This is the mail archive of the
glibc-cvs@sourceware.org
mailing list for the glibc project.
GNU C Library master sources branch release/2.23/master updated. glibc-2.23-62-g1915d6d
- From: fw at sourceware dot org
- To: glibc-cvs at sourceware dot org
- Date: 2 Jun 2016 11:09:36 -0000
- Subject: GNU C Library master sources branch release/2.23/master updated. glibc-2.23-62-g1915d6d
This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "GNU C Library master sources".
The branch, release/2.23/master has been updated
via 1915d6d182a55d1eb852643a78ac24bc17783fb0 (commit)
from e6eea05ee7bc49dbe9531620595fd7f6ca587dcd (commit)
Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.
- Log -----------------------------------------------------------------
http://sourceware.org/git/gitweb.cgi?p=glibc.git;a=commitdiff;h=1915d6d182a55d1eb852643a78ac24bc17783fb0
commit 1915d6d182a55d1eb852643a78ac24bc17783fb0
Author: Florian Weimer <fweimer@redhat.com>
Date: Wed Jun 1 07:14:42 2016 +0200
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.
(cherry picked from commit f06f3f05b48c72e2c9b0fa78671f94fd22d67da8)
diff --git a/ChangeLog b/ChangeLog
index 2da868a..f21a1ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2016-06-01 Florian Weimer <fweimer@redhat.com>
+
+ [BZ #19861]
+ Do not use IFUNC resolver with potentially unrelocated symbol.
+ * nptl/pt-fork.c [HAVE_IFUNC]: Remove.
+ (DEFINE_FORK): Remove macro and inline definition.
+ (fork_alias): Renamed from fork_ifunc.
+ (__fork_alias): Renamed from __fork_ifunc.
+
2016-03-07 Florian Weimer <fweimer@redhat.com>
[BZ #19648]
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
-----------------------------------------------------------------------
Summary of changes:
ChangeLog | 9 +++++++++
nptl/pt-fork.c | 43 ++++++++++---------------------------------
2 files changed, 19 insertions(+), 33 deletions(-)
hooks/post-receive
--
GNU C Library master sources