The patch titled
Subject: ipc: drop non-RCU allocation
has been added to the -mm tree. Its filename is
ipc-drop-non-rcu-allocation.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ipc-drop-non-rcu-allocation.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ipc-drop-non-rcu-allocation.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: ipc: drop non-RCU allocation
The only users of ipc_alloc() were ipc_rcu_alloc() and the on-heap sem_io
fall-back memory. Better to just open-code these to make things easier to
read.
[manfred@xxxxxxxxxxxxxxxx: Rediff due to inclusion of memset() into ipc_rcu_alloc()]
Link: http://lkml.kernel.org/r/20170525185107.12869-5-manfred@xxxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Signed-off-by: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/sem.c | 8 +++++---
ipc/util.c | 27 +++------------------------
ipc/util.h | 6 ------
3 files changed, 8 insertions(+), 33 deletions(-)
diff -puN ipc/sem.c~ipc-drop-non-rcu-allocation ipc/sem.c
--- a/ipc/sem.c~ipc-drop-non-rcu-allocation
+++ a/ipc/sem.c
@@ -1368,7 +1368,8 @@ static int semctl_main(struct ipc_namesp
}
sem_unlock(sma, -1);
rcu_read_unlock();
- sem_io = ipc_alloc(sizeof(ushort)*nsems);
+ sem_io = kvmalloc_array(nsems, sizeof(ushort),
+ GFP_KERNEL);
if (sem_io == NULL) {
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
return -ENOMEM;
@@ -1402,7 +1403,8 @@ static int semctl_main(struct ipc_namesp
rcu_read_unlock();
if (nsems > SEMMSL_FAST) {
- sem_io = ipc_alloc(sizeof(ushort)*nsems);
+ sem_io = kvmalloc_array(nsems, sizeof(ushort),
+ GFP_KERNEL);
if (sem_io == NULL) {
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free);
return -ENOMEM;
@@ -1480,7 +1482,7 @@ out_rcu_wakeup:
wake_up_q(&wake_q);
out_free:
if (sem_io != fast_sem_io)
- ipc_free(sem_io);
+ kvfree(sem_io);
return err;
}
diff -puN ipc/util.c~ipc-drop-non-rcu-allocation ipc/util.c
--- a/ipc/util.c~ipc-drop-non-rcu-allocation
+++ a/ipc/util.c
@@ -395,29 +395,6 @@ void ipc_rmid(struct ipc_ids *ids, struc
}
/**
- * ipc_alloc - allocate ipc space
- * @size: size desired
- *
- * Allocate memory from the appropriate pools and return a pointer to it.
- * NULL is returned if the allocation fails
- */
-void *ipc_alloc(int size)
-{
- return kvmalloc(size, GFP_KERNEL);
-}
-
-/**
- * ipc_free - free ipc space
- * @ptr: pointer returned by ipc_alloc
- *
- * Free a block created with ipc_alloc().
- */
-void ipc_free(void *ptr)
-{
- kvfree(ptr);
-}
-
-/**
* ipc_rcu_alloc - allocate ipc space
* @size: size desired
*
@@ -429,9 +406,11 @@ struct kern_ipc_perm *ipc_rcu_alloc(int
/*
* We prepend the allocation with the rcu struct
*/
- struct kern_ipc_perm *out = ipc_alloc(size);
+ struct kern_ipc_perm *out = kvmalloc(size, GFP_KERNEL);
if (unlikely(!out))
return NULL;
+
+ memset(out, 0, size);
atomic_set(&out->refcount, 1);
return out;
}
diff -puN ipc/util.h~ipc-drop-non-rcu-allocation ipc/util.h
--- a/ipc/util.h~ipc-drop-non-rcu-allocation
+++ a/ipc/util.h
@@ -107,12 +107,6 @@ void ipc_rmid(struct ipc_ids *, struct k
/* must be called with ipcp locked */
int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg);
-/* for rare, potentially huge allocations.
- * both function can sleep
- */
-void *ipc_alloc(int size);
-void ipc_free(void *ptr);
-
/*
* For allocation that need to be freed by RCU.
* Objects are reference counted, they start with reference count 1.
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
ipc-drop-non-rcu-allocation.patch
ipc-sem-do-not-use-ipc_rcu_free.patch
ipc-shm-do-not-use-ipc_rcu_free.patch
ipc-msg-do-not-use-ipc_rcu_free.patch
ipc-util-drop-ipc_rcu_free.patch
ipc-sem-avoid-ipc_rcu_alloc.patch
ipc-shm-avoid-ipc_rcu_alloc.patch
ipc-msg-avoid-ipc_rcu_alloc.patch
ipc-util-drop-ipc_rcu_alloc.patch
ipc-move-atomic_set-to-where-it-is-needed.patch
ipc-shm-remove-special-shm_alloc-free.patch
ipc-msg-remove-special-msg_alloc-free.patch
ipc-sem-drop-__sem_free.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
