]> git.baikalelectronics.ru Git - kernel.git/commit
mm: slub: add missing TID bump in kmem_cache_alloc_bulk()
authorJann Horn <jannh@google.com>
Tue, 17 Mar 2020 00:28:45 +0000 (01:28 +0100)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 18 Mar 2020 16:21:51 +0000 (09:21 -0700)
commit8bdac38938351b1d3ecfe631d4e2ed449d8b09c2
tree5cee56264d8299427ddebfc0b394f6b4a8f0bcb9
parenteb2708716e4975013a3c71f647ffa27db7bbd2bf
mm: slub: add missing TID bump in kmem_cache_alloc_bulk()

When kmem_cache_alloc_bulk() attempts to allocate N objects from a percpu
freelist of length M, and N > M > 0, it will first remove the M elements
from the percpu freelist, then call ___slab_alloc() to allocate the next
element and repopulate the percpu freelist. ___slab_alloc() can re-enable
IRQs via allocate_slab(), so the TID must be bumped before ___slab_alloc()
to properly commit the freelist head change.

Fix it by unconditionally bumping c->tid when entering the slowpath.

Cc: stable@vger.kernel.org
Fixes: 34093caf9990 ("slub: improve bulk alloc strategy")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/slub.c