From: "Colin King (gmail)" <colin.i.king@gmail.com>
To: Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
Jiri Pirko <jpirko@redhat.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: starfire: set_vlan_mode contains dead code in a while loop
Date: Tue, 10 Mar 2026 15:04:26 +0000 [thread overview]
Message-ID: <299e76bf-6e7e-4332-a4e2-61698cf95c9a@gmail.com> (raw)
[-- Attachment #1.1.1: Type: text/plain, Size: 1263 bytes --]
Hi,
There is an issue in function set_vlan_mode with code that is never
executed in the following commit:
commit 5da96be53a16a62488316810d0c7c5d58ce3ee4f
Author: Jiri Pirko <jiri@resnulli.us>
Date: Wed Jul 20 04:54:31 2011 +0000
starfire: do vlan cleanup
The issue is as follows:
static u32 set_vlan_mode(struct netdev_private *np)
{
u32 ret = VlanMode;
u16 vid;
void __iomem *filter_addr = np->base + HashTable + 8;
int vlan_count = 0;
for_each_set_bit(vid, np->active_vlans, VLAN_N_VID) {
if (vlan_count == 32)
break;
writew(vid, filter_addr);
filter_addr += 16;
vlan_count++;
}
if (vlan_count == 32) {
ret |= PerfectFilterVlan;
while (vlan_count < 32) {
writew(0, filter_addr);
filter_addr += 16;
vlan_count++;
}
}
return ret;
}
If vlan_count is 32 then the while loop is currently dead code since
vlan_count cannot be less than 32 (so the loop is never executed).
This logic seems broken.
Colin
[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 4901 bytes --]
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 840 bytes --]
reply other threads:[~2026-03-10 15:05 UTC|newest]
Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=299e76bf-6e7e-4332-a4e2-61698cf95c9a@gmail.com \
--to=colin.i.king@gmail.com \
--cc=andrew+netdev@lunn.ch \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=jpirko@redhat.com \
--cc=kuba@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox