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authorAndrew Morton <akpm@linux-foundation.org>2009-02-12 16:43:17 -0800
committerDavid S. Miller <davem@davemloft.net>2009-02-12 16:43:17 -0800
commit99709372736a216f99eb32b76fba835a2bfc93a8 (patch)
tree62a84b976965436b841c65b63e52240d0b06bc29
parentfb0886745a75ce98bde3aac421adc69fe61a1905 (diff)
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 <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/sock.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/net/sock.h b/include/net/sock.h
index 5a3a151bd730..ce3b5b622683 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)