From: santosh.shilimkar@oracle.com Date: Thu, 14 Apr 2016 17:43:27 +0000 (-0700) Subject: RDS: Fix the atomicity for congestion map update X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=403642a01b6dceaff7054480d6a52f3b5e07cb8e;p=GitHub%2Fmt8127%2Fandroid_kernel_alcatel_ttab.git RDS: Fix the atomicity for congestion map update commit e47db94e10447fc467777a40302f2b393e9af2fa upstream. Two different threads with different rds sockets may be in rds_recv_rcvbuf_delta() via receive path. If their ports both map to the same word in the congestion map, then using non-atomic ops to update it could cause the map to be incorrect. Lets use atomics to avoid such an issue. Full credit to Wengang for finding the issue, analysing it and also pointing out to offending code with spin lock based fix. Reviewed-by: Leon Romanovsky Signed-off-by: Wengang Wang Signed-off-by: Santosh Shilimkar Signed-off-by: David S. Miller Cc: Julia Lawall Signed-off-by: Jiri Slaby Signed-off-by: Willy Tarreau --- diff --git a/net/rds/cong.c b/net/rds/cong.c index e5b65acd650b..cec4c4e6d905 100644 --- a/net/rds/cong.c +++ b/net/rds/cong.c @@ -285,7 +285,7 @@ void rds_cong_set_bit(struct rds_cong_map *map, __be16 port) i = be16_to_cpu(port) / RDS_CONG_MAP_PAGE_BITS; off = be16_to_cpu(port) % RDS_CONG_MAP_PAGE_BITS; - __set_bit_le(off, (void *)map->m_page_addrs[i]); + set_bit_le(off, (void *)map->m_page_addrs[i]); } void rds_cong_clear_bit(struct rds_cong_map *map, __be16 port) @@ -299,7 +299,7 @@ void rds_cong_clear_bit(struct rds_cong_map *map, __be16 port) i = be16_to_cpu(port) / RDS_CONG_MAP_PAGE_BITS; off = be16_to_cpu(port) % RDS_CONG_MAP_PAGE_BITS; - __clear_bit_le(off, (void *)map->m_page_addrs[i]); + clear_bit_le(off, (void *)map->m_page_addrs[i]); } static int rds_cong_test_bit(struct rds_cong_map *map, __be16 port)