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Commit 8c4af38e authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
Browse files

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



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: default avatarAndi Kleen <ak@linux.intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 547415d5

kernel/printk.c

+5 −5
Original line number Diff line number Diff line
@@ -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)) {