Commit 4241c1a3 authored by Manfred Spraul's avatar Manfred Spraul Committed by Linus Torvalds
Browse files

ipc: rename ipcctl_pre_down_nolock() 

Both the comment and the name of ipcctl_pre_down_nolock() are misleading:
The function must be called while holdling the rw semaphore.

Therefore the patch renames the function to ipcctl_obtain_check(): This
name matches the other names used in util.c:

- "obtain" function look up a pointer in the idr, without
  acquiring the object lock.
- The caller is responsible for locking.
- _check means that the sequence number is checked.

Link: http://lkml.kernel.org/r/20180712185241.4017-5-manfred@colorfullife.com


Signed-off-by: default avatarManfred Spraul <manfred@colorfullife.com>
Reviewed-by: default avatarDavidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 39cfffd7

ipc/msg.c

+1 −1
Original line number Diff line number Diff line
@@ -386,7 +386,7 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd, 
	down_write(&msg_ids(ns).rwsem);

	rcu_read_lock();



	ipcp = ipcctl_pre_down_nolock(ns, &msg_ids(ns), msqid, cmd,

	ipcp = ipcctl_obtain_check(ns, &msg_ids(ns), msqid, cmd,

				      &msqid64->msg_perm, msqid64->msg_qbytes);

	if (IS_ERR(ipcp)) {

		err = PTR_ERR(ipcp);

ipc/sem.c

+1 −1
Original line number Diff line number Diff line
@@ -1596,7 +1596,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid, 
	down_write(&sem_ids(ns).rwsem);

	rcu_read_lock();



	ipcp = ipcctl_pre_down_nolock(ns, &sem_ids(ns), semid, cmd,

	ipcp = ipcctl_obtain_check(ns, &sem_ids(ns), semid, cmd,

				      &semid64->sem_perm, 0);

	if (IS_ERR(ipcp)) {

		err = PTR_ERR(ipcp);

ipc/shm.c

+1 −1
Original line number Diff line number Diff line
@@ -881,7 +881,7 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd, 
	down_write(&shm_ids(ns).rwsem);

	rcu_read_lock();



	ipcp = ipcctl_pre_down_nolock(ns, &shm_ids(ns), shmid, cmd,

	ipcp = ipcctl_obtain_check(ns, &shm_ids(ns), shmid, cmd,

				      &shmid64->shm_perm, 0);

	if (IS_ERR(ipcp)) {

		err = PTR_ERR(ipcp);

ipc/util.c

+4 −4
Original line number Diff line number Diff line
@@ -688,7 +688,7 @@ int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) 
}



/**

 * ipcctl_pre_down_nolock - retrieve an ipc and check permissions for some IPC_XXX cmd

 * ipcctl_obtain_check - retrieve an ipc object and check permissions

 * @ns:  ipc namespace

 * @ids:  the table of ids where to look for the ipc

 * @id:   the id of the ipc to retrieve
@@ -698,16 +698,16 @@ int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out) 
 *

 * This function does some common audit and permissions check for some IPC_XXX

 * cmd and is called from semctl_down, shmctl_down and msgctl_down.

 * It must be called without any lock held and:

 *

 *   - retrieves the ipc with the given id in the given table.

 * It:

 *   - retrieves the ipc object with the given id in the given table.

 *   - performs some audit and permission check, depending on the given cmd

 *   - returns a pointer to the ipc object or otherwise, the corresponding

 *     error.

 *

 * Call holding the both the rwsem and the rcu read lock.

 */

struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,

struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns,

					struct ipc_ids *ids, int id, int cmd,

					struct ipc64_perm *perm, int extra_perm)

{

ipc/util.h

+1 −1
Original line number Diff line number Diff line
@@ -148,7 +148,7 @@ struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id); 
void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);

void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);

int ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);

struct kern_ipc_perm *ipcctl_pre_down_nolock(struct ipc_namespace *ns,

struct kern_ipc_perm *ipcctl_obtain_check(struct ipc_namespace *ns,

					     struct ipc_ids *ids, int id, int cmd,

					     struct ipc64_perm *perm, int extra_perm);

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