I haven't checked the entire context, but it could be useful to look at
line 1251.
julia
---------- Forwarded message ----------
Date: Sun, 16 Oct 2016 01:34:18 +0800
From: kbuild test robot <fengguang...@intel.com>
To: kbu...@01.org
Cc: Julia Lawall <julia.law...@lip6.fr>
Subject: [net:master 10/15] net/ipv6/addrconf.c:1251:14-30: WARNING: Unsigned
expression compared with zero: tmp_prefered_lft < 0
CC: kbuild-...@01.org
CC: netdev@vger.kernel.org
TO: Jiri Bohac <jbo...@suse.cz>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git master
head: 9e55d0f95460a067def5400fa5eee5dabb0fc5a5
commit: 76506a986dc31394fd1f2741db037d29c7e57843 [10/15] IPv6: fix DESYNC_FACTOR
:::::: branch date: 21 hours ago
:::::: commit date: 27 hours ago
>> net/ipv6/addrconf.c:1251:14-30: WARNING: Unsigned expression compared with
>> zero: tmp_prefered_lft < 0
git remote add net https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git
git remote update net
git checkout 76506a986dc31394fd1f2741db037d29c7e57843
vim +1251 net/ipv6/addrconf.c
76506a986 Jiri Bohac 2016-10-13 1235 if
(unlikely(idev->desync_factor > max_desync_factor)) {
76506a986 Jiri Bohac 2016-10-13 1236 if (max_desync_factor >
0) {
76506a986 Jiri Bohac 2016-10-13 1237
get_random_bytes(&idev->desync_factor,
76506a986 Jiri Bohac 2016-10-13 1238
sizeof(idev->desync_factor));
76506a986 Jiri Bohac 2016-10-13 1239
idev->desync_factor %= max_desync_factor;
76506a986 Jiri Bohac 2016-10-13 1240 } else {
76506a986 Jiri Bohac 2016-10-13 1241
idev->desync_factor = 0;
76506a986 Jiri Bohac 2016-10-13 1242 }
76506a986 Jiri Bohac 2016-10-13 1243 }
76506a986 Jiri Bohac 2016-10-13 1244
^1da177e4 Linus Torvalds 2005-04-16 1245 tmp_valid_lft = min_t(__u32,
^1da177e4 Linus Torvalds 2005-04-16 1246
ifp->valid_lft,
7a876b0ef Glenn Wurster 2010-09-27 1247
idev->cnf.temp_valid_lft + age);
76506a986 Jiri Bohac 2016-10-13 1248 tmp_prefered_lft =
idev->cnf.temp_prefered_lft + age -
76506a986 Jiri Bohac 2016-10-13 1249
idev->desync_factor;
76506a986 Jiri Bohac 2016-10-13 1250 /* guard against underflow in
case of concurrent updates to cnf */
76506a986 Jiri Bohac 2016-10-13 @1251 if (unlikely(tmp_prefered_lft <
0))
76506a986 Jiri Bohac 2016-10-13 1252 tmp_prefered_lft = 0;
76506a986 Jiri Bohac 2016-10-13 1253 tmp_prefered_lft = min_t(__u32,
ifp->prefered_lft, tmp_prefered_lft);
^1da177e4 Linus Torvalds 2005-04-16 1254 tmp_plen = ifp->prefix_len;
^1da177e4 Linus Torvalds 2005-04-16 1255 tmp_tstamp = ifp->tstamp;
^1da177e4 Linus Torvalds 2005-04-16 1256 spin_unlock_bh(&ifp->lock);
^1da177e4 Linus Torvalds 2005-04-16 1257
53bd67491 Jiri Pirko 2013-12-06 1258 write_unlock_bh(&idev->lock);
95c385b4d Neil Horman 2007-04-25 1259
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