Bug#762390: Patch for hppa arch
On Sun, Sep 21, 2014 at 08:53:39PM +0200, Helge Deller wrote:
> Package: linux
> Version: 3.16.3-2
> Severity: bug
> Tags: patch
>
> Dear Debian Kernel maintainers,
>
> could you please temporarily add this hppa-specific patch to the debian
> kernel sources?
>
> Currently the 64bit hppa kernel gets miscompiled by gcc-4.8 and as such
> it will not boot.
>
> The attached patch fixes one of the problems. Latest changes in gcc-4.8
> made changes to the -mfast-indirect-calls option which now produces wrong code
> when compiling for 64bit. The problem is being worked on in upstream gcc-4.8,
> and we don't know yet if we will implement -mfast-indirect-calls for 64bit
> (which might introduce side-effects) or not. That's the reason why I don't want
> to push attached patch upstream yet.
>
> The second problem is, that gcc-4.9 (which is used in debian to bootstrap gcc-4.8)
> miscompiles one specific gcc-4.8 source code path and this bug is reported upstream in
> GCC PR:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63302
> We work on that too.
>
> So, if you could apply the attached patch temporarily for now it would help us
> to get further. I will either send the patch upstream or we will fix the compiler.
> The decision is still pending, but I will inform you when this patch can be removed
> from debian kernel sources again (hopefully soon!).
>
> BTW: If you apply it, there is no need to trigger a new upload specifically for this bug/hppa...
>
> Thanks,
> Helge
> diff --git a/arch/parisc/Makefile b/arch/parisc/Makefile
> index 7187664..5db8882 100644
> --- a/arch/parisc/Makefile
> +++ b/arch/parisc/Makefile
> @@ -48,7 +48,12 @@ cflags-y := -pipe
>
> # These flags should be implied by an hppa-linux configuration, but they
> # are not in gcc 3.2.
> -cflags-y += -mno-space-regs -mfast-indirect-calls
> +cflags-y += -mno-space-regs
> +
> +# -mfast-indirect-calls is only relevant for 32-bit kernels.
Would it make sense to point out here that -mfast-indirect-calls is not
only unneeded but bad until http://link.to/relevant-discussion is
resolved?
> +ifndef CONFIG_64BIT
> +cflags-y += -mfast-indirect-calls
> +endif
>
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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