Subject: [merged] ipcshm-shorten-critical-region-for-shmat.patch removed from -mm tree To: davidlohr.bueso@xxxxxx,manfred@xxxxxxxxxxxxxxxx,riel@xxxxxxxxxx,sasha.levin@xxxxxxxxxx,sedat.dilek@xxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Thu, 12 Sep 2013 12:50:53 -0700 The patch titled Subject: ipc,shm: shorten critical region for shmat has been removed from the -mm tree. Its filename was ipcshm-shorten-critical-region-for-shmat.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Davidlohr Bueso <davidlohr.bueso@xxxxxx> Subject: ipc,shm: shorten critical region for shmat Similar to other system calls, acquire the kern_ipc_perm lock after doing the initial permission and security checks. [sasha.levin@xxxxxxxxxx: dont leave do_shmat with rcu lock held] Signed-off-by: Davidlohr Bueso <davidlohr.bueso@xxxxxx> Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- ipc/shm.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff -puN ipc/shm.c~ipcshm-shorten-critical-region-for-shmat ipc/shm.c --- a/ipc/shm.c~ipcshm-shorten-critical-region-for-shmat +++ a/ipc/shm.c @@ -19,6 +19,9 @@ * namespaces support * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@xxxxxxxxxx> + * + * Better ipc lock (kern_ipc_perm.lock) handling + * Davidlohr Bueso <davidlohr.bueso@xxxxxx>, June 2013. */ #include <linux/slab.h> @@ -1086,10 +1089,11 @@ long do_shmat(int shmid, char __user *sh * additional creator id... */ ns = current->nsproxy->ipc_ns; - 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_unlock; } err = -EACCES; @@ -1100,11 +1104,13 @@ long do_shmat(int shmid, char __user *sh if (err) goto out_unlock; + ipc_lock_object(&shp->shm_perm); path = shp->shm_file->f_path; path_get(&path); shp->shm_nattch++; size = i_size_read(path.dentry->d_inode); - shm_unlock(shp); + ipc_unlock_object(&shp->shm_perm); + rcu_read_unlock(); err = -ENOMEM; sfd = kzalloc(sizeof(*sfd), GFP_KERNEL); @@ -1175,7 +1181,7 @@ out_nattch: return err; out_unlock: - shm_unlock(shp); + rcu_read_unlock(); out: return err; } _ Patches currently in -mm which might be from davidlohr.bueso@xxxxxx are origin.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html