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| author | Jason Wang <jasowang@redhat.com> | 2016-06-30 14:45:31 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-07-01 05:32:16 -0400 |
| commit | 982fb490c298896d15e9323a882f34a57c11ff56 (patch) | |
| tree | 453a3c8afc504c726462412c5b61cb90785c1069 /include/linux/ptr_ring.h | |
| parent | 8dc7243abbf514e208aee1c0b430f35b866f8cc4 (diff) | |
| download | linux-982fb490c298896d15e9323a882f34a57c11ff56.tar.gz linux-982fb490c298896d15e9323a882f34a57c11ff56.tar.bz2 linux-982fb490c298896d15e9323a882f34a57c11ff56.zip | |
ptr_ring: support zero length ring
Sometimes, we need zero length ring. But current code will crash since
we don't do any check before accessing the ring. This patch fixes this.
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/ptr_ring.h')
| -rw-r--r-- | include/linux/ptr_ring.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h index 562a65e8bcc0..d78b8b89c707 100644 --- a/include/linux/ptr_ring.h +++ b/include/linux/ptr_ring.h @@ -102,7 +102,7 @@ static inline bool ptr_ring_full_bh(struct ptr_ring *r) */ static inline int __ptr_ring_produce(struct ptr_ring *r, void *ptr) { - if (r->queue[r->producer]) + if (unlikely(!r->size) || r->queue[r->producer]) return -ENOSPC; r->queue[r->producer++] = ptr; @@ -164,7 +164,9 @@ static inline int ptr_ring_produce_bh(struct ptr_ring *r, void *ptr) */ static inline void *__ptr_ring_peek(struct ptr_ring *r) { - return r->queue[r->consumer]; + if (likely(r->size)) + return r->queue[r->consumer]; + return NULL; } /* Note: callers invoking this in a loop must use a compiler barrier, |