diff options
| author | Jianlin Shi <shijianlin11@foxmail.com> | 2026-06-15 10:27:41 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-07-30 19:50:00 -0700 |
| commit | 2a28cb9c9475458f672c28e72a81b5e380f24512 (patch) | |
| tree | 2970317fd7d176ffe3aadf16a1b7ccf1036ab5cf /ipc/ipc_sysctl.c | |
| parent | b0934cd39d3dc4f2cdfc2584b67b1845bcb886ed (diff) | |
| download | linux-next-2a28cb9c9475458f672c28e72a81b5e380f24512.tar.gz linux-next-2a28cb9c9475458f672c28e72a81b5e380f24512.zip | |
ipc: only destroy orphaned shm segments on sysctl write
proc_ipc_dointvec_minmax_orphans() currently calls shm_destroy_orphaned()
whenever shm_rmid_forced is set, including on sysctl reads. Reading
/proc/sys/kernel/shm_rmid_forced should not take shm_ids rwsem for write
and walk all segments.
Only run the cleanup when the sysctl is written and the forced RMID policy
is enabled.
When shm_rmid_forced=1, monitoring tools that read
/proc/sys/kernel/shm_rmid_forced trigger the cleanup on every read.
Link: https://lore.kernel.org/all/?q=only+destroy+orphaned+shm+segments+on+sysctl+write
Link: https://lore.kernel.org/tencent_738A8BC6E9EA205F555E4B0DAA154D4F8E0A@qq.com
Signed-off-by: Jianlin Shi <shijianlin11@foxmail.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'ipc/ipc_sysctl.c')
| -rw-r--r-- | ipc/ipc_sysctl.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c index 9b087ebeb643..d038d944257f 100644 --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -28,7 +28,7 @@ static int proc_ipc_dointvec_minmax_orphans(const struct ctl_table *table, int w if (err < 0) return err; - if (ns->shm_rmid_forced) + if (write && ns->shm_rmid_forced) shm_destroy_orphaned(ns); return err; } |