On 24/07/2018 12:00 AM, David Miller wrote:
From: Cong Wang <xiyou.wangc...@gmail.com>
Date: Mon, 23 Jul 2018 13:37:22 -0700
On Sun, Jul 22, 2018 at 12:29 AM Tariq Toukan <tar...@mellanox.com> wrote:
On 19/07/2018 8:21 PM, Cong Wang wrote:
On Thu, Jul 19, 2018 at 7:50 AM Tariq Toukan <tar...@mellanox.com> wrote:
--- a/net/core/dev_ioctl.c
+++ b/net/core/dev_ioctl.c
@@ -282,14 +282,7 @@ static int dev_ifsioc(struct net *net, struct ifreq *ifr,
unsigned int cmd)
return dev_mc_del_global(dev, ifr->ifr_hwaddr.sa_data);
case SIOCSIFTXQLEN:
- if (ifr->ifr_qlen < 0)
- return -EINVAL;
Are you sure we can remove this if check too?
The other one is safe to remove.
Hmm, let's see:
dev_change_tx_queue_len gets unsigned long new_len, any negative value
passed is interpreted as a very large number, then we test:
if (new_len != (unsigned int)new_len)
This test returns true if range of unsigned long is larger than range of
unsigned int. AFAIK these ranges are Arch dependent and there is no
guarantee this holds.
I am not sure either, you probably have to give it a test.
And at least, explain it in changelog if you still want to remove it.
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.
I think, therefore, that the < 0 check should be retained.
Agree.
I am sending a re-spin.
Thank you.
