Re: [PATCH] gcc: Include patch scheduled for GCC 4.8.3 to fix epilogue on ARM

[Martin Jansa <martin.jansa@gmail.com>]

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On Fri, Jan 31, 2014 at 10:45:17AM +0100, Holger Hans Peter Freyther wrote:
> GCC 4.8.0, 4.8.1 and 4.8.2 can generate broken epilogues for the
> ABI used by the kernel. Apply the patch that is included for GCC
> 4.8.3 from http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58854.
> 
> The issue was found on Yocto/Dora and the patch should be backported
> to this branch. A kernel built with Dora's GCC 4.8.1 misbehaved on:
> 
>  while true;
>  do
>     (for i in `seq 1 100`;
>         do
>             echo "Log message... $RANDOM";
>         done) | logger;
>  done
> 
> busybox's syslogd would from time to read a huge negative value and
> then exit, strace would get stuck waiting on a syscall. After this
> patch it appears to work better.
> 
> Signed-off-by: Holger Hans Peter Freyther <holger@moiji-mobile.com>
> ---
>  meta/recipes-devtools/gcc/gcc-4.8.inc              |  1 +
>  .../0048-PR58854_fix_arm_apcs_epilogue.patch       | 23 ++++++++++++++++++++++
>  2 files changed, 24 insertions(+)
>  create mode 100644 meta/recipes-devtools/gcc/gcc-4.8/0048-PR58854_fix_arm_apcs_epilogue.patch
> 
> diff --git a/meta/recipes-devtools/gcc/gcc-4.8.inc b/meta/recipes-devtools/gcc/gcc-4.8.inc
> index a140573..fdd0c12 100644
> --- a/meta/recipes-devtools/gcc/gcc-4.8.inc
> +++ b/meta/recipes-devtools/gcc/gcc-4.8.inc
> @@ -68,6 +68,7 @@ SRC_URI = "${GNU_MIRROR}/gcc/gcc-${PV}/gcc-${PV}.tar.bz2 \
>  	   file://0045-gcc-4.8-PR57717-PowerPC-E500v2.patch \
>  	   file://0046-libatomic-deptracking.patch \
>  	   file://0047-repomembug.patch \
> +	   file://0048-PR58854_fix_arm_apcs_epilogue.patch \

You're not the first in this file, but please don't mix tabs and spaces
for indentation.

>  	  "
>  SRC_URI[md5sum] = "a3d7d63b9cb6b6ea049469a0c4a43c9d"
>  SRC_URI[sha256sum] = "09dc2276c73424bbbfda1dbddc62bbbf900c9f185acf7f3e1d773ce2d7e3cdc8"
> diff --git a/meta/recipes-devtools/gcc/gcc-4.8/0048-PR58854_fix_arm_apcs_epilogue.patch b/meta/recipes-devtools/gcc/gcc-4.8/0048-PR58854_fix_arm_apcs_epilogue.patch
> new file mode 100644
> index 0000000..0ef245a
> --- /dev/null
> +++ b/meta/recipes-devtools/gcc/gcc-4.8/0048-PR58854_fix_arm_apcs_epilogue.patch
> @@ -0,0 +1,23 @@
> +Backport fix for PR target/58854
> +
> +2013-11-11  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
> +
> +       Backported from mainline
> +        2013-10-30  Ramana Radhakrishnan  <ramana.radhakrishnan@arm.com>
> +
> +       PR target/58854
> +       * config/arm/arm.c (arm_expand_epilogue_apcs_frame): Emit blockage
> +
> +
> +Upstream-Status: Backport
> +
> +--- gcc-4_8-branch/gcc/config/arm/arm.c	2013/11/11 08:00:45	204664
> ++++ gcc-4_8-branch/gcc/config/arm/arm.c	2013/11/11 09:38:14	204665
> +@@ -23555,6 +23555,7 @@
> +   num_regs = bit_count (saved_regs_mask);
> +   if ((offsets->outgoing_args != (1 + num_regs)) || cfun->calls_alloca)
> +     {
> ++      emit_insn (gen_blockage ());
> +       /* Unwind the stack to just below the saved registers.  */
> +       emit_insn (gen_addsi3 (stack_pointer_rtx,
> +                              hard_frame_pointer_rtx,
> -- 
> 1.8.5.2
> 
> _______________________________________________
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> Openembedded-core@lists.openembedded.org
> http://lists.openembedded.org/mailman/listinfo/openembedded-core

-- 
Martin 'JaMa' Jansa     jabber: Martin.Jansa@gmail.com

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