This is a note to let you know that I've just added the patch titled
ipc,shm: shorten critical region for shmctl
to the 3.10-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:
ipc-shm-shorten-critical-region-for-shmctl.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 2caacaa82a51b78fc0c800e206473874094287ed Mon Sep 17 00:00:00 2001
From: Davidlohr Bueso <[email protected]>
Date: Wed, 11 Sep 2013 14:26:21 -0700
Subject: ipc,shm: shorten critical region for shmctl
From: Davidlohr Bueso <[email protected]>
commit 2caacaa82a51b78fc0c800e206473874094287ed upstream.
With the *_INFO, *_STAT, IPC_RMID and IPC_SET commands already optimized,
deal with the remaining SHM_LOCK and SHM_UNLOCK commands. Take the
shm_perm lock after doing the initial auditing and security checks. The
rest of the logic remains unchanged.
Signed-off-by: Davidlohr Bueso <[email protected]>
Tested-by: Sedat Dilek <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Manfred Spraul <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
ipc/shm.c | 49 +++++++++++++++++++++++++------------------------
1 file changed, 25 insertions(+), 24 deletions(-)
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -940,10 +940,8 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int,
int err, version;
struct ipc_namespace *ns;
- if (cmd < 0 || shmid < 0) {
- err = -EINVAL;
- goto out;
- }
+ if (cmd < 0 || shmid < 0)
+ return -EINVAL;
version = ipc_parse_version(&cmd);
ns = current->nsproxy->ipc_ns;
@@ -954,36 +952,40 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int,
case SHM_STAT:
case IPC_STAT:
return shmctl_nolock(ns, shmid, cmd, version, buf);
+ case IPC_RMID:
+ case IPC_SET:
+ return shmctl_down(ns, shmid, cmd, buf, version);
case SHM_LOCK:
case SHM_UNLOCK:
{
struct file *shm_file;
- shp = shm_lock_check(ns, shmid);
+ rcu_read_lock();
+ shp = shm_obtain_object_check(ns, shmid);
if (IS_ERR(shp)) {
err = PTR_ERR(shp);
- goto out;
+ goto out_unlock1;
}
audit_ipc_obj(&(shp->shm_perm));
+ err = security_shm_shmctl(shp, cmd);
+ if (err)
+ goto out_unlock1;
+ ipc_lock_object(&shp->shm_perm);
if (!ns_capable(ns->user_ns, CAP_IPC_LOCK)) {
kuid_t euid = current_euid();
err = -EPERM;
if (!uid_eq(euid, shp->shm_perm.uid) &&
!uid_eq(euid, shp->shm_perm.cuid))
- goto out_unlock;
+ goto out_unlock0;
if (cmd == SHM_LOCK && !rlimit(RLIMIT_MEMLOCK))
- goto out_unlock;
+ goto out_unlock0;
}
- err = security_shm_shmctl(shp, cmd);
- if (err)
- goto out_unlock;
-
shm_file = shp->shm_file;
if (is_file_hugepages(shm_file))
- goto out_unlock;
+ goto out_unlock0;
if (cmd == SHM_LOCK) {
struct user_struct *user = current_user();
@@ -992,32 +994,31 @@ SYSCALL_DEFINE3(shmctl, int, shmid, int,
shp->shm_perm.mode |= SHM_LOCKED;
shp->mlock_user = user;
}
- goto out_unlock;
+ goto out_unlock0;
}
/* SHM_UNLOCK */
if (!(shp->shm_perm.mode & SHM_LOCKED))
- goto out_unlock;
+ goto out_unlock0;
shmem_lock(shm_file, 0, shp->mlock_user);
shp->shm_perm.mode &= ~SHM_LOCKED;
shp->mlock_user = NULL;
get_file(shm_file);
- shm_unlock(shp);
+ ipc_unlock_object(&shp->shm_perm);
+ rcu_read_unlock();
shmem_unlock_mapping(shm_file->f_mapping);
+
fput(shm_file);
- goto out;
- }
- case IPC_RMID:
- case IPC_SET:
- err = shmctl_down(ns, shmid, cmd, buf, version);
return err;
+ }
default:
return -EINVAL;
}
-out_unlock:
- shm_unlock(shp);
-out:
+out_unlock0:
+ ipc_unlock_object(&shp->shm_perm);
+out_unlock1:
+ rcu_read_unlock();
return err;
}
Patches currently in stable-queue which might be from [email protected] are
queue-3.10/ipc-shm-shorten-critical-region-in-shmctl_down.patch
queue-3.10/ipc-msg-introduce-lockless-functions-to-obtain-the-ipc-object.patch
queue-3.10/ipc-msg-shorten-critical-region-in-msgctl_down.patch
queue-3.10/ipc-shm-introduce-lockless-functions-to-obtain-the-ipc-object.patch
queue-3.10/ipc-remove-unused-functions.patch
queue-3.10/ipc-shm-shorten-critical-region-for-shmat.patch
queue-3.10/ipc-msg-introduce-msgctl_nolock.patch
queue-3.10/ipc-move-rcu-lock-out-of-ipc_addid.patch
queue-3.10/ipc-sem-separate-wait-for-zero-and-alter-tasks-into-seperate-queues.patch
queue-3.10/ipc-shm-shorten-critical-region-for-shmctl.patch
queue-3.10/ipc-msg-shorten-critical-region-in-msgsnd.patch
queue-3.10/ipc-shm-introduce-shmctl_nolock.patch
queue-3.10/ipc-drop-ipcctl_pre_down.patch
queue-3.10/ipc-util.c-ipc_rcu_alloc-cacheline-align-allocation.patch
queue-3.10/ipc-introduce-ipc-object-locking-helpers.patch
queue-3.10/ipc-sem.c-cacheline-align-the-semaphore-structures.patch
queue-3.10/ipc-msg-shorten-critical-region-in-msgrcv.patch
queue-3.10/ipc-msg-make-msgctl_nolock-lockless.patch
queue-3.10/ipc-sem.c-always-use-only-one-queue-for-alter-operations.patch
queue-3.10/ipc-shm-cleanup-do_shmat-pasta.patch
queue-3.10/ipc-move-locking-out-of-ipcctl_pre_down_nolock.patch
queue-3.10/ipc-close-open-coded-spin-lock-calls.patch
queue-3.10/ipc-sem.c-rename-try_atomic_semop-to-perform_atomic_semop-docu-update.patch
queue-3.10/ipc-shm-make-shmctl_nolock-lockless.patch
queue-3.10/ipc-sem.c-replace-shared-sem_otime-with-per-semaphore-value.patch
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