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gcc-4.6: printk: use stable variable to dump kmsg buffer

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kmsg_dump takes care to sample the global variables
inside a spinlock, but then goes on to use the same
variables outside the spinlock region too.

Use the correct variable. This will make the race
window smaller.

Found by gcc 4.6's new warnings.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andi Kleen 2010-08-09 17:20:36 -07:00 committed by Linus Torvalds
parent 547415d5ed
commit 8c4af38e9b
1 changed files with 5 additions and 5 deletions
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10
kernel/printk.c
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@ -1549,9 +1549,9 @@ void kmsg_dump(enum kmsg_dump_reason reason)
chars = logged_chars;
spin_unlock_irqrestore(&logbuf_lock, flags);
if (logged_chars > end) {
s1 = log_buf + log_buf_len - logged_chars + end;
l1 = logged_chars - end;
if (chars > end) {
s1 = log_buf + log_buf_len - chars + end;
l1 = chars - end;
s2 = log_buf;
l2 = end;
@ -1559,8 +1559,8 @@ void kmsg_dump(enum kmsg_dump_reason reason)
s1 = "";
l1 = 0;
s2 = log_buf + end - logged_chars;
l2 = logged_chars;
s2 = log_buf + end - chars;
l2 = chars;
}
if (!spin_trylock_irqsave(&dump_list_lock, flags)) {