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>
diff --git a/ipc/shm.c b/ipc/shm.c
index f239d87..faa46da 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -555,12 +555,14 @@
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;