]> git.proxmox.com Git - mirror_ubuntu-disco-kernel.git/commit
highmem: Fix race in debug_kmap_atomic() which could cause warn_count to underflow
authorSoeren Sandmann <sandmann@daimi.au.dk>
Wed, 28 Oct 2009 17:55:36 +0000 (18:55 +0100)
committerIngo Molnar <mingo@elte.hu>
Tue, 10 Nov 2009 03:15:32 +0000 (04:15 +0100)
commit5ebd4c22897dce65845807a9bd3a31cc4e142b53
treed56865116e9961450c48c46ae3d346956f66b180
parent83f5b01ffbbaea6f97c9a79d21e240dbfb69f2f1
highmem: Fix race in debug_kmap_atomic() which could cause warn_count to underflow

debug_kmap_atomic() tries to prevent ever printing more than 10
warnings, but it does so by testing whether an unsigned integer
is equal to 0. However, if the warning is caused by a nested
IRQ, then this counter may underflow and the stream of warnings
will never end.

Fix that by using a signed integer instead.

Signed-off-by: Soeren Sandmann Pedersen <sandmann@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: a.p.zijlstra@chello.nl
Cc: <stable@kernel.org> # .31.x
LKML-Reference: <ye8zl7b8ktj.fsf@camel23.daimi.au.dk>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
mm/highmem.c