From 7c527c15cdda2e0a26a05ac15a44d3e14738fc55 Mon Sep 17 00:00:00 2001 From: Takashi Sakamoto Date: Sun, 3 Aug 2025 21:20:12 +0900 Subject: firewire: core: use reference counting to invoke address handlers safely The lifetime of address handler has been managed by linked list and RCU. This approach was introduced in commit 35202f7d8420 ("firewire: remove global lock around address handlers, convert to RCU"). The invocations of address handler are performed within RCU read-side critical sections. In commit 57e6d9f85fff ("firewire: ohci: use workqueue to handle events of AR request/response contexts"), the invocations are in a workqueue context. The approach still imposes limitation that sleeping is not allowed within RCU read-side critical sections. However, since sleeping is not permitted within RCU read-side critical sections, this approach still has a limitation. This commit adds reference counting to decouple handler invocation from handler discovery. The linked list and RCU is used to discover the handlers, while the reference counting is used to invoke them safely. Link: https://lore.kernel.org/r/20250803122015.236493-2-o-takashi@sakamocchi.jp Signed-off-by: Takashi Sakamoto --- include/linux/firewire.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/firewire.h b/include/linux/firewire.h index cceb70415ed2..d38c6e538e5c 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -341,7 +341,11 @@ struct fw_address_handler { u64 length; fw_address_callback_t address_callback; void *callback_data; + + // Only for core functions. struct list_head link; + struct kref kref; + struct completion done; }; struct fw_address_region { -- cgit v1.2.3 From 2c223f7239f376a90d71903ec474ba887cf21d94 Mon Sep 17 00:00:00 2001 From: Oreoluwa Babatunde Date: Wed, 6 Aug 2025 10:24:21 -0700 Subject: of: reserved_mem: Restructure call site for dma_contiguous_early_fixup() Restructure the call site for dma_contiguous_early_fixup() to where the reserved_mem nodes are being parsed from the DT so that dma_mmu_remap[] is populated before dma_contiguous_remap() is called. Fixes: 8a6e02d0c00e ("of: reserved_mem: Restructure how the reserved memory regions are processed") Signed-off-by: Oreoluwa Babatunde Tested-by: William Zhang Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20250806172421.2748302-1-oreoluwa.babatunde@oss.qualcomm.com --- drivers/of/of_reserved_mem.c | 16 ++++++++++++---- include/linux/dma-map-ops.h | 3 +++ kernel/dma/contiguous.c | 2 -- 3 files changed, 15 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 77016c0cc296..7350b23cb734 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -25,6 +25,7 @@ #include #include #include +#include #include "of_private.h" @@ -175,13 +176,17 @@ static int __init __reserved_mem_reserve_reg(unsigned long node, base = dt_mem_next_cell(dt_root_addr_cells, &prop); size = dt_mem_next_cell(dt_root_size_cells, &prop); - if (size && - early_init_dt_reserve_memory(base, size, nomap) == 0) + if (size && early_init_dt_reserve_memory(base, size, nomap) == 0) { + /* Architecture specific contiguous memory fixup. */ + if (of_flat_dt_is_compatible(node, "shared-dma-pool") && + of_get_flat_dt_prop(node, "reusable", NULL)) + dma_contiguous_early_fixup(base, size); pr_debug("Reserved memory: reserved region for node '%s': base %pa, size %lu MiB\n", uname, &base, (unsigned long)(size / SZ_1M)); - else + } else { pr_err("Reserved memory: failed to reserve memory for node '%s': base %pa, size %lu MiB\n", uname, &base, (unsigned long)(size / SZ_1M)); + } len -= t_len; } @@ -472,7 +477,10 @@ static int __init __reserved_mem_alloc_size(unsigned long node, const char *unam uname, (unsigned long)(size / SZ_1M)); return -ENOMEM; } - + /* Architecture specific contiguous memory fixup. */ + if (of_flat_dt_is_compatible(node, "shared-dma-pool") && + of_get_flat_dt_prop(node, "reusable", NULL)) + dma_contiguous_early_fixup(base, size); /* Save region in the reserved_mem array */ fdt_reserved_mem_save_node(node, uname, base, size); return 0; diff --git a/include/linux/dma-map-ops.h b/include/linux/dma-map-ops.h index f48e5fb88bd5..332b80c42b6f 100644 --- a/include/linux/dma-map-ops.h +++ b/include/linux/dma-map-ops.h @@ -153,6 +153,9 @@ static inline void dma_free_contiguous(struct device *dev, struct page *page, { __free_pages(page, get_order(size)); } +static inline void dma_contiguous_early_fixup(phys_addr_t base, unsigned long size) +{ +} #endif /* CONFIG_DMA_CMA*/ #ifdef CONFIG_DMA_DECLARE_COHERENT diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index 67af8a55185d..d9b9dcba6ff7 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -483,8 +483,6 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) pr_err("Reserved memory: unable to setup CMA region\n"); return err; } - /* Architecture specific contiguous memory fixup. */ - dma_contiguous_early_fixup(rmem->base, rmem->size); if (default_cma) dma_contiguous_default_area = cma; -- cgit v1.2.3 From 6d3c3ca4c77e93660cce5819bf707f75df03e0c8 Mon Sep 17 00:00:00 2001 From: Vlastimil Babka Date: Fri, 8 Aug 2025 15:28:47 +0200 Subject: module: Rename EXPORT_SYMBOL_GPL_FOR_MODULES to EXPORT_SYMBOL_FOR_MODULES Christoph suggested that the explicit _GPL_ can be dropped from the module namespace export macro, as it's intended for in-tree modules only. It would be possible to restrict it technically, but it was pointed out [2] that some cases of using an out-of-tree build of an in-tree module with the same name are legitimate. But in that case those also have to be GPL anyway so it's unnecessary to spell it out in the macro name. Link: https://lore.kernel.org/all/aFleJN_fE-RbSoFD@infradead.org/ [1] Link: https://lore.kernel.org/all/CAK7LNATRkZHwJGpojCnvdiaoDnP%2BaeUXgdey5sb_8muzdWTMkA@mail.gmail.com/ [2] Suggested-by: Christoph Hellwig Reviewed-by: Shivank Garg Acked-by: David Hildenbrand Acked-by: Nicolas Schier Reviewed-by: Daniel Gomez Reviewed-by: Christian Brauner Signed-off-by: Vlastimil Babka Link: https://lore.kernel.org/20250808-export_modules-v4-1-426945bcc5e1@suse.cz Signed-off-by: Christian Brauner --- Documentation/core-api/symbol-namespaces.rst | 11 ++++++----- drivers/tty/serial/8250/8250_rsa.c | 8 ++++---- fs/anon_inodes.c | 2 +- include/linux/export.h | 2 +- 4 files changed, 12 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/Documentation/core-api/symbol-namespaces.rst b/Documentation/core-api/symbol-namespaces.rst index 32fc73dc5529..034898e81ba2 100644 --- a/Documentation/core-api/symbol-namespaces.rst +++ b/Documentation/core-api/symbol-namespaces.rst @@ -76,20 +76,21 @@ unit as preprocessor statement. The above example would then read:: within the corresponding compilation unit before the #include for . Typically it's placed before the first #include statement. -Using the EXPORT_SYMBOL_GPL_FOR_MODULES() macro ------------------------------------------------ +Using the EXPORT_SYMBOL_FOR_MODULES() macro +------------------------------------------- Symbols exported using this macro are put into a module namespace. This -namespace cannot be imported. +namespace cannot be imported. These exports are GPL-only as they are only +intended for in-tree modules. The macro takes a comma separated list of module names, allowing only those modules to access this symbol. Simple tail-globs are supported. For example:: - EXPORT_SYMBOL_GPL_FOR_MODULES(preempt_notifier_inc, "kvm,kvm-*") + EXPORT_SYMBOL_FOR_MODULES(preempt_notifier_inc, "kvm,kvm-*") -will limit usage of this symbol to modules whoes name matches the given +will limit usage of this symbol to modules whose name matches the given patterns. How to use Symbols exported in Namespaces diff --git a/drivers/tty/serial/8250/8250_rsa.c b/drivers/tty/serial/8250/8250_rsa.c index d34093cc03ad..12a65b79583c 100644 --- a/drivers/tty/serial/8250/8250_rsa.c +++ b/drivers/tty/serial/8250/8250_rsa.c @@ -147,7 +147,7 @@ void rsa_enable(struct uart_8250_port *up) if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) serial_out(up, UART_RSA_FRR, 0); } -EXPORT_SYMBOL_GPL_FOR_MODULES(rsa_enable, "8250_base"); +EXPORT_SYMBOL_FOR_MODULES(rsa_enable, "8250_base"); /* * Attempts to turn off the RSA FIFO and resets the RSA board back to 115kbps compat mode. It is @@ -179,7 +179,7 @@ void rsa_disable(struct uart_8250_port *up) up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16; uart_port_unlock_irq(&up->port); } -EXPORT_SYMBOL_GPL_FOR_MODULES(rsa_disable, "8250_base"); +EXPORT_SYMBOL_FOR_MODULES(rsa_disable, "8250_base"); void rsa_autoconfig(struct uart_8250_port *up) { @@ -192,7 +192,7 @@ void rsa_autoconfig(struct uart_8250_port *up) if (__rsa_enable(up)) up->port.type = PORT_RSA; } -EXPORT_SYMBOL_GPL_FOR_MODULES(rsa_autoconfig, "8250_base"); +EXPORT_SYMBOL_FOR_MODULES(rsa_autoconfig, "8250_base"); void rsa_reset(struct uart_8250_port *up) { @@ -201,7 +201,7 @@ void rsa_reset(struct uart_8250_port *up) serial_out(up, UART_RSA_FRR, 0); } -EXPORT_SYMBOL_GPL_FOR_MODULES(rsa_reset, "8250_base"); +EXPORT_SYMBOL_FOR_MODULES(rsa_reset, "8250_base"); #ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS #ifndef MODULE diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c index 1d847a939f29..180a458fc4f7 100644 --- a/fs/anon_inodes.c +++ b/fs/anon_inodes.c @@ -129,7 +129,7 @@ struct inode *anon_inode_make_secure_inode(struct super_block *sb, const char *n } return inode; } -EXPORT_SYMBOL_GPL_FOR_MODULES(anon_inode_make_secure_inode, "kvm"); +EXPORT_SYMBOL_FOR_MODULES(anon_inode_make_secure_inode, "kvm"); static struct file *__anon_inode_getfile(const char *name, const struct file_operations *fops, diff --git a/include/linux/export.h b/include/linux/export.h index f35d03b4113b..a686fd0ba406 100644 --- a/include/linux/export.h +++ b/include/linux/export.h @@ -91,6 +91,6 @@ #define EXPORT_SYMBOL_NS(sym, ns) __EXPORT_SYMBOL(sym, "", ns) #define EXPORT_SYMBOL_NS_GPL(sym, ns) __EXPORT_SYMBOL(sym, "GPL", ns) -#define EXPORT_SYMBOL_GPL_FOR_MODULES(sym, mods) __EXPORT_SYMBOL(sym, "GPL", "module:" mods) +#define EXPORT_SYMBOL_FOR_MODULES(sym, mods) __EXPORT_SYMBOL(sym, "GPL", "module:" mods) #endif /* _LINUX_EXPORT_H */ -- cgit v1.2.3 From 5634c8cb298a7146b4e38873473e280b50e27a2c Mon Sep 17 00:00:00 2001 From: Nitin Gote Date: Fri, 18 Jul 2025 16:20:51 +0530 Subject: iosys-map: Fix undefined behavior in iosys_map_clear() The current iosys_map_clear() implementation reads the potentially uninitialized 'is_iomem' boolean field to decide which union member to clear. This causes undefined behavior when called on uninitialized structures, as 'is_iomem' may contain garbage values like 0xFF. UBSAN detects this as: UBSAN: invalid-load in include/linux/iosys-map.h:267 load of value 255 is not a valid value for type '_Bool' Fix by unconditionally clearing the entire structure with memset(), eliminating the need to read uninitialized data and ensuring all fields are set to known good values. Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14639 Fixes: 01fd30da0474 ("dma-buf: Add struct dma-buf-map for storing struct dma_buf.vaddr_ptr") Signed-off-by: Nitin Gote Reviewed-by: Andi Shyti Reviewed-by: Thomas Zimmermann Signed-off-by: Thomas Zimmermann Link: https://lore.kernel.org/r/20250718105051.2709487-1-nitin.r.gote@intel.com --- include/linux/iosys-map.h | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/iosys-map.h b/include/linux/iosys-map.h index 4696abfd311c..3e85afe794c0 100644 --- a/include/linux/iosys-map.h +++ b/include/linux/iosys-map.h @@ -264,12 +264,7 @@ static inline bool iosys_map_is_set(const struct iosys_map *map) */ static inline void iosys_map_clear(struct iosys_map *map) { - if (map->is_iomem) { - map->vaddr_iomem = NULL; - map->is_iomem = false; - } else { - map->vaddr = NULL; - } + memset(map, 0, sizeof(*map)); } /** -- cgit v1.2.3 From ccba9f6baa900e31ad1a4c36e6f3c176694f9eac Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 8 Aug 2025 17:12:04 -0700 Subject: net: update NAPI threaded config even for disabled NAPIs We have to make sure that all future NAPIs will have the right threaded state when the state is configured on the device level. We chose not to have an "unset" state for threaded, and not to wipe the NAPI config clean when channels are explicitly disabled. This means the persistent config structs "exist" even when their NAPIs are not instantiated. Differently put - the NAPI persistent state lives in the net_device (ncfg == struct napi_config): ,--- [napi 0] - [napi 1] [dev] | | `--- [ncfg 0] - [ncfg 1] so say we a device with 2 queues but only 1 enabled: ,--- [napi 0] [dev] | `--- [ncfg 0] - [ncfg 1] now we set the device to threaded=1: ,---------- [napi 0 (thr:1)] [dev(thr:1)] | `---------- [ncfg 0 (thr:1)] - [ncfg 1 (thr:?)] Since [ncfg 1] was not attached to a NAPI during configuration we skipped it. If we create a NAPI for it later it will have the old setting (presumably disabled). One could argue if this is right or not "in principle", but it's definitely not how things worked before per-NAPI config.. Fixes: 2677010e7793 ("Add support to set NAPI threaded for individual NAPI") Signed-off-by: Jakub Kicinski Reviewed-by: Joe Damato Link: https://patch.msgid.link/20250809001205.1147153-3-kuba@kernel.org Signed-off-by: Paolo Abeni --- include/linux/netdevice.h | 5 ++++- net/core/dev.c | 7 ++++++- 2 files changed, 10 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 5e5de4b0a433..f3a3b761abfb 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2071,6 +2071,8 @@ enum netdev_reg_state { * @max_pacing_offload_horizon: max EDT offload horizon in nsec. * @napi_config: An array of napi_config structures containing per-NAPI * settings. + * @num_napi_configs: number of allocated NAPI config structs, + * always >= max(num_rx_queues, num_tx_queues). * @gro_flush_timeout: timeout for GRO layer in NAPI * @napi_defer_hard_irqs: If not zero, provides a counter that would * allow to avoid NIC hard IRQ, on busy queues. @@ -2482,8 +2484,9 @@ struct net_device { u64 max_pacing_offload_horizon; struct napi_config *napi_config; - unsigned long gro_flush_timeout; + u32 num_napi_configs; u32 napi_defer_hard_irqs; + unsigned long