Hi Richard

On 03/04/2019 11:28, Richard Henderson wrote:
> On 4/3/19 5:19 PM, Sudakshina Das wrote:
>> +      /* PT_NOTE header: namesz, descsz, type.
>> +     namesz = 4 ("GNU\0")
>> +     descsz = 16 (Size of the program property array)
>> +     type   = 5 (NT_GNU_PROPERTY_TYPE_0).  */
>> +      assemble_align (POINTER_SIZE);
>> +      assemble_integer (GEN_INT (4), 4, 32, 1);
>> +      assemble_integer (GEN_INT (16), 4, 32, 1);
> 
> So, it's 16 only if POINTER_SIZE == 64.
> 
> I think ROUND_UP (12, POINTER_BYTES) is what you want here.
>


Ah yes. I have made that change now.

Thanks
Sudi

> 
> r~
> 

diff --git a/gcc/config/aarch64/aarch64-linux.h b/gcc/config/aarch64/aarch64-linux.h
index 9d0292d64f20939ccedd7ab56027aa1282826b23..5e8b34ded03c78493f868e38647bf57c2da5187c 100644
--- a/gcc/config/aarch64/aarch64-linux.h
+++ b/gcc/config/aarch64/aarch64-linux.h
@@ -83,7 +83,7 @@
 
 #define GNU_USER_TARGET_D_CRITSEC_SIZE 48
 
-#define TARGET_ASM_FILE_END file_end_indicate_exec_stack
+#define TARGET_ASM_FILE_END aarch64_file_end_indicate_exec_stack
 
 /* Uninitialized common symbols in non-PIE executables, even with
    strong definitions in dependent shared libraries, will resolve
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index b38505b0872688634b2d3f625ab8d313e89cfca0..83b8ef84808c19fa1214fa06c32957936f5eb520 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -18744,6 +18744,57 @@ aarch64_stack_protect_guard (void)
   return NULL_TREE;
 }
 
+/* Implement TARGET_ASM_FILE_END for AArch64.  This adds the AArch64 GNU NOTE
+   section at the end if needed.  */
+#define GNU_PROPERTY_AARCH64_FEATURE_1_AND	0xc0000000
+#define GNU_PROPERTY_AARCH64_FEATURE_1_BTI	(1U << 0)
+#define GNU_PROPERTY_AARCH64_FEATURE_1_PAC	(1U << 1)
+void
+aarch64_file_end_indicate_exec_stack ()
+{
+  file_end_indicate_exec_stack ();
+
+  unsigned feature_1_and = 0;
+  if (aarch64_bti_enabled ())
+    feature_1_and |= GNU_PROPERTY_AARCH64_FEATURE_1_BTI;
+
+  if (aarch64_ra_sign_scope != AARCH64_FUNCTION_NONE)
+    feature_1_and |= GNU_PROPERTY_AARCH64_FEATURE_1_PAC;
+
+  if (feature_1_and)
+    {
+      /* Generate .note.gnu.property section.  */
+      switch_to_section (get_section (".note.gnu.property",
+				      SECTION_NOTYPE, NULL));
+
+      /* PT_NOTE header: namesz, descsz, type.
+	 namesz = 4 ("GNU\0")
+	 descsz = 16 (Size of the program property array)
+		  [(12 + padding) * Number of array elements]
+	 type   = 5 (NT_GNU_PROPERTY_TYPE_0).  */
+      assemble_align (POINTER_SIZE);
+      assemble_integer (GEN_INT (4), 4, 32, 1);
+      assemble_integer (GEN_INT (ROUND_UP (12, POINTER_BYTES)), 4, 32, 1);
+      assemble_integer (GEN_INT (5), 4, 32, 1);
+
+      /* PT_NOTE name.  */
+      assemble_string ("GNU", 4);
+
+      /* PT_NOTE contents for NT_GNU_PROPERTY_TYPE_0:
+	 type   = GNU_PROPERTY_AARCH64_FEATURE_1_AND
+	 datasz = 4
+	 data   = feature_1_and.  */
+      assemble_integer (GEN_INT (GNU_PROPERTY_AARCH64_FEATURE_1_AND), 4, 32, 1);
+      assemble_integer (GEN_INT (4), 4, 32, 1);
+      assemble_integer (GEN_INT (feature_1_and), 4, 32, 1);
+
+      /* Pad the size of the note to the required alignment.  */
+      assemble_align (POINTER_SIZE);
+    }
+}
+#undef GNU_PROPERTY_AARCH64_FEATURE_1_PAC
+#undef GNU_PROPERTY_AARCH64_FEATURE_1_BTI
+#undef GNU_PROPERTY_AARCH64_FEATURE_1_AND
 
 /* Target-specific selftests.  */
 
diff --git a/gcc/testsuite/gcc.target/aarch64/bti-1.c b/gcc/testsuite/gcc.target/aarch64/bti-1.c
index a8c60412e310a4f322372f334ae5314f426d310e..5a556b08ed15679b25676a11fe9c7a64641ee671 100644
--- a/gcc/testsuite/gcc.target/aarch64/bti-1.c
+++ b/gcc/testsuite/gcc.target/aarch64/bti-1.c
@@ -61,3 +61,4 @@ lab2:
 }
 /* { dg-final { scan-assembler-times "hint\t34" 1 } } */
 /* { dg-final { scan-assembler-times "hint\t36" 12 } } */
+/* { dg-final { scan-assembler ".note.gnu.property" { target *-*-linux* } } } */
diff --git a/gcc/testsuite/gcc.target/aarch64/va_arg_1.c b/gcc/testsuite/gcc.target/aarch64/va_arg_1.c
index e8e3cdac51350b545e5c2a644a3e1f4d1c37f88d..1fe92ff08935d4c6f08affcbd77ea91537030640 100644
--- a/gcc/testsuite/gcc.target/aarch64/va_arg_1.c
+++ b/gcc/testsuite/gcc.target/aarch64/va_arg_1.c
@@ -4,7 +4,9 @@
 int
 f (int a, ...)
 {
-  /* { dg-final { scan-assembler-not "str" } } */
+  /* Fails on aarch64*-*-linux* if configured with
+    --enable-standard-branch-protection because of the GNU NOTE section.  */
+  /* { dg-final { scan-assembler-not "str" { target { ! aarch64*-*-linux* } || { ! default_branch_protection } } } } */
   return a;
 }
 

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