The patch titled Subject: bounds: use the right number of bits for power-of-two CONFIG_NR_CPUS has been added to the -mm mm-hotfixes-unstable branch. Its filename is bounds-use-the-right-number-of-bits-for-power-of-two-config_nr_cpus.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days
------------------------------------------------------ From: "Matthew Wilcox (Oracle)" willy@infradead.org Subject: bounds: use the right number of bits for power-of-two CONFIG_NR_CPUS Date: Mon, 29 Apr 2024 15:47:51 +0100
bits_per() rounds up to the next power of two when passed a power of two. This causes crashes on some machines and configurations.
Link: https://lkml.kernel.org/r/20240429144807.3012361-1-willy@infradead.org Fixes: f2d5dcb48f7b (bounds: support non-power-of-two CONFIG_NR_CPUS) Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Reported-by: ������������ ������������������ m.novosyolov@rosalinux.ru Tested-by: ������������ ������������������������ i.gaptrakhmanov@rosalinux.ru Link: https://gitlab.freedesktop.org/drm/amd/-/issues/3347 Link: https://lore.kernel.org/all/1c978cf1-2934-4e66-e4b3-e81b04cb3571@rosalinux.r... Cc: Rik van Riel riel@surriel.com Cc: Mel Gorman mgorman@techsingularity.net Cc: Peter Zijlstra peterz@infradead.org Cc: Ingo Molnar mingo@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
kernel/bounds.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/bounds.c~bounds-use-the-right-number-of-bits-for-power-of-two-config_nr_cpus +++ a/kernel/bounds.c @@ -19,7 +19,7 @@ int main(void) DEFINE(NR_PAGEFLAGS, __NR_PAGEFLAGS); DEFINE(MAX_NR_ZONES, __MAX_NR_ZONES); #ifdef CONFIG_SMP - DEFINE(NR_CPUS_BITS, bits_per(CONFIG_NR_CPUS)); + DEFINE(NR_CPUS_BITS, bits_per(CONFIG_NR_CPUS - 1)); #endif DEFINE(SPINLOCK_SIZE, sizeof(spinlock_t)); #ifdef CONFIG_LRU_GEN _
Patches currently in -mm which might be from willy@infradead.org are
bounds-use-the-right-number-of-bits-for-power-of-two-config_nr_cpus.patch doc-improve-the-description-of-__folio_mark_dirty.patch buffer-add-kernel-doc-for-block_dirty_folio.patch buffer-add-kernel-doc-for-try_to_free_buffers.patch buffer-fix-__bread-and-__bread_gfp-kernel-doc.patch buffer-add-kernel-doc-for-brelse-and-__brelse.patch buffer-add-kernel-doc-for-bforget-and-__bforget.patch buffer-improve-bdev_getblk-documentation.patch doc-split-bufferrst-out-of-api-summaryrst.patch doc-split-bufferrst-out-of-api-summaryrst-fix.patch mm-memory-failure-remove-fsdax_pgoff-argument-from-__add_to_kill.patch mm-memory-failure-pass-addr-to-__add_to_kill.patch mm-return-the-address-from-page_mapped_in_vma.patch mm-make-page_mapped_in_vma-conditional-on-config_memory_failure.patch mm-memory-failure-convert-shake_page-to-shake_folio.patch mm-convert-hugetlb_page_mapping_lock_write-to-folio.patch mm-memory-failure-convert-memory_failure-to-use-a-folio.patch mm-memory-failure-convert-hwpoison_user_mappings-to-take-a-folio.patch mm-memory-failure-add-some-folio-conversions-to-unpoison_memory.patch mm-memory-failure-use-folio-functions-throughout-collect_procs.patch mm-memory-failure-pass-the-folio-to-collect_procs_ksm.patch fscrypt-convert-bh_get_inode_and_lblk_num-to-use-a-folio.patch f2fs-convert-f2fs_clear_page_cache_dirty_tag-to-use-a-folio.patch memory-failure-remove-calls-to-page_mapping.patch migrate-expand-the-use-of-folio-in-__migrate_device_pages.patch userfault-expand-folio-use-in-mfill_atomic_install_pte.patch mm-remove-page_mapping.patch mm-remove-page_cache_alloc.patch mm-remove-put_devmap_managed_page.patch mm-convert-put_devmap_managed_page_refs-to-put_devmap_managed_folio_refs.patch mm-remove-page_ref_sub_return.patch gup-use-folios-for-gup_devmap.patch mm-add-kernel-doc-for-folio_mark_accessed.patch mm-remove-pagereferenced.patch mm-simplify-thp_vma_allowable_order.patch mm-assert-the-mmap_lock-is-held-in-__anon_vma_prepare.patch mm-delay-the-check-for-a-null-anon_vma.patch mm-fix-some-minor-per-vma-lock-issues-in-userfaultfd.patch mm-optimise-vmf_anon_prepare-for-vmas-without-an-anon_vma.patch squashfs-convert-squashfs_symlink_read_folio-to-use-folio-apis.patch squashfs-remove-calls-to-set-the-folio-error-flag.patch