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

* [PATCH] gcc: Include patch scheduled for GCC 4.8.3 to fix epilogue on ARM
@ 2014-01-31  9:45 Holger Hans Peter Freyther
  2014-01-31 17:26 ` Martin Jansa
  0 siblings, 1 reply; 2+ messages in thread
From: Holger Hans Peter Freyther @ 2014-01-31  9:45 UTC (permalink / raw)
  To: openembedded-core; +Cc: Holger Hans Peter Freyther

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 \
 	  "
 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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