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| author | Hidayath Khan <hidayath@linux.ibm.com> | 2026-08-20 09:46:41 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-09-07 17:37:21 +0200 |
| commit | 2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec (patch) | |
| tree | 175df10aab94fa918672a52a4831ef681db10359 | |
| parent | adef84cc85d449ac28d2b4b4c49cf19619c56e27 (diff) | |
| download | linux-2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec.tar.gz linux-2cb7a8d64b7e8ccdc69bbe48fe9c4eaa79c33aec.zip | |
net/smc: stop killed, freed and out_of_sync sharing a byte
commit db51a8658c11a82432b64999519a269c3aabb447 upstream.
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: b286a0651e44 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/smc/smc.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/net/smc/smc.h b/net/smc/smc.h index 52145df83f6e..427b6d63b993 100644 --- a/net/smc/smc.h +++ b/net/smc/smc.h @@ -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 */ |