dhcpcd: fix delay after dhcp down.

[ipfire-2.x.git] / src / patches / glibc / glibc-rh846342.patch

This is a workaround for broken code which issues memcpy requests with
overlapping arguments.  With this patch installed, if the file
/etc/sysconfig/32bit_ssse3_memcpy_via_32bit_ssse3_memmove exists then a
32bit memcpy call which normally would be handled by the SSSE3 memcpy
implementation would instead be handled by the 32bit SSSE3 memmove
implementation which is more tolerant of overlaps.

diff -Nrup a/sysdeps/i386/i686/multiarch/memcpy.S b/sysdeps/i386/i686/multiarch/memcpy.S
--- a/sysdeps/i386/i686/multiarch/memcpy.S	2010-05-04 05:27:23.000000000 -0600
+++ b/sysdeps/i386/i686/multiarch/memcpy.S	2012-11-20 14:19:52.890780415 -0700
@@ -21,6 +21,10 @@
 #include <sysdep.h>
 #include <init-arch.h>
 
+        .section .rodata
+L(magicfile):
+	.ascii "/etc/sysconfig/32bit_ssse3_memcpy_via_32bit_ssse3_memmove"
+
 /* Define multiple versions only for the definition in lib and for
    DSO.  In static binaries we need memcpy before the initialization
    happened.  */
@@ -48,6 +52,26 @@ ENTRY(memcpy)
 1:	leal	__memcpy_ia32@GOTOFF(%ebx), %eax
 	testl	$bit_SSSE3, CPUID_OFFSET+index_SSSE3+__cpu_features@GOTOFF(%ebx)
 	jz	2f
+
+	/* This is an inlined access (magicfile, 0) syscall.  
+
+	   Note that it clobbers %ebx, so we have to save/restore
+	   it around the syscall.  */
+	mov	%ebx, %edx
+	leal 	L(magicfile)@GOTOFF(%ebx), %ebx
+	xor	%ecx, %ecx
+	movl	$33, %eax
+	int	$0x80
+	mov	%edx, %ebx
+
+	/* If the file did not exist, then %eax will be -1..-4095 and we
+	   do nothing special.  */
+	cmpl	$-4095, %eax
+	jae	4f
+
+	leal	__memmove_ssse3@GOTOFF(%ebx), %eax
+	jmp	2f
+4:
 	leal	__memcpy_ssse3@GOTOFF(%ebx), %eax
 	testl	$bit_Fast_Rep_String, FEATURE_OFFSET+index_Fast_Rep_String+__cpu_features@GOTOFF(%ebx)
 	jz	2f