Make the linker return an error status if it fails to merge ARM binaries with

different architecture tags.  Add a test case to make sure that this works,
and update readelf so that it will not seg-fault when trying to display the
attributes of binaries with invalid architecture tags.

	* elf32-arm.c (elf32_arm_merge_eabi_attributes): Return false if
	failed to merge.

	* ld-arm/attr-merge-arch-2.d: New test case.
	* ld-arm/attr-merge-arch-2a.s: New test case source file.
	* ld-arm/attr-merge-arch-2b.s: Likewise.
	* ld-arm/arm-elf.exp: Run new test case.

	* readelf.c (display_arm_attribute): Use unsigned int type for
	tag, val and type variables.

bfd/ChangeLog

@@ -1,3 +1,8 @@
+2014-09-16  Terry Guo  <terry.guo@arm.com>
+
+	* elf32-arm.c (elf32_arm_merge_eabi_attributes): Return false if
+	failed to merge.
+
 2014-09-16  Kuan-Lin Chen  <kuanlinchentw@gmail.com>
 
 	* bfd-in2.h: Regenerate.

bfd/elf32-arm.c

@@ -11778,7 +11778,9 @@ elf32_arm_merge_eabi_attributes (bfd *ibfd, bfd *obfd)
 	  {
 	    int secondary_compat = -1, secondary_compat_out = -1;
 	    unsigned int saved_out_attr = out_attr[i].i;
-	    static const char *name_table[] = {
+	    int arch_attr;
+	    static const char *name_table[] =
+	      {
 		/* These aren't real CPU names, but we can't guess
 		   that from the architecture version alone.  */
 		"Pre v4",
@@ -11800,10 +11802,17 @@ elf32_arm_merge_eabi_attributes (bfd *ibfd, bfd *obfd)
 	    /* Merge Tag_CPU_arch and Tag_also_compatible_with.  */
 	    secondary_compat = get_secondary_compatible_arch (ibfd);
 	    secondary_compat_out = get_secondary_compatible_arch (obfd);
-	    out_attr[i].i = tag_cpu_arch_combine (ibfd, out_attr[i].i,
-						  &secondary_compat_out,
-						  in_attr[i].i,
-						  secondary_compat);
+	    arch_attr = tag_cpu_arch_combine (ibfd, out_attr[i].i,
+					      &secondary_compat_out,
+					      in_attr[i].i,
+					      secondary_compat);
+
+	    /* Return with error if failed to merge.  */
+	    if (arch_attr == -1)
+	      return FALSE;
+
+	    out_attr[i].i = arch_attr;
+
 	    set_secondary_compatible_arch (obfd, secondary_compat_out);
 
 	    /* Merge Tag_CPU_name and Tag_CPU_raw_name.  */

binutils/ChangeLog

@@ -1,3 +1,8 @@
+2014-09-16  Nick Clifton  <nickc@redhat.com>
+
+	* readelf.c (display_arm_attribute): Use unsigned int type for
+	tag, val and type variables.
+
 2014-09-16  Kuan-Lin Chen  <kuanlinchentw@gmail.com>
 
 	* readelf.c (decode_NDS32_machine_flags): Display ABI2 FP+.

binutils/readelf.c

@@ -11548,10 +11548,10 @@ display_tag_value (int tag,
 /* ARM EABI attributes section.  */
 typedef struct
 {
-  int tag;
+  unsigned int tag;
   const char * name;
   /* 0 = special, 1 = string, 2 = uleb123, > 0x80 == table lookup.  */
-  int type;
+  unsigned int type;
   const char ** table;
 } arm_attr_public_tag;
 
@@ -11669,12 +11669,12 @@ static unsigned char *
 display_arm_attribute (unsigned char * p,
 		       const unsigned char * const end)
 {
-  int tag;
+  unsigned int tag;
   unsigned int len;
-  int val;
+  unsigned int val;
   arm_attr_public_tag * attr;
   unsigned i;
-  int type;
+  unsigned int type;
 
   tag = read_uleb128 (p, &len, end);
   p += len;

ld/testsuite/ChangeLog

@@ -1,3 +1,10 @@
+2014-09-16  Terry Guo  <terry.guo@arm.com>
+
+	* ld-arm/attr-merge-arch-2.d: New test case.
+	* ld-arm/attr-merge-arch-2a.s: New test case source file.
+	* ld-arm/attr-merge-arch-2b.s: Likewise.
+	* ld-arm/arm-elf.exp: Run new test case.
+
 2014-09-12  Andrew Bennett  <andrew.bennett@imgtec.com>
 
 	* ld-mips-elf/mips-elf.exp: Add support for mips*-img-elf* target

ld/testsuite/ld-arm/arm-elf.exp

@@ -878,6 +878,7 @@ run_dump_test "attr-merge-vfp-6r"
 run_dump_test "attr-merge-vfp-7"
 run_dump_test "attr-merge-vfp-7r"
 run_dump_test "attr-merge-incompatible"
+run_dump_test "attr-merge-arch-2"
 run_dump_test "unresolved-1"
 if { ![istarget "arm*-*-nacl*"] } {
     run_dump_test "unresolved-1-dyn"

ld/testsuite/ld-arm/attr-merge-arch-2.d

@@ -0,0 +1,5 @@
+#source: attr-merge-arch-2a.s
+#source: attr-merge-arch-2b.s
+#as:
+#ld: -e main
+#error: Conflicting CPU architectures 13/0

ld/testsuite/ld-arm/attr-merge-arch-2a.s

@@ -0,0 +1,18 @@
+        .syntax unified
+        .cpu cortex-m4
+        .fpu softvfp
+        .thumb
+        .file   "m.c"
+        .text
+        .align  2
+        .global main
+        .thumb
+        .thumb_func
+        .type   main, %function
+main:
+        push    {r7, lr}
+        add     r7, sp, #0
+        bl      foo
+        mov     r3, r0
+        mov     r0, r3
+        pop     {r7, pc}

ld/testsuite/ld-arm/attr-merge-arch-2b.s

@@ -0,0 +1,8 @@
+        .eabi_attribute 6, 0  @Tag_CPU_arch, 0 means pre-v4.
+        .file   "f.c"
+        .text
+        .align  2
+        .global foo
+        .type   foo, %function
+foo:
+        bx      lr