sparc/ppc/arm compat siginfo ABI regressions: sending SIGFPE via kill() returns wrong values in si_pid and si_uid

[Russell King - ARM Linux]

On Thu, Apr 12, 2018 at 09:50:26AM -0700, Linus Torvalds wrote:
> Does this attached patch perhaps fix the ARM case?
> 
> It just uses FPE_FLTUNK as the default si_code for SIGFPE, which seems
> sane enough. And then gets rid of FPE_FIXME, which should resolve the
> nasty case.
> 
> Hmm? Entirely untested, and I didn't really look at the test-case in
> question since I can't really run it anyway.

I'll test tomorrow and let you know.

>  arch/arm/include/uapi/asm/siginfo.h | 7 -------
>  arch/arm/vfp/vfpmodule.c            | 4 ++--
>  2 files changed, 2 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/include/uapi/asm/siginfo.h b/arch/arm/include/uapi/asm/siginfo.h
> index d0513880be21..d87beeedb4c4 100644
> --- a/arch/arm/include/uapi/asm/siginfo.h
> +++ b/arch/arm/include/uapi/asm/siginfo.h
> @@ -3,11 +3,4 @@
>  
>  #include <asm-generic/siginfo.h>
>  
> -/*
> - * SIGFPE si_codes
> - */
> -#ifdef __KERNEL__
> -#define FPE_FIXME	0	/* Broken dup of SI_USER */
> -#endif /* __KERNEL__ */
> -
>  #endif

This file was created to contain FPE_FIXME, by the "signal/arm: Document
conflicts with SI_USER and SIGFPE" commit so if we're removing it, it
would be better to remove the whole file.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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