIRK_SHORT_SET_ADDRESS_REQ_TIMEOUT (Reduce timeout of the SET_ADDRESS request from 5000 ms to 500 ms); + q = USB_QUIRK_FORCE_ONE_CONFIG (Device + claims zero configurations, + forcing to 1); Example: quirks=0781:5580:bk,0a5c:5834:gij usbhid.mousepoll= diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c index 1cd5fa61dc76..6a1fd967e0a6 100644 --- a/drivers/usb/core/config.c +++ b/drivers/usb/core/config.c @@ -927,7 +927,11 @@ int usb_get_configuration(struct usb_device *dev) dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG; } - if (ncfg < 1) { + if (ncfg < 1 && dev->quirks & USB_QUIRK_FORCE_ONE_CONFIG) { + dev_info(ddev, "Device claims zero configurations, forcing to 1\n"); + dev->descriptor.bNumConfigurations = 1; + ncfg = 1; + } else if (ncfg < 1) { dev_err(ddev, "no configurations\n"); return -EINVAL; } diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c index e347236d83e8..7bd408db05f4 100644 --- a/drivers/usb/core/quirks.c +++ b/drivers/usb/core/quirks.c @@ -140,6 +140,8 @@ static int quirks_param_set(const char *value, const struct kernel_param *kp) case 'p': flags |= USB_QUIRK_SHORT_SET_ADDRESS_REQ_TIMEOUT; break; + case 'q': + flags |= USB_QUIRK_FORCE_ONE_CONFIG; /* Ignore unrecognized flag characters */ } } @@ -589,6 +591,9 @@ static const struct usb_device_id usb_quirk_list[] = { /* VCOM device */ { USB_DEVICE(0x4296, 0x7570), .driver_info = USB_QUIRK_CONFIG_INTF_STRINGS }, + /* Noji-MCS SmartCard Reader */ + { USB_DEVICE(0x5131, 0x2007), .driver_info = USB_QUIRK_FORCE_ONE_CONFIG }, + /* INTEL VALUE SSD */ { USB_DEVICE(0x8086, 0xf1a5), .driver_info = USB_QUIRK_RESET_RESUME }, diff --git a/include/linux/usb/quirks.h b/include/linux/usb/quirks.h index 2f7bd2fdc616..b3cc7beab4a3 100644 --- a/include/linux/usb/quirks.h +++ b/include/linux/usb/quirks.h @@ -78,4 +78,7 @@ /* skip BOS descriptor request */ #define USB_QUIRK_NO_BOS BIT(17) +/* Device claims zero configurations, forcing to 1 */ +#define USB_QUIRK_FORCE_ONE_CONFIG BIT(18) + #endif /* __LINUX_USB_QUIRKS_H */ -- cgit v1.2.3 From 96189080265e6bb5dde3a4afbaf947af493e3f82 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 9 Mar 2026 14:21:37 -0600 Subject: io_uring: ensure ctx->rings is stable for task work flags manipulation If DEFER_TASKRUN | SETUP_TASKRUN is used and task work is added while the ring is being resized, it's possible for the OR'ing of IORING_SQ_TASKRUN to happen in the small window of swapping into the new rings and the old rings being freed. Prevent this by adding a 2nd ->rings pointer, ->rings_rcu, which is protected by RCU. The task work flags manipulation is inside RCU already, and if the resize ring freeing is done post an RCU synchronize, then there's no need to add locking to the fast path of task work additions. Note: this is only done for DEFER_TASKRUN, as that's the only setup mode that supports ring resizing. If this ever changes, then they too need to use the io_ctx_mark_taskrun() helper. Link: https://lore.kernel.org/io-uring/20260309062759.482210-1-naup96721@gmail.com/ Cc: stable@vger.kernel.org Fixes: 79cfe9e59c2a ("io_uring/register: add IORING_REGISTER_RESIZE_RINGS") Reported-by: Hao-Yu Yang Suggested-by: Pavel Begunkov Signed-off-by: Jens Axboe --- include/linux/io_uring_types.h | 1 + io_uring/io_uring.c | 2 ++ io_uring/register.c | 11 +++++++++++ io_uring/tw.c | 22 ++++++++++++++++++++-- 4 files changed, 34 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index 3e4a82a6f817..dd1420bfcb73 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -388,6 +388,7 @@ struct io_ring_ctx { * regularly bounce b/w CPUs. */ struct { + struct io_rings __rcu *rings_rcu; struct llist_head work_llist; struct llist_head retry_llist; unsigned long check_cq; diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index ccab8562d273..20fdc442e014 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -2066,6 +2066,7 @@ static void io_rings_free(struct io_ring_ctx *ctx) io_free_region(ctx->user, &ctx->sq_region); io_free_region(ctx->user, &ctx->ring_region); ctx->rings = NULL; + RCU_INIT_POINTER(ctx->rings_rcu, NULL); ctx->sq_sqes = NULL; } @@ -2703,6 +2704,7 @@ static __cold int io_allocate_scq_urings(struct io_ring_ctx *ctx, if (ret) return ret; ctx->rings = rings = io_region_get_ptr(&ctx->ring_region); + rcu_assign_pointer(ctx->rings_rcu, rings); if (!(ctx->flags & IORING_SETUP_NO_SQARRAY)) ctx->sq_array = (u32 *)((char *)rings + rl->sq_array_offset); diff --git a/io_uring/register.c b/io_uring/register.c index a839b22fd392..5f3eb018fb32 100644 --- a/io_uring/register.c +++ b/io_uring/register.c @@ -633,7 +633,15 @@ overflow: ctx->sq_entries = p->sq_entries; ctx->cq_entries = p->cq_entries; + /* + * Just mark any flag we may have missed and that the application + * should act on unconditionally. Worst case it'll be an extra + * syscall. + */ + atomic_or(IORING_SQ_TASKRUN | IORING_SQ_NEED_WAKEUP, &n.rings->sq_flags); ctx->rings = n.rings; + rcu_assign_pointer(ctx->rings_rcu, n.rings); + ctx->sq_sqes = n.sq_sqes; swap_old(ctx, o, n, ring_region); swap_old(ctx, o, n, sq_region); @@ -642,6 +650,9 @@ overflow: out: spin_unlock(&ctx->completion_lock); mutex_unlock(&ctx->mmap_lock); + /* Wait for concurrent io_ctx_mark_taskrun() */ + if (to_free == &o) + synchronize_rcu_expedited(); io_register_free_rings(ctx, to_free); if (ctx->sq_data) diff --git a/io_uring/tw.c b/io_uring/tw.c index 1ee2b8ab07c8..2f2b4ac4b126 100644 --- a/io_uring/tw.c +++ b/io_uring/tw.c @@ -152,6 +152,21 @@ void tctx_task_work(struct callback_head *cb) WARN_ON_ONCE(ret); } +/* + * Sets IORING_SQ_TASKRUN in the sq_flags shared with userspace, using the + * RCU protected rings pointer to be safe against concurrent ring resizing. + */ +static void io_ctx_mark_taskrun(struct io_ring_ctx *ctx) +{ + lockdep_assert_in_rcu_read_lock(); + + if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) { + struct io_rings *rings = rcu_dereference(ctx->rings_rcu); + + atomic_or(IORING_SQ_TASKRUN, &rings->sq_flags); + } +} + void io_req_local_work_add(struct io_kiocb *req, unsigned flags) { struct io_ring_ctx *ctx = req->ctx; @@ -206,8 +221,7 @@ void io_req_local_work_add(struct io_kiocb *req, unsigned flags) */ if (!head) { - if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) - atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); + io_ctx_mark_taskrun(ctx); if (ctx->has_evfd) io_eventfd_signal(ctx, false); } @@ -231,6 +245,10 @@ void io_req_normal_work_add(struct io_kiocb *req) if (!llist_add(&req->io_task_work.node, &tctx->task_list)) return; + /* + * Doesn't need to use ->rings_rcu, as resizing isn't supported for + * !DEFER_TASKRUN. + */ if (ctx->flags & IORING_SETUP_TASKRUN_FLAG) atomic_or(IORING_SQ_TASKRUN, &ctx->rings->sq_flags); -- cgit v1.2.3 From 94a4b1f959989de9c54d43c3a102fb1ee92e1414 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sat, 7 Mar 2026 17:50:53 -0300 Subject: ipv6: move the disable_ipv6_mod knob to core code From: Jakub Kicinski Make sure disable_ipv6_mod itself is not part of the IPv6 module, in case core code wants to refer to it. We will remove support for IPv6=m soon, this change helps make fixes we commit before that less messy. Link: https://patch.msgid.link/20260307-net-nd_tbl_fixes-v4-1-e2677e85628c@suse.com Signed-off-by: Jakub Kicinski --- include/linux/ipv6.h | 7 ++++++- net/ipv4/af_inet.c | 6 ++++++ net/ipv6/af_inet6.c | 8 -------- 3 files changed, 12 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h index 443053a76dcf..a7421382a916 100644 --- a/include/linux/ipv6.h +++ b/include/linux/ipv6.h @@ -333,7 +333,12 @@ struct tcp6_timewait_sock { }; #if IS_ENABLED(CONFIG_IPV6) -bool ipv6_mod_enabled(void); +extern int disable_ipv6_mod; + +static inline bool ipv6_mod_enabled(void) +{ + return disable_ipv6_mod == 0; +} static inline struct ipv6_pinfo *inet6_sk(const struct sock *__sk) { diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 8036e76aa1e4..c7731e300a44 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -124,6 +124,12 @@ #include +/* Keep the definition of IPv6 disable here for now, to avoid annoying linker + * issues in case IPv6=m + */ +int disable_ipv6_mod; +EXPORT_SYMBOL(disable_ipv6_mod); + /* The inetsw table contains everything that inet_create needs to * build a new socket. */ diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 23cc9b4cb2f1..4cbd45b68088 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -86,8 +86,6 @@ struct ipv6_params ipv6_defaults = { .autoconf = 1, }; -static int disable_ipv6_mod; - module_param_named(disable, disable_ipv6_mod, int, 0444); MODULE_PARM_DESC(disable, "Disable IPv6 module such that it is non-functional"); @@ -97,12 +95,6 @@ MODULE_PARM_DESC(disable_ipv6, "Disable IPv6 on all interfaces"); module_param_named(autoconf, ipv6_defaults.autoconf, int, 0444); MODULE_PARM_DESC(autoconf, "Enable IPv6 address autoconfiguration on all interfaces"); -bool ipv6_mod_enabled(void) -{ - return disable_ipv6_mod == 0; -} -EXPORT_SYMBOL_GPL(ipv6_mod_enabled); - static struct ipv6_pinfo *inet6_sk_generic(struct sock *sk) { const int offset = sk->sk_prot->ipv6_pinfo_offset; -- cgit v1.2.3 From 14de1552a4e3fece78bb20314887e70888c9d448 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Wed, 11 Mar 2026 16:14:55 -0700 Subject: include/linux/local_lock_internal.h: Make this header file again compatible with sparse There are two versions of the __this_cpu_local_lock() definitions in include/linux/local_lock_internal.h: one version that relies on the Clang overloading functionality and another version that does not. Select the latter version when using sparse. This patch fixes the following errors reported by sparse: include/linux/local_lock_internal.h:331:40: sparse: sparse: multiple definitions for function '__this_cpu_local_lock' include/linux/local_lock_internal.h:325:37: sparse: the previous one is here Closes: https://lore.kernel.org/oe-kbuild-all/202603062334.wgI5htP0-lkp@intel.com/ Fixes: d3febf16dee2 ("locking/local_lock: Support Clang's context analysis") Reported-by: kernel test robot Signed-off-by: Bart Van Assche Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Marco Elver Link: https://patch.msgid.link/20260311231455.1961413-1-bvanassche@acm.org --- include/linux/local_lock_internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h index eff711bf973f..234be7f12c15 100644 --- a/include/linux/local_lock_internal.h +++ b/include/linux/local_lock_internal.h @@ -315,7 +315,7 @@ do { \ #endif /* CONFIG_PREEMPT_RT */ -#if defined(WARN_CONTEXT_ANALYSIS) +#if defined(WARN_CONTEXT_ANALYSIS) && !defined(__CHECKER__) /* * Because the compiler only knows about the base per-CPU variable, use this * helper function to make the compiler think we lock/unlock the @base variable, -- cgit v1.2.3 From 8324a54f604da18f21070702a8ad82ab2062787b Mon Sep 17 00:00:00 2001 From: Ilpo Järvinen Date: Tue, 3 Feb 2026 19:10:45 +0200 Subject: serial: 8250: Add serial8250_handle_irq_locked() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 8250_port exports serial8250_handle_irq() to HW specific 8250 drivers. It takes port's lock within but a HW specific 8250 driver may want to take port's lock itself, do something, and then call the generic handler in 8250_port but to do that, the caller has to release port's lock for no good reason. Introduce serial8250_handle_irq_locked() which a HW specific driver can call while already holding port's lock. As this is new export, put it straight into a namespace (where all 8250 exports should eventually be moved). Tested-by: Bandal, Shankar Tested-by: Murthy, Shanth Cc: stable Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://patch.msgid.link/20260203171049.4353-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 24 ++++++++++++++++-------- include/linux/serial_8250.h | 1 + 2 files changed, 17 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 20cf123a0540..14d6aca44551 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -1782,20 +1783,16 @@ static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir) } /* - * This handles the interrupt from one port. + * Context: port's lock must be held by the caller. */ -int serial8250_handle_irq(struct uart_port *port, unsigned int iir) +void serial8250_handle_irq_locked(struct uart_port *port, unsigned int iir) { struct uart_8250_port *up = up_to_u8250p(port); struct tty_port *tport = &port->state->port; bool skip_rx = false; - unsigned long flags; u16 status; - if (iir & UART_IIR_NO_INT) - return 0; - - uart_port_lock_irqsave(port, &flags); + lockdep_assert_held_once(&port->lock); status = serial_lsr_in(up); @@ -1828,8 +1825,19 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir) else if (!up->dma->tx_running) __stop_tx(up); } +} +EXPORT_SYMBOL_NS_GPL(serial8250_handle_irq_locked, "SERIAL_8250"); - uart_unlock_and_check_sysrq_irqrestore(port, flags); +/* + * This handles the interrupt from one port. + */ +int serial8250_handle_irq(struct uart_port *port, unsigned int iir) +{ + if (iir & UART_IIR_NO_INT) + return 0; + + guard(uart_port_lock_irqsave)(port); + serial8250_handle_irq_locked(port, iir); return 1; } diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h index 01efdce0fda0..a95b2d143d24 100644 --- a/include/linux/serial_8250.h +++ b/include/linux/serial_8250.h @@ -195,6 +195,7 @@ void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl); void serial8250_do_set_divisor(struct uart_port *port, unsigned int baud, unsigned int quot); int fsl8250_handle_irq(struct uart_port *port); +void serial8250_handle_irq_locked(struct uart_port *port, unsigned int iir); int serial8250_handle_irq(struct uart_port *port, unsigned int iir); u16 serial8250_rx_chars(struct uart_8250_port *up, u16 lsr); void serial8250_read_char(struct uart_8250_port *up, u16 lsr); -- cgit v1.2.3 From 8431c602f551549f082bbfa67f3003f2d8e3e132 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 11 Mar 2026 12:31:10 +0000 Subject: ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS Blamed commits forgot that vxlan/geneve use udp_tunnel[6]_xmit_skb() which call iptunnel_xmit_stats(). iptunnel_xmit_stats() was assuming tunnels were only using NETDEV_PCPU_STAT_TSTATS. @syncp offset in pcpu_sw_netstats and pcpu_dstats is different. 32bit kernels would either have corruptions or freezes if the syncp sequence was overwritten. This patch also moves pcpu_stat_type closer to dev->{t,d}stats to avoid a potential cache line miss since iptunnel_xmit_stats() needs to read it. Fixes: 6fa6de302246 ("geneve: Handle stats using NETDEV_PCPU_STAT_DSTATS.") Fixes: be226352e8dc ("vxlan: Handle stats using NETDEV_PCPU_STAT_DSTATS.") Signed-off-by: Eric Dumazet Reviewed-by: Guillaume Nault Link: https://patch.msgid.link/20260311123110.1471930-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/linux/netdevice.h | 3 +-- include/net/ip_tunnels.h | 30 +++++++++++++++++++++++------- 2 files changed, 24 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index ae269a2e7f4d..d7aac6f185bc 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2155,6 +2155,7 @@ struct net_device { unsigned long state; unsigned int flags; unsigned short hard_header_len; + enum netdev_stat_type pcpu_stat_type:8; netdev_features_t features; struct inet6_dev __rcu *ip6_ptr; __cacheline_group_end(net_device_read_txrx); @@ -2404,8 +2405,6 @@ struct net_device { void *ml_priv; enum netdev_ml_priv_type ml_priv_type; - enum netdev_stat_type pcpu_stat_type:8; - #if IS_ENABLED(CONFIG_GARP) struct garp_port __rcu *garp_port; #endif diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h index 80662f812080..1f577a4f8ce9 100644 --- a/include/net/ip_tunnels.h +++ b/include/net/ip_tunnels.h @@ -665,13 +665,29 @@ static inline int iptunnel_pull_offloads(struct sk_buff *skb) static inline void iptunnel_xmit_stats(struct net_device *dev, int pkt_len) { if (pkt_len > 0) { - struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats); - - u64_stats_update_begin(&tstats->syncp); - u64_stats_add(&tstats->tx_bytes, pkt_len); - u64_stats_inc(&tstats->tx_packets); - u64_stats_update_end(&tstats->syncp); - put_cpu_ptr(tstats); + if (dev->pcpu_stat_type == NETDEV_PCPU_STAT_DSTATS) { + struct pcpu_dstats *dstats = get_cpu_ptr(dev->dstats); + + u64_stats_update_begin(&dstats->syncp); + u64_stats_add(&dstats->tx_bytes, pkt_len); + u64_stats_inc(&dstats->tx_packets); + u64_stats_update_end(&dstats->syncp); + put_cpu_ptr(dstats); + return; + } + if (dev->pcpu_stat_type == NETDEV_PCPU_STAT_TSTATS) { + struct pcpu_sw_netstats *tstats = get_cpu_ptr(dev->tstats); + + u64_stats_update_begin(&tstats->syncp); + u64_stats_add(&tstats->tx_bytes, pkt_len); + u64_stats_inc(&tstats->tx_packets); + u64_stats_update_end(&tstats->syncp); + put_cpu_ptr(tstats); + return; + } + pr_err_once("iptunnel_xmit_stats pcpu_stat_type=%d\n", + dev->pcpu_stat_type); + WARN_ON_ONCE(1); return; } -- cgit v1.2.3 From 5eb608319bb56464674a71b4a66ea65c6c435d64 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 27 Jan 2026 17:56:01 -0500 Subject: vt: save/restore unicode screen buffer for alternate screen The alternate screen support added by commit 23743ba64709 ("vt: add support for smput/rmput escape codes") only saves and restores the regular screen buffer (vc_origin), but completely ignores the corresponding unicode screen buffer (vc_uni_lines) creating a messed-up display. Add vc_saved_uni_lines to save the unicode screen buffer when entering the alternate screen, and restore it when leaving. Also ensure proper cleanup in reset_terminal() and vc_deallocate(). Fixes: 23743ba64709 ("vt: add support for smput/rmput escape codes") Cc: stable Signed-off-by: Nicolas Pitre Link: https://patch.msgid.link/5o2p6qp3-91pq-0p17-or02-1oors4417ns7@onlyvoer.pbz Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vt.c | 8 ++++++++ include/linux/console_struct.h | 1 + 2 files changed, 9 insertions(+) (limited to 'include/linux') diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index c1f152d8b03b..e2df99e3d458 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -1339,6 +1339,8 @@ struct vc_data *vc_deallocate(unsigned int currcons) kfree(vc->vc_saved_screen); vc->vc_saved_screen = NULL; } + vc_uniscr_free(vc->vc_saved_uni_lines); + vc->vc_saved_uni_lines = NULL; } return vc; } @@ -1884,6 +1886,8 @@ static void enter_alt_screen(struct vc_data *vc) vc->vc_saved_screen = kmemdup((u16 *)vc->vc_origin, size, GFP_KERNEL); if (vc->vc_saved_screen == NULL) return; + vc->vc_saved_uni_lines = vc->vc_uni_lines; + vc->vc_uni_lines = NULL; vc->vc_saved_rows = vc->vc_rows; vc->vc_saved_cols = vc->vc_cols; save_cur(vc); @@ -1905,6 +1909,8 @@ static void leave_alt_screen(struct vc_data *vc) dest = ((u16 *)vc->vc_origin) + r * vc->vc_cols; memcpy(dest, src, 2 * cols); } + vc_uniscr_set(vc, vc->vc_saved_uni_lines); + vc->vc_saved_uni_lines = NULL; restore_cur(vc); /* Update the entire screen */ if (con_should_update(vc)) @@ -2227,6 +2233,8 @@ static void reset_terminal(struct vc_data *vc, int do_clear) if (vc->vc_saved_screen != NULL) { kfree(vc->vc_saved_screen); vc->vc_saved_screen = NULL; + vc_uniscr_free(vc->vc_saved_uni_lines); + vc->vc_saved_uni_lines = NULL; vc->vc_saved_rows = 0; vc->vc_saved_cols = 0; } diff --git a/include/linux/console_struct.h b/include/linux/console_struct.h index 13b35637bd5a..d5ca855116df 100644 --- a/include/linux/console_struct.h +++ b/include/linux/console_struct.h @@ -160,6 +160,7 @@ struct vc_data { struct uni_pagedict **uni_pagedict_loc; /* [!] Location of uni_pagedict variable for this console */ u32 **vc_uni_lines; /* unicode screen content */ u16 *vc_saved_screen; + u32 **vc_saved_uni_lines; unsigned int vc_saved_cols; unsigned int vc_saved_rows; /* additional information is in vt_kern.h */ -- cgit v1.2.3 From b7405dcf7385445e10821777143f18c3ce20fa04 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 15 Mar 2026 10:41:52 +0000 Subject: bonding: prevent potential infinite loop in bond_header_parse() bond_header_parse() can loop if a stack of two bonding devices is setup, because skb->dev always points to the hierarchy top. Add new "const struct net_device *dev" parameter to (struct header_ops)->parse() method to make sure the recursion is bounded, and that the final leaf parse method is called. Fixes: 950803f72547 ("bonding: fix type confusion in bond_setup_by_slave()") Signed-off-by: Eric Dumazet Reviewed-by: Jiayuan Chen Tested-by: Jiayuan Chen Cc: Jay Vosburgh Cc: Andrew Lunn Link: https://patch.msgid.link/20260315104152.1436867-1-edumazet@google.com Signed-off-by: Jakub Kicinski --- drivers/firewire/net.c | 5 +++-- drivers/net/bonding/bond_main.c | 8 +++++--- include/linux/etherdevice.h | 3 ++- include/linux/if_ether.h | 3 ++- include/linux/netdevice.h | 6 ++++-- net/ethernet/eth.c | 9 +++------ net/ipv4/ip_gre.c | 3 ++- net/mac802154/iface.c | 4 +++- net/phonet/af_phonet.c | 5 ++++- 9 files changed, 28 insertions(+), 18 deletions(-) (limited to 'include/linux') diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c index f1a2bee39bf1..82b3b6d9ed2d 100644 --- a/drivers/firewire/net.c +++ b/drivers/firewire/net.c @@ -257,9 +257,10 @@ static void fwnet_header_cache_update(struct hh_cache *hh, memcpy((u8 *)hh->hh_data + HH_DATA_OFF(FWNET_HLEN), haddr, net->addr_len); } -static int fwnet_header_parse(const struct sk_buff *skb, unsigned char *haddr) +static int fwnet_header_parse(const struct sk_buff *skb, const struct net_device *dev, + unsigned char *haddr) { - memcpy(haddr, skb->dev->dev_addr, FWNET_ALEN); + memcpy(haddr, dev->dev_addr, FWNET_ALEN); return FWNET_ALEN; } diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 707419270ebf..33f414d03ab9 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -1530,9 +1530,11 @@ static int bond_header_create(struct sk_buff *skb, struct net_device *bond_dev, return ret; } -static int bond_header_parse(const struct sk_buff *skb, unsigned char *haddr) +static int bond_header_parse(const struct sk_buff *skb, + const struct net_device *dev, + unsigned char *haddr) { - struct bonding *bond = netdev_priv(skb->dev); + struct bonding *bond = netdev_priv(dev); const struct header_ops *slave_ops; struct slave *slave; int ret = 0; @@ -1542,7 +1544,7 @@ static int bond_header_parse(const struct sk_buff *skb, unsigned char *haddr) if (slave) { slave_ops = READ_ONCE(slave->dev->header_ops); if (slave_ops && slave_ops->parse) - ret = slave_ops->parse(skb, haddr); + ret = slave_ops->parse(skb, slave->dev, haddr); } rcu_read_unlock(); return ret; diff --git a/include/linux/etherdevice.h b/include/linux/etherdevice.h index 9a1eacf35d37..df8f88f63a70 100644 --- a/include/linux/etherdevice.h +++ b/include/linux/etherdevice.h @@ -42,7 +42,8 @@ extern const struct header_ops eth_header_ops; int eth_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, const void *daddr, const void *saddr, unsigned len); -int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr); +int eth_header_parse(const struct sk_buff *skb, const struct net_device *dev, + unsigned char *haddr); int eth_header_cache(const struct neighbour *neigh, struct hh_cache *hh, __be16 type); void eth_header_cache_update(struct hh_cache *hh, const struct net_device *dev, diff --git a/include/linux/if_ether.h b/include/linux/if_ether.h index 61b7335aa037..ca9afa824aa4 100644 --- a/include/linux/if_ether.h +++ b/include/linux/if_ether.h @@ -40,7 +40,8 @@ static inline struct ethhdr *inner_eth_hdr(const struct sk_buff *skb) return (struct ethhdr *)skb_inner_mac_header(skb); } -int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr); +int eth_header_parse(const struct sk_buff *skb, const struct net_device *dev, + unsigned char *haddr); extern ssize_t sysfs_format_mac(char *buf, const unsigned char *addr, int len); diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index d7aac6f185bc..7ca01eb3f7d2 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -311,7 +311,9 @@ struct header_ops { int (*create) (struct sk_buff *skb, struct net_device *dev, unsigned short type, const void *daddr, const void *saddr, unsigned int len); - int (*parse)(const struct sk_buff *skb, unsigned char *haddr); + int (*parse)(const struct sk_buff *skb, + const struct net_device *dev, + unsigned char *haddr); int (*cache)(const struct neighbour *neigh, struct hh_cache *hh, __be16 type); void (*cache_update)(struct hh_cache *hh, const struct net_device *dev, @@ -3445,7 +3447,7 @@ static inline int dev_parse_header(const struct sk_buff *skb, if (!dev->header_ops || !dev->header_ops->parse) return 0; - return dev->header_ops->parse(skb, haddr); + return dev->header_ops->parse(skb, dev, haddr); } static inline __be16 dev_parse_header_protocol(const struct sk_buff *skb) diff --git a/net/ethernet/eth.c b/net/ethernet/eth.c index 13a63b48b7ee..d9faadbe9b6c 100644 --- a/net/ethernet/eth.c +++ b/net/ethernet/eth.c @@ -193,14 +193,11 @@ __be16 eth_type_trans(struct sk_buff *skb, struct net_device *dev) } EXPORT_SYMBOL(eth_type_trans); -/** - * eth_header_parse - extract hardware address from packet - * @skb: packet to extract header from - * @haddr: destination buffer - */ -int eth_header_parse(const struct sk_buff *skb, unsigned char *haddr) +int eth_header_parse(const struct sk_buff *skb, const struct net_device *dev, + unsigned char *haddr) { const struct ethhdr *eth = eth_hdr(skb); + memcpy(haddr, eth->h_source, ETH_ALEN); return ETH_ALEN; } diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c index e13244729ad8..35f0baa99d40 100644 --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -919,7 +919,8 @@ static int ipgre_header(struct sk_buff *skb, struct net_device *dev, return -(t->hlen + sizeof(*iph)); } -static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) +static int ipgre_header_parse(const struct sk_buff *skb, const struct net_device *dev, + unsigned char *haddr) { const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb); memcpy(haddr, &iph->saddr, 4); diff --git a/net/mac802154/iface.c b/net/mac802154/iface.c index 9e4631fade90..000be60d9580 100644 --- a/net/mac802154/iface.c +++ b/net/mac802154/iface.c @@ -469,7 +469,9 @@ static int mac802154_header_create(struct sk_buff *skb, } static int -mac802154_header_parse(const struct sk_buff *skb, unsigned char *haddr) +mac802154_header_parse(const struct sk_buff *skb, + const struct net_device *dev, + unsigned char *haddr) { struct ieee802154_hdr hdr; diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c index 238a9638d2b0..d89225d6bfd3 100644 --- a/net/phonet/af_phonet.c +++ b/net/phonet/af_phonet.c @@ -129,9 +129,12 @@ static int pn_header_create(struct sk_buff *skb, struct net_device *dev, return 1; } -static int pn_header_parse(const struct sk_buff *skb, unsigned char *haddr) +static int pn_header_parse(const struct sk_buff *skb, + const struct net_device *dev, + unsigned char *haddr) { const u8 *media = skb_mac_header(skb); + *haddr = *media; return 1; } -- cgit v1.2.3 From 45c6a2dc7ec8339052666b06065c521a10cc29bb Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Sun, 1 Mar 2026 16:52:14 -0800 Subject: iommu/io-pgtable: fix all kernel-doc warnings in io-pgtable.h Avoid kernel-doc warnings in io-pgtable.h: - use the correct struct member names or kernel-doc format - add a missing struct member description - add a missing function return comment section Warning: include/linux/io-pgtable.h:187 struct member 'coherent_walk' not described in 'io_pgtable_cfg' Warning: include/linux/io-pgtable.h:187 struct member 'arm_lpae_s1_cfg' not described in 'io_pgtable_cfg' Warning: include/linux/io-pgtable.h:187 struct member 'arm_lpae_s2_cfg' not described in 'io_pgtable_cfg' Warning: include/linux/io-pgtable.h:187 struct member 'arm_v7s_cfg' not described in 'io_pgtable_cfg' Warning: include/linux/io-pgtable.h:187 struct member 'arm_mali_lpae_cfg' not described in 'io_pgtable_cfg' Warning: include/linux/io-pgtable.h:187 struct member 'apple_dart_cfg' not described in 'io_pgtable_cfg' Warning: include/linux/io-pgtable.h:187 struct member 'amd' not described in 'io_pgtable_cfg' Warning: include/linux/io-pgtable.h:223 struct member 'read_and_clear_dirty' not described in 'io_pgtable_ops' Warning: include/linux/io-pgtable.h:237 No description found for return value of 'alloc_io_pgtable_ops' Signed-off-by: Randy Dunlap Reviewed-by: Jason Gunthorpe Signed-off-by: Joerg Roedel --- include/linux/io-pgtable.h | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h index 7a1516011ccf..e19872e37e06 100644 --- a/include/linux/io-pgtable.h +++ b/include/linux/io-pgtable.h @@ -53,7 +53,7 @@ struct iommu_flush_ops { * tables. * @ias: Input address (iova) size, in bits. * @oas: Output address (paddr) size, in bits. - * @coherent_walk A flag to indicate whether or not page table walks made + * @coherent_walk: A flag to indicate whether or not page table walks made * by the IOMMU are coherent with the CPU caches. * @tlb: TLB management callbacks for this set of tables. * @iommu_dev: The device representing the DMA configuration for the @@ -136,6 +136,7 @@ struct io_pgtable_cfg { void (*free)(void *cookie, void *pages, size_t size); /* Low-level data specific to the table format */ + /* private: */ union { struct { u64 ttbr; @@ -203,6 +204,9 @@ struct arm_lpae_io_pgtable_walk_data { * @unmap_pages: Unmap a range of virtually contiguous pages of the same size. * @iova_to_phys: Translate iova to physical address. * @pgtable_walk: (optional) Perform a page table walk for a given iova. + * @read_and_clear_dirty: Record dirty info per IOVA. If an IOVA is dirty, + * clear its dirty state from the PTE unless the + * IOMMU_DIRTY_NO_CLEAR flag is passed in. * * These functions map directly onto the iommu_ops member functions with * the same names. @@ -231,7 +235,9 @@ struct io_pgtable_ops { * the configuration actually provided by the allocator (e.g. the * pgsize_bitmap may be restricted). * @cookie: An opaque token provided by the IOMMU driver and passed back to - * the callback routines in cfg->tlb. + * the callback routines. + * + * Returns: Pointer to the &struct io_pgtable_ops for this set of page tables. */ struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, struct io_pgtable_cfg *cfg, -- cgit v1.2.3 From cb3d1049f4ea77d5ad93f17d8ac1f2ed4da70501 Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Tue, 3 Mar 2026 12:53:18 +0100 Subject: driver core: generalize driver_override in struct device Currently, there are 12 busses (including platform and PCI) that duplicate the driver_override logic for their individual devices. All of them seem to be prone to the bug described in [1]. While this could be solved for every bus individually using a separate lock, solving this in the driver-core generically results in less (and cleaner) changes overall. Thus, move driver_override to struct device, provide corresponding accessors for busses and handle locking with a separate lock internally. In particular, add device_set_driver_override(), device_has_driver_override(), device_match_driver_override() and generalize the sysfs store() and show() callbacks via a driver_override feature flag in struct bus_type. Until all busses have migrated, keep driver_set_override() in place. Note that we can't use the device lock for the reasons described in [2]. Link: https://bugzilla.kernel.org/show_bug.cgi?id=220789 [1] Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [2] Tested-by: Gui-Dong Han Co-developed-by: Gui-Dong Han Signed-off-by: Gui-Dong Han Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260303115720.48783-2-dakr@kernel.org [ Use dev->bus instead of sp->bus for consistency; fix commit message to refer to the struct bus_type's driver_override feature flag. - Danilo ] Signed-off-by: Danilo Krummrich --- drivers/base/bus.c | 43 ++++++++++++++++++++++++++++++++- drivers/base/core.c | 2 ++ drivers/base/dd.