diff mbox series

[7/12] arm: Emit build attributes for PACBTI target feature

Message ID gkrsfpxv8wx.fsf@arm.com
State Superseded
Headers
Series arm: Enables return address verification and branch target identification on Cortex-M |

Commit Message

Andrea Corallo April 28, 2022, 9:45 a.m. UTC 
  This patch emits assembler directives for PACBTI build attributes as
defined by the
ABI.

<https://github.com/ARM-software/abi-aa/releases/download/2021Q1/addenda32.pdf>

gcc/ChangeLog:

	* config/arm/arm.c (arm_file_start): Emit EABI attributes for
	Tag_PAC_extension, Tag_BTI_extension, TAG_BTI_use, TAG_PACRET_use.

gcc/testsuite/ChangeLog:

	* gcc.target/arm/acle/pacbti-m-predef-1.c: New test.
	* gcc.target/arm/acle/pacbti-m-predef-3: Likewise.
	* gcc.target/arm/acle/pacbti-m-predef-6.c: Likewise.
	* gcc.target/arm/acle/pacbti-m-predef-7.c: Likewise.

Co-Authored-By: Tejas Belagod  <tbelagod@arm.com>

Comments

Richard Earnshaw July 1, 2022, 2:49 p.m. UTC | #1 
On 28/04/2022 10:45, Andrea Corallo via Gcc-patches wrote:
> This patch emits assembler directives for PACBTI build attributes as
> defined by the
> ABI.
> 
> <https://github.com/ARM-software/abi-aa/releases/download/2021Q1/addenda32.pdf>
> 
> gcc/ChangeLog:
> 
> 	* config/arm/arm.c (arm_file_start): Emit EABI attributes for
> 	Tag_PAC_extension, Tag_BTI_extension, TAG_BTI_use, TAG_PACRET_use.

This bit is OK.

> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.target/arm/acle/pacbti-m-predef-1.c: New test.
> 	* gcc.target/arm/acle/pacbti-m-predef-3: Likewise.
> 	* gcc.target/arm/acle/pacbti-m-predef-6.c: Likewise.
> 	* gcc.target/arm/acle/pacbti-m-predef-7.c: Likewise.

These tests contain directives like:

+/* { dg-additional-options " -mbranch-protection=pac-ret+bti 
--save-temps" } */

But they don't check that the architecture permits this (it has to be 
armv8-m.main or later).

> 
> Co-Authored-By: Tejas Belagod  <tbelagod@arm.com>
> 

R.
diff mbox series

Patch

diff --git a/gcc/config/arm/arm.cc b/gcc/config/arm/arm.cc
index 0068817b0f2..ceec14f84b6 100644
--- a/gcc/config/arm/arm.cc
+++ b/gcc/config/arm/arm.cc
@@ -28349,6 +28349,8 @@  static void
 arm_file_start (void)
 {
   int val;
+  bool pac = (aarch_ra_sign_scope != AARCH_FUNCTION_NONE);
+  bool bti = (aarch_enable_bti == 1);
 
   arm_print_asm_arch_directives
     (asm_out_file, TREE_TARGET_OPTION (target_option_default_node));
@@ -28419,6 +28421,22 @@  arm_file_start (void)
 	arm_emit_eabi_attribute ("Tag_ABI_FP_16bit_format", 38,
 			     (int) arm_fp16_format);
 
+      if (TARGET_HAVE_PACBTI)
+	{
+	  arm_emit_eabi_attribute ("Tag_PAC_extension", 50, 2);
+	  arm_emit_eabi_attribute ("Tag_BTI_extension", 52, 2);
+	}
+      else if (pac || bti)
+	{
+	  arm_emit_eabi_attribute ("Tag_PAC_extension", 50, 1);
+	  arm_emit_eabi_attribute ("Tag_BTI_extension", 52, 1);
+	}
+
+      if (bti)
+        arm_emit_eabi_attribute ("TAG_BTI_use", 74, 1);
+      if (pac)
+	arm_emit_eabi_attribute ("TAG_PACRET_use", 76, 1);
+
       if (arm_lang_output_object_attributes_hook)
 	arm_lang_output_object_attributes_hook();
     }
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-1.c b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-1.c
new file mode 100644
index 00000000000..75d3e00ef64
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-1.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-additional-options " -mbranch-protection=pac-ret+bti --save-temps" } */
+
+#if !defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be defined."
+#endif
+
+#if !defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_PAC_DEFAULT should be defined."
+#endif
+
+/* { dg-final { scan-assembler-not "\.arch_extension pacbti" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 50, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 52, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 74, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 76, 1" } } */
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-3.c b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-3.c
new file mode 100644
index 00000000000..bf6c3ba90c9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-3.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-additional-options " -mbranch-protection=pac-ret+leaf --save-temps" } */
+
+#if defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be undefined."
+#endif
+
+#if !defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_PAC_DEFAULT should be defined."
+#endif
+
+/* { dg-final { scan-assembler-not "\.arch_extension pacbti" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 50, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 52, 1" } } */
+/* { dg-final { scan-assembler-not "\.eabi_attribute 74" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 76, 1" } } */
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-6.c b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-6.c
new file mode 100644
index 00000000000..82af11ee407
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-6.c
@@ -0,0 +1,15 @@ 
+/* { dg-do compile } */
+/* { dg-additional-options " -mbranch-protection=bti --save-temps" } */
+
+#if !defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be defined."
+#endif
+
+#if defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_PAC_DEFAULT should be undefined."
+#endif
+/* { dg-final { scan-assembler-not "\.arch_extension pacbti" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 50, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 52, 1" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 74, 1" } } */
+/* { dg-final { scan-assembler-not "\.eabi_attribute 76" } } */
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-7.c b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-7.c
new file mode 100644
index 00000000000..48a40e64c11
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-7.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-additional-options "-march=armv8.1-m.main+pacbti --save-temps" } */
+
+#if defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be undefined."
+#endif
+
+#if defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_PAC_DEFAULT should be undefined."
+#endif
+
+/* { dg-final { scan-assembler "\.arch_extension pacbti" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 50, 2" } } */
+/* { dg-final { scan-assembler "\.eabi_attribute 52, 2" } } */
+/* { dg-final { scan-assembler-not "\.eabi_attribute 74" } } */
+/* { dg-final { scan-assembler-not "\.eabi_attribute 76" } } */