| Message ID | 20131215171806.GA1715@order.stressinduktion.org |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On Sun, Dec 15, 2013 at 06:18:06PM +0100, Hannes Frederic Sowa wrote: > This essentlally reverts commit f52d81dc27c3456c702e83183035142c222acdc7 > ("ipv6: fix compiler warning in ipv6_exthdrs_len") and silences the > warning with uninitialized_var. David, please discard this. Jerry already posted a nicer cleanup. Sorry, Hannes -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Hannes Frederic Sowa <hannes@stressinduktion.org> Date: Sun, 15 Dec 2013 18:23:22 +0100 > On Sun, Dec 15, 2013 at 06:18:06PM +0100, Hannes Frederic Sowa wrote: >> This essentlally reverts commit f52d81dc27c3456c702e83183035142c222acdc7 >> ("ipv6: fix compiler warning in ipv6_exthdrs_len") and silences the >> warning with uninitialized_var. > > David, please discard this. Jerry already posted a nicer cleanup. I can't resolve these two patches in any reasonable way. Specifically, whether I revert your patch or not, I cannot get Jerry's patch to apply cleanly. I can't figure out what Jerry's patch is against at all. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index 08861f1..0a578fc 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -161,7 +161,7 @@ static int ipv6_exthdrs_len(struct ipv6hdr *iph, const struct net_offload **opps) { struct ipv6_opt_hdr *opth = NULL; - int len = 0, optlen = 0, proto; + int len = 0, proto, uninitialized_var(optlen); proto = iph->nexthdr; for (;;) { @@ -172,12 +172,11 @@ static int ipv6_exthdrs_len(struct ipv6hdr *iph, if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR)) break; } - if (opth == NULL) { + if (opth == NULL) opth = (void *)(iph+1); - } else { - optlen = ipv6_optlen(opth); + else opth = (void *)opth + optlen; - } + optlen = ipv6_optlen(opth); len += optlen; proto = opth->nexthdr; }
This essentlally reverts commit f52d81dc27c3456c702e83183035142c222acdc7 ("ipv6: fix compiler warning in ipv6_exthdrs_len") and silences the warning with uninitialized_var. Cc: Jerry Chu <hkchu@google.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> --- On Mon, Dec 16, 2013 at 12:20:22AM +0800, Jerry Chu wrote: > On Sat, Dec 14, 2013 at 3:02 PM, David Miller <davem@davemloft.net> wrote: > > From: Hannes Frederic Sowa <hannes@stressinduktion.org> > > Date: Sat, 14 Dec 2013 07:29:29 +0100 > > > >> Commit 299603e8370a93dd5d8e8d800f0dff1ce2c53d36 ("net-gro: Prepare GRO > >> stack for the upcoming tunneling support") used an uninitialized variable > >> which leads to the following compiler warning: > >> > >> net/ipv6/ip6_offload.c: In function ‘ipv6_gro_complete’: > >> net/ipv6/ip6_offload.c:178:24: warning: ‘optlen’ may be used uninitialized in this function [-Wmaybe-uninitialized] > >> opth = (void *)opth + optlen; > >> ^ > >> net/ipv6/ip6_offload.c:164:22: note: ‘optlen’ was declared here > >> int len = 0, proto, optlen; > >> ^ > >> Fix it up. > >> > >> Cc: Jerry Chu <hkchu@google.com> > >> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> > > > > Applied. > > Please back out the above "fix" - it actually breaks the original code because > the fix will cause exthdrs_len to be one optlen short. > > There was no bug in the original code, just the compiler warning (and I do not > get any warning, although I admit I did not run with the -W flag). Sorry, I see now, of course. Btw. I didn't use any special flags, just a normal kernel build with gcc 4.8.2. > In any case I will submit a revision shortly that will silent any > warning if exists. I hope you are ok with this. Sorry, Hannes net/ipv6/ip6_offload.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)