kernel/linux.git/arch/powerpc, branch v6.18.33

powerpc/warp: Fix error handling in pika_dtm_thread

2026-05-23T11:07:18+00:00

commit 108d7f951271cbd36ca36efc5e5d106966f5180c upstream. pika_dtm_thread() acquires client through of_find_i2c_device_by_node() but fails to release it in error handling path. This could result in a reference count leak, preventing proper cleanup and potentially leading to resource exhaustion. Add put_device() to release the reference in the error handling path. Found by code review. Cc: stable@vger.kernel.org Fixes: 3984114f0562 ("powerpc/warp: Platform fix for i2c change") Signed-off-by: Ma Ke Reviewed-by: Christophe Leroy Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20251116024411.21968-1-make24@iscas.ac.cn Signed-off-by: Greg Kroah-Hartman

Revert "papr-hvpipe: convert papr_hvpipe_dev_create_handle() to FD_PREPARE()"

2026-05-23T11:07:14+00:00

This reverts commit 09c15bbbed533903e600660ea09098b3b0524f48. Signed-off-by: Sasha Levin

Revert "pseries/papr-hvpipe: Fix race with interrupt handler"

2026-05-23T11:07:14+00:00

This reverts commit 6542e180fa6e1c701aba446a555c65556e6fd1a5. Signed-off-by: Sasha Levin

powerpc/crash: Update backup region offset in elfcorehdr on memory hotplug

2026-05-23T11:06:29+00:00

[ Upstream commit f53b24d1fa263f56155213eabab734c18d884aff ] When elfcorehdr is prepared for kdump, the program header representing the first 64 KB of memory is expected to have its offset point to the backup region. This is required because purgatory copies the first 64 KB of the crashed kernel memory to this backup region following a kernel crash. This allows the capture kernel to use the first 64 KB of memory to place the exception vectors and other required data. When elfcorehdr is recreated due to memory hotplug, the offset of the program header representing the first 64 KB is not updated. As a result, the capture kernel exports the first 64 KB at offset 0, even though the data actually resides in the backup region. Fix this by calling sync_backup_region_phdr() to update the program header offset in the elfcorehdr created during memory hotplug. sync_backup_region_phdr() works for images loaded via the kexec_file_load syscall. However, it does not work for kexec_load, because image->arch.backup_start is not initialized in that case. So introduce machine_kexec_post_load() to process the elfcorehdr prepared by kexec-tools and initialize image->arch.backup_start for kdump images loaded via kexec_load syscall. Rename update_backup_region_phdr() to sync_backup_region_phdr() and extend it to synchronize the backup region offset between the kdump image and the ELF core header. The helper now supports updating either the kdump image from the ELF program header or updating the ELF program header from the kdump image, avoiding code duplication. Define ARCH_HAS_KIMAGE_ARCH and struct kimage_arch when CONFIG_KEXEC_FILE or CONFIG_CRASH_DUMP is enabled so that kimage->arch.backup_start is available with the kexec_load system call. This patch depends on the patch titled "powerpc/crash: fix backup region offset update to elfcorehdr". Fixes: 849599b702ef ("powerpc/crash: add crash memory hotplug support") Reviewed-by: Aditya Gupta Signed-off-by: Sourabh Jain Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260312083051.1935737-3-sourabhjain@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/crash: fix backup region offset update to elfcorehdr

2026-05-23T11:06:29+00:00

[ Upstream commit 789335cacdf37da93bb7c70322dff8c7e82881df ] update_backup_region_phdr() in file_load_64.c iterates over all the program headers in the kdump kernel’s elfcorehdr and updates the p_offset of the program header whose physical address starts at 0. However, the loop logic is incorrect because the program header pointer is not updated during iteration. Since elfcorehdr typically contains PT_NOTE entries first, the PT_LOAD program header with physical address 0 is never reached. As a result, its p_offset is not updated to point to the backup region. Because of this behavior, the capture kernel exports the first 64 KB of the crashed kernel’s memory at offset 0, even though that memory actually lives in the backup region. When a crash happens, purgatory copies the first 64 KB of the crashed kernel’s memory into the backup region so the capture kernel can safely use it. This has not caused problems so far because the first 64 KB is usually identical in both the crashed and capture kernels. However, this is just an assumption and is not guaranteed to always hold true. Fix update_backup_region_phdr() to correctly update the p_offset of the program header with a starting physical address of 0 by correcting the logic used to iterate over the program headers. Fixes: cb350c1f1f86 ("powerpc/kexec_file: Prepare elfcore header for crashing kernel") Reviewed-by: Aditya Gupta Signed-off-by: Sourabh Jain Reviewed-by: Hari Bathini Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260312083051.1935737-2-sourabhjain@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/pgtable-frag: Fix bad page state in pte_frag_destroy