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 54 +++++++++++++++++++++++++++++++++++++++++ include/linux/device/bus.h | 4 ++++ 5 files changed, 162 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/drivers/base/bus.c b/drivers/base/bus.c index bb61d8adbab1..8b6722ff8590 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -504,6 +504,36 @@ int bus_for_each_drv(const struct bus_type *bus, struct device_driver *start, } EXPORT_SYMBOL_GPL(bus_for_each_drv); +static ssize_t driver_override_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int ret; + + ret = __device_set_driver_override(dev, buf, count); + if (ret) + return ret; + + return count; +} + +static ssize_t driver_override_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + guard(spinlock)(&dev->driver_override.lock); + return sysfs_emit(buf, "%s\n", dev->driver_override.name); +} +static DEVICE_ATTR_RW(driver_override); + +static struct attribute *driver_override_dev_attrs[] = { + &dev_attr_driver_override.attr, + NULL, +}; + +static const struct attribute_group driver_override_dev_group = { + .attrs = driver_override_dev_attrs, +}; + /** * bus_add_device - add device to bus * @dev: device being added @@ -537,9 +567,15 @@ int bus_add_device(struct device *dev) if (error) goto out_put; + if (dev->bus->driver_override) { + error = device_add_group(dev, &driver_override_dev_group); + if (error) + goto out_groups; + } + error = sysfs_create_link(&sp->devices_kset->kobj, &dev->kobj, dev_name(dev)); if (error) - goto out_groups; + goto out_override; error = sysfs_create_link(&dev->kobj, &sp->subsys.kobj, "subsystem"); if (error) @@ -550,6 +586,9 @@ int bus_add_device(struct device *dev) out_subsys: sysfs_remove_link(&sp->devices_kset->kobj, dev_name(dev)); +out_override: + if (dev->bus->driver_override) + device_remove_group(dev, &driver_override_dev_group); out_groups: device_remove_groups(dev, sp->bus->dev_groups); out_put: @@ -607,6 +646,8 @@ void bus_remove_device(struct device *dev) sysfs_remove_link(&dev->kobj, "subsystem"); sysfs_remove_link(&sp->devices_kset->kobj, dev_name(dev)); + if (dev->bus->driver_override) + device_remove_group(dev, &driver_override_dev_group); device_remove_groups(dev, dev->bus->dev_groups); if (klist_node_attached(&dev->p->knode_bus)) klist_del(&dev->p->knode_bus); diff --git a/drivers/base/core.c b/drivers/base/core.c index 791f9e444df8..09b98f02f559 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2556,6 +2556,7 @@ static void device_release(struct kobject *kobj) devres_release_all(dev); kfree(dev->dma_range_map); + kfree(dev->driver_override.name); if (dev->release) dev->release(dev); @@ -3159,6 +3160,7 @@ void device_initialize(struct device *dev) kobject_init(&dev->kobj, &device_ktype); INIT_LIST_HEAD(&dev->dma_pools); mutex_init(&dev->mutex); + spin_lock_init(&dev->driver_override.lock); lockdep_set_novalidate_class(&dev->mutex); spin_lock_init(&dev->devres_lock); INIT_LIST_HEAD(&dev->devres_head); diff --git a/drivers/base/dd.c b/drivers/base/dd.c index bea8da5f8a3a..37c7e54e0e4c 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -381,6 +381,66 @@ static void __exit deferred_probe_exit(void) } __exitcall(deferred_probe_exit); +int __device_set_driver_override(struct device *dev, const char *s, size_t len) +{ + const char *new, *old; + char *cp; + + if (!s) + return -EINVAL; + + /* + * The stored value will be used in sysfs show callback (sysfs_emit()), + * which has a length limit of PAGE_SIZE and adds a trailing newline. + * Thus we can store one character less to avoid truncation during sysfs + * show. + */ + if (len >= (PAGE_SIZE - 1)) + return -EINVAL; + + /* + * Compute the real length of the string in case userspace sends us a + * bunch of \0 characters like python likes to do. + */ + len = strlen(s); + + if (!len) { + /* Empty string passed - clear override */ + spin_lock(&dev->driver_override.lock); + old = dev->driver_override.name; + dev->driver_override.name = NULL; + spin_unlock(&dev->driver_override.lock); + kfree(old); + + return 0; + } + + cp = strnchr(s, len, '\n'); + if (cp) + len = cp - s; + + new = kstrndup(s, len, GFP_KERNEL); + if (!new) + return -ENOMEM; + + spin_lock(&dev->driver_override.lock); + old = dev->driver_override.name; + if (cp != s) { + dev->driver_override.name = new; + spin_unlock(&dev->driver_override.lock); + } else { + /* "\n" passed - clear override */ + dev->driver_override.name = NULL; + spin_unlock(&dev->driver_override.lock); + + kfree(new); + } + kfree(old); + + return 0; +} +EXPORT_SYMBOL_GPL(__device_set_driver_override); + /** * device_is_bound() - Check if device is bound to a driver * @dev: device to check diff --git a/include/linux/device.h b/include/linux/device.h index 0be95294b6e6..e65d564f01cd 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -483,6 +483,8 @@ struct device_physical_location { * on. This shrinks the "Board Support Packages" (BSPs) and * minimizes board-specific #ifdefs in drivers. * @driver_data: Private pointer for driver specific info. + * @driver_override: Driver name to force a match. Do not touch directly; use + * device_set_driver_override() instead. * @links: Links to suppliers and consumers of this device. * @power: For device power management. * See Documentation/driver-api/pm/devices.rst for details. @@ -576,6 +578,10 @@ struct device { core doesn't touch it */ void *driver_data; /* Driver data, set and get with dev_set_drvdata/dev_get_drvdata */ + struct { + const char *name; + spinlock_t lock; + } driver_override; struct mutex mutex; /* mutex to synchronize calls to * its driver. */ @@ -701,6 +707,54 @@ struct device_link { #define kobj_to_dev(__kobj) container_of_const(__kobj, struct device, kobj) +int __device_set_driver_override(struct device *dev, const char *s, size_t len); + +/** + * device_set_driver_override() - Helper to set or clear driver override. + * @dev: Device to change + * @s: NUL-terminated string, new driver name to force a match, pass empty + * string to clear it ("" or "\n", where the latter is only for sysfs + * interface). + * + * Helper to set or clear driver override of a device. + * + * Returns: 0 on success or a negative error code on failure. + */ +static inline int device_set_driver_override(struct device *dev, const char *s) +{ + return __device_set_driver_override(dev, s, s ? strlen(s) : 0); +} + +/** + * device_has_driver_override() - Check if a driver override has been set. + * @dev: device to check + * + * Returns true if a driver override has been set for this device. + */ +static inline bool device_has_driver_override(struct device *dev) +{ + guard(spinlock)(&dev->driver_override.lock); + return !!dev->driver_override.name; +} + +/** + * device_match_driver_override() - Match a driver against the device's driver_override. + * @dev: device to check + * @drv: driver to match against + * + * Returns > 0 if a driver override is set and matches the given driver, 0 if a + * driver override is set but does not match, or < 0 if a driver override is not + * set at all. + */ +static inline int device_match_driver_override(struct device *dev, + const struct device_driver *drv) +{ + guard(spinlock)(&dev->driver_override.lock); + if (dev->driver_override.name) + return !strcmp(dev->driver_override.name, drv->name); + return -1; +} + /** * device_iommu_mapped - Returns true when the device DMA is translated * by an IOMMU diff --git a/include/linux/device/bus.h b/include/linux/device/bus.h index 63de5f053c33..c1b463cd6464 100644 --- a/include/linux/device/bus.h +++ b/include/linux/device/bus.h @@ -65,6 +65,9 @@ struct fwnode_handle; * this bus. * @pm: Power management operations of this bus, callback the specific * device driver's pm-ops. + * @driver_override: Set to true if this bus supports the driver_override + * mechanism, which allows userspace to force a specific + * driver to bind to a device via a sysfs attribute. * @need_parent_lock: When probing or removing a device on this bus, the * device core should lock the device's parent. * @@ -106,6 +109,7 @@ struct bus_type { const struct dev_pm_ops *pm; + bool driver_override; bool need_parent_lock; }; -- cgit v1.2.3 From 2b38efc05bf7a8568ec74bfffea0f5cfa62bc01d Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Tue, 3 Mar 2026 12:53:21 +0100 Subject: driver core: platform: use generic driver_override infrastructure When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") Reviewed-by: Greg Kroah-Hartman Link: https://patch.msgid.link/20260303115720.48783-5-dakr@kernel.org Signed-off-by: Danilo Krummrich --- drivers/base/platform.c | 37 +++++-------------------------------- drivers/bus/simple-pm-bus.c | 4 ++-- drivers/clk/imx/clk-scu.c | 3 +-- drivers/slimbus/qcom-ngd-ctrl.c | 6 ++---- include/linux/platform_device.h | 5 ----- sound/soc/samsung/i2s.c | 6 +++--- 6 files changed, 13 insertions(+), 48 deletions(-) (limited to 'include/linux') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index b45d41b018ca..d44591d52e36 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -603,7 +603,6 @@ static void platform_device_release(struct device *dev) kfree(pa->pdev.dev.platform_data); kfree(pa->pdev.mfd_cell); kfree(pa->pdev.resource); - kfree(pa->pdev.driver_override); kfree(pa); } @@ -1306,38 +1305,9 @@ static ssize_t numa_node_show(struct device *dev, } static DEVICE_ATTR_RO(numa_node); -static ssize_t driver_override_show(struct device *dev, - struct device_attribute *attr, char *buf) -{ - struct platform_device *pdev = to_platform_device(dev); - ssize_t len; - - device_lock(dev); - len = sysfs_emit(buf, "%s\n", pdev->driver_override); - device_unlock(dev); - - return len; -} - -static ssize_t driver_override_store(struct device *dev, - struct device_attribute *attr, - const char *buf, size_t count) -{ - struct platform_device *pdev = to_platform_device(dev); - int ret; - - ret = driver_set_override(dev, &pdev->driver_override, buf, count); - if (ret) - return ret; - - return count; -} -static DEVICE_ATTR_RW(driver_override); - static struct attribute *platform_dev_attrs[] = { &dev_attr_modalias.attr, &dev_attr_numa_node.attr, - &dev_attr_driver_override.attr, NULL, }; @@ -1377,10 +1347,12 @@ static int platform_match(struct device *dev, const struct device_driver *drv) { struct platform_device *pdev = to_platform_device(dev); struct platform_driver *pdrv = to_platform_driver(drv); + int ret; /* When driver_override is set, only bind to the matching driver */ - if (pdev->driver_override) - return !strcmp(pdev->driver_override, drv->name); + ret = device_match_driver_override(dev, drv); + if (ret >= 0) + return ret; /* Attempt an OF style match first */ if (of_driver_match_device(dev, drv)) @@ -1516,6 +1488,7 @@ static const struct dev_pm_ops platform_dev_pm_ops = { const struct bus_type platform_bus_type = { .name = "platform", .dev_groups = platform_dev_groups, + .driver_override = true, .match = platform_match, .uevent = platform_uevent, .probe = platform_probe, diff --git a/drivers/bus/simple-pm-bus.c b/drivers/bus/simple-pm-bus.c index 3f00d953fb9a..c920bd6fbaaf 100644 --- a/drivers/bus/simple-pm-bus.c +++ b/drivers/bus/simple-pm-bus.c @@ -36,7 +36,7 @@ static int simple_pm_bus_probe(struct platform_device *pdev) * that's not listed in simple_pm_bus_of_match. We don't want to do any * of the simple-pm-bus tasks for these devices, so return early. */ - if (pdev->driver_override) + if (device_has_driver_override(&pdev->dev)) return 0; match = of_match_device(dev->driver->of_match_table, dev); @@ -78,7 +78,7 @@ static void simple_pm_bus_remove(struct platform_device *pdev) { const void *data = of_device_get_match_data(&pdev->dev); - if (pdev->driver_override || data) + if (device_has_driver_override(&pdev->dev) || data) return; dev_dbg(&pdev->dev, "%s\n", __func__); diff --git a/drivers/clk/imx/clk-scu.c b/drivers/clk/imx/clk-scu.c index a85ec48a798b..9b33df9967ec 100644 --- a/drivers/clk/imx/clk-scu.c +++ b/drivers/clk/imx/clk-scu.c @@ -706,8 +706,7 @@ struct clk_hw *imx_clk_scu_alloc_dev(const char *name, if (ret) goto put_device; - ret = driver_set_override(&pdev->dev, &pdev->driver_override, - "imx-scu-clk", strlen("imx-scu-clk")); + ret = device_set_driver_override(&pdev->dev, "imx-scu-clk"); if (ret) goto put_device; diff --git a/drivers/slimbus/qcom-ngd-ctrl.c b/drivers/slimbus/qcom-ngd-ctrl.c index 9aa7218b4e8d..1ed6be6e85d2 100644 --- a/drivers/slimbus/qcom-ngd-ctrl.c +++ b/drivers/slimbus/qcom-ngd-ctrl.c @@ -1535,10 +1535,8 @@ static int of_qcom_slim_ngd_register(struct device *parent, ngd->id = id; ngd->pdev->dev.parent = parent; - ret = driver_set_override(&ngd->pdev->dev, - &ngd->pdev->driver_override, - QCOM_SLIM_NGD_DRV_NAME, - strlen(QCOM_SLIM_NGD_DRV_NAME)); + ret = device_set_driver_override(&ngd->pdev->dev, + QCOM_SLIM_NGD_DRV_NAME); if (ret) { platform_device_put(ngd->pdev); kfree(ngd); diff --git a/include/linux/platform_device.h b/include/linux/platform_device.h index 813da101b5bf..ed1d50d1c3c1 100644 --- a/include/linux/platform_device.h +++ b/include/linux/platform_device.h @@ -31,11 +31,6 @@ struct platform_device { struct resource *resource; const struct platform_device_id *id_entry; - /* - * Driver name to force a match. Do not set directly, because core - * frees it. Use driver_set_override() to set or clear it. - */ - const char *driver_override; /* MFD cell pointer */ struct mfd_cell *mfd_cell; diff --git a/sound/soc/samsung/i2s.c b/sound/soc/samsung/i2s.c index e9964f0e010a..140907a41a70 100644 --- a/sound/soc/samsung/i2s.c +++ b/sound/soc/samsung/i2s.c @@ -1360,10 +1360,10 @@ static int i2s_create_secondary_device(struct samsung_i2s_priv *priv) if (!pdev_sec) return -ENOMEM; - pdev_sec->driver_override = kstrdup("samsung-i2s", GFP_KERNEL); - if (!pdev_sec->driver_override) { + ret = device_set_driver_override(&pdev_sec->dev, "samsung-i2s"); + if (ret) { platform_device_put(pdev_sec); - return -ENOMEM; + return ret; } ret = platform_device_add(pdev_sec); -- cgit v1.2.3 From 418eab7a6f3c002d8e64d6e95ec27118017019af Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 19 Mar 2026 14:29:20 -0600 Subject: io_uring/kbuf: propagate BUF_MORE through early buffer commit path When io_should_commit() returns true (eg for non-pollable files), buffer commit happens at buffer selection time and sel->buf_list is set to NULL. When __io_put_kbufs() generates CQE flags at completion time, it calls __io_put_kbuf_ring() which finds a NULL buffer_list and hence cannot determine whether the buffer was consumed or not. This means that IORING_CQE_F_BUF_MORE is never set for non-pollable input with incrementally consumed buffers. Likewise for io_buffers_select(), which always commits upfront and discards the return value of io_kbuf_commit(). Add REQ_F_BUF_MORE to store the result of io_kbuf_commit() during early commit. Then __io_put_kbuf_ring() can check this flag and set IORING_F_BUF_MORE accordingy. Reported-by: Martin Michaelis Cc: stable@vger.kernel.org Fixes: ae98dbf43d75 ("io_uring/kbuf: add support for incremental buffer consumption") Link: https://github.com/axboe/liburing/issues/1553 Signed-off-by: Jens Axboe --- include/linux/io_uring_types.h | 3 +++ io_uring/kbuf.c | 10 +++++++--- 2 files changed, 10 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index dd1420bfcb73..214fdbd49052 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -541,6 +541,7 @@ enum { REQ_F_BL_NO_RECYCLE_BIT, REQ_F_BUFFERS_COMMIT_BIT, REQ_F_BUF_NODE_BIT, + REQ_F_BUF_MORE_BIT, REQ_F_HAS_METADATA_BIT, REQ_F_IMPORT_BUFFER_BIT, REQ_F_SQE_COPIED_BIT, @@ -626,6 +627,8 @@ enum { REQ_F_BUFFERS_COMMIT = IO_REQ_FLAG(REQ_F_BUFFERS_COMMIT_BIT), /* buf node is valid */ REQ_F_BUF_NODE = IO_REQ_FLAG(REQ_F_BUF_NODE_BIT), + /* incremental buffer consumption, more space available */ + REQ_F_BUF_MORE = IO_REQ_FLAG(REQ_F_BUF_MORE_BIT), /* request has read/write metadata assigned */ REQ_F_HAS_METADATA = IO_REQ_FLAG(REQ_F_HAS_METADATA_BIT), /* diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index a4cb6752b7aa..f72f38d22d2b 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -216,7 +216,8 @@ static struct io_br_sel io_ring_buffer_select(struct io_kiocb *req, size_t *len, sel.addr = u64_to_user_ptr(READ_ONCE(buf->addr)); if (io_should_commit(req, issue_flags)) { - io_kbuf_commit(req, sel.buf_list, *len, 1); + if (!io_kbuf_commit(req, sel.buf_list, *len, 1)) + req->flags |= REQ_F_BUF_MORE; sel.buf_list = NULL; } return sel; @@ -349,7 +350,8 @@ int io_buffers_select(struct io_kiocb *req, struct buf_sel_arg *arg, */ if (ret > 0) { req->flags |= REQ_F_BUFFERS_COMMIT | REQ_F_BL_NO_RECYCLE; - io_kbuf_commit(req, sel->buf_list, arg->out_len, ret); + if (!io_kbuf_commit(req, sel->buf_list, arg->out_len, ret)) + req->flags |= REQ_F_BUF_MORE; } } else { ret = io_provided_buffers_select(req, &arg->out_len, sel->buf_list, arg->iovs); @@ -395,8 +397,10 @@ static inline bool __io_put_kbuf_ring(struct io_kiocb *req, if (bl) ret = io_kbuf_commit(req, bl, len, nr); + if (ret && (req->flags & REQ_F_BUF_MORE)) + ret = false; - req->flags &= ~REQ_F_BUFFER_RING; + req->flags &= ~(REQ_F_BUFFER_RING | REQ_F_BUF_MORE); return ret; } -- cgit v1.2.3 From 9bb0a4d6a4433b75274204b083dac8e515d2007d Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Mon, 16 Mar 2026 21:06:47 +0200 Subject: dma-mapping: Clarify valid conditions for CPU cache line overlap Rename the DMA_ATTR_CPU_CACHE_CLEAN attribute to better reflect that it is debugging aid to inform DMA core code that CPU cache line overlaps are allowed, and refine the documentation describing its use. Signed-off-by: Leon Romanovsky Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20260316-dma-debug-overlap-v3-3-1dde90a7f08b@nvidia.com --- Documentation/core-api/dma-attributes.rst | 22 ++++++++++++++-------- drivers/virtio/virtio_ring.c | 10 +++++----- include/linux/dma-mapping.h | 8 ++++---- include/trace/events/dma.h | 2 +- kernel/dma/debug.c | 2 +- 5 files changed, 25 insertions(+), 19 deletions(-) (limited to 'include/linux') diff --git a/Documentation/core-api/dma-attributes.rst b/Documentation/core-api/dma-attributes.rst index 1d7bfad73b1c..48cfe86cc06d 100644 --- a/Documentation/core-api/dma-attributes.rst +++ b/Documentation/core-api/dma-attributes.rst @@ -149,11 +149,17 @@ For architectures that require cache flushing for DMA coherence DMA_ATTR_MMIO will not perform any cache flushing. The address provided must never be mapped cacheable into the CPU. -DMA_ATTR_CPU_CACHE_CLEAN ------------------------- - -This attribute indicates the CPU will not dirty any cacheline overlapping this -DMA_FROM_DEVICE/DMA_BIDIRECTIONAL buffer while it is mapped. This allows -multiple small buffers to safely share a cacheline without risk of data -corruption, suppressing DMA debug warnings about overlapping mappings. -All mappings sharing a cacheline should have this attribute. +DMA_ATTR_DEBUGGING_IGNORE_CACHELINES +------------------------------------ + +This attribute indicates that CPU cache lines may overlap for buffers mapped +with DMA_FROM_DEVICE or DMA_BIDIRECTIONAL. + +Such overlap may occur when callers map multiple small buffers that reside +within the same cache line. In this case, callers must guarantee that the CPU +will not dirty these cache lines after the mappings are established. When this +condition is met, multiple buffers can safely share a cache line without risking +data corruption. + +All mappings that share a cache line must set this attribute to suppress DMA +debug warnings about overlapping mappings. diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 335692d41617..fbca7ce1c6bf 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -2912,10 +2912,10 @@ EXPORT_SYMBOL_GPL(virtqueue_add_inbuf); * @data: the token identifying the buffer. * @gfp: how to do memory allocations (if necessary). * - * Same as virtqueue_add_inbuf but passes DMA_ATTR_CPU_CACHE_CLEAN to indicate - * that the CPU will not dirty any cacheline overlapping this buffer while it - * is available, and to suppress overlapping cacheline warnings in DMA debug - * builds. + * Same as virtqueue_add_inbuf but passes DMA_ATTR_DEBUGGING_IGNORE_CACHELINES + * to indicate that the CPU will not dirty any cacheline overlapping this buffer + * while it is available, and to suppress overlapping cacheline warnings in DMA + * debug builds. * * Caller must ensure we don't call this with other virtqueue operations * at the same time (except where noted). @@ -2928,7 +2928,7 @@ int virtqueue_add_inbuf_cache_clean(struct virtqueue *vq, gfp_t gfp) { return virtqueue_add(vq, &sg, num, 0, 1, data, NULL, false, gfp, - DMA_ATTR_CPU_CACHE_CLEAN); + DMA_ATTR_DEBUGGING_IGNORE_CACHELINES); } EXPORT_SYMBOL_GPL(virtqueue_add_inbuf_cache_clean); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 29973baa0581..da44394b3a1a 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -80,11 +80,11 @@ #define DMA_ATTR_MMIO (1UL << 10) /* - * DMA_ATTR_CPU_CACHE_CLEAN: Indicates the CPU will not dirty any cacheline - * overlapping this buffer while it is mapped for DMA. All mappings sharing - * a cacheline must have this attribute for this to be considered safe. + * DMA_ATTR_DEBUGGING_IGNORE_CACHELINES: Indicates the CPU cache line can be + * overlapped. All mappings sharing a cacheline must have this attribute for + * this to be considered safe. */ -#define DMA_ATTR_CPU_CACHE_CLEAN (1UL << 11) +#define DMA_ATTR_DEBUGGING_IGNORE_CACHELINES (1UL << 11) /* * A dma_addr_t can hold any valid DMA or bus address for the platform. It can diff --git a/include/trace/events/dma.h b/include/trace/events/dma.h index 69cb3805ee81..8c64bc0721fe 100644 --- a/include/trace/events/dma.h +++ b/include/trace/events/dma.h @@ -33,7 +33,7 @@ TRACE_DEFINE_ENUM(DMA_NONE); { DMA_ATTR_NO_WARN, "NO_WARN" }, \ { DMA_ATTR_PRIVILEGED, "PRIVILEGED" }, \ { DMA_ATTR_MMIO, "MMIO" }, \ - { DMA_ATTR_CPU_CACHE_CLEAN, "CACHE_CLEAN" }) + { DMA_ATTR_DEBUGGING_IGNORE_CACHELINES, "CACHELINES_OVERLAP" }) DECLARE_EVENT_CLASS(dma_map, TP_PROTO(struct device *dev, phys_addr_t phys_addr, dma_addr_t dma_addr, diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index be207be74996..83e1cfe05f08 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -601,7 +601,7 @@ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs) unsigned long flags; int rc; - entry->is_cache_clean = !!(attrs & DMA_ATTR_CPU_CACHE_CLEAN); + entry->is_cache_clean = attrs & DMA_ATTR_DEBUGGING_IGNORE_CACHELINES; bucket = get_hash_bucket(entry, &flags); hash_bucket_add(bucket, entry); -- cgit v1.2.3 From e6a58fa2556203a7f6731b4071705dc81cca5ca5 Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Mon, 16 Mar 2026 21:06:48 +0200 Subject: dma-mapping: Introduce DMA require coherency attribute The mapping buffers which carry this attribute require DMA coherent system. This means that they can't take SWIOTLB path, can perform CPU cache overlap and doesn't perform cache flushing. Signed-off-by: Leon Romanovsky Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20260316-dma-debug-overlap-v3-4-1dde90a7f08b@nvidia.com --- Documentation/core-api/dma-attributes.rst | 16 ++++++++++++++++ include/linux/dma-mapping.h | 7 +++++++ include/trace/events/dma.h | 3 ++- kernel/dma/debug.c | 3 ++- kernel/dma/mapping.c | 6 ++++++ 5 files changed, 33 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/Documentation/core-api/dma-attributes.rst b/Documentation/core-api/dma-attributes.rst index 48cfe86cc06d..123c8468d58f 100644 --- a/Documentation/core-api/dma-attributes.rst +++ b/Documentation/core-api/dma-attributes.rst @@ -163,3 +163,19 @@ data corruption. All mappings that share a cache line must set this attribute to suppress DMA debug warnings about overlapping mappings. + +DMA_ATTR_REQUIRE_COHERENT +------------------------- + +DMA mapping requests with the DMA_ATTR_REQUIRE_COHERENT fail on any +system where SWIOTLB or cache management is required. This should only +be used to support uAPI designs that require continuous HW DMA +coherence with userspace processes, for example RDMA and DRM. At a +minimum the memory being mapped must be userspace memory from +pin_user_pages() or similar. + +Drivers should consider using dma_mmap_pages() instead of this +interface when building their uAPIs, when possible. + +It must never be used in an in-kernel driver that only works with +kernel memory. diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index da44394b3a1a..482b919f040f 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -86,6 +86,13 @@ */ #define DMA_ATTR_DEBUGGING_IGNORE_CACHELINES (1UL << 11) +/* + * DMA_ATTR_REQUIRE_COHERENT: Indicates that DMA coherency is required. + * All mappings that carry this attribute can't work with SWIOTLB and cache + * flushing. + */ +#define DMA_ATTR_REQUIRE_COHERENT (1UL << 12) + /* * A dma_addr_t can hold any valid DMA or bus address for the platform. It can * be given to a device to use as a DMA source or target. It is specific to a diff --git a/include/trace/events/dma.h b/include/trace/events/dma.h index 8c64bc0721fe..63597b004424 100644 --- a/include/trace/events/dma.h +++ b/include/trace/events/dma.h @@ -33,7 +33,8 @@ TRACE_DEFINE_ENUM(DMA_NONE); { DMA_ATTR_NO_WARN, "NO_WARN" }, \ { DMA_ATTR_PRIVILEGED, "PRIVILEGED" }, \ { DMA_ATTR_MMIO, "MMIO" }, \ - { DMA_ATTR_DEBUGGING_IGNORE_CACHELINES, "CACHELINES_OVERLAP" }) + { DMA_ATTR_DEBUGGING_IGNORE_CACHELINES, "CACHELINES_OVERLAP" }, \ + { DMA_ATTR_REQUIRE_COHERENT, "REQUIRE_COHERENT" }) DECLARE_EVENT_CLASS(dma_map, TP_PROTO(struct device *dev, phys_addr_t phys_addr, dma_addr_t dma_addr, diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c index 83e1cfe05f08..0677918f06a8 100644 --- a/kernel/dma/debug.c +++ b/kernel/dma/debug.c @@ -601,7 +601,8 @@ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs) unsigned long flags; int rc; - entry->is_cache_clean = attrs & DMA_ATTR_DEBUGGING_IGNORE_CACHELINES; + entry->is_cache_clean = attrs & (DMA_ATTR_DEBUGGING_IGNORE_CACHELINES | + DMA_ATTR_REQUIRE_COHERENT); bucket = get_hash_bucket(entry, &flags); hash_bucket_add(bucket, entry); diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 3928a509c44c..6d3dd0bd3a88 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -164,6 +164,9 @@ dma_addr_t dma_map_phys(struct device *dev, phys_addr_t phys, size_t size, if (WARN_ON_ONCE(!dev->dma_mask)) return DMA_MAPPING_ERROR; + if (!dev_is_dma_coherent(dev) && (attrs & DMA_ATTR_REQUIRE_COHERENT)) + return DMA_MAPPING_ERROR; + if (dma_map_direct(dev, ops) || (!is_mmio && arch_dma_map_phys_direct(dev, phys + size))) addr = dma_direct_map_phys(dev, phys, size, dir, attrs); @@ -235,6 +238,9 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, BUG_ON(!valid_dma_direction(dir)); + if (!dev_is_dma_coherent(dev) && (attrs & DMA_ATTR_REQUIRE_COHERENT)) + return -EOPNOTSUPP; + if (WARN_ON_ONCE(!dev->dma_mask)) return 0; -- cgit v1.2.3 From 1613462be621ad5103ec338a7b0ca0746ec4e5f1 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Tue, 14 Oct 2025 13:28:15 +0200 Subject: xen/privcmd: add boot control for restricted usage in domU When running in an unprivileged domU under Xen, the privcmd driver is restricted to allow only hypercalls against a target domain, for which the current domU is acting as a device model. Add a boot parameter "unrestricted" to allow all hypercalls (the hypervisor will still refuse destructive hypercalls affecting other guests). Make this new parameter effective only in case the domU wasn't started using secure boot, as otherwise hypercalls targeting the domU itself might result in violating the secure boot functionality. This is achieved by adding another lockdown reason, which can be tested to not being set when applying the "unrestricted" option. This is part of XSA-482 Signed-off-by: Juergen Gross --- V2: - new patch --- drivers/xen/privcmd.c | 13 +++++++++++++ include/linux/security.h | 1 + security/security.c | 1 + 3 files changed, 15 insertions(+) (limited to 'include/linux') diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index a83bad69f4f2..bbf9ee21306c 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -72,6 +73,11 @@ module_param_named(dm_op_buf_max_size, privcmd_dm_op_buf_max_size, uint, MODULE_PARM_DESC(dm_op_buf_max_size, "Maximum size of a dm_op hypercall buffer"); +static bool unrestricted; +module_param(unrestricted, bool, 0); +MODULE_PARM_DESC(unrestricted, + "Don't restrict hypercalls to target domain if running in a domU"); + struct privcmd_data { domid_t domid; }; @@ -1708,6 +1714,13 @@ static struct notifier_block xenstore_notifier = { static void __init restrict_driver(void) { + if (unrestricted) { + if (security_locked_down(LOCKDOWN_XEN_USER_ACTIONS)) + pr_warn("Kernel is locked down, parameter \"unrestricted\" ignored\n"); + else + return; + } + restrict_wait = true; register_xenstore_notifier(&xenstore_notifier); diff --git a/include/linux/security.h b/include/linux/security.h index 83a646d72f6f..ee88dd2d2d1f 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -145,6 +145,7 @@ enum lockdown_reason { LOCKDOWN_BPF_WRITE_USER, LOCKDOWN_DBG_WRITE_KERNEL, LOCKDOWN_RTAS_ERROR_INJECTION, + LOCKDOWN_XEN_USER_ACTIONS, LOCKDOWN_INTEGRITY_MAX, LOCKDOWN_KCORE, LOCKDOWN_KPROBES, diff --git a/security/security.c b/security/security.c index 67af9228c4e9..a26c1474e2e4 100644 --- a/security/security.c +++ b/security/security.c @@ -61,6 +61,7 @@ const char *const lockdown_reasons[LOCKDOWN_CONFIDENTIALITY_MAX + 1] = { [LOCKDOWN_BPF_WRITE_USER] = "use of bpf to write user RAM", [LOCKDOWN_DBG_WRITE_KERNEL] = "use of kgdb/kdb to write kernel RAM", [LOCKDOWN_RTAS_ERROR_INJECTION] = "RTAS error injection", + [LOCKDOWN_XEN_USER_ACTIONS] = "Xen guest user action", [LOCKDOWN_INTEGRITY_MAX] = "integrity", [LOCKDOWN_KCORE] = "/proc/kcore access", [LOCKDOWN_KPROBES] = "use of kprobes", -- cgit v1.2.3 From 76f9377cd2ab7a9220c25d33940d9ca20d368172 Mon Sep 17 00:00:00 2001 From: Joanne Koong Date: Thu, 19 Mar 2026 17:51:45 -0700 Subject: writeback: don't block sync for filesystems with no data integrity guarantees Add a SB_I_NO_DATA_INTEGRITY superblock flag for filesystems that cannot guarantee data persistence on sync (eg fuse). For superblocks with this flag set, sync kicks off writeback of dirty inodes but does not wait for the flusher threads to complete the writeback. This replaces the per-inode AS_NO_DATA_INTEGRITY mapping flag added in commit f9a49aa302a0 ("fs/writeback: skip AS_NO_DATA_INTEGRITY mappings in wait_sb_inodes()"). The flag belongs at the superblock level because data integrity is a filesystem-wide property, not a per-inode one. Having this flag at the superblock level also allows us to skip having to iterate every dirty inode in wait_sb_inodes() only to skip each inode individually. Prior to this commit, mappings with no data integrity guarantees skipped waiting on writeback completion but still waited on the flusher threads to finish initiating the writeback. Waiting on the flusher threads is unnecessary. This commit kicks off writeback but does not wait on the flusher threads. This change properly addresses a recent report [1] for a suspend-to-RAM hang seen on fuse-overlayfs that was caused by waiting on the flusher threads to finish: Workqueue: pm_fs_sync pm_fs_sync_work_fn Call Trace: __schedule+0x457/0x1720 schedule+0x27/0xd0 wb_wait_for_completion+0x97/0xe0 sync_inodes_sb+0xf8/0x2e0 __iterate_supers+0xdc/0x160 ksys_sync+0x43/0xb0 pm_fs_sync_work_fn+0x17/0xa0 process_one_work+0x193/0x350 worker_thread+0x1a1/0x310 kthread+0xfc/0x240 ret_from_fork+0x243/0x280 ret_from_fork_asm+0x1a/0x30 On fuse this is problematic because there are paths that may cause the flusher thread to block (eg if systemd freezes the user session cgroups first, which freezes the fuse daemon, before invoking the kernel suspend. The kernel suspend triggers ->write_node() which on fuse issues a synchronous setattr request, which cannot be processed since the daemon is frozen. Or if the daemon is buggy and cannot properly complete writeback, initiating writeback on a dirty folio already under writeback leads to writeback_get_folio() -> folio_prepare_writeback() -> unconditional wait on writeback to finish, which will cause a hang). This commit restores fuse to its prior behavior before tmp folios were removed, where sync was essentially a no-op. [1] https://lore.kernel.org/linux-fsdevel/CAJnrk1a-asuvfrbKXbEwwDSctvemF+6zfhdnuzO65Pt8HsFSRw@mail.gmail.com/T/#m632c4648e9cafc4239299887109ebd880ac6c5c1 Fixes: 0c58a97f919c ("fuse: remove tmp folio for writebacks and internal rb tree") Reported-by: John Cc: stable@vger.kernel.org Signed-off-by: Joanne Koong Link: https://patch.msgid.link/20260320005145.2483161-2-joannelkoong@gmail.com Reviewed-by: Jan Kara Reviewed-by: David Hildenbrand (Arm) Signed-off-by: Christian Brauner --- fs/fs-writeback.c | 18 ++++++++++++------ fs/fuse/file.c | 4 +--- fs/fuse/inode.c | 1 + include/linux/fs/super_types.h | 1 + include/linux/pagemap.h | 11 ----------- 5 files changed, 15 insertions(+), 20 deletions(-) (limited to 'include/linux') diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index d8dac1931595..3c75ee025bda 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -2787,13 +2787,8 @@ static void wait_sb_inodes(struct super_block *sb) * The mapping can appear untagged while still on-list since we * do not have the mapping lock. Skip it here, wb completion * will remove it. - * - * If the mapping does not have data integrity semantics, - * there's no need to wait for the writeout to complete, as the - * mapping cannot guarantee that data is persistently stored. */ - if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK) || - mapping_no_data_integrity(mapping)) + if (!mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) continue; spin_unlock_irq(&sb->s_inode_wblist_lock); @@ -2928,6 +2923,17 @@ void sync_inodes_sb(struct super_block *sb) */ if (bdi == &noop_backing_dev_info) return; + + /* + * If the superblock has SB_I_NO_DATA_INTEGRITY set, there's no need to + * wait for the writeout to complete, as the filesystem cannot guarantee + * data persistence on sync. Just kick off writeback and return. + */ + if (sb->s_iflags & SB_I_NO_DATA_INTEGRITY) { + wakeup_flusher_threads_bdi(bdi, WB_REASON_SYNC); + return; + } + WARN_ON(!rwsem_is_locked(&sb->s_umount)); /* protect against