Re: [PATCH] arm: Build with -fno-dwarf2-cfi-asm

Russell King - ARM Linux
2010-07-26T13:11:45Z

On Mon, Jul 26, 2010 at 03:04:18PM +0200, Michal Marek wrote:
> On 10.7.2010 15:02, Mikael Pettersson wrote:
> > Michal Marek writes:
> > > Commit d0679c7 restricted this workaround to powerpc only, but it turns
> > > out that ARM needs it as well. Fixes
> > > https://bugzilla.kernel.org/show_bug.cgi?id=16310 .
> > >
> > > Reported-and-Tested-by: Robert Nelson <robertcnelson@gmail.com>
> > > Signed-off-by: Michal Marek <mmarek@suse.cz>
> > > ---
> > > arch/arm/Makefile | 5 +++++
> > > 1 files changed, 5 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> > > index 64ba313..862d4ba 100644
> > > --- a/arch/arm/Makefile
> > > +++ b/arch/arm/Makefile
> > > @@ -21,6 +21,11 @@ GZFLAGS :=-9
> > > # Explicitly specifiy 32-bit ARM ISA since toolchain default can be -mthumb:
> > > KBUILD_CFLAGS +=$(call cc-option,-marm,)
> > >
> > > +# FIXME: the module load should be taught about the additional relocs
> > > +# generated by this.
> > > +# revert to pre-gcc-4.4 behaviour of .eh_frame
> > > +KBUILD_CFLAGS += $(call cc-option,-fno-dwarf2-cfi-asm)
> >
> > Appears related to gcc PR40521, which should be fixed in gcc-4.4.3,
> > though it may have been re-broken in gcc-4.5.0 for in a corner case
> > <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40521#c24> that may or
> > may not apply to the kernel. There's also a related binutils issue.
> >
> > The above fix seems appropriate, but the FIXME comment seems wrong:
> > this is about getting the right kind of exception unwind tables in
> > the entire kernel, not just relocs in modules.
> >
> > The comment should just say:
> > # Never generate .eh_frame:
> >
> > So for the fix without the comment part:
> >
> > Acked-by: Mikael Pettersson <mikpe@it.uu.se>
>
> Hi Russell,
>
> should I resend the patch with the comment by Mikael?

Yes please - and please put it in the patch system.