From 8dd30201ce66f2c81077e06056f4a865e512e854 Mon Sep 17 00:00:00 2001 From: Tariq Toukan Date: Tue, 24 Jul 2018 13:53:00 +0300 Subject: [PATCH] net: remove redundant input checks in SIOCSIFTXQLEN case of dev_ifsioc The cited patch added a call to dev_change_tx_queue_len in SIOCSIFTXQLEN case. This obsoletes the new len comparison check done before the function call. Remove it here. For the desicion of keep/remove the negative value check, we examine the range check in dev_change_tx_queue_len. On 64-bit we will fail with -ERANGE. The 32-bit int ifr_qlen will be sign extended to 64-bits when it is passed into dev_change_tx_queue_len(). And then for negative values this test triggers: if (new_len != (unsigned int)new_len) return -ERANGE; because: if (0xffffffffWHATEVER != 0x00000000WHATEVER) On 32-bit the signed value will be accepted, changing behavior. Therefore, the negative value check is kept. Fixes: 3f76df198288 ("net: use dev_change_tx_queue_len() for SIOCSIFTXQLEN") Signed-off-by: Tariq Toukan Reviewed-by: Eran Ben Elisha Cc: Cong Wang Signed-off-by: David S. Miller --- net/core/dev_ioctl.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/net/core/dev_ioctl.c b/net/core/dev_ioctl.c index 50537ff961a7..90e8aa36881e 100644 --- a/net/core/dev_ioctl.c +++ b/net/core/dev_ioctl.c @@ -284,12 +284,7 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr, unsigned int cmd) case SIOCSIFTXQLEN: if (ifr->ifr_qlen < 0) return -EINVAL; - if (dev->tx_queue_len ^ ifr->ifr_qlen) { - err = dev_change_tx_queue_len(dev, ifr->ifr_qlen); - if (err) - return err; - } - return 0; + return dev_change_tx_queue_len(dev, ifr->ifr_qlen); case SIOCSIFNAME: ifr->ifr_newname[IFNAMSIZ-1] = '\0'; -- 2.11.0