From 5ebd4c22897dce65845807a9bd3a31cc4e142b53 Mon Sep 17 00:00:00 2001 From: Soeren Sandmann Date: Wed, 28 Oct 2009 18:55:36 +0100 Subject: 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 Cc: Linus Torvalds Cc: a.p.zijlstra@chello.nl Cc: # .31.x LKML-Reference: Signed-off-by: Ingo Molnar --- mm/highmem.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'mm') diff --git a/mm/highmem.c b/mm/highmem.c index 25878cc49daa..33587de6b871 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -426,9 +426,9 @@ void __init page_address_init(void) void debug_kmap_atomic(enum km_type type) { - static unsigned warn_count = 10; + static int warn_count = 10; - if (unlikely(warn_count == 0)) + if (unlikely(warn_count < 0)) return; if (unlikely(in_interrupt())) { -- cgit v1.2.3