2026-05-23T11:06:26+00:00

[ Upstream commit fda4d71651f71c44b35829d13f3c8bf920032f77 ] powerpc uses pt_frag_refcount as a reference counter for tracking it's pte and pmd page table fragments. For PTE table, in case of Hash with 64K pagesize, we have 16 fragments of 4K size in one 64K page. Patch series [1] "mm: free retracted page table by RCU" added pte_free_defer() to defer the freeing of PTE tables when retract_page_tables() is called for madvise MADV_COLLAPSE on shmem range. [1]: https://lore.kernel.org/all/7cd843a9-aa80-14f-5eb2-33427363c20@google.com/ pte_free_defer() sets the active flag on the corresponding fragment's folio & calls pte_fragment_free(), which reduces the pt_frag_refcount. When pt_frag_refcount reaches 0 (no active fragment using the folio), it checks if the folio active flag is set, if set, it calls call_rcu to free the folio, it the active flag is unset then it calls pte_free_now(). Now, this can lead to following problem in a corner case... [ 265.351553][ T183] BUG: Bad page state in process a.out pfn:20d62 [ 265.353555][ T183] page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20d62 [ 265.355457][ T183] flags: 0x3ffff800000100(active|node=0|zone=0|lastcpupid=0x7ffff) [ 265.358719][ T183] raw: 003ffff800000100 0000000000000000 5deadbeef0000122 0000000000000000 [ 265.360177][ T183] raw: 0000000000000000 c0000000119caf58 00000000ffffffff 0000000000000000 [ 265.361438][ T183] page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set [ 265.362572][ T183] Modules linked in: [ 265.364622][ T183] CPU: 0 UID: 0 PID: 183 Comm: a.out Not tainted 6.18.0-rc3-00141-g1ddeaaace7ff-dirty #53 VOLUNTARY [ 265.364785][ T183] Hardware name: IBM pSeries (emulated by qemu) POWER10 (architected) 0x801200 0xf000006 of:SLOF,git-ee03ae pSeries [ 265.364908][ T183] Call Trace: [ 265.364955][ T183] [c000000011e6f7c0] [c000000001cfaa18] dump_stack_lvl+0x130/0x148 (unreliable) [ 265.365202][ T183] [c000000011e6f7f0] [c000000000794758] bad_page+0xb4/0x1c8 [ 265.365384][ T183] [c000000011e6f890] [c00000000079c020] __free_frozen_pages+0x838/0xd08 [ 265.365554][ T183] [c000000011e6f980] [c0000000000a70ac] pte_frag_destroy+0x298/0x310 [ 265.365729][ T183] [c000000011e6fa30] [c0000000000aa764] arch_exit_mmap+0x34/0x218 [ 265.365912][ T183] [c000000011e6fa80] [c000000000751698] exit_mmap+0xb8/0x820 [ 265.366080][ T183] [c000000011e6fc30] [c0000000001b1258] __mmput+0x98/0x300 [ 265.366244][ T183] [c000000011e6fc80] [c0000000001c81f8] do_exit+0x470/0x1508 [ 265.366421][ T183] [c000000011e6fd70] [c0000000001c95e4] do_group_exit+0x88/0x148 [ 265.366602][ T183] [c000000011e6fdc0] [c0000000001c96ec] pid_child_should_wake+0x0/0x178 [ 265.366780][ T183] [c000000011e6fdf0] [c00000000003a270] system_call_exception+0x1b0/0x4e0 [ 265.366958][ T183] [c000000011e6fe50] [c00000000000d05c] system_call_vectored_common+0x15c/0x2ec The bad page state error occurs when such a folio gets freed (with active flag set), from do_exit() path in parallel. ... this can happen when the pte fragment was allocated from this folio, but when all the fragments get freed, the pte_frag_refcount still had some unused fragments. Now, if this process exits, with such folio as it's cached pte_frag in mm->context, then during pte_frag_destroy(), we simply call pagetable_dtor() and pagetable_free(), meaning it doesn't clear the active flag. This, can lead to the above bug. Since we are anyway in do_exit() path, then if the refcount is 0, then I guess it should be ok to simply clear the folio active flag before calling pagetable_dtor() & pagetable_free(). Fixes: 32cc0b7c9d50 ("powerpc: add pte_free_defer() for pgtables sharing page") Reviewed-by: Christophe Leroy (CS GROUP) Signed-off-by: Ritesh Harjani (IBM) Tested-by: Venkat Rao Bagalkote Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/ee13e7f99b8f258019da2b37655b998e73e5ef8b.1773078178.git.ritesh.list@gmail.com Signed-off-by: Sasha Levin

pseries/papr-hvpipe: Fix race with interrupt handler

2026-05-17T15:15:36+00:00

[ Upstream commit 7a4f0846ee6cc8cf44ae0046ed42e3259d1dd45b ] While executing ->ioctl handler or ->release handler, if an interrupt fires on the same cpu, then we can enter into a deadlock. This patch fixes both these handlers to take spin_lock_irq{save|restore} versions of the lock to prevent this deadlock. Cc: stable@vger.kernel.org Fixes: 814ef095f12c9 ("powerpc/pseries: Add papr-hvpipe char driver for HVPIPE interfaces") Signed-off-by: Ritesh Harjani (IBM) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/e4ed435c44fc191f2eb23c7907ba6f72f193e6aa.1777606826.git.ritesh.list@gmail.com Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

papr-hvpipe: convert papr_hvpipe_dev_create_handle() to FD_PREPARE()

