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Message-ID: <CANP3RGcgBUAqT1fqX7GRyfCu_snXzaKxzfCtWWiTi_eDNbraeA@mail.gmail.com>
Date: Wed, 6 Dec 2023 03:13:44 -0800
From: Maciej Żenczykowski <maze@...gle.com>
To: kernel test robot <lkp@...el.com>
Cc: oe-kbuild-all@...ts.linux.dev,
Linux Network Development Mailing List <netdev@...r.kernel.org>, "David S . Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
David Ahern <dsahern@...nel.org>, Lorenzo Colitti <lorenzo@...gle.com>
Subject: Re: [PATCH net] net: ipv6: support reporting otherwise unknown prefix
flags in RTM_NEWPREFIX
On Wed, Dec 6, 2023 at 3:05 AM Maciej Żenczykowski <maze@...gle.com> wrote:
>
> On Wed, Dec 6, 2023 at 3:00 AM Maciej Żenczykowski <maze@...gle.com> wrote:
> >
> > On Tue, Dec 5, 2023 at 11:12 AM kernel test robot <lkp@...el.com> wrote:
> > >
> > > Hi Maciej,
> > >
> > > kernel test robot noticed the following build errors:
> > >
> > > [auto build test ERROR on net/main]
> > >
> > > url: https://github.com/intel-lab-lkp/linux/commits/Maciej-enczykowski/net-ipv6-support-reporting-otherwise-unknown-prefix-flags-in-RTM_NEWPREFIX/20231205-035333
> > > base: net/main
> > > patch link: https://lore.kernel.org/r/20231204195252.2004515-1-maze%40google.com
> > > patch subject: [PATCH net] net: ipv6: support reporting otherwise unknown prefix flags in RTM_NEWPREFIX
> > > config: arm-rpc_defconfig (https://download.01.org/0day-ci/archive/20231206/202312060307.EaL1FRwu-lkp@intel.com/config)
> > > compiler: arm-linux-gnueabi-gcc (GCC) 13.2.0
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231206/202312060307.EaL1FRwu-lkp@intel.com/reproduce)
> >
> > I followed these steps, and it built just fine...
> >
> > maze@...top:~/K$ git log -n2 --oneline
> > 57cde6e635d5 (HEAD) net: ipv6: support reporting otherwise unknown
> > prefix flags in RTM_NEWPREFIX
> > 7037d95a047c (net/main) r8152: add vendor/device ID pair for ASUS USB-C2500
> >
> > maze@...top:~/K$ file -sL build_dir/vmlinux
> > build_dir/vmlinux: ELF 32-bit LSB executable, ARM, EABI5 version 1
> > (SYSV), statically linked,
> > BuildID[sha1]=ae5a34fc35b264d707b3f16e920282b96c080508, not stripped
>
> ah, the reproduction steps don't actually fetch the .config
the struct *somehow* comes out to be 36 bytes (it was 32 before this patch)
this tentatively looks like it might be triggering a compiler bug?
will dig deeper.
>
> > >
> > > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > > the same patch/commit), kindly add following tags
> > > | Reported-by: kernel test robot <lkp@...el.com>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202312060307.EaL1FRwu-lkp@intel.com/
> > >
> > > All errors (new ones prefixed by >>):
> > >
> > > In file included from include/linux/container_of.h:5,
> > > from include/linux/list.h:5,
> > > from include/linux/module.h:12,
> > > from fs/lockd/svc.c:16:
> > > >> include/linux/build_bug.h:78:41: error: static assertion failed: "sizeof(struct prefix_info) == 32"
> > > 78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
> > > | ^~~~~~~~~~~~~~
> > > include/linux/build_bug.h:77:34: note: in expansion of macro '__static_assert'
> > > 77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
> > > | ^~~~~~~~~~~~~~~
> > > include/net/addrconf.h:58:1: note: in expansion of macro 'static_assert'
> > > 58 | static_assert(sizeof(struct prefix_info) == 32);
> > > | ^~~~~~~~~~~~~
> > > --
> > > In file included from lib/vsprintf.c:21:
> > > >> include/linux/build_bug.h:78:41: error: static assertion failed: "sizeof(struct prefix_info) == 32"
> > > 78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
> > > | ^~~~~~~~~~~~~~
> > > include/linux/build_bug.h:77:34: note: in expansion of macro '__static_assert'
> > > 77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
> > > | ^~~~~~~~~~~~~~~
> > > include/net/addrconf.h:58:1: note: in expansion of macro 'static_assert'
> > > 58 | static_assert(sizeof(struct prefix_info) == 32);
> > > | ^~~~~~~~~~~~~
> > > lib/vsprintf.c: In function 'va_format':
> > > lib/vsprintf.c:1683:9: warning: function 'va_format' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format]
> > > 1683 | buf += vsnprintf(buf, end > buf ? end - buf : 0, va_fmt->fmt, va);
