GNU C Library master sources branch master updated. glibc-2.17-476-g288f7d7

[roland at sourceware dot org]

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, master has been updated
       via  288f7d79fe2dcc8e62c539f57b25d7662a2cd5ff (commit)
      from  dc0a02638583d8e7f7e1cc72643d1b26ec6042fd (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=288f7d79fe2dcc8e62c539f57b25d7662a2cd5ff

commit 288f7d79fe2dcc8e62c539f57b25d7662a2cd5ff
Author: Roland McGrath <roland@hack.frob.com>
Date:   Thu Mar 28 16:15:48 2013 -0700

    Use __ehdr_start, if available, as fallback for AT_PHDR.

diff --git a/ChangeLog b/ChangeLog
index de20ebb..876b577 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2013-03-28  Roland McGrath  <roland@hack.frob.com>
 
+	* csu/libc-start.c (__libc_start_main) [!SHARED]: If _dl_aux_init
+	didn't do it already, then set _dl_phdr and _dl_phnum based on the
+	magic __ehdr_start linker symbol if it's defined.
+	* sysdeps/mach/hurd/i386/init-first.c (init1) [!SHARED]: Don't set
+	them up here if it was already done.
+
 	* elf/dl-support.c (_dl_phdr): Make pointer to const.
 	(_dl_aux_init): Use const in cast when setting it.
 	* sysdeps/mach/hurd/i386/init-first.c (init1): Remove superfluous cast.
diff --git a/csu/libc-start.c b/csu/libc-start.c
index 9c4c01d..fa9085c 100644
--- a/csu/libc-start.c
+++ b/csu/libc-start.c
@@ -15,6 +15,7 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#include <assert.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <unistd.h>
@@ -151,7 +152,24 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
   }
 #  endif
   _dl_aux_init (auxvec);
+  if (GL(dl_phdr) == NULL)
 # endif
+    {
+      /* Starting from binutils-2.23, the linker will define the
+         magic symbol __ehdr_start to point to our own ELF header
+         if it is visible in a segment that also includes the phdrs.
+         So we can set up _dl_phdr and _dl_phnum even without any
+         information from auxv.  */
+
+      extern const ElfW(Ehdr) __ehdr_start __attribute__ ((weak));
+      if (&__ehdr_start != NULL)
+        {
+          assert (__ehdr_start.e_phentsize == sizeof *GL(dl_phdr));
+          GL(dl_phdr) = (const void *) &__ehdr_start + __ehdr_start.e_phoff;
+          GL(dl_phnum) = __ehdr_start.e_phnum;
+        }
+    }
+
 # ifdef DL_SYSDEP_OSCHECK
   if (!__libc_multiple_libcs)
     {
diff --git a/sysdeps/mach/hurd/i386/init-first.c b/sysdeps/mach/hurd/i386/init-first.c
index 59253db..fc3330c 100644
--- a/sysdeps/mach/hurd/i386/init-first.c
+++ b/sysdeps/mach/hurd/i386/init-first.c
@@ -117,14 +117,20 @@ init1 (int argc, char *arg0, ...)
   if ((void *) d == argv[0])
     {
 #ifndef SHARED
-      /* We may need to see our own phdrs, e.g. for TLS setup.
-	 Try the usual kludge to find the headers without help from
-	 the exec server.  */
-      extern const void _start;
-      const ElfW(Ehdr) *const ehdr = &_start;
-      _dl_phdr = (const void *) ehdr + ehdr->e_phoff;
-      _dl_phnum = ehdr->e_phnum;
-      assert (ehdr->e_phentsize == sizeof (ElfW(Phdr)));
+      /* With a new enough linker (binutils-2.23 or better),
+         the magic __ehdr_start symbol will be available and
+         __libc_start_main will have done this that way already.  */
+      if (_dl_phdr == NULL)
+        {
+          /* We may need to see our own phdrs, e.g. for TLS setup.
+             Try the usual kludge to find the headers without help from
+             the exec server.  */
+          extern const void _start;
+          const ElfW(Ehdr) *const ehdr = &_start;
+          _dl_phdr = (const void *) ehdr + ehdr->e_phoff;
+          _dl_phnum = ehdr->e_phnum;
+          assert (ehdr->e_phentsize == sizeof (ElfW(Phdr)));
+        }
 #endif
       return;
     }

-----------------------------------------------------------------------

Summary of changes:
 ChangeLog                           |    6 ++++++
 csu/libc-start.c                    |   18 ++++++++++++++++++
 sysdeps/mach/hurd/i386/init-first.c |   22 ++++++++++++++--------
 3 files changed, 38 insertions(+), 8 deletions(-)


hooks/post-receive
-- 
GNU C Library master sources