gro_flush_timeout; /** * @up: copy of @state's IFF_UP, but safe to read with just @lock. diff --git a/net/core/dev.c b/net/core/dev.c index 68dc47d7e700..f180746382a1 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -6999,7 +6999,7 @@ int netif_set_threaded(struct net_device *dev, enum netdev_napi_threaded threaded) { struct napi_struct *napi; - int err = 0; + int i, err = 0; netdev_assert_locked_or_invisible(dev); @@ -7021,6 +7021,10 @@ int netif_set_threaded(struct net_device *dev, list_for_each_entry(napi, &dev->napi_list, dev_list) WARN_ON_ONCE(napi_set_threaded(napi, threaded)); + /* Override the config for all NAPIs even if currently not listed */ + for (i = 0; i < dev->num_napi_configs; i++) + dev->napi_config[i].threaded = threaded; + return err; } @@ -11873,6 +11877,7 @@ struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name, goto free_all; dev->cfg_pending = dev->cfg; + dev->num_napi_configs = maxqs; napi_config_sz = array_size(maxqs, sizeof(*dev->napi_config)); dev->napi_config = kvzalloc(napi_config_sz, GFP_KERNEL_ACCOUNT); if (!dev->napi_config) -- cgit v1.2.3 From 21924af67d69d7c9fdaf845be69043cfe75196a1 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Tue, 5 Aug 2025 00:10:02 +0000 Subject: locking: Fix __clear_task_blocked_on() warning from __ww_mutex_wound() path The __clear_task_blocked_on() helper added a number of sanity checks ensuring we hold the mutex wait lock and that the task we are clearing blocked_on pointer (if set) matches the mutex. However, there is an edge case in the _ww_mutex_wound() logic where we need to clear the blocked_on pointer for the task that owns the mutex, not the task that is waiting on the mutex. For this case the sanity checks aren't valid, so handle this by allowing a NULL lock to skip the additional checks. K Prateek Nayak and Maarten Lankhorst also pointed out that in this case where we don't hold the owner's mutex wait_lock, we need to be a bit more careful using READ_ONCE/WRITE_ONCE in both the __clear_task_blocked_on() and __set_task_blocked_on() implementations to avoid accidentally tripping WARN_ONs if two instances race. So do that here as well. This issue was easier to miss, I realized, as the test-ww_mutex driver only exercises the wait-die class of ww_mutexes. I've sent a patch[1] to address this so the logic will be easier to test. [1]: https://lore.kernel.org/lkml/20250801023358.562525-2-jstultz@google.com/ Fixes: a4f0b6fef4b0 ("locking/mutex: Add p->blocked_on wrappers for correctness checks") Closes: https://lore.kernel.org/lkml/68894443.a00a0220.26d0e1.0015.GAE@google.com/ Reported-by: syzbot+602c4720aed62576cd79@syzkaller.appspotmail.com Reported-by: Maarten Lankhorst Signed-off-by: John Stultz Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: K Prateek Nayak Acked-by: Maarten Lankhorst Tested-by: K Prateek Nayak Link: https://lore.kernel.org/r/20250805001026.2247040-1-jstultz@google.com --- include/linux/sched.h | 29 +++++++++++++++++------------ kernel/locking/ww_mutex.h | 6 +++++- 2 files changed, 22 insertions(+), 13 deletions(-) (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index 40d2fa90df42..62103dd6a48e 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2144,6 +2144,8 @@ static inline struct mutex *__get_task_blocked_on(struct task_struct *p) static inline void __set_task_blocked_on(struct task_struct *p, struct mutex *m) { + struct mutex *blocked_on = READ_ONCE(p->blocked_on); + WARN_ON_ONCE(!m); /* The task should only be setting itself as blocked */ WARN_ON_ONCE(p != current); @@ -2154,8 +2156,8 @@ static inline void __set_task_blocked_on(struct task_struct *p, struct mutex *m) * with a different mutex. Note, setting it to the same * lock repeatedly is ok. */ - WARN_ON_ONCE(p->blocked_on && p->blocked_on != m); - p->blocked_on = m; + WARN_ON_ONCE(blocked_on && blocked_on != m); + WRITE_ONCE(p->blocked_on, m); } static inline void set_task_blocked_on(struct task_struct *p, struct mutex *m) @@ -2166,16 +2168,19 @@ static inline void set_task_blocked_on(struct task_struct *p, struct mutex *m) static inline void __clear_task_blocked_on(struct task_struct *p, struct mutex *m) { - WARN_ON_ONCE(!m); - /* Currently we serialize blocked_on under the mutex::wait_lock */ - lockdep_assert_held_once(&m->wait_lock); - /* - * There may be cases where we re-clear already cleared - * blocked_on relationships, but make sure we are not - * clearing the relationship with a different lock. - */ - WARN_ON_ONCE(m && p->blocked_on && p->blocked_on != m); - p->blocked_on = NULL; + if (m) { + struct mutex *blocked_on = READ_ONCE(p->blocked_on); + + /* Currently we serialize blocked_on under the mutex::wait_lock */ + lockdep_assert_held_once(&m->wait_lock); + /* + * There may be cases where we re-clear already cleared + * blocked_on relationships, but make sure we are not + * clearing the relationship with a different lock. + */ + WARN_ON_ONCE(blocked_on && blocked_on != m); + } + WRITE_ONCE(p->blocked_on, NULL); } static inline void clear_task_blocked_on(struct task_struct *p, struct mutex *m) diff --git a/kernel/locking/ww_mutex.h b/kernel/locking/ww_mutex.h index 086fd5487ca7..31a785afee6c 100644 --- a/kernel/locking/ww_mutex.h +++ b/kernel/locking/ww_mutex.h @@ -342,8 +342,12 @@ static bool __ww_mutex_wound(struct MUTEX *lock, * When waking up the task to wound, be sure to clear the * blocked_on pointer. Otherwise we can see circular * blocked_on relationships that can't resolve. + * + * NOTE: We pass NULL here instead of lock, because we + * are waking the mutex owner, who may be currently + * blocked on a different mutex. */ - __clear_task_blocked_on(owner, lock); + __clear_task_blocked_on(owner, NULL); wake_q_add(wake_q, owner); } return true; -- cgit v1.2.3 From 9528d32873b38281ae105f2f5799e79ae9d086c2 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 11 Aug 2025 10:27:45 +0200 Subject: kcov, usb: Don't disable interrupts in kcov_remote_start_usb_softirq() kcov_remote_start_usb_softirq() the begin of urb's completion callback. HCDs marked HCD_BH will invoke this function from the softirq and in_serving_softirq() will detect this properly. Root-HUB (RH) requests will not be delayed to softirq but complete immediately in IRQ context. This will confuse kcov because in_serving_softirq() will report true if the softirq is served after the hardirq and if the softirq got interrupted by the hardirq in which currently runs. This was addressed by simply disabling interrupts in kcov_remote_start_usb_softirq() which avoided the interruption by the RH while a regular completion callback was invoked. This not only changes the behaviour while kconv is enabled but also breaks PREEMPT_RT because now sleeping locks can no longer be acquired. Revert the previous fix. Address the issue by invoking kcov_remote_start_usb() only if the context is just "serving softirqs" which is identified by checking in_serving_softirq() and in_hardirq() must be false. Fixes: f85d39dd7ed89 ("kcov, usb: disable interrupts in kcov_remote_start_usb_softirq") Cc: stable Reported-by: Yunseong Kim Closes: https://lore.kernel.org/all/20250725201400.1078395-2-ysk@kzalloc.com/ Tested-by: Yunseong Kim Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20250811082745.ycJqBXMs@linutronix.de Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 12 +++++------- include/linux/kcov.h | 47 +++++++++-------------------------------------- 2 files changed, 14 insertions(+), 45 deletions(-) (limited to 'include/linux') diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index c4a1875b5d3d..6270fbb5c699 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1636,7 +1636,6 @@ static void __usb_hcd_giveback_urb(struct urb *urb) struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus); struct usb_anchor *anchor = urb->anchor; int status = urb->unlinked; - unsigned long flags; urb->hcpriv = NULL; if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) && @@ -1654,14 +1653,13 @@ static void __usb_hcd_giveback_urb(struct urb *urb) /* pass ownership to the completion handler */ urb->status = status; /* - * Only collect coverage in the softirq context and disable interrupts - * to avoid scenarios with nested remote coverage collection sections - * that KCOV does not support. - * See the comment next to kcov_remote_start_usb_softirq() for details. + * This function can be called in task context inside another remote + * coverage collection section, but kcov doesn't support that kind of + * recursion yet. Only collect coverage in softirq context for now. */ - flags = kcov_remote_start_usb_softirq((u64)urb->dev->bus->busnum); + kcov_remote_start_usb_softirq((u64)urb->dev->bus->busnum); urb->complete(urb); - kcov_remote_stop_softirq(flags); + kcov_remote_stop_softirq(); usb_anchor_resume_wakeups(anchor); atomic_dec(&urb->use_count); diff --git a/include/linux/kcov.h b/include/linux/kcov.h index 75a2fb8b16c3..0143358874b0 100644 --- a/include/linux/kcov.h +++ b/include/linux/kcov.h @@ -57,47 +57,21 @@ static inline void kcov_remote_start_usb(u64 id) /* * The softirq flavor of kcov_remote_*() functions is introduced as a temporary - * workaround for KCOV's lack of nested remote coverage sections support. - * - * Adding support is tracked in https://bugzilla.kernel.org/show_bug.cgi?id=210337. - * - * kcov_remote_start_usb_softirq(): - * - * 1. Only collects coverage when called in the softirq context. This allows - * avoiding nested remote coverage collection sections in the task context. - * For example, USB/IP calls usb_hcd_giveback_urb() in the task context - * within an existing remote coverage collection section. Thus, KCOV should - * not attempt to start collecting coverage within the coverage collection - * section in __usb_hcd_giveback_urb() in this case. - * - * 2. Disables interrupts for the duration of the coverage collection section. - * This allows avoiding nested remote coverage collection sections in the - * softirq context (a softirq might occur during the execution of a work in - * the BH workqueue, which runs with in_serving_softirq() > 0). - * For example, usb_giveback_urb_bh() runs in the BH workqueue with - * interrupts enabled, so __usb_hcd_giveback_urb() might be interrupted in - * the middle of its remote coverage collection section, and the interrupt - * handler might invoke __usb_hcd_giveback_urb() again. + * work around for kcov's lack of nested remote coverage sections support in + * task context. Adding support for nested sections is tracked in: + * https://bugzilla.kernel.org/show_bug.cgi?id=210337 */ -static inline unsigned long kcov_remote_start_usb_softirq(u64 id) +static inline void kcov_remote_start_usb_softirq(u64 id) { - unsigned long flags = 0; - - if (in_serving_softirq()) { - local_irq_save(flags); + if (in_serving_softirq() && !in_hardirq()) kcov_remote_start_usb(id); - } - - return flags; } -static inline void kcov_remote_stop_softirq(unsigned long flags) +static inline void kcov_remote_stop_softirq(void) { - if (in_serving_softirq()) { + if (in_serving_softirq() && !in_hardirq()) kcov_remote_stop(); - local_irq_restore(flags); - } } #ifdef CONFIG_64BIT @@ -131,11 +105,8 @@ static inline u64 kcov_common_handle(void) } static inline void kcov_remote_start_common(u64 id) {} static inline void kcov_remote_start_usb(u64 id) {} -static inline unsigned long kcov_remote_start_usb_softirq(u64 id) -{ - return 0; -} -static inline void kcov_remote_stop_softirq(unsigned long flags) {} +static inline void kcov_remote_start_usb_softirq(u64 id) {} +static inline void kcov_remote_stop_softirq(void) {} #endif /* CONFIG_KCOV */ #endif /* _LINUX_KCOV_H */ -- cgit v1.2.3 From a3de58b12ce074ec05b8741fa28d62ccb1070468 Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 14 Aug 2025 22:45:50 +0100 Subject: netfs: Fix unbuffered write error handling If all the subrequests in an unbuffered write stream fail, the subrequest collector doesn't update the stream->transferred value and it retains its initial LONG_MAX value. Unfortunately, if all active streams fail, then we take the smallest value of { LONG_MAX, LONG_MAX, ... } as the value to set in wreq->transferred - which is then returned from ->write_iter(). LONG_MAX was chosen as the initial value so that all the streams can be quickly assessed by taking the smallest value of all stream->transferred - but this only works if we've set any of them. Fix this by adding a flag to indicate whether the value in stream->transferred is valid and checking that when we integrate the values. stream->transferred can then be initialised to zero. This was found by running the generic/750 xfstest against cifs with cache=none. It splices data to the target file. Once (if) it has used up all the available scratch space, the writes start failing with ENOSPC. This causes ->write_iter() to fail. However, it was returning wreq->transferred, i.e. LONG_MAX, rather than an error (because it thought the amount transferred was non-zero) and iter_file_splice_write() would then try to clean up that amount of pipe bufferage - leading to an oops when it overran. The kernel log showed: CIFS: VFS: Send error in write = -28 followed by: BUG: kernel NULL pointer dereference, address: 0000000000000008 with: RIP: 0010:iter_file_splice_write+0x3a4/0x520 do_splice+0x197/0x4e0 or: RIP: 0010:pipe_buf_release (include/linux/pipe_fs_i.h:282) iter_file_splice_write (fs/splice.c:755) Also put a warning check into splice to announce if ->write_iter() returned that it had written more than it was asked to. Fixes: 288ace2f57c9 ("netfs: New writeback implementation") Reported-by: Xiaoli Feng Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220445 Signed-off-by: David Howells Link: https://lore.kernel.org/915443.1755207950@warthog.procyon.org.uk cc: Paulo Alcantara cc: Steve French cc: Shyam Prasad N cc: netfs@lists.linux.dev cc: linux-cifs@vger.kernel.org cc: linux-fsdevel@vger.kernel.org cc: stable@vger.kernel.org Signed-off-by: Christian Brauner --- fs/netfs/read_collect.c | 4 +++- fs/netfs/write_collect.c | 10 ++++++++-- fs/netfs/write_issue.c | 4 ++-- fs/splice.c | 3 +++ include/linux/netfs.h | 1 + 5 files changed, 17 insertions(+), 5 deletions(-) (limited to 'include/linux') diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c index 3e804da1e1eb..a95e7aadafd0 100644 --- a/fs/netfs/read_collect.c +++ b/fs/netfs/read_collect.c @@ -281,8 +281,10 @@ reassess: } else if (test_bit(NETFS_RREQ_SHORT_TRANSFER, &rreq->flags)) { notes |= MADE_PROGRESS; } else { - if (!stream->failed) + if (!stream->failed) { stream->transferred += transferred; + stream->transferred_valid = true; + } if (front->transferred < front->len) set_bit(NETFS_RREQ_SHORT_TRANSFER, &rreq->flags); notes |= MADE_PROGRESS; diff --git a/fs/netfs/write_collect.c b/fs/netfs/write_collect.c index 0f3a36852a4d..cbf3d9194c7b 100644 --- a/fs/netfs/write_collect.c +++ b/fs/netfs/write_collect.c @@ -254,6 +254,7 @@ reassess_streams: if (front->start + front->transferred > stream->collected_to) { stream->collected_to = front->start + front->transferred; stream->transferred = stream->collected_to - wreq->start; + stream->transferred_valid = true; notes |= MADE_PROGRESS; } if (test_bit(NETFS_SREQ_FAILED, &front->flags)) { @@ -356,6 +357,7 @@ bool netfs_write_collection(struct netfs_io_request *wreq) { struct netfs_inode *ictx = netfs_inode(wreq->inode); size_t transferred; + bool transferred_valid = false; int s; _enter("R=%x", wreq->debug_id); @@ -376,12 +378,16 @@ bool netfs_write_collection(struct netfs_io_request *wreq) continue; if (!list_empty(&stream->subrequests)) return false; - if (stream->transferred < transferred) + if (stream->transferred_valid && + stream->transferred < transferred) { transferred = stream->transferred; + transferred_valid = true; + } } /* Okay, declare that all I/O is complete. */ - wreq->transferred = transferred; + if (transferred_valid) + wreq->transferred = transferred; trace_netfs_rreq(wreq, netfs_rreq_trace_write_done); if (wreq->io_streams[1].active && diff --git a/fs/netfs/write_issue.c b/fs/netfs/write_issue.c index 50bee2c4130d..0584cba1a043 100644 --- a/fs/netfs/write_issue.c +++ b/fs/netfs/write_issue.c @@ -118,12 +118,12 @@ struct netfs_io_request *netfs_create_write_req(struct address_space *mapping, wreq->io_streams[0].prepare_write = ictx->ops->prepare_write; wreq->io_streams[0].issue_write = ictx->ops->issue_write; wreq->io_streams[0].collected_to = start; - wreq->io_streams[0].transferred = LONG_MAX; + wreq->io_streams[0].transferred = 0; wreq->io_streams[1].stream_nr = 1; wreq->io_streams[1].source = NETFS_WRITE_TO_CACHE; wreq->io_streams[1].collected_to = start; - wreq->io_streams[1].transferred = LONG_MAX; + wreq->io_streams[1].transferred = 0; if (fscache_resources_valid(&wreq->cache_resources)) { wreq->io_streams[1].avail = true; wreq->io_streams[1].active = true; diff --git a/fs/splice.c b/fs/splice.c index 4d6df083e0c0..f5094b6d00a0 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -739,6 +739,9 @@ iter_file_splice_write(struct pipe_inode_info *pipe, struct file *out, sd.pos = kiocb.ki_pos; if (ret <= 0) break; + WARN_ONCE(ret > sd.total_len - left, + "Splice Exceeded! ret=%zd tot=%zu left=%zu\n", + ret, sd.total_len, left); sd.num_spliced += ret; sd.total_len -= ret; diff --git a/include/linux/netfs.h b/include/linux/netfs.h index 185bd8196503..98c96d649bf9 100644 --- a/include/linux/netfs.h +++ b/include/linux/netfs.h @@ -150,6 +150,7 @@ struct netfs_io_stream { bool active; /* T if stream is active */ bool need_retry; /* T if this stream needs retrying */ bool failed; /* T if this stream failed */ + bool transferred_valid; /* T is ->transferred is valid */ }; /* -- cgit v1.2.3 From a032fe30cf09b6723ab61a05aee057311b00f9e1 Mon Sep 17 00:00:00 2001 From: Dongcheng Yan Date: Fri, 25 Apr 2025 18:43:30 +0800 Subject: platform/x86: int3472: add hpd pin support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Typically HDMI to MIPI CSI-2 bridges have a pin to signal image data is being received. On the host side this is wired to a GPIO for polling or interrupts. This includes the Lontium HDMI to MIPI CSI-2 bridges lt6911uxe and lt6911uxc. The GPIO "hpd" is used already by other HDMI to CSI-2 bridges, use it here as well. Signed-off-by: Dongcheng Yan Reviewed-by: Sakari Ailus Acked-by: Ilpo Järvinen Reviewed-by: Hans de Goede Reviewed-by: Andy Shevchenko Fixes: 20244cbafbd6 ("media: i2c: change lt6911uxe irq_gpio name to "hpd"") Cc: stable@vger.kernel.org Signed-off-by: Sakari Ailus Signed-off-by: Hans Verkuil --- drivers/platform/x86/intel/int3472/discrete.c | 6 ++++++ include/linux/platform_data/x86/int3472.h | 1 + 2 files changed, 7 insertions(+) (limited to 'include/linux') diff --git a/drivers/platform/x86/intel/int3472/discrete.c b/drivers/platform/x86/intel/int3472/discrete.c index 4c0aed6e626f..bdfb8a800c54 100644 --- a/drivers/platform/x86/intel/int3472/discrete.c +++ b/drivers/platform/x86/intel/int3472/discrete.c @@ -193,6 +193,10 @@ static void int3472_get_con_id_and_polarity(struct int3472_discrete_device *int3 *con_id = "privacy-led"; *gpio_flags = GPIO_ACTIVE_HIGH; break; + case INT3472_GPIO_TYPE_HOTPLUG_DETECT: + *con_id = "hpd"; + *gpio_flags = GPIO_ACTIVE_HIGH; + break; case INT3472_GPIO_TYPE_POWER_ENABLE: *con_id = "avdd"; *gpio_flags = GPIO_ACTIVE_HIGH; @@ -223,6 +227,7 @@ static void int3472_get_con_id_and_polarity(struct int3472_discrete_device *int3 * 0x0b Power enable * 0x0c Clock enable * 0x0d Privacy LED + * 0x13 Hotplug detect * * There are some known platform specific quirks where that does not quite * hold up; for example where a pin with type 0x01 (Power down) is mapped to @@ -292,6 +297,7 @@ static int skl_int3472_handle_gpio_resources(struct acpi_resource *ares, switch (type) { case INT3472_GPIO_TYPE_RESET: case INT3472_GPIO_TYPE_POWERDOWN: + case INT3472_GPIO_TYPE_HOTPLUG_DETECT: ret = skl_int3472_map_gpio_to_sensor(int3472, agpio, con_id, gpio_flags); if (ret) err_msg = "Failed to map GPIO pin to sensor\n"; diff --git a/include/linux/platform_data/x86/int3472.h b/include/linux/platform_data/x86/int3472.h index 78276a11c48d..1571e9157fa5 100644 --- a/include/linux/platform_data/x86/int3472.h +++ b/include/linux/platform_data/x86/int3472.h @@ -27,6 +27,7 @@ #define INT3472_GPIO_TYPE_CLK_ENABLE 0x0c #define INT3472_GPIO_TYPE_PRIVACY_LED 0x0d #define INT3472_GPIO_TYPE_HANDSHAKE 0x12 +#define INT3472_GPIO_TYPE_HOTPLUG_DETECT 0x13 #define INT3472_PDEV_MAX_NAME_LEN 23 #define INT3472_MAX_SENSOR_GPIOS 3 -- cgit v1.2.3 From 8ea815399c3fcce1889bd951fec25b5b9a3979c1 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 14 Apr 2025 16:41:07 +0200 Subject: compiler: remove __ADDRESSABLE_ASM{_STR,}() again __ADDRESSABLE_ASM_STR() is where the necessary stringification happens. As long as "sym" doesn't contain any odd characters, no quoting is required for its use with .quad / .long. In fact the quotation gets in the way with gas 2.25; it's only from 2.26 onwards that quoted symbols are half-way properly supported. However, assembly being different from C anyway, drop __ADDRESSABLE_ASM_STR() and its helper macro altogether. A simple .global directive will suffice to get the symbol "declared", i.e. into the symbol table. While there also stop open-coding STATIC_CALL_TRAMP() and STATIC_CALL_KEY(). Fixes: 0ef8047b737d ("x86/static-call: provide a way to do very early static-call updates") Signed-off-by: Jan Beulich Acked-by: Josh Poimboeuf Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross Message-ID: <609d2c74-de13-4fae-ab1a-1ec44afb948d@suse.com> --- arch/x86/include/asm/xen/hypercall.h | 5 +++-- include/linux/compiler.h | 8 -------- 2 files changed, 3 insertions(+), 10 deletions(-) (limited to 'include/linux') diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h index 59a62c3780a2..a16d4631547c 100644 --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -94,12 +94,13 @@ DECLARE_STATIC_CALL(xen_hypercall, xen_hypercall_func); #ifdef MODULE #define __ADDRESSABLE_xen_hypercall #else -#define __ADDRESSABLE_xen_hypercall __ADDRESSABLE_ASM_STR(__SCK__xen_hypercall) +#define __ADDRESSABLE_xen_hypercall \ + __stringify(.global STATIC_CALL_KEY(xen_hypercall);) #endif #define __HYPERCALL \ __ADDRESSABLE_xen_hypercall \ - "call __SCT__xen_hypercall" + __stringify(call STATIC_CALL_TRAMP(xen_hypercall)) #define __HYPERCALL_ENTRY(x) "a" (x) diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 6f04a1d8c720..64ff73c533e5 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -288,14 +288,6 @@ static inline void *offset_to_ptr(const int *off) #define __ADDRESSABLE(sym) \ ___ADDRESSABLE(sym, __section(".discard.addressable")) -#define __ADDRESSABLE_ASM(sym) \ - .pushsection .discard.addressable,"aw"; \ - .align ARCH_SEL(8,4); \ - ARCH_SEL(.quad, .long) __stringify(sym); \ - .popsection; - -#define __ADDRESSABLE_ASM_STR(sym) __stringify(__ADDRESSABLE_ASM(sym)) - /* * This returns a constant expression while determining if an argument is * a constant expression, most importantly without evaluating the argument. -- cgit v1.2.3 From 76d2e3890fb169168c73f2e4f8375c7cc24a765e Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sat, 16 Aug 2025 07:25:20 -0700 Subject: NFS: Fix a race when updating an existing write After nfs_lock_and_join_requests() tests for whether the request is still attached to the mapping, nothing prevents a call to nfs_inode_remove_request() from succeeding until we actually lock the page group. The reason is that whoever called nfs_inode_remove_request() doesn't necessarily have a lock on the page group head. So in order to avoid races, let's take the page group lock earlier in nfs_lock_and_join_requests(), and hold it across the removal of the request in nfs_inode_remove_request(). Reported-by: Jeff Layton Tested-by: Joe Quanaim Tested-by: Andrew Steffen Reviewed-by: Jeff Layton Fixes: bd37d6fce184 ("NFSv4: Convert nfs_lock_and_join_requests() to use nfs_page_find_head_request()") Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust --- fs/nfs/pagelist.c | 9 +++++---- fs/nfs/write.c | 29 ++++++++++------------------- include/linux/nfs_page.h | 1 + 3 files changed, 16 insertions(+), 23 deletions(-) (limited to 'include/linux') diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c index 11968dcb7243..6e69ce43a13f 100644 --- a/fs/nfs/pagelist.c +++ b/fs/nfs/pagelist.c @@ -253,13 +253,14 @@ nfs_page_group_unlock(struct nfs_page *req) nfs_page_clear_headlock(req); } -/* - * nfs_page_group_sync_on_bit_locked +/** + * nfs_page_group_sync_on_bit_locked - Test if all requests have @bit set + * @req: request in page group + * @bit: PG_* bit that is used to sync page group * * must be called with page group lock held */ -static bool -nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit) +bool nfs_page_group_sync_on_bit_locked(struct nfs_page *req, unsigned int bit) { struct nfs_page *head = req->wb_head; struct nfs_page *tmp; diff --git a/fs/nfs/write.c b/fs/nfs/write.c index fa5c41d0989a..8b7c04737967 100644 --- a/fs/nfs/write.c +++ b/fs/nfs/write.c @@ -153,20 +153,10 @@ nfs_page_set_inode_ref(struct nfs_page *req, struct inode *inode) } } -static int -nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode) +static void nfs_cancel_remove_inode(struct nfs_page *req, struct inode *inode) { - int ret; - - if (!test_bit(PG_REMOVE, &req->wb_flags)) - return 0; - ret = nfs_page_group_lock(req); - if (ret) - return ret; if (test_and_clear_bit(PG_REMOVE, &req->wb_flags)) nfs_page_set_inode_ref(req, inode); - nfs_page_group_unlock(req); - return 0; } /** @@ -585,19 +575,18 @@ retry: } } + ret = nfs_page_group_lock(head); + if (ret < 0) + goto out_unlock; + /* Ensure that nobody removed the request before we locked it */ if (head != folio->private) { + nfs_page_group_unlock(head); nfs_unlock_and_release_request(head); goto retry; } - ret = nfs_cancel_remove_inode(head, inode); - if (ret < 0) - goto out_unlock; - - ret = nfs_page_group_lock(head); - if (ret < 0) - goto out_unlock; + nfs_cancel_remove_inode(head, inode); /* lock each request in the page group */ for (subreq = head->wb_this_page; @@ -786,7 +775,8 @@ static void nfs_inode_remove_request(struct nfs_page *req) { struct nfs_inode *nfsi = NFS_I(nfs_page_to_inode(req)); - if (nfs_page_group_sync_on_bit(req, PG_REMOVE)) { + nfs_page_group_lock(req); + if (nfs_page_group_sync_on_bit_locked(req, PG_REMOVE)) { struct folio *folio = nfs_page_to_folio(req->wb_head); struct address_space *mapping = folio->mapping; @@ -798,6 +788,7 @@ static void nfs_inode_remove_request(struct nfs_page *req) } spin_unlock(&mapping->i_private_lock); } + nfs_page_group_unlock(req); if (test_and_clear_bit(PG_INODE_REF, &req->wb_flags)) { atomic_long_dec(&nfsi->nrequests); diff --git a/include/linux/nfs_page.h b/include/linux/nfs_page.h index 169b4ae30ff4..9aed39abc94b 100644 --- a/include/linux/nfs_page.h +++ b/include/linux/nfs_page.h @@ -160,6 +160,7 @@ extern void nfs_join_page_group(struct nfs_page *head, extern int nfs_page_group_lock(struct nfs_page *); extern void nfs_page_group_unlock(struct nfs_page *); extern bool nfs_page_group_sync_on_bit(struct nfs_page *, unsigned int); +extern bool nfs_page_group_sync_on_bit_locked(struct nfs_page *, unsigned int); extern int nfs_page_set_headlock(struct nfs_page *req); extern void nfs_page_clear_headlock(struct nfs_page *req); extern bool nfs_async_iocounter_wait(struct rpc_task *, struct nfs_lock_context *); -- cgit v1.2.3 From 808471ddb0fa785559c3e7aee59be20a13b46ef5 Mon Sep 17 00:00:00 2001 From: Dominique Martinet Date: Wed, 13 Aug 2025 15:04:55 +0900 Subject: iov_iter: iterate_folioq: fix handling of offset >= folio size It's apparently possible to get an iov advanced all the way up to the end of the current page we're looking at, e.g. (gdb) p *iter $24 = {iter_type = 4 '\004', nofault = false, data_source = false, iov_offset = 4096, {__ubuf_iovec = { iov_base = 0xffff88800f5bc000, iov_len = 655}, {{__iov = 0xffff88800f5bc000, kvec = 0xffff88800f5bc000, bvec = 0xffff88800f5bc000, folioq = 0xffff88800f5bc000, xarray = 0xffff88800f5bc000, ubuf = 0xffff88800f5bc000}, count = 655}}, {nr_segs = 2, folioq_slot = 2 '\002', xarray_start = 2}} Where iov_offset is 4k with 4k-sized folios This should have