glibc: fix i686 crashes via an upstream patch

vcunat · vcunat · commit c30b12b9a5cc · 2017-04-10T11:13:00.000+02:00
Fixes #23177.
diff --git a/pkgs/development/libraries/glibc/common.nix b/pkgs/development/libraries/glibc/common.nix
@@ -48,6 +48,8 @@ stdenv.mkDerivation ({
          "/bin:/usr/bin", which is inappropriate on NixOS machines. This
          patch extends the search path by "/run/current-system/sw/bin". */
       ./fix_path_attribute_in_getconf.patch
+
+      ./fix-i686-memchr.patch
     ];
 
   postPatch =
diff --git a/pkgs/development/libraries/glibc/fix-i686-memchr.patch b/pkgs/development/libraries/glibc/fix-i686-memchr.patch
@@ -0,0 +1,23 @@
+Fix i686 memchr overflow calculation (BZ#21182)
+
+https://sourceware.org/git/?p=glibc.git;a=commit;h=3abeeec5f46ff03
+diff --git a/sysdeps/i386/i686/multiarch/memchr-sse2.S b/sysdeps/i386/i686/multiarch/memchr-sse2.S
+index 910679c..e41f324 100644
+--- a/sysdeps/i386/i686/multiarch/memchr-sse2.S
++++ b/sysdeps/i386/i686/multiarch/memchr-sse2.S
+@@ -117,7 +117,6 @@ L(crosscache):
+ 
+ # ifndef USE_AS_RAWMEMCHR
+ 	jnz	L(match_case2_prolog1)
+-	lea	-16(%edx), %edx
+         /* Calculate the last acceptable address and check for possible
+            addition overflow by using satured math:
+            edx = ecx + edx
+@@ -125,6 +124,7 @@ L(crosscache):
+ 	add	%ecx, %edx
+ 	sbb	%eax, %eax
+ 	or	%eax, %edx
++	sub	$16, %edx
+ 	jbe	L(return_null)
+ 	lea	16(%edi), %edi
+ # else
