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authorTony Battersby <tonyb@cybernetics.com>2009-04-02 16:58:26 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-04-02 19:05:01 -0700
commite562aebc6ccd4385cbbf24debe88ab4bb500c5b4 (patch)
treea9dee6eac97d75c688a84d5fe268b2e5a0b73e23 /ipc
parent40e8a10de2c9f87e892dcd5a6f9d1b208329ffea (diff)
downloadlinux-e562aebc6ccd4385cbbf24debe88ab4bb500c5b4.tar.gz
ipc: make shm_get_stat() more robust
shm_get_stat() assumes idr_find(&shm_ids(ns).ipcs_idr) returns "struct
shmid_kernel *"; all other callers assume that it returns "struct
kern_ipc_perm *".  This works because "struct kern_ipc_perm" is currently
the first member of "struct shmid_kernel", but it would be better to use
container_of() to prevent future breakage.

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Cc: Jiri Olsa <olsajiri@gmail.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc')
-rw-r--r--ipc/shm.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index f239d87e0d37..faa46da99ebe 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -555,12 +555,14 @@ static void shm_get_stat(struct ipc_namespace *ns, unsigned long *rss,
 	in_use = shm_ids(ns).in_use;
 
 	for (total = 0, next_id = 0; total < in_use; next_id++) {
+		struct kern_ipc_perm *ipc;
 		struct shmid_kernel *shp;
 		struct inode *inode;
 
-		shp = idr_find(&shm_ids(ns).ipcs_idr, next_id);
-		if (shp == NULL)
+		ipc = idr_find(&shm_ids(ns).ipcs_idr, next_id);
+		if (ipc == NULL)
 			continue;
+		shp = container_of(ipc, struct shmid_kernel, shm_perm);
 
 		inode = shp->shm_file->f_path.dentry->d_inode;