been fine because we're only in the 2nd slot and there's another one after this, but iterate_folioq should not try to map a folio that skips the whole size, and more importantly part here does not end up zero (because 'PAGE_SIZE - skip % PAGE_SIZE' ends up PAGE_SIZE and not zero..), so skip forward to the "advance to next folio" code Link: https://lkml.kernel.org/r/20250813-iot_iter_folio-v3-0-a0ffad2b665a@codewreck.org Link: https://lkml.kernel.org/r/20250813-iot_iter_folio-v3-1-a0ffad2b665a@codewreck.org Signed-off-by: Dominique Martinet Fixes: db0aa2e9566f ("mm: Define struct folio_queue and ITER_FOLIOQ to handle a sequence of folios") Reported-by: Maximilian Bosch Reported-by: Ryan Lahfa Reported-by: Christian Theune Reported-by: Arnout Engelen Link: https://lkml.kernel.org/r/D4LHHUNLG79Y.12PI0X6BEHRHW@mbosch.me/ Acked-by: David Howells Cc: Al Viro Cc: Christian Brauner Cc: Matthew Wilcox (Oracle) Cc: [6.12+] Signed-off-by: Andrew Morton --- include/linux/iov_iter.h | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'include/linux') diff --git a/include/linux/iov_iter.h b/include/linux/iov_iter.h index c4aa58032faf..f9a17fbbd398 100644 --- a/include/linux/iov_iter.h +++ b/include/linux/iov_iter.h @@ -160,7 +160,7 @@ size_t iterate_folioq(struct iov_iter *iter, size_t len, void *priv, void *priv2 do { struct folio *folio = folioq_folio(folioq, slot); - size_t part, remain, consumed; + size_t part, remain = 0, consumed; size_t fsize; void *base; @@ -168,14 +168,16 @@ size_t iterate_folioq(struct iov_iter *iter, size_t len, void *priv, void *priv2 break; fsize = folioq_folio_size(folioq, slot); - base = kmap_local_folio(folio, skip); - part = umin(len, PAGE_SIZE - skip % PAGE_SIZE); - remain = step(base, progress, part, priv, priv2); - kunmap_local(base); - consumed = part - remain; - len -= consumed; - progress += consumed; - skip += consumed; + if (skip < fsize) { + base = kmap_local_folio(folio, skip); + part = umin(len, PAGE_SIZE - skip % PAGE_SIZE); + remain = step(base, progress, part, priv, priv2); + kunmap_local(base); + consumed = part - remain; + len -= consumed; + progress += consumed; + skip += consumed; + } if (skip >= fsize) { skip = 0; slot++; -- cgit v1.2.3 From 053c8ebe74f7e1f4c072e59428da80b9d78bc4b7 Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Sun, 17 Aug 2025 23:17:59 +0800 Subject: mm/migrate: fix NULL movable_ops if CONFIG_ZSMALLOC=m After commit 84caf98838a3e5f4bdb34 ("mm: stop storing migration_ops in page->mapping") we get such an error message if CONFIG_ZSMALLOC=m: WARNING: CPU: 3 PID: 42 at mm/migrate.c:142 isolate_movable_ops_page+0xa8/0x1c0 CPU: 3 UID: 0 PID: 42 Comm: kcompactd0 Not tainted 6.16.0-rc5+ #2133 PREEMPT pc 9000000000540bd8 ra 9000000000540b84 tp 9000000100420000 sp 9000000100423a60 a0 9000000100193a80 a1 000000000000000c a2 000000000000001b a3 ffffffffffffffff a4 ffffffffffffffff a5 0000000000000267 a6 0000000000000000 a7 9000000100423ae0 t0 00000000000000f1 t1 00000000000000f6 t2 0000000000000000 t3 0000000000000001 t4 ffffff00010eb834 t5 0000000000000040 t6 900000010c89d380 t7 90000000023fcc70 t8 0000000000000018 u0 0000000000000000 s9 ffffff00010eb800 s0 ffffff00010eb800 s1 000000000000000c s2 0000000000043ae0 s3 0000800000000000 s4 900000000219cc40 s5 0000000000000000 s6 ffffff00010eb800 s7 0000000000000001 s8 90000000025b4000 ra: 9000000000540b84 isolate_movable_ops_page+0x54/0x1c0 ERA: 9000000000540bd8 isolate_movable_ops_page+0xa8/0x1c0 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) CPU: 3 UID: 0 PID: 42 Comm: kcompactd0 Not tainted 6.16.0-rc5+ #2133 PREEMPT Stack : 90000000021fd000 0000000000000000 9000000000247720 9000000100420000 90000001004236a0 90000001004236a8 0000000000000000 90000001004237e8 90000001004237e0 90000001004237e0 9000000100423550 0000000000000001 0000000000000001 90000001004236a8 725a84864a19e2d9 90000000023fcc58 9000000100420000 90000000024c6848 9000000002416848 0000000000000001 0000000000000000 000000000000000a 0000000007fe0000 ffffff00010eb800 0000000000000000 90000000021fd000 0000000000000000 900000000205cf30 000000000000008e 0000000000000009 ffffff00010eb800 0000000000000001 90000000025b4000 0000000000000000 900000000024773c 00007ffff103d748 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d ... Call Trace: [<900000000024773c>] show_stack+0x5c/0x190 [<90000000002415e0>] dump_stack_lvl+0x70/0x9c [<90000000004abe6c>] isolate_migratepages_block+0x3bc/0x16e0 [<90000000004af408>] compact_zone+0x558/0x1000 [<90000000004b0068>] compact_node+0xa8/0x1e0 [<90000000004b0aa4>] kcompactd+0x394/0x410 [<90000000002b3c98>] kthread+0x128/0x140 [<9000000001779148>] ret_from_kernel_thread+0x28/0xc0 [<9000000000245528>] ret_from_kernel_thread_asm+0x10/0x88 The reason is that defined(CONFIG_ZSMALLOC) evaluates to 1 only when CONFIG_ZSMALLOC=y, we should use IS_ENABLED(CONFIG_ZSMALLOC) instead. But when I use IS_ENABLED(CONFIG_ZSMALLOC), page_movable_ops() cannot access zsmalloc_mops because zsmalloc_mops is in a module. To solve this problem, we define a set_movable_ops() interface to register and unregister offline_movable_ops / zsmalloc_movable_ops in mm/migrate.c, and call them at mm/balloon_compaction.c & mm/zsmalloc.c. Since offline_movable_ops / zsmalloc_movable_ops are always accessible, all #ifdef / #endif are removed in page_movable_ops(). Link: https://lkml.kernel.org/r/20250817151759.2525174-1-chenhuacai@loongson.cn Fixes: 84caf98838a3 ("mm: stop storing migration_ops in page->mapping") Signed-off-by: Huacai Chen Acked-by: Zi Yan Acked-by: David Hildenbrand Cc: Huacai Chen Cc: Huacai Chen Cc: Lorenzo Stoakes Cc: "Michael S. Tsirkin" Cc: Minchan Kim Cc: Sergey Senozhatsky Signed-off-by: Andrew Morton --- include/linux/migrate.h | 5 +++++ mm/balloon_compaction.c | 6 ++++++ mm/migrate.c | 38 ++++++++++++++++++++++++++++++-------- mm/zsmalloc.c | 10 ++++++++++ 4 files changed, 51 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/include/linux/migrate.h b/include/linux/migrate.h index acadd41e0b5c..9009e27b5f44 100644 --- a/include/linux/migrate.h +++ b/include/linux/migrate.h @@ -79,6 +79,7 @@ void migration_entry_wait_on_locked(swp_entry_t entry, spinlock_t *ptl) void folio_migrate_flags(struct folio *newfolio, struct folio *folio); int folio_migrate_mapping(struct address_space *mapping, struct folio *newfolio, struct folio *folio, int extra_count); +int set_movable_ops(const struct movable_operations *ops, enum pagetype type); #else @@ -100,6 +101,10 @@ static inline int migrate_huge_page_move_mapping(struct address_space *mapping, { return -ENOSYS; } +static inline int set_movable_ops(const struct movable_operations *ops, enum pagetype type) +{ + return -ENOSYS; +} #endif /* CONFIG_MIGRATION */ diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c index 2a4a649805c1..03c5dbabb156 100644 --- a/mm/balloon_compaction.c +++ b/mm/balloon_compaction.c @@ -254,4 +254,10 @@ const struct movable_operations balloon_mops = { .putback_page = balloon_page_putback, }; +static int __init balloon_init(void) +{ + return set_movable_ops(&balloon_mops, PGTY_offline); +} +core_initcall(balloon_init); + #endif /* CONFIG_BALLOON_COMPACTION */ diff --git a/mm/migrate.c b/mm/migrate.c index 425401b2d4e1..9e5ef39ce73a 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -43,8 +43,6 @@ #include #include #include -#include -#include #include @@ -53,6 +51,33 @@ #include "internal.h" #include "swap.h" +static const struct movable_operations *offline_movable_ops; +static const struct movable_operations *zsmalloc_movable_ops; + +int set_movable_ops(const struct movable_operations *ops, enum pagetype type) +{ + /* + * We only allow for selected types and don't handle concurrent + * registration attempts yet. + */ + switch (type) { + case PGTY_offline: + if (offline_movable_ops && ops) + return -EBUSY; + offline_movable_ops = ops; + break; + case PGTY_zsmalloc: + if (zsmalloc_movable_ops && ops) + return -EBUSY; + zsmalloc_movable_ops = ops; + break; + default: + return -EINVAL; + } + return 0; +} +EXPORT_SYMBOL_GPL(set_movable_ops); + static const struct movable_operations *page_movable_ops(struct page *page) { VM_WARN_ON_ONCE_PAGE(!page_has_movable_ops(page), page); @@ -62,15 +87,12 @@ static const struct movable_operations *page_movable_ops(struct page *page) * it as movable, the page type must be sticky until the page gets freed * back to the buddy. */ -#ifdef CONFIG_BALLOON_COMPACTION if (PageOffline(page)) /* Only balloon compaction sets PageOffline pages movable. */ - return &balloon_mops; -#endif /* CONFIG_BALLOON_COMPACTION */ -#if defined(CONFIG_ZSMALLOC) && defined(CONFIG_COMPACTION) + return offline_movable_ops; if (PageZsmalloc(page)) - return &zsmalloc_mops; -#endif /* defined(CONFIG_ZSMALLOC) && defined(CONFIG_COMPACTION) */ + return zsmalloc_movable_ops; + return NULL; } diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c index 2c5e56a65354..805a10b41266 100644 --- a/mm/zsmalloc.c +++ b/mm/zsmalloc.c @@ -2246,8 +2246,15 @@ EXPORT_SYMBOL_GPL(zs_destroy_pool); static int __init zs_init(void) { + int rc __maybe_unused; + #ifdef CONFIG_ZPOOL zpool_register_driver(&zs_zpool_driver); +#endif +#ifdef CONFIG_COMPACTION + rc = set_movable_ops(&zsmalloc_mops, PGTY_zsmalloc); + if (rc) + return rc; #endif zs_stat_init(); return 0; @@ -2257,6 +2264,9 @@ static void __exit zs_exit(void) { #ifdef CONFIG_ZPOOL zpool_unregister_driver(&zs_zpool_driver); +#endif +#ifdef CONFIG_COMPACTION + set_movable_ops(NULL, PGTY_zsmalloc); #endif zs_stat_exit(); } -- cgit v1.2.3 From 8ef7f3132e4005a103b382e71abea7ad01fbeb86 Mon Sep 17 00:00:00 2001 From: Xianglai Li Date: Wed, 20 Aug 2025 22:23:44 +0800 Subject: LoongArch: Add cpuhotplug hooks to fix high cpu usage of vCPU threads When the CPU is offline, the timer of LoongArch is not correctly closed. This is harmless for real machines, but resulting in an excessively high cpu usage rate of the offline vCPU thread in the virtual machines. To correctly close the timer, we have made the following modifications: Register the cpu hotplug event (CPUHP_AP_LOONGARCH_ARCH_TIMER_STARTING) for LoongArch. This event's hooks will be called to close the timer when the CPU is offline. Clear the timer interrupt when the timer is turned off. Since before the timer is turned off, there may be a timer interrupt that has already been in the pending state due to the interruption of the disabled, which also affects the halt state of the offline vCPU. Signed-off-by: Xianglai Li Signed-off-by: Huacai Chen --- arch/loongarch/kernel/time.c | 22 ++++++++++++++++++++++ include/linux/cpuhotplug.h | 1 + 2 files changed, 23 insertions(+) (limited to 'include/linux') diff --git a/arch/loongarch/kernel/time.c b/arch/loongarch/kernel/time.c index 367906b10f81..f3092f2de8b5 100644 --- a/arch/loongarch/kernel/time.c +++ b/arch/loongarch/kernel/time.c @@ -5,6 +5,7 @@ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited */ #include +#include #include #include #include @@ -102,6 +103,23 @@ static int constant_timer_next_event(unsigned long delta, struct clock_event_dev return 0; } +static int arch_timer_starting(unsigned int cpu) +{ + set_csr_ecfg(ECFGF_TIMER); + + return 0; +} + +static int arch_timer_dying(unsigned int cpu) +{ + constant_set_state_shutdown(this_cpu_ptr(&constant_clockevent_device)); + + /* Clear Timer Interrupt */ + write_csr_tintclear(CSR_TINTCLR_TI); + + return 0; +} + static unsigned long get_loops_per_jiffy(void) { unsigned long lpj = (unsigned long)const_clock_freq; @@ -172,6 +190,10 @@ int constant_clockevent_init(void) lpj_fine = get_loops_per_jiffy(); pr_info("Constant clock event device register\n"); + cpuhp_setup_state(CPUHP_AP_LOONGARCH_ARCH_TIMER_STARTING, + "clockevents/loongarch/timer:starting", + arch_timer_starting, arch_timer_dying); + return 0; } diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index edfa61d80702..62cd7b35a29c 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h @@ -168,6 +168,7 @@ enum cpuhp_state { CPUHP_AP_QCOM_TIMER_STARTING, CPUHP_AP_TEGRA_TIMER_STARTING, CPUHP_AP_ARMADA_TIMER_STARTING, + CPUHP_AP_LOONGARCH_ARCH_TIMER_STARTING, CPUHP_AP_MIPS_GIC_TIMER_STARTING, CPUHP_AP_ARC_TIMER_STARTING, CPUHP_AP_REALTEK_TIMER_STARTING, -- cgit v1.2.3 From 370ac285f23aecae40600851fb4a1a9e75e50973 Mon Sep 17 00:00:00 2001 From: Nilay Shroff Date: Thu, 14 Aug 2025 13:54:59 +0530 Subject: block: avoid cpu_hotplug_lock depedency on freeze_lock A recent lockdep[1] splat observed while running blktest block/005 reveals a potential deadlock caused by the cpu_hotplug_lock dependency on ->freeze_lock. This dependency was introduced by commit 033b667a823e ("block: blk-rq-qos: guard rq-qos helpers by static key"). That change added a static key to avoid fetching q->rq_qos when neither blk-wbt nor blk-iolatency is configured. The static key dynamically patches kernel text to a NOP when disabled, eliminating overhead of fetching q->rq_qos in the I/O hot path. However, enabling a static key at runtime requires acquiring both cpu_hotplug_lock and jump_label_mutex. When this happens after the queue has already been frozen (i.e., while holding ->freeze_lock), it creates a locking dependency from cpu_hotplug_lock to ->freeze_lock, which leads to a potential deadlock reported by lockdep [1]. To resolve this, replace the static key mechanism with q->queue_flags: QUEUE_FLAG_QOS_ENABLED. This flag is evaluated in the fast path before accessing q->rq_qos. If the flag is set, we proceed to fetch q->rq_qos; otherwise, the access is skipped. Since q->queue_flags is commonly accessed in IO hotpath and resides in the first cacheline of struct request_queue, checking it imposes minimal overhead while eliminating the deadlock risk. This change avoids the lockdep splat without introducing performance regressions. [1] https://lore.kernel.org/linux-block/4fdm37so3o4xricdgfosgmohn63aa7wj3ua4e5vpihoamwg3ui@fq42f5q5t5ic/ Reported-by: Shinichiro Kawasaki Closes: https://lore.kernel.org/linux-block/4fdm37so3o4xricdgfosgmohn63aa7wj3ua4e5vpihoamwg3ui@fq42f5q5t5ic/ Fixes: 033b667a823e ("block: blk-rq-qos: guard rq-qos helpers by static key") Tested-by: Shin'ichiro Kawasaki Signed-off-by: Nilay Shroff Reviewed-by: Ming Lei Reviewed-by: Yu Kuai Link: https://lore.kernel.org/r/20250814082612.500845-4-nilay@linux.ibm.com Signed-off-by: Jens Axboe --- block/blk-mq-debugfs.c | 1 + block/blk-rq-qos.c | 9 ++++----- block/blk-rq-qos.h | 54 +++++++++++++++++++++++++++++--------------------- include/linux/blkdev.h | 1 + 4 files changed, 37 insertions(+), 28 deletions(-) (limited to 'include/linux') diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 7ed3e71f2fc0..32c65efdda46 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -95,6 +95,7 @@ static const char *const blk_queue_flag_name[] = { QUEUE_FLAG_NAME(SQ_SCHED), QUEUE_FLAG_NAME(DISABLE_WBT_DEF), QUEUE_FLAG_NAME(NO_ELV_SWITCH), + QUEUE_FLAG_NAME(QOS_ENABLED), }; #undef QUEUE_FLAG_NAME diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c index b1e24bb85ad2..654478dfbc20 100644 --- a/block/blk-rq-qos.c +++ b/block/blk-rq-qos.c @@ -2,8 +2,6 @@ #include "blk-rq-qos.h" -__read_mostly DEFINE_STATIC_KEY_FALSE(block_rq_qos); - /* * Increment 'v', if 'v' is below 'below'. Returns true if we succeeded, * false if 'v' + 1 would be bigger than 'below'. @@ -319,8 +317,8 @@ void rq_qos_exit(struct request_queue *q) struct rq_qos *rqos = q->rq_qos; q->rq_qos = rqos->next; rqos->ops->exit(rqos); - static_branch_dec(&block_rq_qos); } + blk_queue_flag_clear(QUEUE_FLAG_QOS_ENABLED, q); mutex_unlock(&q->rq_qos_mutex); } @@ -346,7 +344,7 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id, goto ebusy; rqos->next = q->rq_qos; q->rq_qos = rqos; - static_branch_inc(&block_rq_qos); + blk_queue_flag_set(QUEUE_FLAG_QOS_ENABLED, q); blk_mq_unfreeze_queue(q, memflags); @@ -374,10 +372,11 @@ void rq_qos_del(struct rq_qos *rqos) for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) { if (*cur == rqos) { *cur = rqos->next; - static_branch_dec(&block_rq_qos); break; } } + if (!q->rq_qos) + blk_queue_flag_clear(QUEUE_FLAG_QOS_ENABLED, q); blk_mq_unfreeze_queue(q, memflags); mutex_lock(&q->debugfs_mutex); diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h index 28125fc49eff..1fe22000a379 100644 --- a/block/blk-rq-qos.h +++ b/block/blk-rq-qos.h @@ -12,7 +12,6 @@ #include "blk-mq-debugfs.h" struct blk_mq_debugfs_attr; -extern struct static_key_false block_rq_qos; enum rq_qos_id { RQ_QOS_WBT, @@ -113,49 +112,55 @@ void __rq_qos_queue_depth_changed(struct rq_qos *rqos); static inline void rq_qos_cleanup(struct request_queue *q, struct bio *bio) { - if (static_branch_unlikely(&block_rq_qos) && q->rq_qos) + if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && + q->rq_qos) __rq_qos_cleanup(q->rq_qos, bio); } static inline void rq_qos_done(struct request_queue *q, struct request *rq) { - if (static_branch_unlikely(&block_rq_qos) && q->rq_qos && - !blk_rq_is_passthrough(rq)) + if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && + q->rq_qos && !blk_rq_is_passthrough(rq)) __rq_qos_done(q->rq_qos, rq); } static inline void rq_qos_issue(struct request_queue *q, struct request *rq) { - if (static_branch_unlikely(&block_rq_qos) && q->rq_qos) + if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && + q->rq_qos) __rq_qos_issue(q->rq_qos, rq); } static inline void rq_qos_requeue(struct request_queue *q, struct request *rq) { - if (static_branch_unlikely(&block_rq_qos) && q->rq_qos) + if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && + q->rq_qos) __rq_qos_requeue(q->rq_qos, rq); } static inline void rq_qos_done_bio(struct bio *bio) { - if (static_branch_unlikely(&block_rq_qos) && - bio->bi_bdev && (bio_flagged(bio, BIO_QOS_THROTTLED) || - bio_flagged(bio, BIO_QOS_MERGED))) { - struct request_queue *q = bdev_get_queue(bio->bi_bdev); - - /* - * If a bio has BIO_QOS_xxx set, it implicitly implies that - * q->rq_qos is present. So, we skip re-checking q->rq_qos - * here as an extra optimization and directly call - * __rq_qos_done_bio(). - */ - __rq_qos_done_bio(q->rq_qos, bio); - } + struct request_queue *q; + + if (!bio->bi_bdev || (!bio_flagged(bio, BIO_QOS_THROTTLED) && + !bio_flagged(bio, BIO_QOS_MERGED))) + return; + + q = bdev_get_queue(bio->bi_bdev); + + /* + * If a bio has BIO_QOS_xxx set, it implicitly implies that + * q->rq_qos is present. So, we skip re-checking q->rq_qos + * here as an extra optimization and directly call + * __rq_qos_done_bio(). + */ + __rq_qos_done_bio(q->rq_qos, bio); } static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) { - if (static_branch_unlikely(&block_rq_qos) && q->rq_qos) { + if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && + q->rq_qos) { bio_set_flag(bio, BIO_QOS_THROTTLED); __rq_qos_throttle(q->rq_qos, bio); } @@ -164,14 +169,16 @@ static inline void rq_qos_throttle(struct request_queue *q, struct bio *bio) static inline void rq_qos_track(struct request_queue *q, struct request *rq, struct bio *bio) { - if (static_branch_unlikely(&block_rq_qos) && q->rq_qos) + if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && + q->rq_qos) __rq_qos_track(q->rq_qos, rq, bio); } static inline void rq_qos_merge(struct request_queue *q, struct request *rq, struct bio *bio) { - if (static_branch_unlikely(&block_rq_qos) && q->rq_qos) { + if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && + q->rq_qos) { bio_set_flag(bio, BIO_QOS_MERGED); __rq_qos_merge(q->rq_qos, rq, bio); } @@ -179,7 +186,8 @@ static inline void rq_qos_merge(struct request_queue *q, struct request *rq, static inline void rq_qos_queue_depth_changed(struct request_queue *q) { - if (static_branch_unlikely(&block_rq_qos) && q->rq_qos) + if (unlikely(test_bit(QUEUE_FLAG_QOS_ENABLED, &q->queue_flags)) && + q->rq_qos) __rq_qos_queue_depth_changed(q->rq_qos); } diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 95886b404b16..fe1797bbec42 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -656,6 +656,7 @@ enum { QUEUE_FLAG_SQ_SCHED, /* single queue style io dispatch */ QUEUE_FLAG_DISABLE_WBT_DEF, /* for sched to disable/enable wbt */ QUEUE_FLAG_NO_ELV_SWITCH, /* can't switch elevator any more */ + QUEUE_FLAG_QOS_ENABLED, /* qos is enabled */ QUEUE_FLAG_MAX }; -- cgit v1.2.3 From b08a784a5d1495c42ff9b0c70887d49211cddfe0 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 18 Aug 2025 19:03:54 +0100 Subject: net: Introduce skb_copy_datagram_from_iter_full() In a similar manner to copy_from_iter()/copy_from_iter_full(), introduce skb_copy_datagram_from_iter_full() which reverts the iterator to its initial state when returning an error. A subsequent fix for a vsock regression will make use of this new function. Cc: Christian Brauner Cc: Alexander Viro Signed-off-by: Will Deacon Acked-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi Link: https://patch.msgid.link/20250818180355.29275-2-will@kernel.org Signed-off-by: Jakub Kicinski --- include/linux/skbuff.h | 2 ++ net/core/datagram.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+) (limited to 'include/linux') diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 14b923ddb6df..fa633657e4c0 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -4172,6 +4172,8 @@ int skb_copy_and_crc32c_datagram_iter(const struct sk_buff *skb, int offset, struct iov_iter *to, int len, u32 *crcp); int skb_copy_datagram_from_iter(struct sk_buff *skb, int offset, struct iov_iter *from, int len); +int skb_copy_datagram_from_iter_full(struct sk_buff *skb, int offset, + struct iov_iter *from, int len); int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *frm); void skb_free_datagram(struct sock *sk, struct sk_buff *skb); int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags); diff --git a/net/core/datagram.c b/net/core/datagram.c index 94cc4705e91d..f474b9b120f9 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -618,6 +618,20 @@ fault: } EXPORT_SYMBOL(skb_copy_datagram_from_iter); +int skb_copy_datagram_from_iter_full(struct sk_buff *skb, int offset, + struct iov_iter *from, int len) +{ + struct iov_iter_state state; + int ret; + + iov_iter_save_state(from, &state); + ret = skb_copy_datagram_from_iter(skb, offset, from, len); + if (ret) + iov_iter_restore(from, &state); + return ret; +} +EXPORT_SYMBOL(skb_copy_datagram_from_iter_full); + int zerocopy_fill_skb_from_iter(struct sk_buff *skb, struct iov_iter *from, size_t length) { -- cgit v1.2.3 From ec79003c5f9d2c7f9576fc69b8dbda80305cbe3a Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Thu, 21 Aug 2025 02:18:24 +0000 Subject: atm: atmtcp: Prevent arbitrary write in atmtcp_recv_control(). syzbot reported the splat below. [0] When atmtcp_v_open() or atmtcp_v_close() is called via connect() or close(), atmtcp_send_control() is called to send an in-kernel special message. The message has ATMTCP_HDR_MAGIC in atmtcp_control.hdr.length. Also, a pointer of struct atm_vcc is set to atmtcp_control.vcc. The notable thing is struct atmtcp_control is uAPI but has a space for an in-kernel pointer. struct atmtcp_control { struct atmtcp_hdr hdr; /* must be first */ ... atm_kptr_t vcc; /* both directions */ ... } __ATM_API_ALIGN; typedef struct { unsigned char _[8]; } __ATM_API_ALIGN atm_kptr_t; The special message is processed in atmtcp_recv_control() called from atmtcp_c_send(). atmtcp_c_send() is vcc->dev->ops->send() and called from 2 paths: 1. .ndo_start_xmit() (vcc->send() == atm_send_aal0()) 2. vcc_sendmsg() The problem is sendmsg() does not validate the message length and userspace can abuse atmtcp_recv_control() to overwrite any kptr by atmtcp_control. Let's add a new ->pre_send() hook to validate messages from sendmsg(). [0]: Oops: general protection fault, probably for non-canonical address 0xdffffc00200000ab: 0000 [#1] SMP KASAN PTI KASAN: probably user-memory-access in range [0x0000000100000558-0x000000010000055f] CPU: 0 UID: 0 PID: 5865 Comm: syz-executor331 Not tainted 6.17.0-rc1-syzkaller-00215-gbab3ce404553 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:atmtcp_recv_control drivers/atm/atmtcp.c:93 [inline] RIP: 0010:atmtcp_c_send+0x1da/0x950 drivers/atm/atmtcp.c:297 Code: 4d 8d 75 1a 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 15 06 00 00 41 0f b7 1e 4d 8d b7 60 05 00 00 4c 89 f0 48 c1 e8 03 <42> 0f b6 04 20 84 c0 0f 85 13 06 00 00 66 41 89 1e 4d 8d 75 1c 4c RSP: 0018:ffffc90003f5f810 EFLAGS: 00010203 RAX: 00000000200000ab RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88802a510000 RSI: 00000000ffffffff RDI: ffff888030a6068c RBP: ffff88802699fb40 R08: ffff888030a606eb R09: 1ffff1100614c0dd R10: dffffc0000000000 R11: ffffffff8718fc40 R12: dffffc0000000000 R13: ffff888030a60680 R14: 000000010000055f R15: 00000000ffffffff FS: 00007f8d7e9236c0(0000) GS:ffff888125c1c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000045ad50 CR3: 0000000075bde000 CR4: 00000000003526f0 Call Trace: vcc_sendmsg+0xa10/0xc60 net/atm/common.c:645 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x219/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2614 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668 __sys_sendmsg net/socket.c:2700 [inline] __do_sys_sendmsg net/socket.c:2705 [inline] __se_sys_sendmsg net/socket.c:2703 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8d7e96a4a9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 18 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8d7e923198 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f8d7e9f4308 RCX: 00007f8d7e96a4a9 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000005 RBP: 00007f8d7e9f4300 R08: 65732f636f72702f R09: 65732f636f72702f R10: 65732f636f72702f R11: 0000000000000246 R12: 00007f8d7e9c10ac R13: 00007f8d7e9231a0 R14: 0000200000000200 R15: 0000200000000250 Modules linked in: Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+1741b56d54536f4ec349@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68a6767c.050a0220.3d78fd.0011.GAE@google.com/ Tested-by: syzbot+1741b56d54536f4ec349@syzkaller.appspotmail.com Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250821021901.2814721-1-kuniyu@google.com Signed-off-by: Jakub Kicinski --- drivers/atm/atmtcp.c | 17 ++++++++++++++--- include/linux/atmdev.h | 1 + net/atm/common.c | 15 ++++++++++++--- 3 files changed, 27 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/drivers/atm/atmtcp.c b/drivers/atm/atmtcp.c index eeae160c898d..fa3c76a2b49d 100644 --- a/drivers/atm/atmtcp.c +++ b/drivers/atm/atmtcp.c @@ -279,6 +279,19 @@ static struct atm_vcc *find_vcc(struct atm_dev *dev, short vpi, int vci) return NULL; } +static int atmtcp_c_pre_send(struct atm_vcc *vcc, struct sk_buff *skb) +{ + struct atmtcp_hdr *hdr; + + if (skb->len < sizeof(struct atmtcp_hdr)) + return -EINVAL; + + hdr = (struct atmtcp_hdr *)skb->data; + if (hdr->length == ATMTCP_HDR_MAGIC) + return -EINVAL; + + return 0; +} static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb) { @@ -288,9 +301,6 @@ static int atmtcp_c_send(struct atm_vcc *vcc,struct sk_buff *skb) struct sk_buff *new_skb; int result = 0; - if (skb->len < sizeof(struct atmtcp_hdr)) - goto done; - dev = vcc->dev_data; hdr = (struct atmtcp_hdr *) skb->data; if (hdr->length == ATMTCP_HDR_MAGIC) { @@ -347,6 +357,7 @@ static const struct atmdev_ops atmtcp_v_dev_ops = { static const struct atmdev_ops atmtcp_c_dev_ops = { .close = atmtcp_c_close, + .pre_send = atmtcp_c_pre_send, .send = atmtcp_c_send }; diff --git a/include/linux/atmdev.h b/include/linux/atmdev.h index 45f2f278b50a..70807c679f1a 100644 --- a/include/linux/atmdev.h +++ b/include/linux/atmdev.h @@ -185,6 +185,7 @@ struct atmdev_ops { /* only send is required */ int (*compat_ioctl)(struct atm_dev *dev,unsigned int cmd, void __user *arg); #endif + int (*pre_send)(struct atm_vcc *vcc, struct sk_buff *skb); int (*send)(struct atm_vcc *vcc,struct sk_buff *skb); int (*send_bh)(struct atm_vcc *vcc, struct sk_buff *skb); int (*send_oam)(struct atm_vcc *vcc,void *cell,int flags); diff --git a/net/atm/common.c b/net/atm/common.c index d7f7976ea13a..881c7f259dbd 100644 --- a/net/atm/common.c +++ b/net/atm/common.c @@ -635,18 +635,27 @@ int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size) skb->dev = NULL; /* for paths shared with net_device interfaces */ if (!copy_from_iter_full(skb_put(skb, size), size, &m->msg_iter)) { - atm_return_tx(vcc, skb); - kfree_skb(skb); error = -EFAULT; - goto out; + goto free_skb; } if (eff != size) memset(skb->data + size, 0, eff-size); + + if (vcc->dev->ops->pre_send) { + error = vcc->dev->ops->pre_send(vcc, skb); + if (error) + goto free_skb; + } + error = vcc->dev->ops->send(vcc, skb); error = error ? error : size; out: release_sock(sk); return error; +free_skb: + atm_return_tx(vcc, skb); + kfree_skb(skb); + goto out; } __poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait) -- cgit v1.2.3 From ced17ee32a9988b8a260628e7c31a100d7dc082e Mon Sep 17 00:00:00 2001 From: Igor Torrente Date: Thu, 7 Aug 2025 09:41:45 -0300 Subject: Revert "virtio: reject shm region if length is zero" The commit 206cc44588f7 ("virtio: reject shm region if length is zero") breaks the Virtio-gpu `host_visible` feature. As you can see in the snippet below, host_visible_region is zero because of the `kzalloc`. It's using the `vm_get_shm_region` (drivers/virtio/virtio_mmio.c:536) to read the `addr` and `len` from qemu/crosvm. ``` drivers/gpu/drm/virtio/virtgpu_kms.c 132 vgdev = drmm_kzalloc(dev, sizeof(struct virtio_gpu_device), GFP_KERNEL); [...] 