> > > | ^~~
> > > --
> > > In file included from include/linux/container_of.h:5,
> > > from include/linux/list.h:5,
> > > from include/linux/module.h:12,
> > > from net/ipv4/route.c:63:
> > > >> include/linux/build_bug.h:78:41: error: static assertion failed: "sizeof(struct prefix_info) == 32"
> > > 78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
> > > | ^~~~~~~~~~~~~~
> > > include/linux/build_bug.h:77:34: note: in expansion of macro '__static_assert'
> > > 77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
> > > | ^~~~~~~~~~~~~~~
> > > include/net/addrconf.h:58:1: note: in expansion of macro 'static_assert'
> > > 58 | static_assert(sizeof(struct prefix_info) == 32);
> > > | ^~~~~~~~~~~~~
> > > net/ipv4/route.c: In function 'ip_rt_send_redirect':
> > > net/ipv4/route.c:880:13: warning: variable 'log_martians' set but not used [-Wunused-but-set-variable]
> > > 880 | int log_martians;
> > > | ^~~~~~~~~~~~
> > > --
> > > In file included from include/linux/container_of.h:5,
> > > from include/linux/list.h:5,
> > > from include/linux/timer.h:5,
> > > from include/linux/workqueue.h:9,
> > > from include/linux/bpf.h:10,
> > > from net/ipv6/ip6_fib.c:18:
> > > >> include/linux/build_bug.h:78:41: error: static assertion failed: "sizeof(struct prefix_info) == 32"
> > > 78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
> > > | ^~~~~~~~~~~~~~
> > > include/linux/build_bug.h:77:34: note: in expansion of macro '__static_assert'
> > > 77 | #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
> > > | ^~~~~~~~~~~~~~~
> > > include/net/addrconf.h:58:1: note: in expansion of macro 'static_assert'
> > > 58 | static_assert(sizeof(struct prefix_info) == 32);
> > > | ^~~~~~~~~~~~~
> > > net/ipv6/ip6_fib.c: In function 'fib6_add':
> > > net/ipv6/ip6_fib.c:1384:32: warning: variable 'pn' set but not used [-Wunused-but-set-variable]
> > > 1384 | struct fib6_node *fn, *pn = NULL;
> > > | ^~
> > >
> > >
> > > vim +78 include/linux/build_bug.h
> > >
> > > bc6245e5efd70c Ian Abbott 2017-07-10 60
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 61 /**
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 62 * static_assert - check integer constant expression at build time
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 63 *
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 64 * static_assert() is a wrapper for the C11 _Static_assert, with a
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 65 * little macro magic to make the message optional (defaulting to the
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 66 * stringification of the tested expression).
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 67 *
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 68 * Contrary to BUILD_BUG_ON(), static_assert() can be used at global
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 69 * scope, but requires the expression to be an integer constant
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 70 * expression (i.e., it is not enough that __builtin_constant_p() is
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 71 * true for expr).
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 72 *
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 73 * Also note that BUILD_BUG_ON() fails the build if the condition is
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 74 * true, while static_assert() fails the build if the expression is
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 75 * false.
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 76 */
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 77 #define static_assert(expr, ...) __static_assert(expr, ##__VA_ARGS__, #expr)
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 @78 #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)
> > > 6bab69c65013be Rasmus Villemoes 2019-03-07 79
> > > 07a368b3f55a79 Maxim Levitsky 2022-10-25 80
> > >
> > > --
> > > 0-DAY CI Kernel Test Service
> > > https://github.com/intel/lkp-tests/wikiMaciej Żenczykowski, Kernel Networking Developer @ GoogleMaciej Żenczykowski, Kernel Networking Developer @ GoogleMaciej Żenczykowski, Kernel Networking Developer @ Google
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