Commit e562aebc authored Apr 02, 2009 by Tony Battersby Committed by Linus Torvalds Apr 02, 2009

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>

parent 40e8a10d

ipc/shm.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -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;

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