177 if (virtio_get_shm_region(vgdev->vdev, &vgdev->host_visible_region, 178 VIRTIO_GPU_SHM_ID_HOST_VISIBLE)) { ``` Now it always fails. To fix, revert the offending commit. Fixes: 206cc44588f7 ("virtio: reject shm region if length is zero") Signed-off-by: Igor Torrente Message-Id: <20250807124145.81816-1-igor.torrente@collabora.com> Signed-off-by: Michael S. Tsirkin --- include/linux/virtio_config.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/linux') diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 918cf25cd3c6..8bf156dde554 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -328,8 +328,6 @@ static inline bool virtio_get_shm_region(struct virtio_device *vdev, struct virtio_shm_region *region, u8 id) { - if (!region->len) - return false; if (!vdev->config->get_shm_region) return false; return vdev->config->get_shm_region(vdev, region, id); -- cgit v1.2.3 From b3dcc9d1d806fb1e175f85978713eef868531da4 Mon Sep 17 00:00:00 2001 From: "Mike Rapoport (Microsoft)" Date: Tue, 26 Aug 2025 10:19:46 +0300 Subject: memblock: fix kernel-doc for MEMBLOCK_RSRV_NOINIT The kernel-doc description of MEMBLOCK_RSRV_NOINIT and memblock_reserved_mark_noinit() do not accurately describe their functionality. Expand their kernel doc to make it clear that the user of MEMBLOCK_RSRV_NOINIT is responsible to properly initialize the struct pages for such regions and add more details about effects of using this flag. Reviewed-by: David Hildenbrand Link: https://lore.kernel.org/r/f8140a17-c4ec-489b-b314-d45abe48bf36@redhat.com Link: https://lore.kernel.org/r/20250826071947.1949725-1-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) --- include/linux/memblock.h | 5 +++-- mm/memblock.c | 15 +++++++++++---- 2 files changed, 14 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/memblock.h b/include/linux/memblock.h index b96746376e17..fcda8481de9a 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -40,8 +40,9 @@ extern unsigned long long max_possible_pfn; * via a driver, and never indicated in the firmware-provided memory map as * system RAM. This corresponds to IORESOURCE_SYSRAM_DRIVER_MANAGED in the * kernel resource tree. - * @MEMBLOCK_RSRV_NOINIT: memory region for which struct pages are - * not initialized (only for reserved regions). + * @MEMBLOCK_RSRV_NOINIT: reserved memory region for which struct pages are not + * fully initialized. Users of this flag are responsible to properly initialize + * struct pages of this region * @MEMBLOCK_RSRV_KERN: memory region that is reserved for kernel use, * either explictitly with memblock_reserve_kern() or via memblock * allocation APIs. All memblock allocations set this flag. diff --git a/mm/memblock.c b/mm/memblock.c index 8a0ed3074af4..117d963e677c 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1091,13 +1091,20 @@ int __init_memblock memblock_clear_nomap(phys_addr_t base, phys_addr_t size) /** * memblock_reserved_mark_noinit - Mark a reserved memory region with flag - * MEMBLOCK_RSRV_NOINIT which results in the struct pages not being initialized - * for this region. + * MEMBLOCK_RSRV_NOINIT + * * @base: the base phys addr of the region * @size: the size of the region * - * struct pages will not be initialized for reserved memory regions marked with - * %MEMBLOCK_RSRV_NOINIT. + * The struct pages for the reserved regions marked %MEMBLOCK_RSRV_NOINIT will + * not be fully initialized to allow the caller optimize their initialization. + * + * When %CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, setting this flag + * completely bypasses the initialization of struct pages for such region. + * + * When %CONFIG_DEFERRED_STRUCT_PAGE_INIT is disabled, struct pages in this + * region will be initialized with default values but won't be marked as + * reserved. * * Return: 0 on success, -errno on failure. */ -- cgit v1.2.3 From 3c17001b21b9f168c957ced9384abe969019b609 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:24 +0200 Subject: pidfs: validate extensible ioctls Validate extensible ioctls stricter than we do now. Reviewed-by: Aleksa Sarai Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/pidfs.c | 2 +- include/linux/fs.h | 14 ++++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/fs/pidfs.c b/fs/pidfs.c index edc35522d75c..0a5083b9cce5 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -440,7 +440,7 @@ static bool pidfs_ioctl_valid(unsigned int cmd) * erronously mistook the file descriptor for a pidfd. * This is not perfect but will catch most cases. */ - return (_IOC_TYPE(cmd) == _IOC_TYPE(PIDFD_GET_INFO)); + return extensible_ioctl_valid(cmd, PIDFD_GET_INFO, PIDFD_INFO_SIZE_VER0); } return false; diff --git a/include/linux/fs.h b/include/linux/fs.h index d7ab4f96d705..2f2edc53bf3c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -4023,4 +4023,18 @@ static inline bool vfs_empty_path(int dfd, const char __user *path) int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter); +static inline bool extensible_ioctl_valid(unsigned int cmd_a, + unsigned int cmd_b, size_t min_size) +{ + if (_IOC_DIR(cmd_a) != _IOC_DIR(cmd_b)) + return false; + if (_IOC_TYPE(cmd_a) != _IOC_TYPE(cmd_b)) + return false; + if (_IOC_NR(cmd_a) != _IOC_NR(cmd_b)) + return false; + if (_IOC_SIZE(cmd_a) < min_size) + return false; + return true; +} + #endif /* _LINUX_FS_H */ -- cgit v1.2.3 From e3e1812f8e25ac277f5cc9249802365300c582e3 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:28 +0200 Subject: ns: move to_ns_common() to ns_common.h Move the helper to ns_common.h where it belongs. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 20 ++++++++++++++++++++ include/linux/nsproxy.h | 11 ----------- 2 files changed, 20 insertions(+), 11 deletions(-) (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index 7d22ea50b098..bc2e0758e1c9 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -6,6 +6,15 @@ struct proc_ns_operations; +struct cgroup_namespace; +struct ipc_namespace; +struct mnt_namespace; +struct net; +struct pid_namespace; +struct time_namespace; +struct user_namespace; +struct uts_namespace; + struct ns_common { struct dentry *stashed; const struct proc_ns_operations *ops; @@ -13,4 +22,15 @@ struct ns_common { refcount_t count; }; +#define to_ns_common(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: &(__ns)->ns, \ + struct ipc_namespace *: &(__ns)->ns, \ + struct mnt_namespace *: &(__ns)->ns, \ + struct net *: &(__ns)->ns, \ + struct pid_namespace *: &(__ns)->ns, \ + struct time_namespace *: &(__ns)->ns, \ + struct user_namespace *: &(__ns)->ns, \ + struct uts_namespace *: &(__ns)->ns) + #endif diff --git a/include/linux/nsproxy.h b/include/linux/nsproxy.h index dab6a1734a22..e6bec522b139 100644 --- a/include/linux/nsproxy.h +++ b/include/linux/nsproxy.h @@ -42,17 +42,6 @@ struct nsproxy { }; extern struct nsproxy init_nsproxy; -#define to_ns_common(__ns) \ - _Generic((__ns), \ - struct cgroup_namespace *: &(__ns->ns), \ - struct ipc_namespace *: &(__ns->ns), \ - struct net *: &(__ns->ns), \ - struct pid_namespace *: &(__ns->ns), \ - struct mnt_namespace *: &(__ns->ns), \ - struct time_namespace *: &(__ns->ns), \ - struct user_namespace *: &(__ns->ns), \ - struct uts_namespace *: &(__ns->ns)) - /* * A structure to encompass all bits needed to install * a partial or complete new set of namespaces. -- cgit v1.2.3 From 9296f46a9645cf753d2522093485cebe77635aa6 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:29 +0200 Subject: nsfs: add nsfs.h header And move the stuff out from proc_ns.h where it really doesn't belong. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/nsfs.h | 26 ++++++++++++++++++++++++++ include/linux/proc_ns.h | 13 +------------ 2 files changed, 27 insertions(+), 12 deletions(-) create mode 100644 include/linux/nsfs.h (limited to 'include/linux') diff --git a/include/linux/nsfs.h b/include/linux/nsfs.h new file mode 100644 index 000000000000..fb84aa538091 --- /dev/null +++ b/include/linux/nsfs.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2025 Christian Brauner */ + +#ifndef _LINUX_NSFS_H +#define _LINUX_NSFS_H + +#include + +struct path; +struct task_struct; +struct proc_ns_operations; + +int ns_get_path(struct path *path, struct task_struct *task, + const struct proc_ns_operations *ns_ops); +typedef struct ns_common *ns_get_path_helper_t(void *); +int ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb, + void *private_data); + +bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino); + +int ns_get_name(char *buf, size_t size, struct task_struct *task, + const struct proc_ns_operations *ns_ops); +void nsfs_init(void); + +#endif /* _LINUX_NSFS_H */ + diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 4b20375f3783..5e1a4b378b79 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -5,7 +5,7 @@ #ifndef _LINUX_PROC_NS_H #define _LINUX_PROC_NS_H -#include +#include #include struct pid_namespace; @@ -75,16 +75,5 @@ static inline int ns_alloc_inum(struct ns_common *ns) #define ns_free_inum(ns) proc_free_inum((ns)->inum) #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private) -extern int ns_get_path(struct path *path, struct task_struct *task, - const struct proc_ns_operations *ns_ops); -typedef struct ns_common *ns_get_path_helper_t(void *); -extern int ns_get_path_cb(struct path *path, ns_get_path_helper_t ns_get_cb, - void *private_data); - -extern bool ns_match(const struct ns_common *ns, dev_t dev, ino_t ino); - -extern int ns_get_name(char *buf, size_t size, struct task_struct *task, - const struct proc_ns_operations *ns_ops); -extern void nsfs_init(void); #endif /* _LINUX_PROC_NS_H */ -- cgit v1.2.3 From 660def10b01b248fd97255afacb7b0e305ac833a Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:30 +0200 Subject: ns: uniformly initialize ns_common No point in cargo-culting the same code across all the different types. Use one common initializer. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/proc_ns.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/linux') diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index 5e1a4b378b79..dbb119bda097 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -72,6 +72,22 @@ static inline int ns_alloc_inum(struct ns_common *ns) return proc_alloc_inum(&ns->inum); } +static inline int ns_common_init(struct ns_common *ns, + const struct proc_ns_operations *ops, + bool alloc_inum) +{ + if (alloc_inum) { + int ret; + ret = proc_alloc_inum(&ns->inum); + if (ret) + return ret; + } + refcount_set(&ns->count, 1); + ns->stashed = NULL; + ns->ops = ops; + return 0; +} + #define ns_free_inum(ns) proc_free_inum((ns)->inum) #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private) -- cgit v1.2.3 From 86c5aba210b145d7de011a5abaf9b785aa70a183 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:39 +0200 Subject: ns: remove ns_alloc_inum() It's now unused. Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- include/linux/proc_ns.