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ipc: rename ipcctl_pre_down_nolock()

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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: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr 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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Manfred Spraul 2018-08-21 22:01:34 -07:00 committed by Linus Torvalds
parent 39cfffd774
commit 4241c1a304
5 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
ipc/msg.c
View File

@ -386,7 +386,7 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
down_write(&msg_ids(ns).rwsem); down_write(&msg_ids(ns).rwsem);
rcu_read_lock(); 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); &msqid64->msg_perm, msqid64->msg_qbytes);
if (IS_ERR(ipcp)) { if (IS_ERR(ipcp)) {
err = PTR_ERR(ipcp); err = PTR_ERR(ipcp);

2
ipc/sem.c
View File

@ -1596,7 +1596,7 @@ static int semctl_down(struct ipc_namespace *ns, int semid,
down_write(&sem_ids(ns).rwsem); down_write(&sem_ids(ns).rwsem);
rcu_read_lock(); 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); &semid64->sem_perm, 0);
if (IS_ERR(ipcp)) { if (IS_ERR(ipcp)) {
err = PTR_ERR(ipcp); err = PTR_ERR(ipcp);

2
ipc/shm.c
View File

@ -881,7 +881,7 @@ static int shmctl_down(struct ipc_namespace *ns, int shmid, int cmd,
down_write(&shm_ids(ns).rwsem); down_write(&shm_ids(ns).rwsem);
rcu_read_lock(); 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); &shmid64->shm_perm, 0);
if (IS_ERR(ipcp)) { if (IS_ERR(ipcp)) {
err = PTR_ERR(ipcp); err = PTR_ERR(ipcp);

8
ipc/util.c
View File

@ -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 * @ns: ipc namespace
* @ids: the table of ids where to look for the ipc * @ids: the table of ids where to look for the ipc
* @id: the id of the ipc to retrieve * @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 * 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. * 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 * - performs some audit and permission check, depending on the given cmd
* - returns a pointer to the ipc object or otherwise, the corresponding * - returns a pointer to the ipc object or otherwise, the corresponding
* error. * error.
* *
* Call holding the both the rwsem and the rcu read lock. * 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 ipc_ids *ids, int id, int cmd,
struct ipc64_perm *perm, int extra_perm) struct ipc64_perm *perm, int extra_perm)
{ {

2
ipc/util.h
View File

@ -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 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); 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); 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 ipc_ids *ids, int id, int cmd,
struct ipc64_perm *perm, int extra_perm); struct ipc64_perm *perm, int extra_perm);