From: Andrew Morton Date: Fri, 13 Feb 2009 00:43:17 +0000 (-0800) Subject: net: don't use in_atomic() in gfp_any() X-Git-Tag: v2.6.29-rc5~3^2~9 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=99709372736a216f99eb32b76fba835a2bfc93a8;p=platform%2Fkernel%2Flinux-3.10.git net: don't use in_atomic() in gfp_any() The problem is that in_atomic() will return false inside spinlocks if CONFIG_PREEMPT=n. This will lead to deadlockable GFP_KERNEL allocations from spinlocked regions. Secondly, if CONFIG_PREEMPT=y, this bug solves itself because networking will instead use GFP_ATOMIC from this callsite. Hence we won't get the might_sleep() debugging warnings which would have informed us of the buggy callsites. Solve both these problems by switching to in_interrupt(). Now, if someone runs a gfp_any() allocation from inside spinlock we will get the warning if CONFIG_PREEMPT=y. I reviewed all callsites and most of them were too complex for my little brain and none of them documented their interface requirements. I have no idea what this patch will do. Signed-off-by: Andrew Morton Signed-off-by: David S. Miller --- diff --git a/include/net/sock.h b/include/net/sock.h index 5a3a151..ce3b5b6 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1308,7 +1308,7 @@ static inline int sock_writeable(const struct sock *sk) static inline gfp_t gfp_any(void) { - return in_atomic() ? GFP_ATOMIC : GFP_KERNEL; + return in_softirq() ? GFP_ATOMIC : GFP_KERNEL; } static inline long sock_rcvtimeo(const struct sock *sk, int noblock)