This is a note to let you know that I've just added the patch titled
RDS: Fix the atomicity for congestion map update
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
rds-fix-the-atomicity-for-congestion-map-update.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From e47db94e10447fc467777a40302f2b393e9af2fa Mon Sep 17 00:00:00 2001
From: "santosh.shilimkar@xxxxxxxxxx" <santosh.shilimkar@xxxxxxxxxx>
Date: Thu, 14 Apr 2016 10:43:27 -0700
Subject: RDS: Fix the atomicity for congestion map update
From: santosh.shilimkar@xxxxxxxxxx <santosh.shilimkar@xxxxxxxxxx>
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 <wen.gang.wang@xxxxxxxxxx> for
finding the issue, analysing it and also pointing out
to offending code with spin lock based fix.
Reviewed-by: Leon Romanovsky <leon@xxxxxxx>
Signed-off-by: Wengang Wang <wen.gang.wang@xxxxxxxxxx>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Julia Lawall <julia.lawall@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/rds/cong.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/rds/cong.c
+++ b/net/rds/cong.c
@@ -299,7 +299,7 @@ void rds_cong_set_bit(struct rds_cong_ma
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)
@@ -313,7 +313,7 @@ void rds_cong_clear_bit(struct rds_cong_
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)
Patches currently in stable-queue which might be from santosh.shilimkar@xxxxxxxxxx are
queue-4.4/rds-fix-the-atomicity-for-congestion-map-update.patch