github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-22 12:44:03 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

net/smc: stop killed, freed and out_of_sync sharing a byte

Browse Source 
The three connection state flags are single-bit bitfields, so they occupy
one byte of struct smc_connection and every store to one is a
read-modify-write of the other two:

    u8  killed : 1;
    u8  freed : 1;
    u8  out_of_sync : 1;

They are not written under a common lock. smc_cdc_msg_validate() sets
out_of_sync from the receive tasklet, while smc_conn_kill() sets killed
from process context under lock_sock(), and the receive path does not defer
to the backlog when the socket is owned -- smc_cdc_msg_recv() takes only
bh_lock_sock().

Give each flag its own byte so a store no longer touches its neighbours.
All readers test them as booleans and are unchanged. struct smc_connection
grows by two bytes.

Fixes: b286a0651e ("net/smc: handle incoming CDC validation message")
Cc: stable@vger.kernel.org
Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Signed-off-by: Hidayath Khan <hidayath@linux.ibm.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260820074642.966856-2-hidayath@linux.ibm.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Hidayath Khan 2026-08-20 09:46:41 +02:00 committed by Jakub Kicinski
parent 719296c4aa
commit db51a8658c
1 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
net/smc/smc.h
View File

@ -277,9 +277,9 @@ struct smc_connection {
* 0 for SMC-R, 32 for SMC-D
*/
u64 peer_token; /* SMC-D token of peer */
u8 killed : 1; /* abnormal termination */
u8 freed : 1; /* normal termination */
u8 out_of_sync : 1; /* out of sync with peer */
u8 killed; /* abnormal termination */
u8 freed; /* normal termination */
u8 out_of_sync; /* out of sync with peer */
};
struct smc_sock { /* smc sock container */