The patch titled
Subject: ipc: rename ipc_lock() to ipc_lock_idr()
has been added to the -mm tree. Its filename is
ipc-rename-ipc_lock-to-ipc_lock_idr.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ipc-rename-ipc_lock-to-ipc_lock_idr.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ipc-rename-ipc_lock-to-ipc_lock_idr.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Subject: ipc: rename ipc_lock() to ipc_lock_idr()
ipc/util.c contains multiple functions to get the ipc object pointer given
an id number.
There are two sets of function: One set verifies the sequence counter part
of the id number, other functions do not check the sequence counter.
The standard for function names in ipc/util.c is
- ..._check() functions verify the sequence counter
- ..._idr() functions do not verify the sequence counter
ipc_lock() is an exception: It does not verify the sequence counter value,
but this is not obvious from the function name.
Therefore: Rename the function to ipc_lock_idr(), to make it obvious that
it does not check the sequence counter.
Link: http://lkml.kernel.org/r/20180709151019.1336-7-manfred@xxxxxxxxxxxxxxxx
Signed-off-by: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Michael Kerrisk <mtk.manpages@xxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/shm.c | 4 ++--
ipc/util.c | 10 ++++++----
ipc/util.h | 2 +-
3 files changed, 9 insertions(+), 7 deletions(-)
diff -puN ipc/shm.c~ipc-rename-ipc_lock-to-ipc_lock_idr ipc/shm.c
--- a/ipc/shm.c~ipc-rename-ipc_lock-to-ipc_lock_idr
+++ a/ipc/shm.c
@@ -179,11 +179,11 @@ static inline struct shmid_kernel *shm_o
*/
static inline struct shmid_kernel *shm_lock(struct ipc_namespace *ns, int id)
{
- struct kern_ipc_perm *ipcp = ipc_lock(&shm_ids(ns), id);
+ struct kern_ipc_perm *ipcp = ipc_lock_idr(&shm_ids(ns), id);
/*
* Callers of shm_lock() must validate the status of the returned ipc
- * object pointer (as returned by ipc_lock()), and error out as
+ * object pointer (as returned by ipc_lock_idr()), and error out as
* appropriate.
*/
if (IS_ERR(ipcp))
diff -puN ipc/util.c~ipc-rename-ipc_lock-to-ipc_lock_idr ipc/util.c
--- a/ipc/util.c~ipc-rename-ipc_lock-to-ipc_lock_idr
+++ a/ipc/util.c
@@ -604,15 +604,17 @@ struct kern_ipc_perm *ipc_obtain_object_
}
/**
- * ipc_lock - lock an ipc structure without rwsem held
+ * ipc_lock_idr - lock an ipc structure without rwsem held
* @ids: ipc identifier set
* @id: ipc id to look for
*
* Look for an id in the ipc ids idr and lock the associated ipc object.
+ * The function does not check if the sequence counter matches the
+ * found ipc object.
*
* The ipc object is locked on successful exit.
*/
-struct kern_ipc_perm *ipc_lock(struct ipc_ids *ids, int id)
+struct kern_ipc_perm *ipc_lock_idr(struct ipc_ids *ids, int id)
{
struct kern_ipc_perm *out;
@@ -624,8 +626,8 @@ struct kern_ipc_perm *ipc_lock(struct ip
spin_lock(&out->lock);
/*
- * ipc_rmid() may have already freed the ID while ipc_lock()
- * was spinning: here verify that the structure is still valid.
+ * ipc_rmid() may have already freed the ID while waiting for
+ * the lock. Here verify that the structure is still valid.
* Upon races with RMID, return -EIDRM, thus indicating that
* the ID points to a removed identifier.
*/
diff -puN ipc/util.h~ipc-rename-ipc_lock-to-ipc_lock_idr ipc/util.h
--- a/ipc/util.h~ipc-rename-ipc_lock-to-ipc_lock_idr
+++ a/ipc/util.h
@@ -142,7 +142,7 @@ int ipc_rcu_getref(struct kern_ipc_perm
void ipc_rcu_putref(struct kern_ipc_perm *ptr,
void (*func)(struct rcu_head *head));
-struct kern_ipc_perm *ipc_lock(struct ipc_ids *, int);
+struct kern_ipc_perm *ipc_lock_idr(struct ipc_ids *ids, int id);
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);
_
Patches currently in -mm which might be from manfred@xxxxxxxxxxxxxxxx are
ipc-reorganize-initialization-of-kern_ipc_permid.patch
ipc-reorganize-initialization-of-kern_ipc_permseq.patch
ipc-utilc-use-ipc_rcu_putref-for-failues-in-ipc_addid.patch
ipc-rename-ipcctl_pre_down_nolock.patch
ipc-utilc-correct-comment-in-ipc_obtain_object_check.patch
ipc-rename-ipc_lock-to-ipc_lock_idr.patch
ipc-utilc-further-ipc_idr_alloc-cleanups.patch
--
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