From 8c4af38e9b2c2a78369c4e2e5706fe539ac64eb2 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Mon, 9 Aug 2010 17:20:36 -0700 Subject: [PATCH] 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: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/printk.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/kernel/printk.c b/kernel/printk.c index 4ab0164bcf84..8fe465ac008a 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -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)) {