| Message ID | dcb4bfa3fe810236475b338f2f6401ec3d1a1c57.1610607906.git.mrezanin@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fixing several GCC 11 warnings | expand |
+Jason +Dmitry On 1/14/21 8:07 AM, Miroslav Rezanina wrote: > When building qemu with GCC 11, compiling eth.c file produce following warning: > > warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] > > This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more > attributes. > > As this usage is expected, suppress the warning temporarily through the function > using this retyping. This is not expected, this is a bug... > > Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> > --- > net/eth.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/eth.c b/net/eth.c > index 1e0821c5f8..b9bdd0435c 100644 > --- a/net/eth.c > +++ b/net/eth.c > @@ -405,6 +405,8 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > struct ip6_ext_hdr *ext_hdr, > struct in6_address *dst_addr) > { > +#pragma GCC diagnostic push > +#pragma GCC diagnostic ignored "-Warray-bounds" > struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr; eth_parse_ipv6_hdr() called iov_to_buf() to fill the 2 bytes of ext_hdr. > if ((rthdr->rtype == 2) && Here we access after the 2 bytes filled... rthdr->rtype is somewhere on eth_parse_ipv6_hdr's stack, its content is unknown. > @@ -426,6 +428,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > } > > return false; > +#pragma GCC diagnostic pop Nacked-by: Philippe Mathieu-Daudé <philmd@redhat.com>
On 210114 1415, Philippe Mathieu-Daudé wrote: > +Jason +Dmitry > > On 1/14/21 8:07 AM, Miroslav Rezanina wrote: > > When building qemu with GCC 11, compiling eth.c file produce following warning: > > > > warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] > > > > This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more > > attributes. > > > > As this usage is expected, suppress the warning temporarily through the function > > using this retyping. > > This is not expected, this is a bug... > Seems related: https://bugs.launchpad.net/qemu/+bug/1879531 -Alex > > > > Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> > > --- > > net/eth.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/net/eth.c b/net/eth.c > > index 1e0821c5f8..b9bdd0435c 100644 > > --- a/net/eth.c > > +++ b/net/eth.c > > @@ -405,6 +405,8 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > struct ip6_ext_hdr *ext_hdr, > > struct in6_address *dst_addr) > > { > > +#pragma GCC diagnostic push > > +#pragma GCC diagnostic ignored "-Warray-bounds" > > struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr; > > eth_parse_ipv6_hdr() called iov_to_buf() to fill the 2 bytes of ext_hdr. > > > if ((rthdr->rtype == 2) && > > Here we access after the 2 bytes filled... rthdr->rtype is somewhere on > eth_parse_ipv6_hdr's stack, its content is unknown. > > > @@ -426,6 +428,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > } > > > > return false; > > +#pragma GCC diagnostic pop > > Nacked-by: Philippe Mathieu-Daudé <philmd@redhat.com> > >
On 1/14/21 3:19 PM, Alexander Bulekov wrote: > On 210114 1415, Philippe Mathieu-Daudé wrote: >> +Jason +Dmitry >> >> On 1/14/21 8:07 AM, Miroslav Rezanina wrote: >>> When building qemu with GCC 11, compiling eth.c file produce following warning: >>> >>> warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] >>> >>> This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more >>> attributes. >>> >>> As this usage is expected, suppress the warning temporarily through the function >>> using this retyping. >> >> This is not expected, this is a bug... >> > > Seems related: https://bugs.launchpad.net/qemu/+bug/1879531 Yes!
On Thu, Jan 14, 2021 at 02:15:59PM +0100, Philippe Mathieu-Daudé wrote: > +Jason +Dmitry > > On 1/14/21 8:07 AM, Miroslav Rezanina wrote: > > When building qemu with GCC 11, compiling eth.c file produce following warning: > > > > warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] > > > > This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more > > attributes. > > > > As this usage is expected, suppress the warning temporarily through the function > > using this retyping. > > This is not expected, this is a bug... Thanks for confirmation, my initial idea was the same but then I got impression (do not remember where) that ip6_ext_hdr is not type where data are initially written to so the overflow here is expected. Mirek > > > > > Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> > > --- > > net/eth.c | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/net/eth.c b/net/eth.c > > index 1e0821c5f8..b9bdd0435c 100644 > > --- a/net/eth.c > > +++ b/net/eth.c > > @@ -405,6 +405,8 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > struct ip6_ext_hdr *ext_hdr, > > struct in6_address *dst_addr) > > { > > +#pragma GCC diagnostic push > > +#pragma GCC diagnostic ignored "-Warray-bounds" > > struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr; > > eth_parse_ipv6_hdr() called iov_to_buf() to fill the 2 bytes of ext_hdr. > > > if ((rthdr->rtype == 2) && > > Here we access after the 2 bytes filled... rthdr->rtype is somewhere on > eth_parse_ipv6_hdr's stack, its content is unknown. > > > @@ -426,6 +428,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > } > > > > return false; > > +#pragma GCC diagnostic pop > > Nacked-by: Philippe Mathieu-Daudé <philmd@redhat.com> > >
