[PATCH] Avoid check-testrel failing on all sparc*, alpha or ppc32 -mbss-plt shared libraries

[Jakub Jelinek <jakub at redhat dot com>]

Hi!

SPARC, Alpha and PowerPC32 without -msecure-plt have writable and executable
.plt section mandated by the ABI.  This patch keeps the warnings in
elf/check-testrel.out, but doesn't fail the test because of this.

2006-03-02  Jakub Jelinek  <jakub@redhat.com>

	* elf/check-textrel.c: Include config.h.
	(AB(handle_file)): Don't fail if PF_X | PF_W on architectures known
	to have executable writable PLT.
	* sysdeps/powerpc/powerpc32/configure.in (HAVE_PPC_SECURE_PLT): New
	test.
	* sysdeps/powerpc/powerpc32/configure: Rebuilt.
	* config.h.in (HAVE_PPC_SECURE_PLT): Add.

--- libc/elf/check-textrel.c.jj	2006-01-14 17:41:01.000000000 +0100
+++ libc/elf/check-textrel.c	2006-03-02 10:43:00.000000000 +0100
@@ -18,6 +18,7 @@
    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
    02111-1307 USA.  */
 
+#include "config.h"
 #include <byteswap.h>
 #include <elf.h>
 #include <endian.h>
@@ -88,7 +89,15 @@ AB(handle_file) (const char *fname, int 
       {
 	printf ("%s: segment %zu is executable and writable\n",
 		fname, cnt);
+#if !defined __sparc__ \
+    && !defined __alpha__ \
+    && (!defined __powerpc__ || defined __powerpc64__ || defined HAVE_PPC_SECURE_PLT)
+	/* sparc, sparc64, alpha and powerpc32 (the last one only when using
+	   -mbss-plt) are expected to have PF_X | PF_W segment containing .plt
+	   section, it is part of their ABI.  It is bad security wise, nevertheless
+	   this test shouldn't fail because of this.  */
 	return 1;
+#endif
       }
 
   if (dynphdr == NULL)
--- libc/sysdeps/powerpc/powerpc32/configure.in.jj	2005-06-18 00:58:48.000000000 +0200
+++ libc/sysdeps/powerpc/powerpc32/configure.in	2006-03-02 10:37:54.000000000 +0100
@@ -16,3 +16,17 @@ rm -f conftest*])
 if test $libc_cv_ppc_rel16 = yes; then
   AC_DEFINE(HAVE_ASM_PPC_REL16)
 fi
+
+# See whether GCC uses -msecure-plt.
+AC_CACHE_CHECK(for -msecure-plt by default, libc_cv_ppc_secure_plt, [dnl
+echo 'int foo (void) { extern int bar; return bar; }' > conftest.c
+libc_cv_ppc_secure_plt=no
+if AC_TRY_COMMAND(${CC-cc} -S $CFLAGS conftest.c -fpic -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
+  if grep '_GLOBAL_OFFSET_TABLE_-.*@ha' conftest.s > /dev/null 2>&1; then
+    libc_cv_ppc_secure_plt=yes
+  fi
+fi
+rm -rf conftest*])
+if test $libc_cv_ppc_secure_plt = yes; then
+  AC_DEFINE(HAVE_PPC_SECURE_PLT)
+fi
--- libc/sysdeps/powerpc/powerpc32/configure.jj	2005-06-18 00:58:48.000000000 +0200
+++ libc/sysdeps/powerpc/powerpc32/configure	2006-03-02 10:37:54.000000000 +0100
@@ -31,3 +31,32 @@ if test $libc_cv_ppc_rel16 = yes; then
 _ACEOF
 
 fi
+
+# See whether GCC uses -msecure-plt.
+echo "$as_me:$LINENO: checking for -msecure-plt by default" >&5
+echo $ECHO_N "checking for -msecure-plt by default... $ECHO_C" >&6
+if test "${libc_cv_ppc_secure_plt+set}" = set; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  echo 'int foo (void) { extern int bar; return bar; }' > conftest.c
+libc_cv_ppc_secure_plt=no
+if { ac_try='${CC-cc} -S $CFLAGS conftest.c -fpic -o conftest.s 1>&5'
+  { (eval echo "$as_me:$LINENO: \"$ac_try\"") >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); }; }; then
+  if grep '_GLOBAL_OFFSET_TABLE_-.*@ha' conftest.s > /dev/null 2>&1; then
+    libc_cv_ppc_secure_plt=yes
+  fi
+fi
+rm -rf conftest*
+fi
+echo "$as_me:$LINENO: result: $libc_cv_ppc_secure_plt" >&5
+echo "${ECHO_T}$libc_cv_ppc_secure_plt" >&6
+if test $libc_cv_ppc_secure_plt = yes; then
+  cat >>confdefs.h <<\_ACEOF
+#define HAVE_PPC_SECURE_PLT 1
+_ACEOF
+
+fi
--- libc/config.h.in.jj	2006-02-27 18:30:50.000000000 +0100
+++ libc/config.h.in	2006-03-02 10:37:54.000000000 +0100
@@ -200,6 +200,9 @@
 /* Define if your assembler and linker support R_PPC_REL16* relocs.  */
 #undef HAVE_ASM_PPC_REL16
 
+/* Define if your compiler defaults to -msecure-plt mode on ppc.  */
+#undef HAVE_PPC_SECURE_PLT
+
 /* Define if __stack_chk_guard canary should be randomized at program startup.  */
 #undef ENABLE_STACKGUARD_RANDOMIZE
 

	Jakub