inode wb switch, see inode_switch_wbs_work_fn() */ diff --git a/fs/fuse/file.c b/fs/fuse/file.c index b1bb7153cb78..676fd9856bfb 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -3201,10 +3201,8 @@ void fuse_init_file_inode(struct inode *inode, unsigned int flags) inode->i_fop = &fuse_file_operations; inode->i_data.a_ops = &fuse_file_aops; - if (fc->writeback_cache) { + if (fc->writeback_cache) mapping_set_writeback_may_deadlock_on_reclaim(&inode->i_data); - mapping_set_no_data_integrity(&inode->i_data); - } INIT_LIST_HEAD(&fi->write_files); INIT_LIST_HEAD(&fi->queued_writes); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index e57b8af06be9..c795abe47a4f 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1709,6 +1709,7 @@ static void fuse_sb_defaults(struct super_block *sb) sb->s_export_op = &fuse_export_operations; sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE; sb->s_iflags |= SB_I_NOIDMAP; + sb->s_iflags |= SB_I_NO_DATA_INTEGRITY; if (sb->s_user_ns != &init_user_ns) sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER; sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION); diff --git a/include/linux/fs/super_types.h b/include/linux/fs/super_types.h index fa7638b81246..383050e7fdf5 100644 --- a/include/linux/fs/super_types.h +++ b/include/linux/fs/super_types.h @@ -338,5 +338,6 @@ struct super_block { #define SB_I_NOUMASK 0x00001000 /* VFS does not apply umask */ #define SB_I_NOIDMAP 0x00002000 /* No idmapped mounts on this superblock */ #define SB_I_ALLOW_HSM 0x00004000 /* Allow HSM events on this superblock */ +#define SB_I_NO_DATA_INTEGRITY 0x00008000 /* fs cannot guarantee data persistence on sync */ #endif /* _LINUX_FS_SUPER_TYPES_H */ diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index ec442af3f886..31a848485ad9 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -210,7 +210,6 @@ enum mapping_flags { AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM = 9, AS_KERNEL_FILE = 10, /* mapping for a fake kernel file that shouldn't account usage to user cgroups */ - AS_NO_DATA_INTEGRITY = 11, /* no data integrity guarantees */ /* Bits 16-25 are used for FOLIO_ORDER */ AS_FOLIO_ORDER_BITS = 5, AS_FOLIO_ORDER_MIN = 16, @@ -346,16 +345,6 @@ static inline bool mapping_writeback_may_deadlock_on_reclaim(const struct addres return test_bit(AS_WRITEBACK_MAY_DEADLOCK_ON_RECLAIM, &mapping->flags); } -static inline void mapping_set_no_data_integrity(struct address_space *mapping) -{ - set_bit(AS_NO_DATA_INTEGRITY, &mapping->flags); -} - -static inline bool mapping_no_data_integrity(const struct address_space *mapping) -{ - return test_bit(AS_NO_DATA_INTEGRITY, &mapping->flags); -} - static inline gfp_t mapping_gfp_mask(const struct address_space *mapping) { return mapping->gfp_mask; -- cgit v1.2.3 From 26f775a054c3cda86ad465a64141894a90a9e145 Mon Sep 17 00:00:00 2001 From: SeongJae Park Date: Thu, 19 Mar 2026 07:52:17 -0700 Subject: mm/damon/core: avoid use of half-online-committed context One major usage of damon_call() is online DAMON parameters update. It is done by calling damon_commit_ctx() inside the damon_call() callback function. damon_commit_ctx() can fail for two reasons: 1) invalid parameters and 2) internal memory allocation failures. In case of failures, the damon_ctx that attempted to be updated (commit destination) can be partially updated (or, corrupted from a perspective), and therefore shouldn't be used anymore. The function only ensures the damon_ctx object can safely deallocated using damon_destroy_ctx(). The API callers are, however, calling damon_commit_ctx() only after asserting the parameters are valid, to avoid damon_commit_ctx() fails due to invalid input parameters. But it can still theoretically fail if the internal memory allocation fails. In the case, DAMON may run with the partially updated damon_ctx. This can result in unexpected behaviors including even NULL pointer dereference in case of damos_commit_dests() failure [1]. Such allocation failure is arguably too small to fail, so the real world impact would be rare. But, given the bad consequence, this needs to be fixed. Avoid such partially-committed (maybe-corrupted) damon_ctx use by saving the damon_commit_ctx() failure on the damon_ctx object. For this, introduce damon_ctx->maybe_corrupted field. damon_commit_ctx() sets it when it is failed. kdamond_call() checks if the field is set after each damon_call_control->fn() is executed. If it is set, ignore remaining callback requests and return. All kdamond_call() callers including kdamond_fn() also check the maybe_corrupted field right after kdamond_call() invocations. If the field is set, break the kdamond_fn() main loop so that DAMON sill doesn't use the context that might be corrupted. [sj@kernel.org: let kdamond_call() with cancel regardless of maybe_corrupted] Link: https://lkml.kernel.org/r/20260320031553.2479-1-sj@kernel.org Link: https://sashiko.dev/#/patchset/20260319145218.86197-1-sj%40kernel.org Link: https://lkml.kernel.org/r/20260319145218.86197-1-sj@kernel.org Link: https://lore.kernel.org/20260319043309.97966-1-sj@kernel.org [1] Fixes: 3301f1861d34 ("mm/damon/sysfs: handle commit command using damon_call()") Signed-off-by: SeongJae Park Cc: [6.15+] Signed-off-by: Andrew Morton --- include/linux/damon.h | 6 ++++++ mm/damon/core.c | 8 ++++++++ 2 files changed, 14 insertions(+) (limited to 'include/linux') diff --git a/include/linux/damon.h b/include/linux/damon.h index a4fea23da857..be3d198043ff 100644 --- a/include/linux/damon.h +++ b/include/linux/damon.h @@ -810,6 +810,12 @@ struct damon_ctx { struct damos_walk_control *walk_control; struct mutex walk_control_lock; + /* + * indicate if this may be corrupted. Currentonly this is set only for + * damon_commit_ctx() failure. + */ + bool maybe_corrupted; + /* Working thread of the given DAMON context */ struct task_struct *kdamond; /* Protects @kdamond field access */ diff --git a/mm/damon/core.c b/mm/damon/core.c index c1d1091d307e..3e1890d64d06 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -1252,6 +1252,7 @@ int damon_commit_ctx(struct damon_ctx *dst, struct damon_ctx *src) { int err; + dst->maybe_corrupted = true; if (!is_power_of_2(src->min_region_sz)) return -EINVAL; @@ -1277,6 +1278,7 @@ int damon_commit_ctx(struct damon_ctx *dst, struct damon_ctx *src) dst->addr_unit = src->addr_unit; dst->min_region_sz = src->min_region_sz; + dst->maybe_corrupted = false; return 0; } @@ -2678,6 +2680,8 @@ static void kdamond_call(struct damon_ctx *ctx, bool cancel) complete(&control->completion); else if (control->canceled && control->dealloc_on_cancel) kfree(control); + if (!cancel && ctx->maybe_corrupted) + break; } mutex_lock(&ctx->call_controls_lock); @@ -2707,6 +2711,8 @@ static int kdamond_wait_activation(struct damon_ctx *ctx) kdamond_usleep(min_wait_time); kdamond_call(ctx, false); + if (ctx->maybe_corrupted) + return -EINVAL; damos_walk_cancel(ctx); } return -EBUSY; @@ -2790,6 +2796,8 @@ static int kdamond_fn(void *data) * kdamond_merge_regions() if possible, to reduce overhead */ kdamond_call(ctx, false); + if (ctx->maybe_corrupted) + break; if (!list_empty(&ctx->schemes)) kdamond_apply_schemes(ctx); else -- cgit v1.2.3 From 38ec410b99a5ee6566f75650ce3d4fd632940fd0 Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Fri, 20 Mar 2026 10:18:17 +0800 Subject: virtio-net: correct hdr_len handling for VIRTIO_NET_F_GUEST_HDRLEN The commit be50da3e9d4a ("net: virtio_net: implement exact header length guest feature") introduces support for the VIRTIO_NET_F_GUEST_HDRLEN feature in virtio-net. This feature requires virtio-net to set hdr_len to the actual header length of the packet when transmitting, the number of bytes from the start of the packet to the beginning of the transport-layer payload. However, in practice, hdr_len was being set using skb_headlen(skb), which is clearly incorrect. This commit fixes that issue. Fixes: be50da3e9d4a ("net: virtio_net: implement exact header length guest feature") Signed-off-by: Xuan Zhuo Link: https://patch.msgid.link/20260320021818.111741-2-xuanzhuo@linux.alibaba.com Acked-by: Michael S. Tsirkin Signed-off-by: Paolo Abeni --- drivers/net/tun_vnet.h | 2 +- drivers/net/virtio_net.c | 6 +++++- include/linux/virtio_net.h | 34 ++++++++++++++++++++++++++++++---- 3 files changed, 36 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/drivers/net/tun_vnet.h b/drivers/net/tun_vnet.h index a5f93b6c4482..fa5cab9d3e55 100644 --- a/drivers/net/tun_vnet.h +++ b/drivers/net/tun_vnet.h @@ -244,7 +244,7 @@ tun_vnet_hdr_tnl_from_skb(unsigned int flags, if (virtio_net_hdr_tnl_from_skb(skb, tnl_hdr, has_tnl_offload, tun_vnet_is_little_endian(flags), - vlan_hlen, true)) { + vlan_hlen, true, false)) { struct virtio_net_hdr_v1 *hdr = &tnl_hdr->hash_hdr.hdr; struct skb_shared_info *sinfo = skb_shinfo(skb); diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 72d6a9c6a5a2..7106333ef904 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -3267,8 +3267,12 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb, bool orphan) struct virtio_net_hdr_v1_hash_tunnel *hdr; int num_sg; unsigned hdr_len = vi->hdr_len; + bool feature_hdrlen; bool can_push; + feature_hdrlen = virtio_has_feature(vi->vdev, + VIRTIO_NET_F_GUEST_HDRLEN); + pr_debug("%s: xmit %p %pM\n", vi->dev->name, skb, dest); /* Make sure it's safe to cast between formats */ @@ -3288,7 +3292,7 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb, bool orphan) if (virtio_net_hdr_tnl_from_skb(skb, hdr, vi->tx_tnl, virtio_is_little_endian(vi->vdev), 0, - false)) + false, feature_hdrlen)) return -EPROTO; if (vi->mergeable_rx_bufs) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 75dabb763c65..361b60c8be68 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -207,6 +207,23 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, return __virtio_net_hdr_to_skb(skb, hdr, little_endian, hdr->gso_type); } +/* This function must be called after virtio_net_hdr_from_skb(). */ +static inline void __virtio_net_set_hdrlen(const struct sk_buff *skb, + struct virtio_net_hdr *hdr, + bool little_endian) +{ + u16 hdr_len; + + hdr_len = skb_transport_offset(skb); + + if (hdr->gso_type == VIRTIO_NET_HDR_GSO_UDP_L4) + hdr_len += sizeof(struct udphdr); + else + hdr_len += tcp_hdrlen(skb); + + hdr->hdr_len = __cpu_to_virtio16(little_endian, hdr_len); +} + static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, struct virtio_net_hdr *hdr, bool little_endian, @@ -385,7 +402,8 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, bool tnl_hdr_negotiated, bool little_endian, int vlan_hlen, - bool has_data_valid) + bool has_data_valid, + bool feature_hdrlen) { struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)vhdr; unsigned int inner_nh, outer_th; @@ -394,9 +412,17 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, tnl_gso_type = skb_shinfo(skb)->gso_type & (SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM); - if (!tnl_gso_type) - return virtio_net_hdr_from_skb(skb, hdr, little_endian, - has_data_valid, vlan_hlen); + if (!tnl_gso_type) { + ret = virtio_net_hdr_from_skb(skb, hdr, little_endian, + has_data_valid, vlan_hlen); + if (ret) + return ret; + + if (feature_hdrlen && hdr->hdr_len) + __virtio_net_set_hdrlen(skb, hdr, little_endian); + + return ret; + } /* Tunnel support not negotiated but skb ask for it. */ if (!tnl_hdr_negotiated) -- cgit v1.2.3 From 6c860dc02a8e60b438e26940227dfa641fcdb66a Mon Sep 17 00:00:00 2001 From: Xuan Zhuo Date: Fri, 20 Mar 2026 10:18:18 +0800 Subject: virtio-net: correct hdr_len handling for tunnel gso The commit a2fb4bc4e2a6a03 ("net: implement virtio helpers to handle UDP GSO tunneling.") introduces support for the UDP GSO tunnel feature in virtio-net. The virtio spec says: If the \field{gso_type} has the VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV4 bit or VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV6 bit set, \field{hdr_len} accounts for all the headers up to and including the inner transport. The commit did not update the hdr_len to include the inner transport. I observed that the "hdr_len" is 116 for this packet: 17:36:18.241105 52:55:00:d1:27:0a > 2e:2c:df:46:a9:e1, ethertype IPv4 (0x0800), length 2912: (tos 0x0, ttl 64, id 45197, offset 0, flags [none], proto UDP (17), length 2898) 192.168.122.100.50613 > 192.168.122.1.4789: [bad udp cksum 0x8106 -> 0x26a0!] VXLAN, flags [I] (0x08), vni 1 fa:c3:ba:82:05:ee > ce:85:0c:31:77:e5, ethertype IPv4 (0x0800), length 2862: (tos 0x0, ttl 64, id 14678, offset 0, flags [DF], proto TCP (6), length 2848) 192.168.3.1.49880 > 192.168.3.2.9898: Flags [P.], cksum 0x9266 (incorrect -> 0xaa20), seq 515667:518463, ack 1, win 64, options [nop,nop,TS val 2990048824 ecr 2798801412], length 2796 116 = 14(mac) + 20(ip) + 8(udp) + 8(vxlan) + 14(inner mac) + 20(inner ip) + 32(innner tcp) Fixes: a2fb4bc4e2a6a03 ("net: implement virtio helpers to handle UDP GSO tunneling.") Signed-off-by: Xuan Zhuo Link: https://patch.msgid.link/20260320021818.111741-3-xuanzhuo@linux.alibaba.com Acked-by: Michael S. Tsirkin Signed-off-by: Paolo Abeni --- include/linux/virtio_net.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'include/linux') diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 361b60c8be68..f36d21b5bc19 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -224,6 +224,22 @@ static inline void __virtio_net_set_hdrlen(const struct sk_buff *skb, hdr->hdr_len = __cpu_to_virtio16(little_endian, hdr_len); } +/* This function must be called after virtio_net_hdr_from_skb(). */ +static inline void __virtio_net_set_tnl_hdrlen(const struct sk_buff *skb, + struct virtio_net_hdr *hdr) +{ + u16 hdr_len; + + hdr_len = skb_inner_transport_offset(skb); + + if (hdr->gso_type == VIRTIO_NET_HDR_GSO_UDP_L4) + hdr_len += sizeof(struct udphdr); + else + hdr_len += inner_tcp_hdrlen(skb); + + hdr->hdr_len = __cpu_to_virtio16(true, hdr_len); +} + static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, struct virtio_net_hdr *hdr, bool little_endian, @@ -440,6 +456,9 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, if (ret) return ret; + if (feature_hdrlen && hdr->hdr_len) + __virtio_net_set_tnl_hdrlen(skb, hdr); + if (skb->protocol == htons(ETH_P_IPV6)) hdr->gso_type |= VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV6; else -- cgit v1.2.3 From cc34d77dd48708d810c12bfd6f5bf03304f6c824 Mon Sep 17 00:00:00 2001 From: Danilo Krummrich Date: Tue, 24 Mar 2026 01:59:15 +0100 Subject: spi: use generic driver_override infrastructure When a driver is probed through __driver_attach(), the bus' match() callback is called without the device lock held, thus accessing the driver_override field without a lock, which can cause a UAF. Fix this by using the driver-core driver_override infrastructure taking care of proper locking internally. Note that calling match() from __driver_attach() without the device lock held is intentional. [1] Also note that we do not enable the driver_override feature of struct bus_type, as SPI - in contrast to most other buses - passes "" to sysfs_emit() when the driver_override pointer is NULL. Thus, printing "\n" instead of "(null)\n". Link: https://lore.kernel.org/driver-core/DGRGTIRHA62X.3RY09D9SOK77P@kernel.org/ [1] Reported-by: Gui-Dong Han Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220789 Fixes: 5039563e7c25 ("spi: Add driver_override SPI device attribute") Signed-off-by: Danilo Krummrich Link: https://patch.msgid.link/20260324005919.2408620-12-dakr@kernel.org Signed-off-by: Mark Brown --- drivers/spi/spi.c | 19 +++++++------------ include/linux/spi/spi.h | 5 ----- 2 files changed, 7 insertions(+), 17 deletions(-) (limited to 'include/linux') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 53dee314d76a..4101c2803eb3 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -50,7 +50,6 @@ static void spidev_release(struct device *dev) struct spi_device *spi = to_spi_device(dev); spi_controller_put(spi->controller); - kfree(spi->driver_override); free_percpu(spi->pcpu_statistics); kfree(spi); } @@ -73,10 +72,9 @@ static ssize_t driver_override_store(struct device *dev, struct device_attribute *a, const char *buf, size_t count) { - struct spi_device *spi = to_spi_device(dev); int ret; - ret = driver_set_override(dev, &spi->driver_override, buf, count); + ret = __device_set_driver_override(dev, buf, count); if (ret) return ret; @@ -86,13 +84,8 @@ static ssize_t driver_override_store(struct device *dev, static ssize_t driver_override_show(struct device *dev, struct