Commit aa3d1fae authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

SUNRPC: Fix pointer arithmetic bug recently introduced in rpc_malloc/free 



Use a cleaner method to find the size of an rpc_buffer.  This actually
works on x86-64!

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent e70c4908

net/sunrpc/sched.c

+15 −7
Original line number Diff line number Diff line
@@ -736,6 +736,11 @@ static void rpc_async_schedule(struct work_struct *work) 
	__rpc_execute(container_of(work, struct rpc_task, u.tk_work));

}



struct rpc_buffer {

	size_t	len;

	char	data[];

};



/**

 * rpc_malloc - allocate an RPC buffer

 * @task: RPC task that will use this buffer
@@ -754,18 +759,18 @@ static void rpc_async_schedule(struct work_struct *work) 
 */

void *rpc_malloc(struct rpc_task *task, size_t size)

{

	size_t *buf;

	struct rpc_buffer *buf;

	gfp_t gfp = RPC_IS_SWAPPER(task) ? GFP_ATOMIC : GFP_NOWAIT;



	size += sizeof(size_t);

	size += sizeof(struct rpc_buffer);

	if (size <= RPC_BUFFER_MAXSIZE)

		buf = mempool_alloc(rpc_buffer_mempool, gfp);

	else

		buf = kmalloc(size, gfp);

	*buf = size;

	buf->len = size;

	dprintk("RPC: %5u allocated buffer of size %zu at %p\n",

			task->tk_pid, size, buf);

	return ++buf;

	return &buf->data;

}



/**
@@ -775,15 +780,18 @@ void *rpc_malloc(struct rpc_task *task, size_t size) 
 */

void rpc_free(void *buffer)

{

	size_t size, *buf = buffer;

	size_t size;

	struct rpc_buffer *buf;



	if (!buffer)

		return;

	size = *buf;

	buf--;



	buf = container_of(buffer, struct rpc_buffer, data);

	size = buf->len;



	dprintk("RPC:       freeing buffer of size %zu at %p\n",

			size, buf);



	if (size <= RPC_BUFFER_MAXSIZE)

		mempool_free(buf, rpc_buffer_mempool);

	else