Enable no-exec stacks for more targets using the Linux kernel.

Building glibc for many different configurations and running the
compilation parts of the testsuite runs into failures of the
elf/check-execstack test for hppa and microblaze.  Those
configurations default to executable stacks in the Linux kernel
because of VM_DATA_DEFAULT_FLAGS definitions including VM_EXEC
(VM_DATA_DEFAULT_FLAGS being the default definition of
VM_STACK_DEFAULT_FLAGS).

This fails because those configurations are not generating
.note.GNU-stack sections to indicate that programs do not need an
executable stack.  This patch fixes GCC to generate those sections on
those architectures (when configured for a target using the Linux
kernel), as it does on other architectures, together with adding that
section to libgcc .S sources, with the same code as used on other
architectures (or a variant using "#ifdef __linux__" instead of the
usual "#if defined(__ELF__) && defined(__linux__)" for microblaze, as
that configuration doesn't use elfos.h and so doesn't define __ELF__).

This suffices to eliminate that glibc test failure.  (For hppa, the
compilation parts of the glibc testsuite still fail because of the
separate elf/check-textrel failure.)

gcc:
	* config/microblaze/linux.h (TARGET_ASM_FILE_END): Likewise.
	* config/pa/pa.h (NEED_INDICATE_EXEC_STACK): Likewise.
	* config/pa/pa-linux.h (NEED_INDICATE_EXEC_STACK): Likewise.
	* config/pa/pa.c (pa_hpux_file_end): Rename to pa_file_end.
	Define unconditionally, with [ASM_OUTPUT_EXTERNAL_REAL]
	conditionals inside the function instead of around it.  Call
	file_end_indicate_exec_stack if NEED_INDICATE_EXEC_STACK.
	(TARGET_ASM_FILE_END): Define unconditionally to pa_file_end.

libgcc:
	* config/microblaze/crti.S, config/microblaze/crtn.S,
	config/microblaze/divsi3.S, config/microblaze/moddi3.S,
	config/microblaze/modsi3.S, config/microblaze/muldi3_hard.S,
	config/microblaze/mulsi3.S,
	config/microblaze/stack_overflow_exit.S,
	config/microblaze/udivsi3.S, config/microblaze/umodsi3.S,
	config/pa/milli64.S: Add .note.GNU-stack section.

From-SVN: r253204

12 files changed, 76 insertions, 0 deletions

diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 90c07fe..6840147 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,13 @@
+2017-09-26  Joseph Myers  <joseph@codesourcery.com>
+
+	* config/microblaze/crti.S, config/microblaze/crtn.S,
+	config/microblaze/divsi3.S, config/microblaze/moddi3.S,
+	config/microblaze/modsi3.S, config/microblaze/muldi3_hard.S,
+	config/microblaze/mulsi3.S,
+	config/microblaze/stack_overflow_exit.S,
+	config/microblaze/udivsi3.S, config/microblaze/umodsi3.S,
+	config/pa/milli64.S: Add .note.GNU-stack section.
+
 2017-09-23  Daniel Santos  <daniel.santos@pobox.com>
 
 	* configure.ac: Add Check for HAVE_AS_AVX.
diff --git a/libgcc/config/microblaze/crti.S b/libgcc/config/microblaze/crti.S
index 61626e2..7356163 100644
--- a/libgcc/config/microblaze/crti.S
+++ b/libgcc/config/microblaze/crti.S
@@ -24,6 +24,12 @@
    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
     .section .init, "ax"
     .global __init
 
diff --git a/libgcc/config/microblaze/crtn.S b/libgcc/config/microblaze/crtn.S
index 3b9bf7e..c784ed4 100644
--- a/libgcc/config/microblaze/crtn.S
+++ b/libgcc/config/microblaze/crtn.S
@@ -24,6 +24,12 @@
    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    <http://www.gnu.org/licenses/>.  */
 
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
     .section .init, "ax"
     lw      r15, r0, r1
     rtsd    r15, 8 
diff --git a/libgcc/config/microblaze/divsi3.S b/libgcc/config/microblaze/divsi3.S
index 42f9cb2..0cd14b3 100644
--- a/libgcc/config/microblaze/divsi3.S
+++ b/libgcc/config/microblaze/divsi3.S
@@ -32,6 +32,12 @@
 # 
 #######################################
 	