device_attribute *a, char *buf) { - const struct spi_device *spi = to_spi_device(dev); - ssize_t len; - - device_lock(dev); - len = sysfs_emit(buf, "%s\n", spi->driver_override ? : ""); - device_unlock(dev); - return len; + guard(spinlock)(&dev->driver_override.lock); + return sysfs_emit(buf, "%s\n", dev->driver_override.name ?: ""); } static DEVICE_ATTR_RW(driver_override); @@ -376,10 +369,12 @@ static int spi_match_device(struct device *dev, const struct device_driver *drv) { const struct spi_device *spi = to_spi_device(dev); const struct spi_driver *sdrv = to_spi_driver(drv); + int ret; /* Check override first, and if set, only use the named driver */ - if (spi->driver_override) - return strcmp(spi->driver_override, drv->name) == 0; + ret = device_match_driver_override(dev, drv); + if (ret >= 0) + return ret; /* Attempt an OF style match */ if (of_driver_match_device(dev, drv)) diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index af7cfee7b8f6..0dc671c07d3a 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -159,10 +159,6 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg, * @modalias: Name of the driver to use with this device, or an alias * for that name. This appears in the sysfs "modalias" attribute * for driver coldplugging, and in uevents used for hotplugging - * @driver_override: If the name of a driver is written to this attribute, then - * the device will bind to the named driver and only the named driver. - * Do not set directly, because core frees it; use driver_set_override() to - * set or clear it. * @pcpu_statistics: statistics for the spi_device * @word_delay: delay to be inserted between consecutive * words of a transfer @@ -224,7 +220,6 @@ struct spi_device { void *controller_state; void *controller_data; char modalias[SPI_NAME_SIZE]; - const char *driver_override; /* The statistics */ struct spi_statistics __percpu *pcpu_statistics; -- cgit v1.2.3 From 2cdaff22ed26f1e619aa2b43f27bb84f2c6ef8f8 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Wed, 25 Mar 2026 02:55:48 +0100 Subject: dma-mapping: add missing `inline` for `dma_free_attrs` Under an UML build for an upcoming series [1], I got `-Wstatic-in-inline` for `dma_free_attrs`: BINDGEN rust/bindings/bindings_generated.rs - due to target missing In file included from rust/helpers/helpers.c:59: rust/helpers/dma.c:17:2: warning: static function 'dma_free_attrs' is used in an inline function with external linkage [-Wstatic-in-inline] 17 | dma_free_attrs(dev, size, cpu_addr, dma_handle, attrs); | ^ rust/helpers/dma.c:12:1: note: use 'static' to give inline function 'rust_helper_dma_free_attrs' internal linkage 12 | __rust_helper void rust_helper_dma_free_attrs(struct device *dev, size_t size, | ^ | static The issue is that `dma_free_attrs` was not marked `inline` when it was introduced alongside the rest of the stubs. Thus mark it. Fixes: ed6ccf10f24b ("dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA") Closes: https://lore.kernel.org/rust-for-linux/20260322194616.89847-1-ojeda@kernel.org/ [1] Signed-off-by: Miguel Ojeda Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20260325015548.70912-1-ojeda@kernel.org --- include/linux/dma-mapping.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 482b919f040f..99ef042ecdb4 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -255,8 +255,8 @@ static inline void *dma_alloc_attrs(struct device *dev, size_t size, { return NULL; } -static void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, - dma_addr_t dma_handle, unsigned long attrs) +static inline void dma_free_attrs(struct device *dev, size_t size, + void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs) { } static inline void *dmam_alloc_attrs(struct device *dev, size_t size, -- cgit v1.2.3 From 175b45ed343a9c547b5f45293d3ea08d38a7b6f4 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 14 Mar 2026 04:12:58 -0700 Subject: srcu: Use raw spinlocks so call_srcu() can be used under preempt_disable() Tree SRCU has used non-raw spinlocks for many years, motivated by a desire to avoid unnecessary real-time latency and the absence of any reason to use raw spinlocks. However, the recent use of SRCU in tracing as the underlying implementation of RCU Tasks Trace means that call_srcu() is invoked from preemption-disabled regions of code, which in turn requires that any locks acquired by call_srcu() or its callees must be raw spinlocks. This commit therefore converts SRCU's spinlocks to raw spinlocks. [boqun: Add Fixes tag] Reported-by: Kumar Kartikeya Dwivedi Fixes: c27cea4416a3 ("rcu: Re-implement RCU Tasks Trace in terms of SRCU-fast") Signed-off-by: Paul E. McKenney Signed-off-by: Boqun Feng Cc: Sebastian Andrzej Siewior --- include/linux/srcutree.h | 8 +-- kernel/rcu/rcu.h | 9 +++ kernel/rcu/srcutree.c | 174 +++++++++++++++++++---------------------------- 3 files changed, 82 insertions(+), 109 deletions(-) (limited to 'include/linux') diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 958cb7ef41cb..dfb31d11ff05 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -34,7 +34,7 @@ struct srcu_data { /* Values: SRCU_READ_FLAVOR_.* */ /* Update-side state. */ - spinlock_t __private lock ____cacheline_internodealigned_in_smp; + raw_spinlock_t __private lock ____cacheline_internodealigned_in_smp; struct rcu_segcblist srcu_cblist; /* List of callbacks.*/ unsigned long srcu_gp_seq_needed; /* Furthest future GP needed. */ unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */ @@ -55,7 +55,7 @@ struct srcu_data { * Node in SRCU combining tree, similar in function to rcu_data. */ struct srcu_node { - spinlock_t __private lock; + raw_spinlock_t __private lock; unsigned long srcu_have_cbs[4]; /* GP seq for children having CBs, but only */ /* if greater than ->srcu_gp_seq. */ unsigned long srcu_data_have_cbs[4]; /* Which srcu_data structs have CBs for given GP? */ @@ -74,7 +74,7 @@ struct srcu_usage { /* First node at each level. */ int srcu_size_state; /* Small-to-big transition state. */ struct mutex srcu_cb_mutex; /* Serialize CB preparation. */ - spinlock_t __private lock; /* Protect counters and size state. */ + raw_spinlock_t __private lock; /* Protect counters and size state. */ struct mutex srcu_gp_mutex; /* Serialize GP work. */ unsigned long srcu_gp_seq; /* Grace-period seq #. */ unsigned long srcu_gp_seq_needed; /* Latest gp_seq needed. */ @@ -156,7 +156,7 @@ struct srcu_struct { #define __SRCU_USAGE_INIT(name) \ { \ - .lock = __SPIN_LOCK_UNLOCKED(name.lock), \ + .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock), \ .srcu_gp_seq = SRCU_GP_SEQ_INITIAL_VAL, \ .srcu_gp_seq_needed = SRCU_GP_SEQ_INITIAL_VAL_WITH_STATE, \ .srcu_gp_seq_needed_exp = SRCU_GP_SEQ_INITIAL_VAL, \ diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index dc5d614b372c..9b10b57b79ad 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -502,6 +502,15 @@ do { \ ___locked; \ }) +#define raw_spin_trylock_irqsave_rcu_node(p, flags) \ +({ \ + bool ___locked = raw_spin_trylock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \ + \ + if (___locked) \ + smp_mb__after_unlock_lock(); \ + ___locked; \ +}) + #define raw_lockdep_assert_held_rcu_node(p) \ lockdep_assert_held(&ACCESS_PRIVATE(p, lock)) diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index aef8e91ad33e..2328827f8775 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -77,42 +77,6 @@ static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay); static void process_srcu(struct work_struct *work); static void srcu_delay_timer(struct timer_list *t); -/* Wrappers for lock acquisition and release, see raw_spin_lock_rcu_node(). */ -#define spin_lock_rcu_node(p) \ -do { \ - spin_lock(&ACCESS_PRIVATE(p, lock)); \ - smp_mb__after_unlock_lock(); \ -} while (0) - -#define spin_unlock_rcu_node(p) spin_unlock(&ACCESS_PRIVATE(p, lock)) - -#define spin_lock_irq_rcu_node(p) \ -do { \ - spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \ - smp_mb__after_unlock_lock(); \ -} while (0) - -#define spin_unlock_irq_rcu_node(p) \ - spin_unlock_irq(&ACCESS_PRIVATE(p, lock)) - -#define spin_lock_irqsave_rcu_node(p, flags) \ -do { \ - spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \ - smp_mb__after_unlock_lock(); \ -} while (0) - -#define spin_trylock_irqsave_rcu_node(p, flags) \ -({ \ - bool ___locked = spin_trylock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \ - \ - if (___locked) \ - smp_mb__after_unlock_lock(); \ - ___locked; \ -}) - -#define spin_unlock_irqrestore_rcu_node(p, flags) \ - spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags) \ - /* * Initialize SRCU per-CPU data. Note that statically allocated * srcu_struct structures might already have srcu_read_lock() and @@ -131,7 +95,7 @@ static void init_srcu_struct_data(struct srcu_struct *ssp) */ for_each_possible_cpu(cpu) { sdp = per_cpu_ptr(ssp->sda, cpu); - spin_lock_init(&ACCESS_PRIVATE(sdp, lock)); + raw_spin_lock_init(&ACCESS_PRIVATE(sdp, lock)); rcu_segcblist_init(&sdp->srcu_cblist); sdp->srcu_cblist_invoking = false; sdp->srcu_gp_seq_needed = ssp->srcu_sup->srcu_gp_seq; @@ -186,7 +150,7 @@ static bool init_srcu_struct_nodes(struct srcu_struct *ssp, gfp_t gfp_flags) /* Each pass through this loop initializes one srcu_node structure. */ srcu_for_each_node_breadth_first(ssp, snp) { - spin_lock_init(&ACCESS_PRIVATE(snp, lock)); + raw_spin_lock_init(&ACCESS_PRIVATE(snp, lock)); BUILD_BUG_ON(ARRAY_SIZE(snp->srcu_have_cbs) != ARRAY_SIZE(snp->srcu_data_have_cbs)); for (i = 0; i < ARRAY_SIZE(snp->srcu_have_cbs); i++) { @@ -242,7 +206,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static) if (!ssp->srcu_sup) return -ENOMEM; if (!is_static) - spin_lock_init(&ACCESS_PRIVATE(ssp->srcu_sup, lock)); + raw_spin_lock_init(&ACCESS_PRIVATE(ssp->srcu_sup, lock)); ssp->srcu_sup->srcu_size_state = SRCU_SIZE_SMALL; ssp->srcu_sup->node = NULL; mutex_init(&ssp->srcu_sup->srcu_cb_mutex); @@ -394,20 +358,20 @@ static void srcu_transition_to_big(struct srcu_struct *ssp) /* Double-checked locking on ->srcu_size-state. */ if (smp_load_acquire(&ssp->srcu_sup->srcu_size_state) != SRCU_SIZE_SMALL) return; - spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags); + raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags); if (smp_load_acquire(&ssp->srcu_sup->srcu_size_state) != SRCU_SIZE_SMALL) { - spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); + raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); return; } __srcu_transition_to_big(ssp); - spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); + raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); } /* * Check to see if the just-encountered contention event justifies * a transition to SRCU_SIZE_BIG. */ -static void spin_lock_irqsave_check_contention(struct srcu_struct *ssp) +static void raw_spin_lock_irqsave_check_contention(struct srcu_struct *ssp) { unsigned long j; @@ -429,16 +393,16 @@ static void spin_lock_irqsave_check_contention(struct srcu_struct *ssp) * to SRCU_SIZE_BIG. But only if the srcutree.convert_to_big module * parameter permits this. */ -static void spin_lock_irqsave_sdp_contention(struct srcu_data *sdp, unsigned long *flags) +static void raw_spin_lock_irqsave_sdp_contention(struct srcu_data *sdp, unsigned long *flags) { struct srcu_struct *ssp = sdp->ssp; - if (spin_trylock_irqsave_rcu_node(sdp, *flags)) + if (raw_spin_trylock_irqsave_rcu_node(sdp, *flags)) return; - spin_lock_irqsave_rcu_node(ssp->srcu_sup, *flags); - spin_lock_irqsave_check_contention(ssp); - spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, *flags); - spin_lock_irqsave_rcu_node(sdp, *flags); + raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, *flags); + raw_spin_lock_irqsave_check_contention(ssp); + raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, *flags); + raw_spin_lock_irqsave_rcu_node(sdp, *flags); } /* @@ -447,12 +411,12 @@ static void spin_lock_irqsave_sdp_contention(struct srcu_data *sdp, unsigned lon * to SRCU_SIZE_BIG. But only if the srcutree.convert_to_big module * parameter permits this. */ -static void spin_lock_irqsave_ssp_contention(struct srcu_struct *ssp, unsigned long *flags) +static void raw_spin_lock_irqsave_ssp_contention(struct srcu_struct *ssp, unsigned long *flags) { - if (spin_trylock_irqsave_rcu_node(ssp->srcu_sup, *flags)) + if (raw_spin_trylock_irqsave_rcu_node(ssp->srcu_sup, *flags)) return; - spin_lock_irqsave_rcu_node(ssp->srcu_sup, *flags); - spin_lock_irqsave_check_contention(ssp); + raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, *flags); + raw_spin_lock_irqsave_check_contention(ssp); } /* @@ -470,13 +434,13 @@ static void check_init_srcu_struct(struct srcu_struct *ssp) /* The smp_load_acquire() pairs with the smp_store_release(). */ if (!rcu_seq_state(smp_load_acquire(&ssp->srcu_sup->srcu_gp_seq_needed))) /*^^^*/ return; /* Already initialized. */ - spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags); + raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags); if (!rcu_seq_state(ssp->srcu_sup->srcu_gp_seq_needed)) { - spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); + raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); return; } init_srcu_struct_fields(ssp, true); - spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); + raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); } /* @@ -742,9 +706,9 @@ void cleanup_srcu_struct(struct srcu_struct *ssp) unsigned long delay; struct srcu_usage *sup = ssp->srcu_sup; - spin_lock_irq_rcu_node(ssp->srcu_sup); + raw_spin_lock_irq_rcu_node(ssp->srcu_sup); delay = srcu_get_delay(ssp); - spin_unlock_irq_rcu_node(ssp->srcu_sup); + raw_spin_unlock_irq_rcu_node(ssp->srcu_sup); if (WARN_ON(!delay)) return; /* Just leak it! */ if (WARN_ON(srcu_readers_active(ssp))) @@ -960,7 +924,7 @@ static void srcu_gp_end(struct srcu_struct *ssp) mutex_lock(&sup->srcu_cb_mutex); /* End the current grace period. */ - spin_lock_irq_rcu_node(sup); + raw_spin_lock_irq_rcu_node(sup); idx = rcu_seq_state(sup->srcu_gp_seq); WARN_ON_ONCE(idx != SRCU_STATE_SCAN2); if (srcu_gp_is_expedited(ssp)) @@ -971,7 +935,7 @@ static void srcu_gp_end(struct srcu_struct *ssp) gpseq = rcu_seq_current(&sup->srcu_gp_seq); if (ULONG_CMP_LT(sup->srcu_gp_seq_needed_exp, gpseq)) WRITE_ONCE(sup->srcu_gp_seq_needed_exp, gpseq); - spin_unlock_irq_rcu_node(sup); + raw_spin_unlock_irq_rcu_node(sup); mutex_unlock(&sup->srcu_gp_mutex); /* A new grace period can start at this point. But only one. */ @@ -983,7 +947,7 @@ static void srcu_gp_end(struct srcu_struct *ssp) } else { idx = rcu_seq_ctr(gpseq) % ARRAY_SIZE(snp->srcu_have_cbs); srcu_for_each_node_breadth_first(ssp, snp) { - spin_lock_irq_rcu_node(snp); + raw_spin_lock_irq_rcu_node(snp); cbs = false; last_lvl = snp >= sup->level[rcu_num_lvls - 1]; if (last_lvl) @@ -998,7 +962,7 @@ static void srcu_gp_end(struct srcu_struct *ssp) else mask = snp->srcu_data_have_cbs[idx]; snp->srcu_data_have_cbs[idx] = 0; - spin_unlock_irq_rcu_node(snp); + raw_spin_unlock_irq_rcu_node(snp); if (cbs) srcu_schedule_cbs_snp(ssp, snp, mask, cbdelay); } @@ -1008,27 +972,27 @@ static void srcu_gp_end(struct srcu_struct *ssp) if (!