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-rw-r--r--patches/source/glibc/glibc-2.17_gcc48-unsafe-optim.diff49
1 files changed, 49 insertions, 0 deletions
diff --git a/patches/source/glibc/glibc-2.17_gcc48-unsafe-optim.diff b/patches/source/glibc/glibc-2.17_gcc48-unsafe-optim.diff
new file mode 100644
index 00000000..4de9fe58
--- /dev/null
+++ b/patches/source/glibc/glibc-2.17_gcc48-unsafe-optim.diff
@@ -0,0 +1,49 @@
+From ea723210a76778c7e86b8df21cb284fc2665ee4f Mon Sep 17 00:00:00 2001
+From: mancha <mancha1 AT zoho DOT com>
+Date: Wed, 22 Oct 2014
+Subject: Fix unsafe compiler optimization
+
+GCC 4.8 enables -ftree-loop-distribute-patterns at -O3 by default and
+this optimization may transform loops into memset/memmove calls. Without
+proper handling this may generate unexpected PLT calls on GLIBC.
+This patch fixes by creating memset/memmove aliases to internal GLIBC
+__GI_memset/__GI_memmove symbols.
+
+This fix for use on glibc 2.17 is based on the following upstream
+commits:
+
+https://sourceware.org/git/?p=glibc.git;h=6a97b62a5b4f
+https://sourceware.org/git/?p=glibc.git;h=4959e284ca9c
+
+---
+ sysdeps/generic/symbol-hacks.h | 7 ++++++-
+ sysdeps/wordsize-32/symbol-hacks.h | 2 ++
+ sysdeps/x86_64/x32/symbol-hacks.h | 2 +-
+ 3 files changed, 9 insertions(+), 2 deletions(-)
+
+--- a/sysdeps/generic/symbol-hacks.h
++++ b/sysdeps/generic/symbol-hacks.h
+@@ -1 +1,6 @@
+-/* Fortunately nothing to do. */
++/* Some compiler optimizations may transform loops into memset/memmove
++ calls and without proper declaration it may generate PLT calls. */
++#if !defined __ASSEMBLER__ && !defined NOT_IN_libc && defined SHARED
++asm ("memmove = __GI_memmove");
++asm ("memset = __GI_memset");
++#endif
+--- a/sysdeps/wordsize-32/symbol-hacks.h
++++ b/sysdeps/wordsize-32/symbol-hacks.h
+@@ -16,6 +16,8 @@
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
++#include_next "symbol-hacks.h"
++
+ /* A very dirty trick: gcc emits references to __divdi3, __udivdi3,
+ __moddi3, and __umoddi3. These functions are exported and
+ therefore we get PLTs. Unnecessarily so. Changing gcc is a big
+--- a/sysdeps/x86_64/x32/symbol-hacks.h
++++ b/sysdeps/x86_64/x32/symbol-hacks.h
+@@ -1 +1 @@
+-/* Fortunately nothing to do. */
++#include <sysdeps/generic/symbol-hacks.h>