On Thu, Jan 14, 2021 at 09:19:20AM -0500, Alexander Bulekov wrote: > On 210114 1415, Philippe Mathieu-Daudé wrote: > > +Jason +Dmitry > > > > On 1/14/21 8:07 AM, Miroslav Rezanina wrote: > > > When building qemu with GCC 11, compiling eth.c file produce following warning: > > > > > > warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] > > > > > > This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more > > > attributes. > > > > > > As this usage is expected, suppress the warning temporarily through the function > > > using this retyping. > > > > This is not expected, this is a bug... > > > > Seems related: https://bugs.launchpad.net/qemu/+bug/1879531 > -Alex > Yes, it is caused by the issue triggering the warning. Do you know whether the patch mentioned in bug was already sent? Mirek > > > > > > Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> > > > --- > > > net/eth.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/net/eth.c b/net/eth.c > > > index 1e0821c5f8..b9bdd0435c 100644 > > > --- a/net/eth.c > > > +++ b/net/eth.c > > > @@ -405,6 +405,8 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > > struct ip6_ext_hdr *ext_hdr, > > > struct in6_address *dst_addr) > > > { > > > +#pragma GCC diagnostic push > > > +#pragma GCC diagnostic ignored "-Warray-bounds" > > > struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr; > > > > eth_parse_ipv6_hdr() called iov_to_buf() to fill the 2 bytes of ext_hdr. > > > > > if ((rthdr->rtype == 2) && > > > > Here we access after the 2 bytes filled... rthdr->rtype is somewhere on > > eth_parse_ipv6_hdr's stack, its content is unknown. > > > > > @@ -426,6 +428,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > > } > > > > > > return false; > > > +#pragma GCC diagnostic pop > > > > Nacked-by: Philippe Mathieu-Daudé <philmd@redhat.com> > > > > >
On 210114 1538, Miroslav Rezanina wrote: > On Thu, Jan 14, 2021 at 09:19:20AM -0500, Alexander Bulekov wrote: > > On 210114 1415, Philippe Mathieu-Daudé wrote: > > > +Jason +Dmitry > > > > > > On 1/14/21 8:07 AM, Miroslav Rezanina wrote: > > > > When building qemu with GCC 11, compiling eth.c file produce following warning: > > > > > > > > warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] > > > > > > > > This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more > > > > attributes. > > > > > > > > As this usage is expected, suppress the warning temporarily through the function > > > > using this retyping. > > > > > > This is not expected, this is a bug... > > > > > > > Seems related: https://bugs.launchpad.net/qemu/+bug/1879531 > > -Alex > > > > Yes, it is caused by the issue triggering the warning. Do you know > whether the patch mentioned in bug was already sent? > > Mirek I don't think so.. -Alex > > > > > > > > Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> > > > > --- > > > > net/eth.c | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > > > diff --git a/net/eth.c b/net/eth.c > > > > index 1e0821c5f8..b9bdd0435c 100644 > > > > --- a/net/eth.c > > > > +++ b/net/eth.c > > > > @@ -405,6 +405,8 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > > > struct ip6_ext_hdr *ext_hdr, > > > > struct in6_address *dst_addr) > > > > { > > > > +#pragma GCC diagnostic push > > > > +#pragma GCC diagnostic ignored "-Warray-bounds" > > > > struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr; > > > > > > eth_parse_ipv6_hdr() called iov_to_buf() to fill the 2 bytes of ext_hdr. > > > > > > > if ((rthdr->rtype == 2) && > > > > > > Here we access after the 2 bytes filled... rthdr->rtype is somewhere on > > > eth_parse_ipv6_hdr's stack, its content is unknown. > > > > > > > @@ -426,6 +428,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, > > > > } > > > > > > > > return false; > > > > +#pragma GCC diagnostic pop > > > > > > Nacked-by: Philippe Mathieu-Daudé <philmd@redhat.com> > > > > > > > > >
On 1/14/21 3:42 PM, Alexander Bulekov wrote: > On 210114 1538, Miroslav Rezanina wrote: >> On Thu, Jan 14, 2021 at 09:19:20AM -0500, Alexander Bulekov wrote: >>> On 210114 1415, Philippe Mathieu-Daudé wrote: >>>> +Jason +Dmitry >>>> >>>> On 1/14/21 8:07 AM, Miroslav Rezanina wrote: >>>>> When building qemu with GCC 11, compiling eth.c file produce following warning: >>>>> >>>>> warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] >>>>> >>>>> This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more >>>>> attributes. >>>>> >>>>> As this usage is expected, suppress the warning temporarily through the function >>>>> using this retyping. >>>> >>>> This is not expected, this is a bug... >>>> >>> >>> Seems related: https://bugs.launchpad.net/qemu/+bug/1879531 >>> -Alex >>> >> >> Yes, it is caused by the issue triggering the warning. Do you know >> whether the patch mentioned in bug was already sent? >> >> Mirek > > I don't think so.. Just sent one: https://lists.gnu.org/archive/html/qemu-devel/2021-01/msg03205.html
diff --git a/net/eth.c b/net/eth.c index 1e0821c5f8..b9bdd0435c 100644 --- a/net/eth.c +++ b/net/eth.c @@ -405,6 +405,8 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, struct ip6_ext_hdr *ext_hdr, struct in6_address *dst_addr) { +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Warray-bounds" struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr; if ((rthdr->rtype == 2) && @@ -426,6 +428,7 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags, } return false; +#pragma GCC diagnostic pop } static bool
When building qemu with GCC 11, compiling eth.c file produce following warning: warning: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Warray-bounds] This is caused by retyping from ip6_ext_hdr to ip6_ext_hdr_routing that has more attributes. As this usage is expected, suppress the warning temporarily through the function using this retyping. Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> --- net/eth.c | 3 +++ 1 file changed, 3 insertions(+)