(gpseq & counter_wrap_check)) for_each_possible_cpu(cpu) { sdp = per_cpu_ptr(ssp->sda, cpu); - spin_lock_irq_rcu_node(sdp); + raw_spin_lock_irq_rcu_node(sdp); if (ULONG_CMP_GE(gpseq, sdp->srcu_gp_seq_needed + 100)) sdp->srcu_gp_seq_needed = gpseq; if (ULONG_CMP_GE(gpseq, sdp->srcu_gp_seq_needed_exp + 100)) sdp->srcu_gp_seq_needed_exp = gpseq; - spin_unlock_irq_rcu_node(sdp); + raw_spin_unlock_irq_rcu_node(sdp); } /* Callback initiation done, allow grace periods after next. */ mutex_unlock(&sup->srcu_cb_mutex); /* Start a new grace period if needed. */ - spin_lock_irq_rcu_node(sup); + raw_spin_lock_irq_rcu_node(sup); gpseq = rcu_seq_current(&sup->srcu_gp_seq); if (!rcu_seq_state(gpseq) && ULONG_CMP_LT(gpseq, sup->srcu_gp_seq_needed)) { srcu_gp_start(ssp); - spin_unlock_irq_rcu_node(sup); + raw_spin_unlock_irq_rcu_node(sup); srcu_reschedule(ssp, 0); } else { - spin_unlock_irq_rcu_node(sup); + raw_spin_unlock_irq_rcu_node(sup); } /* Transition to big if needed. */ @@ -1059,19 +1023,19 @@ static void srcu_funnel_exp_start(struct srcu_struct *ssp, struct srcu_node *snp if (WARN_ON_ONCE(rcu_seq_done(&ssp->srcu_sup->srcu_gp_seq, s)) || (!srcu_invl_snp_seq(sgsne) && ULONG_CMP_GE(sgsne, s))) return; - spin_lock_irqsave_rcu_node(snp, flags); + raw_spin_lock_irqsave_rcu_node(snp, flags); sgsne = snp->srcu_gp_seq_needed_exp; if (!srcu_invl_snp_seq(sgsne) && ULONG_CMP_GE(sgsne, s)) { - spin_unlock_irqrestore_rcu_node(snp, flags); + raw_spin_unlock_irqrestore_rcu_node(snp, flags); return; } WRITE_ONCE(snp->srcu_gp_seq_needed_exp, s); - spin_unlock_irqrestore_rcu_node(snp, flags); + raw_spin_unlock_irqrestore_rcu_node(snp, flags); } - spin_lock_irqsave_ssp_contention(ssp, &flags); + raw_spin_lock_irqsave_ssp_contention(ssp, &flags); if (ULONG_CMP_LT(ssp->srcu_sup->srcu_gp_seq_needed_exp, s)) WRITE_ONCE(ssp->srcu_sup->srcu_gp_seq_needed_exp, s); - spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); + raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); } /* @@ -1109,12 +1073,12 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp, for (snp = snp_leaf; snp != NULL; snp = snp->srcu_parent) { if (WARN_ON_ONCE(rcu_seq_done(&sup->srcu_gp_seq, s)) && snp != snp_leaf) return; /* GP already done and CBs recorded. */ - spin_lock_irqsave_rcu_node(snp, flags); + raw_spin_lock_irqsave_rcu_node(snp, flags); snp_seq = snp->srcu_have_cbs[idx]; if (!srcu_invl_snp_seq(snp_seq) && ULONG_CMP_GE(snp_seq, s)) { if (snp == snp_leaf && snp_seq == s) snp->srcu_data_have_cbs[idx] |= sdp->grpmask; - spin_unlock_irqrestore_rcu_node(snp, flags); + raw_spin_unlock_irqrestore_rcu_node(snp, flags); if (snp == snp_leaf && snp_seq != s) { srcu_schedule_cbs_sdp(sdp, do_norm ? SRCU_INTERVAL : 0); return; @@ -1129,11 +1093,11 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp, sgsne = snp->srcu_gp_seq_needed_exp; if (!do_norm && (srcu_invl_snp_seq(sgsne) || ULONG_CMP_LT(sgsne, s))) WRITE_ONCE(snp->srcu_gp_seq_needed_exp, s); - spin_unlock_irqrestore_rcu_node(snp, flags); + raw_spin_unlock_irqrestore_rcu_node(snp, flags); } /* Top of tree, must ensure the grace period will be started. */ - spin_lock_irqsave_ssp_contention(ssp, &flags); + raw_spin_lock_irqsave_ssp_contention(ssp, &flags); if (ULONG_CMP_LT(sup->srcu_gp_seq_needed, s)) { /* * Record need for grace period s. Pair with load @@ -1160,7 +1124,7 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp, else if (list_empty(&sup->work.work.entry)) list_add(&sup->work.work.entry, &srcu_boot_list); } - spin_unlock_irqrestore_rcu_node(sup, flags); + raw_spin_unlock_irqrestore_rcu_node(sup, flags); } /* @@ -1172,9 +1136,9 @@ static bool try_check_zero(struct srcu_struct *ssp, int idx, int trycount) { unsigned long curdelay; - spin_lock_irq_rcu_node(ssp->srcu_sup); + raw_spin_lock_irq_rcu_node(ssp->srcu_sup); curdelay = !srcu_get_delay(ssp); - spin_unlock_irq_rcu_node(ssp->srcu_sup); + raw_spin_unlock_irq_rcu_node(ssp->srcu_sup); for (;;) { if (srcu_readers_active_idx_check(ssp, idx)) @@ -1285,12 +1249,12 @@ static bool srcu_should_expedite(struct srcu_struct *ssp) return false; /* If the local srcu_data structure has callbacks, not idle. */ sdp = raw_cpu_ptr(ssp->sda); - spin_lock_irqsave_rcu_node(sdp, flags); + raw_spin_lock_irqsave_rcu_node(sdp, flags); if (rcu_segcblist_pend_cbs(&sdp->srcu_cblist)) { - spin_unlock_irqrestore_rcu_node(sdp, flags); + raw_spin_unlock_irqrestore_rcu_node(sdp, flags); return false; /* Callbacks already present, so not idle. */ } - spin_unlock_irqrestore_rcu_node(sdp, flags); + raw_spin_unlock_irqrestore_rcu_node(sdp, flags); /* * No local callbacks, so probabilistically probe global state. @@ -1350,7 +1314,7 @@ static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp, sdp = per_cpu_ptr(ssp->sda, get_boot_cpu_id()); else sdp = raw_cpu_ptr(ssp->sda); - spin_lock_irqsave_sdp_contention(sdp, &flags); + raw_spin_lock_irqsave_sdp_contention(sdp, &flags); if (rhp) rcu_segcblist_enqueue(&sdp->srcu_cblist, rhp); /* @@ -1410,7 +1374,7 @@ static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp, sdp->srcu_gp_seq_needed_exp = s; needexp = true; } - spin_unlock_irqrestore_rcu_node(sdp, flags); + raw_spin_unlock_irqrestore_rcu_node(sdp, flags); /* Ensure that snp node tree is fully initialized before traversing it */ if (ss_state < SRCU_SIZE_WAIT_BARRIER) @@ -1522,7 +1486,7 @@ static void __synchronize_srcu(struct srcu_struct *ssp, bool do_norm) /* * Make sure that later code is ordered after the SRCU grace - * period. This pairs with the spin_lock_irq_rcu_node() + * period. This pairs with the raw_spin_lock_irq_rcu_node() * in srcu_invoke_callbacks(). Unlike Tree RCU, this is needed * because the current CPU might have been totally uninvolved with * (and thus unordered against) that grace period. @@ -1701,7 +1665,7 @@ static void srcu_barrier_cb(struct rcu_head *rhp) */ static void srcu_barrier_one_cpu(struct srcu_struct *ssp, struct srcu_data *sdp) { - spin_lock_irq_rcu_node(sdp); + raw_spin_lock_irq_rcu_node(sdp); atomic_inc(&ssp->srcu_sup->srcu_barrier_cpu_cnt); sdp->srcu_barrier_head.func = srcu_barrier_cb; debug_rcu_head_queue(&sdp->srcu_barrier_head); @@ -1710,7 +1674,7 @@ static void srcu_barrier_one_cpu(struct srcu_struct *ssp, struct srcu_data *sdp) debug_rcu_head_unqueue(&sdp->srcu_barrier_head); atomic_dec(&ssp->srcu_sup->srcu_barrier_cpu_cnt); } - spin_unlock_irq_rcu_node(sdp); + raw_spin_unlock_irq_rcu_node(sdp); } /** @@ -1761,7 +1725,7 @@ static void srcu_expedite_current_cb(struct rcu_head *rhp) bool needcb = false; struct srcu_data *sdp = container_of(rhp, struct srcu_data, srcu_ec_head); - spin_lock_irqsave_sdp_contention(sdp, &flags); + raw_spin_lock_irqsave_sdp_contention(sdp, &flags); if (sdp->srcu_ec_state == SRCU_EC_IDLE) { WARN_ON_ONCE(1); } else if (sdp->srcu_ec_state == SRCU_EC_PENDING) { @@ -1771,7 +1735,7 @@ static void srcu_expedite_current_cb(struct rcu_head *rhp) sdp->srcu_ec_state = SRCU_EC_PENDING; needcb = true; } - spin_unlock_irqrestore_rcu_node(sdp, flags); + raw_spin_unlock_irqrestore_rcu_node(sdp, flags); // If needed, requeue ourselves as an expedited SRCU callback. if (needcb) __call_srcu(sdp->ssp, &sdp->srcu_ec_head, srcu_expedite_current_cb, false); @@ -1795,7 +1759,7 @@ void srcu_expedite_current(struct srcu_struct *ssp) migrate_disable(); sdp = this_cpu_ptr(ssp->sda); - spin_lock_irqsave_sdp_contention(sdp, &flags); + raw_spin_lock_irqsave_sdp_contention(sdp, &flags); if (sdp->srcu_ec_state == SRCU_EC_IDLE) { sdp->srcu_ec_state = SRCU_EC_PENDING; needcb = true; @@ -1804,7 +1768,7 @@ void srcu_expedite_current(struct srcu_struct *ssp) } else { WARN_ON_ONCE(sdp->srcu_ec_state != SRCU_EC_REPOST); } - spin_unlock_irqrestore_rcu_node(sdp, flags); + raw_spin_unlock_irqrestore_rcu_node(sdp, flags); // If needed, queue an expedited SRCU callback. if (needcb) __call_srcu(ssp, &sdp->srcu_ec_head, srcu_expedite_current_cb, false); @@ -1848,17 +1812,17 @@ static void srcu_advance_state(struct srcu_struct *ssp) */ idx = rcu_seq_state(smp_load_acquire(&ssp->srcu_sup->srcu_gp_seq)); /* ^^^ */ if (idx == SRCU_STATE_IDLE) { - spin_lock_irq_rcu_node(ssp->srcu_sup); + raw_spin_lock_irq_rcu_node(ssp->srcu_sup); if (ULONG_CMP_GE(ssp->srcu_sup->srcu_gp_seq, ssp->srcu_sup->srcu_gp_seq_needed)) { WARN_ON_ONCE(rcu_seq_state(ssp->srcu_sup->srcu_gp_seq)); - spin_unlock_irq_rcu_node(ssp->srcu_sup); + raw_spin_unlock_irq_rcu_node(ssp->srcu_sup); mutex_unlock(&ssp->srcu_sup->srcu_gp_mutex); return; } idx = rcu_seq_state(READ_ONCE(ssp->srcu_sup->srcu_gp_seq)); if (idx == SRCU_STATE_IDLE) srcu_gp_start(ssp); - spin_unlock_irq_rcu_node(ssp->srcu_sup); + raw_spin_unlock_irq_rcu_node(ssp->srcu_sup); if (idx != SRCU_STATE_IDLE) { mutex_unlock(&ssp->srcu_sup->srcu_gp_mutex); return; /* Someone else started the grace period. */ @@ -1872,10 +1836,10 @@ static void srcu_advance_state(struct srcu_struct *ssp) return; /* readers present, retry later. */ } srcu_flip(ssp); - spin_lock_irq_rcu_node(ssp->srcu_sup); + raw_spin_lock_irq_rcu_node(ssp->srcu_sup); rcu_seq_set_state(&ssp->srcu_sup->srcu_gp_seq, SRCU_STATE_SCAN2); ssp->srcu_sup->srcu_n_exp_nodelay = 0; - spin_unlock_irq_rcu_node(ssp->srcu_sup); + raw_spin_unlock_irq_rcu_node(ssp->srcu_sup); } if (rcu_seq_state(READ_ONCE(ssp->srcu_sup->srcu_gp_seq)) == SRCU_STATE_SCAN2) { @@ -1913,7 +1877,7 @@ static void srcu_invoke_callbacks(struct work_struct *work) ssp = sdp->ssp; rcu_cblist_init(&ready_cbs); - spin_lock_irq_rcu_node(sdp); + raw_spin_lock_irq_rcu_node(sdp); WARN_ON_ONCE(!rcu_segcblist_segempty(&sdp->srcu_cblist, RCU_NEXT_TAIL)); rcu_segcblist_advance(&sdp->srcu_cblist, rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq)); @@ -1924,7 +1888,7 @@ static void srcu_invoke_callbacks(struct work_struct *work) */ if (sdp->srcu_cblist_invoking || !rcu_segcblist_ready_cbs(&sdp->srcu_cblist)) { - spin_unlock_irq_rcu_node(sdp); + raw_spin_unlock_irq_rcu_node(sdp); return; /* Someone else on the job or nothing to do. */ } @@ -1932,7 +1896,7 @@ static void srcu_invoke_callbacks(struct work_struct *work) sdp->srcu_cblist_invoking = true; rcu_segcblist_extract_done_cbs(&sdp->srcu_cblist, &ready_cbs); len = ready_cbs.len; - spin_unlock_irq_rcu_node(sdp); + raw_spin_unlock_irq_rcu_node(sdp); rhp = rcu_cblist_dequeue(&ready_cbs); for (; rhp != NULL; rhp = rcu_cblist_dequeue(&ready_cbs)) { debug_rcu_head_unqueue(rhp); @@ -1947,11 +1911,11 @@ static void srcu_invoke_callbacks(struct work_struct *work) * Update counts, accelerate new callbacks, and if needed, * schedule another round of callback invocation. */ - spin_lock_irq_rcu_node(sdp); + raw_spin_lock_irq_rcu_node(sdp); rcu_segcblist_add_len(&sdp->srcu_cblist, -len); sdp->srcu_cblist_invoking = false; more = rcu_segcblist_ready_cbs(&sdp->srcu_cblist); - spin_unlock_irq_rcu_node(sdp); + raw_spin_unlock_irq_rcu_node(sdp); /* An SRCU barrier or callbacks from previous nesting work pending */ if (more) srcu_schedule_cbs_sdp(sdp, 0); @@ -1965,7 +1929,7 @@ static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay) { bool pushgp = true; - spin_lock_irq_rcu_node(ssp->srcu_sup); + raw_spin_lock_irq_rcu_node(ssp->srcu_sup); if (ULONG_CMP_GE(ssp->srcu_sup->srcu_gp_seq, ssp->srcu_sup->srcu_gp_seq_needed)) { if (!WARN_ON_ONCE(rcu_seq_state(ssp->srcu_sup->srcu_gp_seq))) { /* All requests fulfilled, time to go idle. */ @@ -1975,7 +1939,7 @@ static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay) /* Outstanding request and no GP. Start one. */ srcu_gp_start(ssp); } - spin_unlock_irq_rcu_node(ssp->srcu_sup); + raw_spin_unlock_irq_rcu_node(ssp->srcu_sup); if (pushgp) queue_delayed_work(rcu_gp_wq, &ssp->srcu_sup->work, delay); @@ -1995,9 +1959,9 @@ static void process_srcu(struct work_struct *work) ssp = sup->srcu_ssp; srcu_advance_state(ssp); - spin_lock_irq_rcu_node(ssp->srcu_sup); + raw_spin_lock_irq_rcu_node(ssp->srcu_sup); curdelay = srcu_get_delay(ssp); - spin_unlock_irq_rcu_node(ssp->srcu_sup); + raw_spin_unlock_irq_rcu_node(ssp->srcu_sup); if (curdelay) { WRITE_ONCE(sup->reschedule_count, 0); } else { -- cgit v1.2.3 From 7c405fb3279b39244b260b54f1bd6488689ae235 Mon Sep 17 00:00:00 2001 From: Boqun Feng Date: Wed, 18 Mar 2026 17:56:21 -0700 Subject: rcu: Use an intermediate irq_work to start process_srcu() Since commit c27cea4416a3 ("rcu: Re-implement RCU Tasks Trace in terms of SRCU-fast") we switched to SRCU in BPF. However as BPF instrument can happen basically everywhere (including where a scheduler lock is held), call_srcu() now needs to avoid acquiring scheduler lock because otherwise it could cause deadlock [1]. Fix this by following what the previous RCU Tasks Trace did: using an irq_work to delay the queuing of the work to start process_srcu(). [boqun: Apply Joel's feedback] [boqun: Apply Andrea's test feedback] Reported-by: Andrea Righi Closes: https://lore.kernel.org/all/abjzvz_tL_siV17s@gpd4/ Fixes: commit c27cea4416a3 ("rcu: Re-implement RCU Tasks Trace in terms of SRCU-fast") Link: https://lore.kernel.org/rcu/3c4c5a29-24ea-492d-aeee-e0d9605b4183@nvidia.com/ [1] Suggested-by: Zqiang Tested-by: Andrea Righi Tested-by: Paul E. McKenney Tested-by: Joel Fernandes Signed-off-by: Boqun Feng --- include/linux/srcutree.h | 1 + kernel/rcu/srcutree.c | 30 ++++++++++++++++++++++++++++-- 2 files changed, 29 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index dfb31d11ff05..be76fa4fc170 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -95,6 +95,7 @@ struct srcu_usage { unsigned long reschedule_jiffies; unsigned long reschedule_count; struct delayed_work work; + struct irq_work irq_work; struct srcu_struct *srcu_ssp; }; diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c index 678bd9a73875..0d01cd8c4b4a 100644 --- a/kernel/rcu/srcutree.c +++ b/kernel/rcu/srcutree.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -75,6 +76,7 @@ static bool __read_mostly srcu_init_done; static void srcu_invoke_callbacks(struct work_struct *work); static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay); static void process_srcu(struct work_struct *work); +static void srcu_irq_work(struct irq_work *work); static void srcu_delay_timer(struct timer_list *t); /* @@ -216,6 +218,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static) mutex_init(&ssp->srcu_sup->srcu_barrier_mutex); atomic_set(&ssp->srcu_sup->srcu_barrier_cpu_cnt, 0); INIT_DELAYED_WORK(&ssp->srcu_sup->work, process_srcu); + init_irq_work(&ssp->srcu_sup->irq_work, srcu_irq_work); ssp->srcu_sup->sda_is_static = is_static; if (!is_static) { ssp->sda = alloc_percpu(struct srcu_data); @@ -716,6 +719,8 @@ void cleanup_srcu_struct(struct srcu_struct *ssp) return; /* Just leak it! */ if (WARN_ON(srcu_readers_active(ssp))) return; /* Just leak it! */ + /* Wait for irq_work to finish first as it may queue a new work. */ + irq_work_sync(&sup->irq_work); flush_delayed_work(&sup->work); for_each_possible_cpu(cpu) { struct srcu_data *sdp = per_cpu_ptr(ssp->sda, cpu); @@ -1121,9 +1126,13 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp, // it isn't. And it does not have to be. After all, it // can only be executed during early boot when there is only // the one boot CPU running with interrupts still disabled. + // + // Use an irq_work here to avoid acquiring runqueue lock with + // srcu rcu_node::lock held. BPF instrument could introduce the + // opposite dependency, hence we need to break the possible + // locking dependency here. if (likely(srcu_init_done)) - queue_delayed_work(rcu_gp_wq, &sup->work, - !!srcu_get_delay(ssp)); + irq_work_queue(&sup->irq_work); else if (list_empty(&sup->work.work.entry)) list_add(&sup->work.work.entry, &srcu_boot_list); } @@ -1982,6 +1991,23 @@ static void process_srcu(struct work_struct *work) srcu_reschedule(ssp, curdelay); } +static void srcu_irq_work(struct irq_work *work) +{ + struct srcu_struct *ssp; + struct srcu_usage *sup; + unsigned long delay; + unsigned long flags; + + sup = container_of(work, struct srcu_usage, irq_work); + ssp = sup->srcu_ssp; + + raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags); + delay = srcu_get_delay(ssp); + raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags); + + queue_delayed_work(rcu_gp_wq, &sup->work, !!delay); +} + void srcutorture_get_gp_data(struct srcu_struct *ssp, int *flags, unsigned long *gp_seq) { -- cgit v1.2.3 From a6fc88b22bc8d12ad52e8412c667ec0f5bf055af Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Mon, 23 Mar 2026 20:14:18 -0400 Subject: srcu: Use irq_work to start GP in tiny SRCU Tiny SRCU's srcu_gp_start_if_needed() directly calls schedule_work(), which acquires the workqueue pool->lock. This causes a lockdep splat when call_srcu() is called with a scheduler lock held, due to: call_srcu() [holding pi_lock] srcu_gp_start_if_needed() schedule_work() -> pool->lock workqueue_init() / create_worker() [holding pool->lock] wake_up_process() -> try_to_wake_up() -> pi_lock Also add irq_work_sync() to cleanup_srcu_struct() to prevent a use-after-free if a queued irq_work fires after cleanup begins. Tested with rcutorture SRCU-T and no lockdep warnings. [ Thanks to Boqun for similar fix in patch "rcu: Use an intermediate irq_work to start process_srcu()" ] Signed-off-by: Joel Fernandes Reviewed-by: Paul E. McKenney Signed-off-by: Boqun Feng --- include/linux/srcutiny.h | 4 ++++ kernel/rcu/srcutiny.c | 19 ++++++++++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h index dec7cbe015aa..905b629e8fa3 100644 --- a/include/linux/srcutiny.h +++ b/include/linux/srcutiny.h @@ -11,6 +11,7 @@ #ifndef _LINUX_SRCU_TINY_H #define _LINUX_SRCU_TINY_H +#include #include struct srcu_struct { @@ -24,18 +25,21 @@ struct srcu_struct { struct rcu_head *srcu_cb_head; /* Pending callbacks: Head. */ struct rcu_head **srcu_cb_tail; /* Pending callbacks: Tail. */ struct work_struct srcu_work; /* For driving grace periods. */ + struct irq_work srcu_irq_work; /* Defer schedule_work() to irq work. */ #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; #endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */ }; void srcu_drive_gp(struct work_struct *wp); +void srcu_tiny_irq_work(struct irq_work *irq_work); #define __SRCU_STRUCT_INIT(name, __ignored, ___ignored, ____ignored) \ { \ .srcu_wq = __SWAIT_QUEUE_HEAD_INITIALIZER(name.srcu_wq), \ .srcu_cb_tail = &name.srcu_cb_head, \ .srcu_work = __WORK_INITIALIZER(name.srcu_work, srcu_drive_gp), \ + .srcu_irq_work = { .func = srcu_tiny_irq_work }, \ __SRCU_DEP_MAP_INIT(name) \ } diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c index 3450c3751ef7..a2e2d516e51b 100644 --- a/kernel/rcu/srcutiny.c +++ b/kernel/rcu/srcutiny.c @@ -9,6 +9,7 @@ */ #include +#include #include #include #include @@ -41,6 +42,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp) ssp->srcu_idx_max = 0; INIT_WORK(&ssp->srcu_work, srcu_drive_gp); INIT_LIST_HEAD(&ssp->srcu_work.entry); + init_irq_work(&ssp->srcu_irq_work, srcu_tiny_irq_work); return 0; } @@ -84,6 +86,7 @@ EXPORT_SYMBOL_GPL(init_srcu_struct); void cleanup_srcu_struct(struct srcu_struct *ssp) { WARN_ON(ssp->srcu_lock_nesting[0] || ssp->srcu_lock_nesting[1]); + irq_work_sync(&ssp->srcu_irq_work); flush_work(&ssp->srcu_work); WARN_ON(ssp->srcu_gp_running); WARN_ON(ssp->srcu_gp_waiting); @@ -177,6 +180,20 @@ void srcu_drive_gp(struct work_struct *wp) } EXPORT_SYMBOL_GPL(srcu_drive_gp); +/* + * Use an irq_work to defer schedule_work() to avoid acquiring the workqueue + * pool->lock while the caller might hold scheduler locks, causing lockdep + * splats due to workqueue_init() doing a wakeup. + */ +void srcu_tiny_irq_work(struct irq_work *irq_work) +{ + struct srcu_struct *ssp; + + ssp = container_of(irq_work, struct srcu_struct, srcu_irq_work); + schedule_work(&ssp->srcu_work); +} +EXPORT_SYMBOL_GPL(srcu_tiny_irq_work); + static void srcu_gp_start_if_needed(struct srcu_struct *ssp) { unsigned long cookie; @@ -189,7 +206,7 @@ static void srcu_gp_start_if_needed(struct srcu_struct *ssp) WRITE_ONCE(ssp->srcu_idx_max, cookie); if (!READ_ONCE(ssp->srcu_gp_running)) { if (likely(srcu_init_done)) - schedule_work(&ssp->srcu_work); + irq_work_queue(&ssp->srcu_irq_work); else if (list_empty(&ssp->srcu_work.entry)) list_add(&ssp->srcu_work.entry, &srcu_boot_list); } -- cgit v1.2.3 From 0e764b9d46071668969410ec5429be0e2f38c6d3 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 25 Mar 2026 08:20:17 +0000 Subject: netfs: Fix the handling of stream->front by removing it The netfs_io_stream::front member is meant to point to the subrequest currently being collected on a stream, but it isn't actually used this way by direct write (which mostly ignores it). However, there's a tracepoint which looks at it. Further, stream->front is actually redundant with stream->subrequests.next. Fix the potential problem in the direct code by just removing the member and using stream->subrequests.next instead, thereby also simplifying the code. Fixes: a0b4c7a49137 ("netfs: Fix unbuffered/DIO writes to dispatch subrequests in strict sequence") Reported-by: Paulo Alcantara Signed-off-by: David Howells Link: https://patch.msgid.link/4158599.1774426817@warthog.procyon.org.uk Reviewed-by: Paulo Alcantara (Red Hat) cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner --- fs/netfs/buffered_read.c | 3 +-- fs/netfs/direct_read.c | 3 +-- fs/netfs/direct_write.c | 1 - fs/netfs/read_collect.c | 4 ++-- fs/netfs/read_single.c | 1 - fs/netfs/write_collect.c | 4 ++-- fs/netfs/write_issue.c | 3 +-- include/linux/netfs.h | 1 - include/trace/events/netfs.h | 8 ++++---- 9 files changed, 11 insertions(+), 17 deletions(-) (limited to 'include/linux') diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c index 88a0d801525f..a8c0d86118c5 100644 --- a/fs/netfs/buffered_read.c +++ b/fs/netfs/buffered_read.c @@ -171,9 +171,8 @@ static void netfs_queue_read(struct netfs_io_request *rreq, spin_lock(&rreq->lock); list_add_tail(&subreq->rreq_link, &stream->subrequests); if (list_is_first(&subreq->rreq_link, &stream->subrequests)) { - stream->front = subreq; if (!stream->active) { - stream->collected_to = stream->front->start; + stream->collected_to = subreq->start; /* Store list pointers before active flag */ smp_store_release(&stream->active, true); } diff --git a/fs/netfs/direct_read.c b/fs/netfs/direct_read.c index a498ee8d6674..f72e6da88cca 100644 --- a/fs/netfs/direct_read.c +++ b/fs/netfs/direct_read.c @@ -71,9 +71,8 @@ static int netfs_dispatch_unbuffered_reads(struct netfs_io_request *rreq) spin_lock(&rreq->lock); list_add_tail(&subreq->rreq_link, &stream->subrequests); if (list_is_first(&subreq->rreq_link, &stream->subrequests)) { - stream->front = subreq; if (!stream->active) { - stream->collected_to = stream->front->start; + stream->collected_to = subreq->start; /* Store list pointers before active flag */ smp_store_release(&stream->active, true); } diff --git a/fs/netfs/direct_write.c b/fs/netfs/direct_write.c index 4d9760e36c11..f9ab69de3e29 100644 --- a/fs/netfs/direct_write.c +++ b/fs/netfs/direct_write.c @@ -111,7 +111,6 @@ static int netfs_unbuffered_write(struct netfs_io_request *wreq) netfs_prepare_write(wreq, stream, wreq->start + wreq->transferred); subreq = stream->construct; stream->construct = NULL; - stream->front = NULL; } /* Check if (re-)preparation failed. */ diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c index 137f0e28a44c..e5f6665b3341 100644 --- a/fs/netfs/read_collect.c +++ b/fs/netfs/read_collect.c @@ -205,7 +205,8 @@ reassess: * in progress. The issuer thread may be adding stuff to the tail * whilst we're doing this. */ - front = READ_ONCE(stream->front); + front = list_first_entry_or_null(&stream->subrequests, + struct netfs_io_subrequest, rreq_link); while (front) { size_t transferred; @@ -301,7 +302,6 @@ reassess: list_del_init(&front->rreq_link); front = list_first_entry_or_null(&stream->subrequests, struct netfs_io_subrequest, rreq_link); - stream->front = front; spin_unlock(&rreq->lock); netfs_put_subrequest(remove, notes & ABANDON_SREQ ? diff --git a/fs/netfs/read_single.c b/fs/netfs/read_single.c index 8e6264f62a8f..d0e23bc42445 100644 --- a/fs/netfs/read_single.c +++ b/fs/netfs/read_single.c @@ -107,7 +107,6 @@ static int netfs_single_dispatch_read(struct netfs_io_request *rreq) spin_lock(&rreq->lock); list_add_tail(&subreq->rreq_link, &stream->subrequests); trace_netfs_sreq(subreq, netfs_sreq_trace_added); - stream->front = subreq; /* Store list pointers before active flag */ smp_store_release(&stream->active, true); spin_unlock(&rreq->lock); diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c index 83eb3dc1adf8..b194447f4b11 100644 --- a/fs/netfs/write_collect.c +++ b/fs/netfs/write_collect.c @@ -228,7 +228,8 @@ reassess_streams: if (!smp_load_acquire(&stream->active)) continue; - front = stream->front; + front = list_first_entry_or_null(&stream->subrequests, + struct netfs_io_subrequest, rreq_link); while (front) { trace_netfs_collect_sreq(wreq, front); //_debug("sreq [%x] %llx %zx/%zx", @@ -279,7 +280,6 @@ reassess_streams: list_del_init(&front->rreq_link); front = list_first_entry_or_null(&stream->subrequests, struct netfs_io_subrequest, rreq_link); - stream->front = front; spin_unlock(&wreq->lock); netfs_put_subrequest(remove, notes & SAW_FAILURE ? diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c index 437268f65640..2db688f94125 100644 --- a/fs/netfs/write_issue.c +++ b/fs/netfs/write_issue.c @@ -206,9 +206,8 @@ void netfs_prepare_write(struct netfs_io_request *wreq, spin_lock(&wreq->lock); list_add_tail(&subreq->rreq_link, &stream->subrequests); if (list_is_first(&subreq->rreq_link, &stream->subrequests)) { - stream->front = subreq; if (!stream->active) { - stream->collected_to = stream->front->start; + stream->collected_to = subreq->start; /* Write list pointers before active flag */ smp_store_release(&stream->active, true); } diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 72ee7d210a74..ba17ac5bf356 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -140,7 +140,6 @@ struct netfs_io_stream { void (*issue_write)(struct netfs_io_subrequest *subreq); /* Collection tracking */ struct list_head subrequests; /* Contributory I/O operations */ - struct netfs_io_subrequest *front; /* Op being collected */ unsigned long long collected_to; /* Position we've collected results to */ size_t transferred; /* The amount transferred from this stream */ unsigned short error; /* Aggregate error for the stream */ diff --git a/include/trace/events/netfs.h b/include/trace/events/netfs.h index 2d366be46a1c..cbe28211106c 100644 --- a/include/trace/events/netfs.h +++ b/include/trace/events/netfs.h @@ -740,19 +740,19 @@ TRACE_EVENT(netfs_collect_stream, __field(unsigned int, wreq) __field(unsigned char, stream) __field(unsigned long long, collected_to) - __field(unsigned long long, front) + __field(unsigned long long, issued_to) ), TP_fast_assign( __entry->wreq = wreq->debug_id; __entry->stream = stream->stream_nr; __entry->collected_to = stream->collected_to; - __entry->front = stream->front ? stream->front->start : UINT_MAX; + __entry->issued_to = atomic64_read(&wreq->issued_to); ), - TP_printk("R=%08x[%x:] cto=%llx frn=%llx", + TP_printk("R=%08x[%x:] cto=%llx ito=%llx", __entry->wreq, __entry->stream, - __entry->collected_to, __entry->front) + __entry->collected_to, __entry->issued_to) ); TRACE_EVENT(netfs_folioq, -- cgit v1.2.3 From 190a8c48ff623c3d67cb295b4536a660db2012aa Mon Sep 17 00:00:00 2001 From: Hao-Yu Yang Date: Fri, 13 Mar 2026 20:47:56 +0800 Subject: futex: Fix UaF between futex_key_to_node_opt() and vma_replace_policy() During futex_key_to_node_opt() execution, vma->vm_policy is read under speculative mmap lock and RCU. Concurrently, mbind() may call vma_replace_policy() which frees the old mempolicy immediately via kmem_cache_free(). This creates a race where __futex_key_to_node() dereferences a freed mempolicy pointer, causing a use-after-free read of mpol->mode. [ 151.412631] BUG: KASAN: slab-use-after-free in __futex_key_to_node (kernel/futex/core.c:349) [ 151.414046] Read of size 2 at addr ffff888001c49634 by task e/87 [ 151.415969] Call Trace: [ 151.416732] __asan_load2 (mm/kasan/generic.c:271) [ 151.416777] __futex_key_to_node (kernel/futex/core.c:349) [ 151.416822] get_futex_key (kernel/futex/core.c:374 kernel/futex/core.c:386 kernel/futex/core.c:593) Fix by adding rcu to __mpol_put(). Fixes: c042c505210d ("futex: Implement FUTEX2_MPOL") Reported-by: Hao-Yu Yang Suggested-by: Eric Dumazet Signed-off-by: Hao-Yu Yang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Eric Dumazet Acked-by: David Hildenbrand (Arm) Link: https://patch.msgid.link/20260324174418.GB1850007@noisy.programming.kicks-ass.net --- include/linux/mempolicy.h | 1 + kernel/futex/core.c | 2 +- mm/mempolicy.c | 10 ++++++++-- 3 files changed, 10 insertions(+), 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h index 0fe96f3ab3ef..65c732d440d2 100644 --- a/include/linux/mempolicy.h +++ b/include/linux/mempolicy.h @@ -55,6 +55,7 @@ struct mempolicy { nodemask_t cpuset_mems_allowed; /* relative to these nodes */ nodemask_t user_nodemask; /* nodemask passed by user */ } w; + struct rcu_head rcu; }; /* diff --git a/kernel/futex/core.c b/kernel/futex/core.c index cf7e610eac42..31e83a09789e 100644 --- a/kernel/futex/core.c +++ b/kernel/futex/core.c @@ -342,7 +342,7 @@ static int __futex_key_to_node(struct mm_struct *mm, unsigned long addr) if (!vma) return FUTEX_NO_NODE; - mpol = vma_policy(vma); + mpol = READ_ONCE(vma->vm_policy); if (!mpol) return FUTEX_NO_NODE; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 0e5175f1c767..cf92bd6a8226 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -487,7 +487,13 @@ void __mpol_put(struct mempolicy *pol) { if (!atomic_dec_and_test(&pol->refcnt)) return; - kmem_cache_free(policy_cache, pol); + /* + * Required to allow mmap_lock_speculative*() access, see for example + * futex_key_to_node_opt(). All accesses are serialized by mmap_lock, + * however the speculative lock section unbound by the normal lock + * boundaries, requiring RCU freeing. + */ + kfree_rcu(pol, rcu); } EXPORT_SYMBOL_FOR_MODULES(__mpol_put, "kvm"); @@ -1020,7 +1026,7 @@ static int vma_replace_policy(struct vm_area_struct *vma, } old = vma->vm_policy; - vma->vm_policy = new; /* protected by mmap_lock */ + WRITE_ONCE(vma->vm_policy, new); /* protected by mmap_lock */ mpol_put(old); return 0; -- cgit v1.2.3 From 4c5e7f0fcd592801c9cc18f29f80fbee84eb8669 Mon Sep 17 00:00:00 2001 From: Jinjiang Tu Date: Thu, 19 Mar 2026 09:25:41 +0800 Subject: mm/huge_memory: fix folio isn't locked in softleaf_to_folio() On arm64 server, we found folio that get from migration entry isn't locked in softleaf_to_folio(). This issue triggers when mTHP splitting and zap_nonpresent_ptes() races, and the root cause is lack of memory barrier in softleaf_to_folio(). The race is as follows: CPU0 CPU1 deferred_split_scan() zap_nonpresent_ptes() lock folio split_folio() unmap_folio() change ptes to migration entries __split_folio_to_order() softleaf_to_folio() set flags(including PG_locked) for tail pages folio = pfn_folio(softleaf_to_pfn(entry)) smp_wmb() VM_WARN_ON_ONCE(!folio_test_locked(folio)) prep_compound_page() for tail pages In __split_folio_to_order(), smp_wmb() guarantees page flags of tail pages are visible before the tail page becomes non-compound. smp_wmb() should be paired with smp_rmb() in softleaf_to_folio(), which is missed. As a result, if zap_nonpresent_ptes() accesses migration entry that stores tail pfn, softleaf_to_folio() may see the updated compound_head of tail page before page->flags. This issue will trigger VM_WARN_ON_ONCE() in pfn_swap_entry_folio() because of the race between folio split and zap_nonpresent_ptes() leading to a folio incorrectly undergoing modification without a folio lock being held. This is a BUG_ON() before commit 93976a20345b ("mm: eliminate further swapops predicates"), which in merged in v6.19-rc1. To fix it, add missing smp_rmb() if the softleaf entry is migration entry in softleaf_to_folio() and softleaf_to_page(). [tujinjiang@huawei.com: update function name and comments] Link: https://lkml.kernel.org/r/20260321075214.3305564-1-tujinjiang@huawei.com Link: https://lkml.kernel.org/r/20260319012541.4158561-1-tujinjiang@huawei.com Fixes: e9b61f19858a ("thp: reintroduce split_huge_page()") Signed-off-by: Jinjiang Tu Acked-by: David Hildenbrand (Arm) Reviewed-by: Lorenzo Stoakes (Oracle) Cc: Barry Song Cc: Kefeng Wang Cc: Liam Howlett Cc: Michal Hocko Cc: Mike Rapoport Cc: Nanyong Sun Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton --- include/linux/leafops.h | 32 +++++++++++++++++++++----------- 1 file changed, 21 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/leafops.h b/include/linux/leafops.h index a9ff94b744f2..05673d3529e7 100644 --- a/include/linux/leafops.h +++ b/include/linux/leafops.h @@ -363,6 +363,23 @@ static inline unsigned long softleaf_to_pfn(softleaf_t entry) return swp_offset(entry) & SWP_PFN_MASK; } +static inline void softleaf_migration_sync(softleaf_t entry, + struct folio *folio) +{ + /* + * Ensure we do not race with split, which might alter tail pages into new + * folios and thus result in observing an unlocked folio. + * This matches the write barrier in __split_folio_to_order(). + */ + smp_rmb(); + + /* + * Any use of migration entries may only occur while the + * corresponding page is locked + */ + VM_WARN_ON_ONCE(!folio_test_locked(folio)); +} + /** * softleaf_to_page() - Obtains struct page for PFN encoded within leaf entry. * @entry: Leaf entry, softleaf_has_pfn(@entry) must return true. @@ -374,11 +391,8 @@ static inline struct page *softleaf_to_page(softleaf_t entry) struct page *page = pfn_to_page(softleaf_to_pfn(entry)); VM_WARN_ON_ONCE(!softleaf_has_pfn(entry)); - /* - * Any use of migration entries may only occur while the - * corresponding page is locked - */ - VM_WARN_ON_ONCE(softleaf_is_migration(entry) && !PageLocked(page)); + if (softleaf_is_migration(entry)) + softleaf_migration_sync(entry, page_folio(page)); return page; } @@ -394,12 +408,8 @@ static inline struct folio *softleaf_to_folio(softleaf_t entry) struct folio *folio = pfn_folio(softleaf_to_pfn(entry)); VM_WARN_ON_ONCE(!softleaf_has_pfn(entry)); - /* - * Any use of migration entries may only occur while the - * corresponding folio is locked. - */ - VM_WARN_ON_ONCE(softleaf_is_migration(entry) && - !folio_test_locked(folio)); + if (softleaf_is_migration(entry)) + softleaf_migration_sync(entry, folio); return folio; } -- cgit v1.2.3