glibc: add patch to fix segfault in forkpty

2 files changed, 78 insertions, 0 deletions

diff --git a/pkgs/development/libraries/glibc/common.nix b/pkgs/development/libraries/glibc/common.nix
index e90fdc4ad7b..24890e56023 100644
--- a/pkgs/development/libraries/glibc/common.nix
+++ b/pkgs/development/libraries/glibc/common.nix
@@ -55,6 +55,9 @@ stdenv.mkDerivation ({
       ./cve-2016-1234.patch
       ./cve-2016-3706.patch
       ./fix_warnings.patch
+
+      # Fixes segfault when calling pty.fork() in python
+      ./forkpty.patch
     ];
 
   postPatch =
diff --git a/pkgs/development/libraries/glibc/forkpty.patch b/pkgs/development/libraries/glibc/forkpty.patch
new file mode 100644
index 00000000000..fe700e5797b
--- /dev/null
+++ b/pkgs/development/libraries/glibc/forkpty.patch
@@ -0,0 +1,75 @@
+From f06f3f05b48c72e2c9b0fa78671f94fd22d67da8 Mon Sep 17 00:00:00 2001
+From: Florian Weimer <fweimer@redhat.com>
+Date: Wed, 1 Jun 2016 07:14:42 +0200
+Subject: [PATCH] fork in libpthread cannot use IFUNC resolver [BZ #19861]
+
+This commit only addresses the fork case, the vfork case has to be a
+tail call, which is why the generic code needs an IFUNC resolver
+there.
+
+diff --git a/nptl/pt-fork.c b/nptl/pt-fork.c
+index b65d6b4..db9b61d 100644
+--- a/nptl/pt-fork.c
++++ b/nptl/pt-fork.c
+@@ -25,33 +25,14 @@
+    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 __fork and fork symbols in
+-   libpthread.so; so we define them using IFUNC to redirect to the libc
+-   function.  */
++   libpthread.so.
+ 
+-#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
+-
+-# if HAVE_IFUNC
+-
+-static __typeof (fork) *
+-__attribute__ ((used))
+-fork_resolve (void)
+-{
+-  return &__libc_fork;
+-}
++   With an IFUNC resolver, it would be possible to avoid the
++   indirection, but the IFUNC resolver might run before the
++   __libc_fork symbol has been relocated, in which case the IFUNC
++   resolver would not be able to provide the correct address.  */
+ 
+-#  ifdef HAVE_ASM_SET_DIRECTIVE
+-#   define DEFINE_FORK(name) \
+-  asm (".set " #name ", fork_resolve\n" \
+-       ".globl " #name "\n" \
+-       ".type " #name ", %gnu_indirect_function");
+-#  else
+-#   define DEFINE_FORK(name) \
+-  asm (#name " = fork_resolve\n" \
+-       ".globl " #name "\n" \
+-       ".type " #name ", %gnu_indirect_function");
+-#  endif
+-
+-# else  /* !HAVE_IFUNC */
++#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
+ 
+ static pid_t __attribute__ ((used))
+ fork_compat (void)
+@@ -59,14 +40,10 @@ fork_compat (void)
+   return __libc_fork ();
+ }
+ 
+-# define DEFINE_FORK(name) strong_alias (fork_compat, name)
+-
+-# endif  /* HAVE_IFUNC */
+-
+-DEFINE_FORK (fork_ifunc)
+-compat_symbol (libpthread, fork_ifunc, fork, GLIBC_2_0);
++strong_alias (fork_compat, fork_alias)
++compat_symbol (libpthread, fork_alias, fork, GLIBC_2_0);
+ 
+-DEFINE_FORK (__fork_ifunc)
+-compat_symbol (libpthread, __fork_ifunc, __fork, GLIBC_2_0);
++strong_alias (fork_compat, __fork_alias)
++compat_symbol (libpthread, __fork_alias, __fork, GLIBC_2_0);
+ 
+ #endif
+-- 
+1.7.1
+