Commit ffe4cfc3 authored by Jack Morgenstein's avatar Jack Morgenstein Committed by David S. Miller
Browse files

net/mlx4_core: Fix error handling when initializing CQ bufs in the driver 



Procedure mlx4_init_user_cqes() handles returns by copy_to_user
incorrectly. copy_to_user() returns the number of bytes not copied.
Thus, a non-zero return should be treated as a -EFAULT error
(as is done elsewhere in the kernel). However, mlx4_init_user_cqes()
error handling simply returns the number of bytes not copied
(instead of -EFAULT).

Note, though, that this is a harmless bug: procedure mlx4_alloc_cq()
(which is the only caller of mlx4_init_user_cqes()) treats any
non-zero return as an error, but that returned error value is processed
internally, and not passed further up the call stack.

In addition, fixes the following sparse warning:
warning: incorrect type in argument 1 (different address spaces)
   expected void [noderef] <asn:1>*to
   got void *buf

Fixes: e4567897 ("{net, IB}/mlx4: Initialize CQ buffers in the driver when possible")
Reported by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: default avatarTariq Toukan <tariqt@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a40ded60

drivers/net/ethernet/mellanox/mlx4/cq.c

+4 −2
Original line number Diff line number Diff line
@@ -306,14 +306,16 @@ static int mlx4_init_user_cqes(void *buf, int entries, int cqe_size) 


	if (entries_per_copy < entries) {

		for (i = 0; i < entries / entries_per_copy; i++) {

			err = copy_to_user(buf, init_ents, PAGE_SIZE);

			err = copy_to_user((void __user *)buf, init_ents, PAGE_SIZE) ?

				-EFAULT : 0;

			if (err)

				goto out;



			buf += PAGE_SIZE;

		}

	} else {

		err = copy_to_user(buf, init_ents, entries * cqe_size);

		err = copy_to_user((void __user *)buf, init_ents, entries * cqe_size) ?

			-EFAULT : 0;

	}



out: