From: Manfred Spraul <manfred@colorfullife.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Davidlohr Bueso <dave@stgolabs.net>,
Dmitry Vyukov <dvyukov@google.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
1vier1@web.de, Kees Cook <keescook@chromium.org>,
Manfred Spraul <manfred@colorfullife.com>
Subject: [PATCH 06/12] ipc: rename ipc_lock() to ipc_lock_idr()
Date: Mon, 9 Jul 2018 17:10:13 +0200 [thread overview]
Message-ID: <20180709151019.1336-7-manfred@colorfullife.com> (raw)
In-Reply-To: <20180709151019.1336-1-manfred@colorfullife.com>
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.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
---
ipc/shm.c | 4 ++--
ipc/util.c | 10 ++++++----
ipc/util.h | 2 +-
3 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/ipc/shm.c b/ipc/shm.c
index 426ba1039a7b..cd8655c7bb77 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -179,11 +179,11 @@ static inline struct shmid_kernel *shm_obtain_object_check(struct ipc_namespace
*/
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 --git a/ipc/util.c b/ipc/util.c
index 8133f10832a9..8bc166bb4981 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -604,15 +604,17 @@ struct kern_ipc_perm *ipc_obtain_object_idr(struct ipc_ids *ids, int id)
}
/**
- * 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 ipc_ids *ids, int id)
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 --git a/ipc/util.h b/ipc/util.h
index fcf81425ae98..25d8ee052ac9 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -142,7 +142,7 @@ int ipc_rcu_getref(struct kern_ipc_perm *ptr);
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);
--
2.17.1
next prev parent reply other threads:[~2018-07-09 15:12 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-09 15:10 [PATCH 0/12 V2] ipc: cleanups & bugfixes, rhashtable update Manfred Spraul
2018-07-09 15:10 ` [PATCH 01/12] ipc: reorganize initialization of kern_ipc_perm.id Manfred Spraul
2018-07-10 22:08 ` Davidlohr Bueso
2018-07-09 15:10 ` [PATCH 02/12] ipc: reorganize initialization of kern_ipc_perm.seq Manfred Spraul
2018-07-09 15:10 ` [PATCH 03/12] ipc/util.c: Use ipc_rcu_putref() for failues in ipc_addid() Manfred Spraul
2018-07-09 15:10 ` [PATCH 04/12] ipc: Rename ipcctl_pre_down_nolock() Manfred Spraul
2018-07-09 19:49 ` Davidlohr Bueso
2018-07-09 15:10 ` [PATCH 05/12] ipc/util.c: correct comment in ipc_obtain_object_check Manfred Spraul
2018-07-09 18:46 ` Davidlohr Bueso
2018-07-09 15:10 ` Manfred Spraul [this message]
2018-07-11 19:38 ` [PATCH 06/12] ipc: rename ipc_lock() to ipc_lock_idr() Davidlohr Bueso
2018-07-09 15:10 ` [PATCH 07/12] ipc_idr_alloc refactoring Manfred Spraul
2018-07-11 19:52 ` Davidlohr Bueso
2018-07-11 20:00 ` Dmitry Vyukov
2018-07-09 15:10 ` [PATCH 08/12] lib/rhashtable: simplify bucket_table_alloc() Manfred Spraul
2018-07-09 15:10 ` [PATCH 09/12] lib/rhashtable: guarantee initial hashtable allocation Manfred Spraul
2018-07-09 15:10 ` [PATCH 10/12] ipc: get rid of ids->tables_initialized hack Manfred Spraul
2018-07-09 15:10 ` [PATCH 11/12] ipc: simplify ipc initialization Manfred Spraul
2018-07-09 21:42 ` Andrew Morton
2018-07-09 23:55 ` Davidlohr Bueso
2018-07-09 15:10 ` [PATCH 12/12] ipc/util.c: Further ipc_idr_alloc cleanups Manfred Spraul
2018-07-09 17:05 ` Dmitry Vyukov
2018-07-09 18:22 ` Manfred Spraul
2018-07-09 18:31 ` Dmitry Vyukov
2018-07-09 20:09 ` [PATCH 0/12 V2] ipc: cleanups & bugfixes, rhashtable update Davidlohr Bueso
2018-07-10 4:44 ` Manfred Spraul
2018-07-10 22:10 ` Davidlohr Bueso
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180709151019.1336-7-manfred@colorfullife.com \
--to=manfred@colorfullife.com \
--cc=1vier1@web.de \
--cc=akpm@linux-foundation.org \
--cc=dave@stgolabs.net \
--cc=dvyukov@google.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).