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author | Michael S. Tsirkin <mst@redhat.com> | 2017-12-05 21:29:37 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-02 20:35:11 +0100 |
commit | 8b032bde28998122bd38cd9e7ee1e52cd15f4773 (patch) | |
tree | 453703557b03dd658edba883e37eb1e170170cbb /net/rds | |
parent | b3b56038bab017847ac9e1c5610fc00567b51d00 (diff) |
ptr_ring: add barriers
[ Upstream commit a8ceb5dbfde1092b466936bca0ff3be127ecf38e ]
Users of ptr_ring expect that it's safe to give the
data structure a pointer and have it be available
to consumers, but that actually requires an smb_wmb
or a stronger barrier.
In absence of such barriers and on architectures that reorder writes,
consumer might read an un=initialized value from an skb pointer stored
in the skb array. This was observed causing crashes.
To fix, add memory barriers. The barrier we use is a wmb, the
assumption being that producers do not need to read the value so we do
not need to order these reads.
Reported-by: George Cherian <george.cherian@cavium.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/rds')
0 files changed, 0 insertions, 0 deletions