Hi Adrian,
On 05/06/2025 08:39, John Paul Adrian Glaubitz wrote:
Hi Jean-Michel,
On Thu, 2025-06-05 at 08:24 +0200, Jean-Michel Hautbois wrote:
I tried to patch gcc-13 with this BIGGEST_ALIGNMENT set to 64. I am
using buildroot+uclibc-ng on a Coldfire (mcf54418).
Thanks a lot for testing! Such contributions are highly appreciated.
Everything build fine, except the kernel:
In function ‘siginfo_build_tests’,
inlined from ‘restore_sigcontext’ at arch/m68k/kernel/signal.c:684:2,
inlined from ‘do_sigreturn’ at arch/m68k/kernel/signal.c:775:9:
././include/linux/compiler_types.h:542:45: error: call to
‘__compiletime_assert_351’ declared with attribute error: BUILD_BUG_ON
failed: offsetof(siginfo_t, si_lower) != 0x12
542 | _compiletime_assert(condition, msg,
__compiletime_assert_, __COUNTER__)
| ^
././include/linux/compiler_types.h:523:25: note: in definition of macro
‘__compiletime_assert’
523 | prefix ## suffix();
\
| ^~~~~~
././include/linux/compiler_types.h:542:9: note: in expansion of macro
‘_compiletime_assert’
542 | _compiletime_assert(condition, msg,
__compiletime_assert_, __COUNTER__)
| ^~~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:39:37: note: in expansion of macro
‘compiletime_assert’
39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond),
msg)
| ^~~~~~~~~~~~~~~~~~
./include/linux/build_bug.h:50:9: note: in expansion of macro
‘BUILD_BUG_ON_MSG’
50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: "
#condition)
| ^~~~~~~~~~~~~~~~
arch/m68k/kernel/signal.c:621:9: note: in expansion of macro ‘BUILD_BUG_ON’
621 | BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x12);
| ^~~~~~~~~~~~
make[5]: *** [scripts/Makefile.build:207: arch/m68k/kernel/signal.o] Error 1
make[4]: *** [scripts/Makefile.build:465: arch/m68k/kernel] Error 2
make[4]: *** Waiting for unfinished jobs....
This is a 6.14.
Any idea about this ?
It looks like this check needs to be patched:
BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x12);
The source code in arch/m68k/kernel/signal.c contains a lot of hard-wired
offsets
which will probably have to be adjusted.
You can try changing 0x12 to 0x14 and see if that fixes it.
I had to change three offsets:
diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index e628b859ef21..5b8ef98565c2 100644
--- a/arch/m68k/kernel/signal.c
+++ b/arch/m68k/kernel/signal.c
@@ -618,11 +618,11 @@ static inline void siginfo_build_tests(void)
BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x10);
/* _sigfault._addr_bnd */
- BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x12);
- BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x16);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x14);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x18);
/* _sigfault._addr_pkey */
- BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x12);
+ BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x14);
/* _sigfault._perf */
BUILD_BUG_ON(offsetof(siginfo_t, si_perf_data) != 0x10);
--
2.39.5
The kernel is booting, so, I suppose it is working :-).
Now, I can't send a patch fixing the offsets like that, as it depends on
the BIGGEST_ALIGNMENT value...
Thanks,
JM