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index dbb119bda097..e50d312f9fee 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -66,12 +66,6 @@ static inline void proc_free_inum(unsigned int inum) {} #endif /* CONFIG_PROC_FS */ -static inline int ns_alloc_inum(struct ns_common *ns) -{ - WRITE_ONCE(ns->stashed, NULL); - return proc_alloc_inum(&ns->inum); -} - static inline int ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, bool alloc_inum) -- cgit v1.2.3 From 885fc8ac0a4dc70f5d87b80b0977292870e35c60 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:40 +0200 Subject: nstree: make iterator generic Move the namespace iteration infrastructure originally introduced for mount namespaces into a generic library usable by all namespace types. Signed-off-by: Christian Brauner --- include/linux/ns_common.h | 9 ++ include/linux/nstree.h | 91 ++++++++++++++++++ include/linux/proc_ns.h | 3 + kernel/Makefile | 2 +- kernel/nstree.c | 233 ++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 337 insertions(+), 1 deletion(-) create mode 100644 include/linux/nstree.h create mode 100644 kernel/nstree.c (limited to 'include/linux') diff --git a/include/linux/ns_common.h b/include/linux/ns_common.h index bc2e0758e1c9..7224072cccc5 100644 --- a/include/linux/ns_common.h +++ b/include/linux/ns_common.h @@ -3,6 +3,7 @@ #define _LINUX_NS_COMMON_H #include +#include struct proc_ns_operations; @@ -20,6 +21,14 @@ struct ns_common { const struct proc_ns_operations *ops; unsigned int inum; refcount_t count; + union { + struct { + u64 ns_id; + struct rb_node ns_tree_node; + struct list_head ns_list_node; + }; + struct rcu_head ns_rcu; + }; }; #define to_ns_common(__ns) \ diff --git a/include/linux/nstree.h b/include/linux/nstree.h new file mode 100644 index 000000000000..29ad6402260c --- /dev/null +++ b/include/linux/nstree.h @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_NSTREE_H +#define _LINUX_NSTREE_H + +#include +#include +#include +#include +#include +#include + +/** + * struct ns_tree - Namespace tree + * @ns_tree: Rbtree of namespaces of a particular type + * @ns_list: Sequentially walkable list of all namespaces of this type + * @ns_tree_lock: Seqlock to protect the tree and list + */ +struct ns_tree { + struct rb_root ns_tree; + struct list_head ns_list; + seqlock_t ns_tree_lock; + int type; +}; + +extern struct ns_tree cgroup_ns_tree; +extern struct ns_tree ipc_ns_tree; +extern struct ns_tree mnt_ns_tree; +extern struct ns_tree net_ns_tree; +extern struct ns_tree pid_ns_tree; +extern struct ns_tree time_ns_tree; +extern struct ns_tree user_ns_tree; +extern struct ns_tree uts_ns_tree; + +#define to_ns_tree(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: &(cgroup_ns_tree), \ + struct ipc_namespace *: &(ipc_ns_tree), \ + struct net *: &(net_ns_tree), \ + struct pid_namespace *: &(pid_ns_tree), \ + struct mnt_namespace *: &(mnt_ns_tree), \ + struct time_namespace *: &(time_ns_tree), \ + struct user_namespace *: &(user_ns_tree), \ + struct uts_namespace *: &(uts_ns_tree)) + +u64 ns_tree_gen_id(struct ns_common *ns); +void __ns_tree_add_raw(struct ns_common *ns, struct ns_tree *ns_tree); +void __ns_tree_remove(struct ns_common *ns, struct ns_tree *ns_tree); +struct ns_common *ns_tree_lookup_rcu(u64 ns_id, int ns_type); +struct ns_common *__ns_tree_adjoined_rcu(struct ns_common *ns, + struct ns_tree *ns_tree, + bool previous); + +static inline void __ns_tree_add(struct ns_common *ns, struct ns_tree *ns_tree) +{ + ns_tree_gen_id(ns); + __ns_tree_add_raw(ns, ns_tree); +} + +/** + * ns_tree_add_raw - Add a namespace to a namespace + * @ns: Namespace to add + * + * This function adds a namespace to the appropriate namespace tree + * without assigning a id. + */ +#define ns_tree_add_raw(__ns) __ns_tree_add_raw(to_ns_common(__ns), to_ns_tree(__ns)) + +/** + * ns_tree_add - Add a namespace to a namespace tree + * @ns: Namespace to add + * + * This function assigns a new id to the namespace and adds it to the + * appropriate namespace tree and list. + */ +#define ns_tree_add(__ns) __ns_tree_add(to_ns_common(__ns), to_ns_tree(__ns)) + +/** + * ns_tree_remove - Remove a namespace from a namespace tree + * @ns: Namespace to remove + * + * This function removes a namespace from the appropriate namespace + * tree and list. + */ +#define ns_tree_remove(__ns) __ns_tree_remove(to_ns_common(__ns), to_ns_tree(__ns)) + +#define ns_tree_adjoined_rcu(__ns, __previous) \ + __ns_tree_adjoined_rcu(to_ns_common(__ns), to_ns_tree(__ns), __previous) + +#define ns_tree_active(__ns) (!RB_EMPTY_NODE(&to_ns_common(__ns)->ns_tree_node)) + +#endif /* _LINUX_NSTREE_H */ diff --git a/include/linux/proc_ns.h b/include/linux/proc_ns.h index e50d312f9fee..7f89f0829e60 100644 --- a/include/linux/proc_ns.h +++ b/include/linux/proc_ns.h @@ -79,6 +79,9 @@ static inline int ns_common_init(struct ns_common *ns, refcount_set(&ns->count, 1); ns->stashed = NULL; ns->ops = ops; + ns->ns_id = 0; + RB_CLEAR_NODE(&ns->ns_tree_node); + INIT_LIST_HEAD(&ns->ns_list_node); return 0; } diff --git a/kernel/Makefile b/kernel/Makefile index c60623448235..b807516a1b43 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -8,7 +8,7 @@ obj-y = fork.o exec_domain.o panic.o \ sysctl.o capability.o ptrace.o user.o \ signal.o sys.o umh.o workqueue.o pid.o task_work.o \ extable.o params.o \ - kthread.o sys_ni.o nsproxy.o \ + kthread.o sys_ni.o nsproxy.o nstree.o \ notifier.o ksysfs.o cred.o reboot.o \ async.o range.o smpboot.o ucount.o regset.o ksyms_common.o diff --git a/kernel/nstree.c b/kernel/nstree.c new file mode 100644 index 000000000000..bbe8bedc924c --- /dev/null +++ b/kernel/nstree.c @@ -0,0 +1,233 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include +#include +#include + +struct ns_tree mnt_ns_tree = { + .ns_tree = RB_ROOT, + .ns_list = LIST_HEAD_INIT(mnt_ns_tree.ns_list), + .ns_tree_lock = __SEQLOCK_UNLOCKED(mnt_ns_tree.ns_tree_lock), + .type = CLONE_NEWNS, +}; + +struct ns_tree net_ns_tree = { + .ns_tree = RB_ROOT, + .ns_list = LIST_HEAD_INIT(net_ns_tree.ns_list), + .ns_tree_lock = __SEQLOCK_UNLOCKED(net_ns_tree.ns_tree_lock), + .type = CLONE_NEWNET, +}; +EXPORT_SYMBOL_GPL(net_ns_tree); + +struct ns_tree uts_ns_tree = { + .ns_tree = RB_ROOT, + .ns_list = LIST_HEAD_INIT(uts_ns_tree.ns_list), + .ns_tree_lock = __SEQLOCK_UNLOCKED(uts_ns_tree.ns_tree_lock), + .type = CLONE_NEWUTS, +}; + +struct ns_tree user_ns_tree = { + .ns_tree = RB_ROOT, + .ns_list = LIST_HEAD_INIT(user_ns_tree.ns_list), + .ns_tree_lock = __SEQLOCK_UNLOCKED(user_ns_tree.ns_tree_lock), + .type = CLONE_NEWUSER, +}; + +struct ns_tree ipc_ns_tree = { + .ns_tree = RB_ROOT, + .ns_list = LIST_HEAD_INIT(ipc_ns_tree.ns_list), + .ns_tree_lock = __SEQLOCK_UNLOCKED(ipc_ns_tree.ns_tree_lock), + .type = CLONE_NEWIPC, +}; + +struct ns_tree pid_ns_tree = { + .ns_tree = RB_ROOT, + .ns_list = LIST_HEAD_INIT(pid_ns_tree.ns_list), + .ns_tree_lock = __SEQLOCK_UNLOCKED(pid_ns_tree.ns_tree_lock), + .type = CLONE_NEWPID, +}; + +struct ns_tree cgroup_ns_tree = { + .ns_tree = RB_ROOT, + .ns_list = LIST_HEAD_INIT(cgroup_ns_tree.ns_list), + .ns_tree_lock = __SEQLOCK_UNLOCKED(cgroup_ns_tree.ns_tree_lock), + .type = CLONE_NEWCGROUP, +}; + +struct ns_tree time_ns_tree = { + .ns_tree = RB_ROOT, + .ns_list = LIST_HEAD_INIT(time_ns_tree.ns_list), + .ns_tree_lock = __SEQLOCK_UNLOCKED(time_ns_tree.ns_tree_lock), + .type = CLONE_NEWTIME, +}; + +DEFINE_COOKIE(namespace_cookie); + +static inline struct ns_common *node_to_ns(const struct rb_node *node) +{ + if (!node) + return NULL; + return rb_entry(node, struct ns_common, ns_tree_node); +} + +static inline int ns_cmp(struct rb_node *a, const struct rb_node *b) +{ + struct ns_common *ns_a = node_to_ns(a); + struct ns_common *ns_b = node_to_ns(b); + u64 ns_id_a = ns_a->ns_id; + u64 ns_id_b = ns_b->ns_id; + + if (ns_id_a < ns_id_b) + return -1; + if (ns_id_a > ns_id_b) + return 1; + return 0; +} + +void __ns_tree_add_raw(struct ns_common *ns, struct ns_tree *ns_tree) +{ + struct rb_node *node, *prev; + + VFS_WARN_ON_ONCE(!ns->ns_id); + + write_seqlock(&ns_tree->ns_tree_lock); + + VFS_WARN_ON_ONCE(ns->ops->type != ns_tree->type); + + node = rb_find_add_rcu(&ns->ns_tree_node, &ns_tree->ns_tree, ns_cmp); + /* + * If there's no previous entry simply add it after the + * head and if there is add it after the previous entry. + */ + prev = rb_prev(&ns->ns_tree_node); + if (!prev) + list_add_rcu(&ns->ns_list_node, &ns_tree->ns_list); + else + list_add_rcu(&ns->ns_list_node, &node_to_ns(prev)->ns_list_node); + + write_sequnlock(&ns_tree->ns_tree_lock); + + VFS_WARN_ON_ONCE(node); +} + +void __ns_tree_remove(struct ns_common *ns, struct ns_tree *ns_tree) +{ + VFS_WARN_ON_ONCE(RB_EMPTY_NODE(&ns->ns_tree_node)); + VFS_WARN_ON_ONCE(list_empty(&ns->ns_list_node)); + VFS_WARN_ON_ONCE(ns->ops->type != ns_tree->type); + + write_seqlock(&ns_tree->ns_tree_lock); + rb_erase(&ns->ns_tree_node, &ns_tree->ns_tree); + list_bidir_del_rcu(&ns->ns_list_node); + RB_CLEAR_NODE(&ns->ns_tree_node); + write_sequnlock(&ns_tree->ns_tree_lock); +} +EXPORT_SYMBOL_GPL(__ns_tree_remove); + +static int ns_find(const void *key, const struct rb_node *node) +{ + const u64 ns_id = *(u64 *)key; + const struct ns_common *ns = node_to_ns(node); + + if (ns_id < ns->ns_id) + return -1; + if (ns_id > ns->ns_id) + return 1; + return 0; +} + + +static struct ns_tree *ns_tree_from_type(int ns_type) +{ + switch (ns_type) { + case CLONE_NEWCGROUP: + return &cgroup_ns_tree; + case CLONE_NEWIPC: + return &ipc_ns_tree; + case CLONE_NEWNS: + return &mnt_ns_tree; + case CLONE_NEWNET: + return &net_ns_tree; + case CLONE_NEWPID: + return &pid_ns_tree; + case CLONE_NEWUSER: + return &user_ns_tree; + case CLONE_NEWUTS: + return &uts_ns_tree; + case CLONE_NEWTIME: + return &time_ns_tree; + } + + return NULL; +} + +struct ns_common *ns_tree_lookup_rcu(u64 ns_id, int ns_type) +{ + struct ns_tree *ns_tree; + struct rb_node *node; + unsigned int seq; + + RCU_LOCKDEP_WARN(!rcu_read_lock_held(), "suspicious ns_tree_lookup_rcu() usage"); + + ns_tree = ns_tree_from_type(ns_type); + if (!ns_tree) + return NULL; + + do { + seq = read_seqbegin(&ns_tree->ns_tree_lock); + node = rb_find_rcu(&ns_id, &ns_tree->ns_tree, ns_find); + if (node) + break; + } while (read_seqretry(&ns_tree->ns_tree_lock, seq)); + + if (!node) + return NULL; + + VFS_WARN_ON_ONCE(node_to_ns(node)->ops->type != ns_type); + + return node_to_ns(node); +} + +/** + * ns_tree_adjoined_rcu - find the next/previous namespace in the same + * tree + * @ns: namespace to start from + * @previous: if true find the previous namespace, otherwise the next + * + * Find the next or previous namespace in the same tree as @ns. If + * there is no next/previous namespace, -ENOENT is returned. + */ +struct ns_common *__ns_tree_adjoined_rcu(struct ns_common *ns, + struct ns_tree *ns_tree, bool previous) +{ + struct list_head *list; + + RCU_LOCKDEP_WARN(!rcu_read_lock_held(), "suspicious ns_tree_adjoined_rcu() usage"); + + if (previous) + list = rcu_dereference(list_bidir_prev_rcu(&ns->ns_list_node)); + else + list = rcu_dereference(list_next_rcu(&ns->ns_list_node)); + if (list_is_head(list, &ns_tree->ns_list)) + return ERR_PTR(-ENOENT); + + VFS_WARN_ON_ONCE(list_entry_rcu(list, struct ns_common, ns_list_node)->ops->type != ns_tree->type); + + return list_entry_rcu(list, struct ns_common, ns_list_node); +} + +/** + * ns_tree_gen_id - generate a new namespace id + * @ns: namespace to generate id for + * + * Generates a new namespace id and assigns it to the namespace. All + * namespaces types share the same id space and thus can be compared + * directly. IOW, when two ids of two namespace are equal, they are + * identical. + */ +u64 ns_tree_gen_id(struct ns_common *ns) +{ + guard(preempt)(); + ns->ns_id = gen_cookie_next(&namespace_cookie); + return ns->ns_id; +} -- cgit v1.2.3 From b36c823b9a4be5b0c8e38c3fd60cade7d41c216c Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:46 +0200 Subject: time: support ns lookup Support the generic ns lookup infrastructure to support file handles for namespaces. Reviewed-by: Thomas Gleixner Signed-off-by: Christian Brauner --- include/linux/time_namespace.h | 5 +++++ init/main.c | 2 ++ kernel/time/namespace.c | 11 ++++++++++- 3 files changed, 17 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index bb2c52f4fc94..7f6af7a9771e 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -33,6 +33,7 @@ struct time_namespace { extern struct time_namespace init_time_ns; #ifdef CONFIG_TIME_NS +void __init time_ns_init(void); extern int vdso_join_timens(struct task_struct *task, struct time_namespace *ns); extern void timens_commit(struct task_struct *tsk, struct time_namespace *ns); @@ -108,6 +109,10 @@ static inline ktime_t timens_ktime_to_host(clockid_t clockid, ktime_t tim) } #else +static inline void __init time_ns_init(void) +{ +} + static inline int vdso_join_timens(struct task_struct *task, struct time_namespace *ns) { diff --git a/init/main.c b/init/main.c index 0ee0ee7b7c2c..e7d2c57c65a7 100644 --- a/init/main.c +++ b/init/main.c @@ -103,6 +103,7 @@ #include #include #include +#include #include #include @@ -1072,6 +1073,7 @@ void start_kernel(void) fork_init(); proc_caches_init(); uts_ns_init(); + time_ns_init(); key_init(); security_init(); dbg_late_init(); diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index 0be93d8f2896..408f60d0a3b6 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -104,6 +105,7 @@ static struct time_namespace *clone_time_ns(struct user_namespace *user_ns, ns->user_ns = get_user_ns(user_ns); ns->offsets = old_ns->offsets; ns->frozen_offsets = false; + ns_tree_add(ns); return ns; fail_free_page: @@ -250,11 +252,13 @@ out: void free_time_ns(struct time_namespace *ns) { + ns_tree_remove(ns); dec_time_namespaces(ns->ucounts); put_user_ns(ns->user_ns); ns_free_inum(&ns->ns); __free_page(ns->vvar_page); - kfree(ns); + /* Concurrent nstree traversal depends on a grace period. */ + kfree_rcu(ns, ns.ns_rcu); } static struct time_namespace *to_time_ns(struct ns_common *ns) @@ -487,3 +491,8 @@ struct time_namespace init_time_ns = { .ns.ops = &timens_operations, .frozen_offsets = true, }; + +void __init time_ns_init(void) +{ + ns_tree_add(&init_time_ns); +} -- cgit v1.2.3 From d7afdf889561058068ab46fd8f306c70ef29216a Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:49 +0200 Subject: ns: add to__ns() to respective headers Every namespace type has a container_of(ns, , ns) static inline function that is currently not exposed in the header. So we have a bunch of places that open-code it via container_of(). Move it to the headers so we can use it directly. Reviewed-by: Aleksa Sarai Signed-off-by: Christian Brauner --- include/linux/cgroup.h | 5 +++++ include/linux/ipc_namespace.h | 5 +++++ include/linux/pid_namespace.h | 5 +++++ include/linux/time_namespace.h | 4 ++++ include/linux/user_namespace.h | 5 +++++ include/linux/utsname.h | 5 +++++ include/net/net_namespace.h | 5 +++++ ipc/namespace.c | 5 ----- kernel/cgroup/namespace.c | 5 ----- kernel/pid_namespace.c | 5 ----- kernel/time/namespace.c | 5 ----- kernel/user_namespace.c | 5 ----- kernel/utsname.c | 5 ----- net/core/net_namespace.c | 5 ----- 14 files changed, 34 insertions(+), 35 deletions(-) (limited to 'include/linux') diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index b18fb5fcb38e..9ca25346f7cb 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -794,6 +794,11 @@ extern struct cgroup_namespace init_cgroup_ns; #ifdef CONFIG_CGROUPS +static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) +{ + return container_of(ns, struct cgroup_namespace, ns); +} + void free_cgroup_ns(struct cgroup_namespace *ns); struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h index e8240cf2611a..924e4754374f 100644 --- a/include/linux/ipc_namespace.h +++ b/include/linux/ipc_namespace.h @@ -129,6 +129,11 @@ static inline int mq_init_ns(struct ipc_namespace *ns) { return 0; } #endif #if defined(CONFIG_IPC_NS) +static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns) +{ + return container_of(ns, struct ipc_namespace, ns); +} + extern struct ipc_namespace *copy_ipcs(unsigned long flags, struct user_namespace *user_ns, struct