2026-05-17T15:15:36+00:00

[ Upstream commit 6d3789d347a7af5c4b0b2da3af47b8d9da607ab2 ] Fixes a UAF for src_info as well. Link: https://patch.msgid.link/20251123-work-fd-prepare-v4-33-b6efa1706cfd@kernel.org Signed-off-by: Christian Brauner Stable-dep-of: 7a4f0846ee6c ("pseries/papr-hvpipe: Fix race with interrupt handler") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/xive: fix kmemleak caused by incorrect chip_data lookup

2026-05-14T13:30:21+00:00

commit 6771c54728c278bf1e4bfdab4fddbbb186e33498 upstream. The kmemleak reports the following memory leak: Unreferenced object 0xc0000002a7fbc640 (size 64): comm "kworker/8:1", pid 540, jiffies 4294937872 hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 00 00 09 04 00 04 00 00 ................ 00 00 a7 81 00 00 0a c0 00 00 08 04 00 04 00 00 ................ backtrace (crc 177d48f6): __kmalloc_cache_noprof+0x520/0x730 xive_irq_alloc_data.constprop.0+0x40/0xe0 xive_irq_domain_alloc+0xd0/0x1b0 irq_domain_alloc_irqs_parent+0x44/0x6c pseries_irq_domain_alloc+0x1cc/0x354 irq_domain_alloc_irqs_parent+0x44/0x6c msi_domain_alloc+0xb0/0x220 irq_domain_alloc_irqs_locked+0x138/0x4d0 __irq_domain_alloc_irqs+0x8c/0xfc __msi_domain_alloc_irqs+0x214/0x4d8 msi_domain_alloc_irqs_all_locked+0x70/0xf8 pci_msi_setup_msi_irqs+0x60/0x78 __pci_enable_msix_range+0x54c/0x98c pci_alloc_irq_vectors_affinity+0x16c/0x1d4 nvme_pci_enable+0xac/0x9c0 [nvme] nvme_probe+0x340/0x764 [nvme] This occurs when allocating MSI-X vectors for an NVMe device. During allocation the XIVE code creates a struct xive_irq_data and stores it in irq_data->chip_data. When the MSI-X irqdomain is later freed, xive_irq_free_data() is responsible for retrieving this structure and freeing it. However, after commit cc0cc23babc9 ("powerpc/xive: Untangle xive from child interrupt controller drivers"), xive_irq_free_data() retrieves the chip_data using irq_get_chip_data(), which looks up the data through the child domain. This is incorrect because the XIVE-specific irq data is associated with the XIVE (parent) domain. As a result the lookup fails and the allocated struct xive_irq_data is never freed, leading to the kmemleak report shown above. Fix this by retrieving the irq_data from the correct domain using irq_domain_get_irq_data() and then accessing the chip_data via irq_data_get_irq_chip_data(). Cc: stable@vger.kernel.org Fixes: cc0cc23babc9 ("powerpc/xive: Untangle xive from child interrupt controller drivers") Signed-off-by: Nilay Shroff Tested-by: Venkat Rao Bagalkote Reviewed-by: Nam Cao Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20260311134336.326996-1-nilay@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

pseries/papr-hvpipe: Fix the usage of copy_to_user()

2026-05-14T13:30:16+00:00

commit d48654bd8b1a75f662e224d257db54de475120dc upstream. copy_to_user() return bytes_not_copied to the user buffer. If there was an error writing bytes into the user buffer, i.e. if copy_to_user returns a non-zero value, then we should simply return -EFAULT from the ->read() call. Otherwise, in the non-patched version, we may end up mixing "bytes_not_copied + bytes_copied (HVPIPE_HDR_LEN)" as the return value to the user in ->read() call Also let's make sure we clear the hvpipe_status flag, if we have consumed the hvpipe msg by making the rtas call. ret = -EFAULT means copy_to_user has failed but that still means that the msg was read from the hvpipe, hence for both cases, success & -EFAULT, we should clear the HVPIPE_MSG_AVAILABLE flag in hvpipe_status. Cc: stable@vger.kernel.org Fixes: cebdb522fd3edd1 ("powerpc/pseries: Receive payload with ibm,receive-hvpipe-msg RTAS") Signed-off-by: Ritesh Harjani (IBM) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/8fda3212a1ad48879c174e92f67472d9b9f1c3b7.1777606826.git.ritesh.list@gmail.com Signed-off-by: Greg Kroah-Hartman