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 	.globl	__divsi3
 	.ent	__divsi3
 	.type	__divsi3,@function
diff --git a/libgcc/config/microblaze/moddi3.S b/libgcc/config/microblaze/moddi3.S
index bcea079..7d2a31d 100644
--- a/libgcc/config/microblaze/moddi3.S
+++ b/libgcc/config/microblaze/moddi3.S
@@ -30,6 +30,12 @@
 #######################################
 
 
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 	.globl	__moddi3
 	.ent	__moddi3
 __moddi3:
diff --git a/libgcc/config/microblaze/modsi3.S b/libgcc/config/microblaze/modsi3.S
index eb671a1..118b18d 100644
--- a/libgcc/config/microblaze/modsi3.S
+++ b/libgcc/config/microblaze/modsi3.S
@@ -32,6 +32,12 @@
 # 
 #######################################
 
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 	.globl	__modsi3
 	.ent	__modsi3
 	.type	__modsi3,@function
diff --git a/libgcc/config/microblaze/muldi3_hard.S b/libgcc/config/microblaze/muldi3_hard.S
index f2188c6..d9f1806 100644
--- a/libgcc/config/microblaze/muldi3_hard.S
+++ b/libgcc/config/microblaze/muldi3_hard.S
@@ -47,6 +47,12 @@
 #
 #######################################
 
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 	.globl	muldi3_hardproc
 	.ent	muldi3_hardproc
 muldi3_hardproc:
diff --git a/libgcc/config/microblaze/mulsi3.S b/libgcc/config/microblaze/mulsi3.S
index f126b56..3d33522 100644
--- a/libgcc/config/microblaze/mulsi3.S
+++ b/libgcc/config/microblaze/mulsi3.S
@@ -32,6 +32,12 @@
 # 
 #######################################
 
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 	.globl	__mulsi3
 	.ent	__mulsi3
 	.type	__mulsi3,@function
diff --git a/libgcc/config/microblaze/stack_overflow_exit.S b/libgcc/config/microblaze/stack_overflow_exit.S
index 63319de..5f6be94 100644
--- a/libgcc/config/microblaze/stack_overflow_exit.S
+++ b/libgcc/config/microblaze/stack_overflow_exit.S
@@ -33,6 +33,12 @@
 # 
 #######################################
 
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 	.globl	_stack_overflow_error
 	.data
 	.align	2
diff --git a/libgcc/config/microblaze/udivsi3.S b/libgcc/config/microblaze/udivsi3.S
index 2e08fb2..f01c027 100644
--- a/libgcc/config/microblaze/udivsi3.S
+++ b/libgcc/config/microblaze/udivsi3.S
@@ -32,6 +32,12 @@
 # 
 #######################################
 	
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 	.globl	__udivsi3
 	.ent	__udivsi3
 	.type	__udivsi3,@function
diff --git a/libgcc/config/microblaze/umodsi3.S b/libgcc/config/microblaze/umodsi3.S
index b230a8c..a91eae7 100644
--- a/libgcc/config/microblaze/umodsi3.S
+++ b/libgcc/config/microblaze/umodsi3.S
@@ -32,6 +32,12 @@
 # 
 #######################################
 	
+/* An executable stack is *not* required for these functions.  */
+#ifdef __linux__
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 	.globl	__umodsi3
 	.ent	__umodsi3
 	.type	__umodsi3,@function
diff --git a/libgcc/config/pa/milli64.S b/libgcc/config/pa/milli64.S
index cfd4d83..4690dd1 100644
--- a/libgcc/config/pa/milli64.S
+++ b/libgcc/config/pa/milli64.S
@@ -25,6 +25,12 @@ a copy of the GCC Runtime Library Exception along with this program;
 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
 <http://www.gnu.org/licenses/>.  */
 
+/* An executable stack is *not* required for these functions.  */
+#if defined(__ELF__) && defined(__linux__)
+.section .note.GNU-stack,"",%progbits
+.previous
+#endif
+
 #ifdef pa64
         .level  2.0w
 #endif