ipc_namespace *ns); diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h index 7c67a5811199..ba0efc8c8596 100644 --- a/include/linux/pid_namespace.h +++ b/include/linux/pid_namespace.h @@ -54,6 +54,11 @@ extern struct pid_namespace init_pid_ns; #define PIDNS_ADDING (1U << 31) #ifdef CONFIG_PID_NS +static inline struct pid_namespace *to_pid_ns(struct ns_common *ns) +{ + return container_of(ns, struct pid_namespace, ns); +} + static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns) { if (ns != &init_pid_ns) diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h index 7f6af7a9771e..a47a4ce4183e 100644 --- a/include/linux/time_namespace.h +++ b/include/linux/time_namespace.h @@ -33,6 +33,10 @@ struct time_namespace { extern struct time_namespace init_time_ns; #ifdef CONFIG_TIME_NS +static inline struct time_namespace *to_time_ns(struct ns_common *ns) +{ + return container_of(ns, struct time_namespace, ns); +} void __init time_ns_init(void); extern int vdso_join_timens(struct task_struct *task, struct time_namespace *ns); diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h index a0bb6d012137..a09056ad090e 100644 --- a/include/linux/user_namespace.h +++ b/include/linux/user_namespace.h @@ -168,6 +168,11 @@ static inline void set_userns_rlimit_max(struct user_namespace *ns, #ifdef CONFIG_USER_NS +static inline struct user_namespace *to_user_ns(struct ns_common *ns) +{ + return container_of(ns, struct user_namespace, ns); +} + static inline struct user_namespace *get_user_ns(struct user_namespace *ns) { if (ns) diff --git a/include/linux/utsname.h b/include/linux/utsname.h index bf7613ba412b..5d34c4f0f945 100644 --- a/include/linux/utsname.h +++ b/include/linux/utsname.h @@ -30,6 +30,11 @@ struct uts_namespace { extern struct uts_namespace init_uts_ns; #ifdef CONFIG_UTS_NS +static inline struct uts_namespace *to_uts_ns(struct ns_common *ns) +{ + return container_of(ns, struct uts_namespace, ns); +} + static inline void get_uts_ns(struct uts_namespace *ns) { refcount_inc(&ns->ns.count); diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 025a7574b275..fd090ceb80bf 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -262,6 +262,11 @@ void ipx_unregister_sysctl(void); #ifdef CONFIG_NET_NS void __put_net(struct net *net); +static inline struct net *to_net_ns(struct ns_common *ns) +{ + return container_of(ns, struct net, ns); +} + /* Try using get_net_track() instead */ static inline struct net *get_net(struct net *net) { diff --git a/ipc/namespace.c b/ipc/namespace.c index 9f923c1a1eb3..89588819956b 100644 --- a/ipc/namespace.c +++ b/ipc/namespace.c @@ -209,11 +209,6 @@ void put_ipc_ns(struct ipc_namespace *ns) } } -static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns) -{ - return container_of(ns, struct ipc_namespace, ns); -} - static struct ns_common *ipcns_get(struct task_struct *task) { struct ipc_namespace *ns = NULL; diff --git a/kernel/cgroup/namespace.c b/kernel/cgroup/namespace.c index fc12c416dfeb..5a327914b565 100644 --- a/kernel/cgroup/namespace.c +++ b/kernel/cgroup/namespace.c @@ -89,11 +89,6 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, return new_ns; } -static inline struct cgroup_namespace *to_cg_ns(struct ns_common *ns) -{ - return container_of(ns, struct cgroup_namespace, ns); -} - static int cgroupns_install(struct nsset *nsset, struct ns_common *ns) { struct nsproxy *nsproxy = nsset->nsproxy; diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 228ae20299f9..9b327420309e 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -345,11 +345,6 @@ int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd) return 0; } -static inline struct pid_namespace *to_pid_ns(struct ns_common *ns) -{ - return container_of(ns, struct pid_namespace, ns); -} - static struct ns_common *pidns_get(struct task_struct *task) { struct pid_namespace *ns; diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c index 408f60d0a3b6..20b65f90549e 100644 --- a/kernel/time/namespace.c +++ b/kernel/time/namespace.c @@ -261,11 +261,6 @@ void free_time_ns(struct time_namespace *ns) kfree_rcu(ns, ns.ns_rcu); } -static struct time_namespace *to_time_ns(struct ns_common *ns) -{ - return container_of(ns, struct time_namespace, ns); -} - static struct ns_common *timens_get(struct task_struct *task) { struct time_namespace *ns = NULL; diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index ade5b6806c5c..cfb0e28f2779 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -1325,11 +1325,6 @@ bool current_in_userns(const struct user_namespace *target_ns) } EXPORT_SYMBOL(current_in_userns); -static inline struct user_namespace *to_user_ns(struct ns_common *ns) -{ - return container_of(ns, struct user_namespace, ns); -} - static struct ns_common *userns_get(struct task_struct *task) { struct user_namespace *user_ns; diff --git a/kernel/utsname.c b/kernel/utsname.c index 64155417ae0c..a682830742d3 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -103,11 +103,6 @@ void free_uts_ns(struct uts_namespace *ns) kfree_rcu(ns, ns.ns_rcu); } -static inline struct uts_namespace *to_uts_ns(struct ns_common *ns) -{ - return container_of(ns, struct uts_namespace, ns); -} - static struct ns_common *utsns_get(struct task_struct *task) { struct uts_namespace *ns = NULL; diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 169ec22c4758..a57b3cda8dbc 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -1541,11 +1541,6 @@ static struct ns_common *netns_get(struct task_struct *task) return net ? &net->ns : NULL; } -static inline struct net *to_net_ns(struct ns_common *ns) -{ - return container_of(ns, struct net, ns); -} - static void netns_put(struct ns_common *ns) { put_net(to_net_ns(ns)); -- cgit v1.2.3 From d2afdb73f8ad77b49eca9d110d0c54bf30d1df0f Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:50 +0200 Subject: nsfs: add current_in_namespace() Add a helper to easily check whether a given namespace is the caller's current namespace. This is currently open-coded in a lot of places. Simply switch on the type and compare the results. Reviewed-by: Aleksa Sarai Signed-off-by: Christian Brauner --- include/linux/nsfs.h | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/nsfs.h b/include/linux/nsfs.h index fb84aa538091..e5a5fa83d36b 100644 --- a/include/linux/nsfs.h +++ b/include/linux/nsfs.h @@ -5,6 +5,8 @@ #define _LINUX_NSFS_H #include +#include +#include struct path; struct task_struct; @@ -22,5 +24,17 @@ int ns_get_name(char *buf, size_t size, struct task_struct *task, const struct proc_ns_operations *ns_ops); void nsfs_init(void); -#endif /* _LINUX_NSFS_H */ +#define __current_namespace_from_type(__ns) \ + _Generic((__ns), \ + struct cgroup_namespace *: current->nsproxy->cgroup_ns, \ + struct ipc_namespace *: current->nsproxy->ipc_ns, \ + struct net *: current->nsproxy->net_ns, \ + struct pid_namespace *: task_active_pid_ns(current), \ + struct mnt_namespace *: current->nsproxy->mnt_ns, \ + struct time_namespace *: current->nsproxy->time_ns, \ + struct user_namespace *: current_user_ns(), \ + struct uts_namespace *: current->nsproxy->uts_ns) + +#define current_in_namespace(__ns) (__current_namespace_from_type(__ns) == __ns) +#endif /* _LINUX_NSFS_H */ -- cgit v1.2.3 From 5222470b2fbb3740f931f189db33dd1367b1ae75 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:51 +0200 Subject: nsfs: support file handles A while ago we added support for file handles to pidfs so pidfds can be encoded and decoded as file handles. Userspace has adopted this quickly and it's proven very useful. Implement file handles for namespaces as well. A process is not always able to open /proc/self/ns/. That requires procfs to be mounted and for /proc/self/ or /proc/self/ns/ to not be overmounted. However, userspace can always derive a namespace fd from a pidfd. And that always works for a task's own namespace. There's no need to introduce unnecessary behavioral differences between /proc/self/ns/ fds, pidfd-derived namespace fds, and file-handle-derived namespace fds. So namespace file handles are always decodable if the caller is located in the namespace the file handle refers to. This also allows a task to e.g., store a set of file handles to its namespaces in a file on-disk so it can verify when it gets rexeced that they're still valid and so on. This is akin to the pidfd use-case. Or just plainly for namespace comparison reasons where a file handle to the task's own namespace can be easily compared against others. Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner --- fs/nsfs.c | 158 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/exportfs.h | 6 ++ include/uapi/linux/nsfs.h | 9 +++ 3 files changed, 173 insertions(+) (limited to 'include/linux') diff --git a/fs/nsfs.c b/fs/nsfs.c index 80e631aeb3ce..926e2680414e 100644 --- a/fs/nsfs.c +++ b/fs/nsfs.c @@ -13,6 +13,12 @@ #include #include #include +#include +#include +#include +#include +#include +#include #include "mount.h" #include "internal.h" @@ -417,12 +423,164 @@ static const struct stashed_operations nsfs_stashed_ops = { .put_data = nsfs_put_data, }; +#define NSFS_FID_SIZE_U32_VER0 (NSFS_FILE_HANDLE_SIZE_VER0 / sizeof(u32)) +#define NSFS_FID_SIZE_U32_LATEST (NSFS_FILE_HANDLE_SIZE_LATEST / sizeof(u32)) + +static int nsfs_encode_fh(struct inode *inode, u32 *fh, int *max_len, + struct inode *parent) +{ + struct nsfs_file_handle *fid = (struct nsfs_file_handle *)fh; + struct ns_common *ns = inode->i_private; + int len = *max_len; + + if (parent) + return FILEID_INVALID; + + if (len < NSFS_FID_SIZE_U32_VER0) { + *max_len = NSFS_FID_SIZE_U32_LATEST; + return FILEID_INVALID; + } else if (len > NSFS_FID_SIZE_U32_LATEST) { + *max_len = NSFS_FID_SIZE_U32_LATEST; + } + + fid->ns_id = ns->ns_id; + fid->ns_type = ns->ops->type; + fid->ns_inum = inode->i_ino; + return FILEID_NSFS; +} + +static struct dentry *nsfs_fh_to_dentry(struct super_block *sb, struct fid *fh, + int fh_len, int fh_type) +{ + struct path path __free(path_put) = {}; + struct nsfs_file_handle *fid = (struct nsfs_file_handle *)fh; + struct user_namespace *owning_ns = NULL; + struct ns_common *ns; + int ret; + + if (fh_len < NSFS_FID_SIZE_U32_VER0) + return NULL; + + /* Check that any trailing bytes are zero. */ + if ((fh_len > NSFS_FID_SIZE_U32_LATEST) && + memchr_inv((void *)fid + NSFS_FID_SIZE_U32_LATEST, 0, + fh_len - NSFS_FID_SIZE_U32_LATEST)) + return NULL; + + switch (fh_type) { + case FILEID_NSFS: + break; + default: + return NULL; + } + + scoped_guard(rcu) { + ns = ns_tree_lookup_rcu(fid->ns_id, fid->ns_type); + if (!ns) + return NULL; + + VFS_WARN_ON_ONCE(ns->ns_id != fid->ns_id); + VFS_WARN_ON_ONCE(ns->ops->type != fid->ns_type); + VFS_WARN_ON_ONCE(ns->inum != fid->ns_inum); + + if (!refcount_inc_not_zero(&ns->count)) + return NULL; + } + + switch (ns->ops->type) { +#ifdef CONFIG_CGROUPS + case CLONE_NEWCGROUP: + if (!current_in_namespace(to_cg_ns(ns))) + owning_ns = to_cg_ns(ns)->user_ns; + break; +#endif +#ifdef CONFIG_IPC_NS + case CLONE_NEWIPC: + if (!current_in_namespace(to_ipc_ns(ns))) + owning_ns = to_ipc_ns(ns)->user_ns; + break; +#endif + case CLONE_NEWNS: + if (!current_in_namespace(to_mnt_ns(ns))) + owning_ns = to_mnt_ns(ns)->user_ns; + break; +#ifdef CONFIG_NET_NS + case CLONE_NEWNET: + if (!current_in_namespace(to_net_ns(ns))) + owning_ns = to_net_ns(ns)->user_ns; + break; +#endif +#ifdef CONFIG_PID_NS + case CLONE_NEWPID: + if (!current_in_namespace(to_pid_ns(ns))) { + owning_ns = to_pid_ns(ns)->user_ns; + } else if (!READ_ONCE(to_pid_ns(ns)->child_reaper)) { + ns->ops->put(ns); + return ERR_PTR(-EPERM); + } + break; +#endif +#ifdef CONFIG_TIME_NS + case CLONE_NEWTIME: + if (!current_in_namespace(to_time_ns(ns))) + owning_ns = to_time_ns(ns)->user_ns; + break; +#endif +#ifdef CONFIG_USER_NS + case CLONE_NEWUSER: + if (!current_in_namespace(to_user_ns(ns))) + owning_ns = to_user_ns(ns); + break; +#endif +#ifdef CONFIG_UTS_NS + case CLONE_NEWUTS: + if (!current_in_namespace(to_uts_ns(ns))) + owning_ns = to_uts_ns(ns)->user_ns; + break; +#endif + default: + return ERR_PTR(-EOPNOTSUPP); + } + + if (owning_ns && !ns_capable(owning_ns, CAP_SYS_ADMIN)) { + ns->ops->put(ns); + return ERR_PTR(-EPERM); + } + + /* path_from_stashed() unconditionally consumes the reference. */ + ret = path_from_stashed(&ns->stashed, nsfs_mnt, ns, &path); + if (ret) + return ERR_PTR(ret); + + return no_free_ptr(path.dentry); +} + +static int nsfs_export_permission(struct handle_to_path_ctx *ctx, + unsigned int oflags) +{ + /* nsfs_fh_to_dentry() performs all permission checks. */ + return 0; +} + +static struct file *nsfs_export_open(struct path *path, unsigned int oflags) +{ + return file_open_root(path, "", oflags, 0); +} + +static const struct export_operations nsfs_export_operations = { + .encode_fh = nsfs_encode_fh, + .fh_to_dentry = nsfs_fh_to_dentry, + .open = nsfs_export_open, + .permission = nsfs_export_permission, +}; + static int nsfs_init_fs_context(struct fs_context *fc) { struct pseudo_fs_context *ctx = init_pseudo(fc, NSFS_MAGIC); if (!ctx) return -ENOMEM; ctx->ops = &nsfs_ops; + ctx->eops = &nsfs_export_operations; ctx->dops = &ns_dentry_operations; fc->s_fs_info = (void *)&nsfs_stashed_ops; return 0; diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index cfb0dd1ea49c..3aac58a520c7 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -122,6 +122,12 @@ enum fid_type { FILEID_BCACHEFS_WITHOUT_PARENT = 0xb1, FILEID_BCACHEFS_WITH_PARENT = 0xb2, + /* + * + * 64 bit namespace identifier, 32 bit namespace type, 32 bit inode number. + */ + FILEID_NSFS = 0xf1, + /* * 64 bit unique kernfs id */ diff --git a/include/uapi/linux/nsfs.h b/include/uapi/linux/nsfs.h index 97d8d80d139f..fa86fe3c8bd3 100644 --- a/include/uapi/linux/nsfs.h +++ b/include/uapi/linux/nsfs.h @@ -53,4 +53,13 @@ enum init_ns_ino { MNT_NS_INIT_INO = 0xEFFFFFF8U, }; +struct nsfs_file_handle { + __u64 ns_id; + __u32 ns_type; + __u32 ns_inum; +}; + +#define NSFS_FILE_HANDLE_SIZE_VER0 16 /* sizeof first published struct */ +#define NSFS_FILE_HANDLE_SIZE_LATEST sizeof(struct nsfs_file_handle) /* sizeof latest published struct */ + #endif /* __LINUX_NSFS_H */ -- cgit v1.2.3