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@colorfullife.com: Rediff due to inclusion of memset() into ipc_rcu_alloc()]
Link: http://lkml.kernel.org/r/20170525185107.12869-5-manfred@colorfullife.com
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/ipc/sem.c b/ipc/sem.c
index bdff6d9..484ccf8 100644 (file)
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -1368,7 +1368,8 @@ static int semctl_main(struct ipc_namespace *ns, int semid, int semnum,
                        }
                        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_namespace *ns, int semid, int semnum,
                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 --git a/ipc/util.c b/ipc/util.c
index 5d1ff10..dd73feb 100644 (file)
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -395,29 +395,6 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp)
 }
 
 /**
- * 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
  *
@@ -429,7 +406,7 @@ struct kern_ipc_perm *ipc_rcu_alloc(int size)
        /*
         * 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;
 

diff --git a/ipc/util.h b/ipc/util.h
index 09d0f91..2578fd9 100644 (file)
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -107,12 +107,6 @@ void ipc_rmid(struct ipc_ids *, struct kern_ipc_perm *);
 /* 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.