[arch-commits] Commit in glibc/trunk (2 files)

[Bartłomiej Piotrowski]

    Date: Friday, September 8, 2017 @ 12:20:46
  Author: bpiotrowski
Revision: 305066

2.26-3 Don't use IFUNC resolver for longjmp or system in libpthread (FS#55220)

Added:
  glibc/trunk/0001-Don-t-use-IFUNC-resolver-for-longjmp-or-system-in-li.patch
Modified:
  glibc/trunk/PKGBUILD

-----------------------------------------------------------------+
 0001-Don-t-use-IFUNC-resolver-for-longjmp-or-system-in-li.patch |  110 ++++++++++
 PKGBUILD                                                        |   11 -
 2 files changed, 118 insertions(+), 3 deletions(-)

Added: 0001-Don-t-use-IFUNC-resolver-for-longjmp-or-system-in-li.patch
===================================================================
--- 0001-Don-t-use-IFUNC-resolver-for-longjmp-or-system-in-li.patch	                        (rev 0)
+++ 0001-Don-t-use-IFUNC-resolver-for-longjmp-or-system-in-li.patch	2017-09-08 12:20:46 UTC (rev 305066)
@@ -0,0 +1,110 @@
+From fc5ad7024c620cdfe9b76e94638aac83b99c5bf8 Mon Sep 17 00:00:00 2001
+From: Andreas Schwab <schwab at suse.de>
+Date: Tue, 8 Aug 2017 16:21:58 +0200
+Subject: [PATCH] Don't use IFUNC resolver for longjmp or system in libpthread
+ (bug 21041)
+
+Unlike the vfork forwarder and like the fork forwarder as in bug 19861,
+there won't be a problem when the compiler does not turn this into a tail
+call.
+---
+ nptl/pt-longjmp.c | 31 ++++++++++---------------------
+ nptl/pt-system.c  | 24 ++++++++----------------
+ 3 files changed, 18 insertions(+), 37 deletions(-)
+
+diff --git a/nptl/pt-longjmp.c b/nptl/pt-longjmp.c
+index 2ef757e687f..8f3c6b3a09f 100644
+--- a/nptl/pt-longjmp.c
++++ b/nptl/pt-longjmp.c
+@@ -25,21 +25,14 @@
+    symbol in libpthread, but the historical ABI requires it.  For static
+    linking, there is no need to provide anything here--the libc version
+    will be linked in.  For shared library ABI compatibility, there must be
+-   longjmp and siglongjmp symbols in libpthread.so; so we define them using
+-   IFUNC to redirect to the libc function.  */
++   longjmp and siglongjmp symbols in libpthread.so.
+ 
+-#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
+-
+-# if HAVE_IFUNC
+-
+-#  undef INIT_ARCH
+-#  define INIT_ARCH()
+-#  define DEFINE_LONGJMP(name) libc_ifunc (name, &__libc_longjmp)
+-
+-extern __typeof(longjmp) longjmp_ifunc;
+-extern __typeof(siglongjmp) siglongjmp_ifunc;
++   With an IFUNC resolver, it would be possible to avoid the indirection,
++   but the IFUNC resolver might run before the __libc_longjmp symbol has
++   been relocated, in which case the IFUNC resolver would not be able to
++   provide the correct address.  */
+ 
+-# else  /* !HAVE_IFUNC */
++#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
+ 
+ static void __attribute__ ((noreturn, used))
+ longjmp_compat (jmp_buf env, int val)
+@@ -47,14 +40,10 @@ longjmp_compat (jmp_buf env, int val)
+   __libc_longjmp (env, val);
+ }
+ 
+-# define DEFINE_LONGJMP(name) strong_alias (longjmp_compat, name)
+-
+-# endif  /* HAVE_IFUNC */
+-
+-DEFINE_LONGJMP (longjmp_ifunc)
+-compat_symbol (libpthread, longjmp_ifunc, longjmp, GLIBC_2_0);
++strong_alias (longjmp_compat, longjmp_alias)
++compat_symbol (libpthread, longjmp_alias, longjmp, GLIBC_2_0);
+ 
+-strong_alias (longjmp_ifunc, siglongjmp_ifunc)
+-compat_symbol (libpthread, siglongjmp_ifunc, siglongjmp, GLIBC_2_0);
++strong_alias (longjmp_alias, siglongjmp_alias)
++compat_symbol (libpthread, siglongjmp_alias, siglongjmp, GLIBC_2_0);
+ 
+ #endif
+diff --git a/nptl/pt-system.c b/nptl/pt-system.c
+index f8ca6ba0d94..b30ddf2b398 100644
+--- a/nptl/pt-system.c
++++ b/nptl/pt-system.c
+@@ -25,29 +25,21 @@
+    libpthread, but the historical ABI requires it.  For static linking,
+    there is no need to provide anything here--the libc version will be
+    linked in.  For shared library ABI compatibility, there must be a
+-   'system' symbol in libpthread.so; so we define it using IFUNC to
+-   redirect to the libc function.  */
++   'system' symbol in libpthread.so.
+ 
+-#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
+-
+-# if HAVE_IFUNC
+-
+-extern __typeof(system) system_ifunc;
+-#  undef INIT_ARCH
+-#  define INIT_ARCH()
+-libc_ifunc (system_ifunc, &__libc_system)
++   With an IFUNC resolver, it would be possible to avoid the indirection,
++   but the IFUNC resolver might run before the __libc_system symbol has
++   been relocated, in which case the IFUNC resolver would not be able to
++   provide the correct address.  */
+ 
+-# else  /* !HAVE_IFUNC */
++#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
+ 
+ static int __attribute__ ((used))
+ system_compat (const char *line)
+ {
+   return __libc_system (line);
+ }
+-strong_alias (system_compat, system_ifunc)
+-
+-# endif  /* HAVE_IFUNC */
+-
+-compat_symbol (libpthread, system_ifunc, system, GLIBC_2_0);
++strong_alias (system_compat, system_alias)
++compat_symbol (libpthread, system_alias, system, GLIBC_2_0);
+ 
+ #endif
+-- 
+2.14.1
+

Modified: PKGBUILD
===================================================================
--- PKGBUILD	2017-09-08 12:20:39 UTC (rev 305065)
+++ PKGBUILD	2017-09-08 12:20:46 UTC (rev 305066)
@@ -7,7 +7,7 @@
 
 pkgname=glibc
 pkgver=2.26
-pkgrel=2
+pkgrel=3
 pkgdesc='GNU C Library'
 arch=(i686 x86_64)
 url='http://www.gnu.org/software/libc'
@@ -24,10 +24,12 @@
 _commit=58270c0049404ef2f878fdd45df55f17f0b8c1f7
 source=(git+https://sourceware.org/git/glibc.git#commit=${_commit}
         locale.gen.txt
-        locale-gen)
+        locale-gen
+        0001-Don-t-use-IFUNC-resolver-for-longjmp-or-system-in-li.patch)
 md5sums=('SKIP'
          '07ac979b6ab5eeb778d55f041529d623'
-         '476e9113489f93b348b21e144b6a8fcf')
+         '476e9113489f93b348b21e144b6a8fcf'
+         'cbc073315c00b03898b7fc614274d6b3')
 
 # pkgver() {
 #   cd glibc
@@ -36,6 +38,9 @@
 
 prepare() {
   mkdir -p glibc-build
+
+  cd glibc
+  patch -p1 -i "$srcdir/0001-Don-t-use-IFUNC-resolver-for-longjmp-or-system-in-li.patch"
 }
 
 build() {