diff mbox series

[5/12] arm: Implement target feature macros for PACBTI

Message ID gkr1qxhwnl3.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State Superseded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, 9:42 a.m. UTC 
  This patch implements target feature macros when PACBTI is enabled
through the -march option or -mbranch-protection.  The target feature
macros __ARM_FEATURE_PAC_DEFAULT and __ARM_FEATURE_BTI_DEFAULT are
specified in ARM ACLE
<https://developer.arm.com/documentation/101028/0012/5--Feature-test-macros?lang=en>
__ARM_FEATURE_PAUTH and __ARM_FEATURE_BTI are specified in the
pull-request <https://github.com/ARM-software/acle/pull/55>.

Approved here
<https://gcc.gnu.org/pipermail/gcc-patches/2021-December/586334.html>.

gcc/ChangeLog:

	* config/arm/arm-c.c (arm_cpu_builtins): Define
	__ARM_FEATURE_BTI_DEFAULT, __ARM_FEATURE_PAC_DEFAULT,
	__ARM_FEATURE_PAUTH and __ARM_FEATURE_BTI.

gcc/testsuite/ChangeLog:

	* gcc.target/arm/acle/pacbti-m-predef-2.c: New test.
	* gcc.target/arm/acle/pacbti-m-predef-4.c: New test.
	* gcc.target/arm/acle/pacbti-m-predef-5.c: New test.

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

Comments

Richard Earnshaw July 1, 2022, 2:26 p.m. UTC | #1 
On 28/04/2022 10:42, Andrea Corallo via Gcc-patches wrote:
> This patch implements target feature macros when PACBTI is enabled
> through the -march option or -mbranch-protection.  The target feature
> macros __ARM_FEATURE_PAC_DEFAULT and __ARM_FEATURE_BTI_DEFAULT are
> specified in ARM ACLE
> <https://developer.arm.com/documentation/101028/0012/5--Feature-test-macros?lang=en>
> __ARM_FEATURE_PAUTH and __ARM_FEATURE_BTI are specified in the
> pull-request <https://github.com/ARM-software/acle/pull/55>.
> 
> Approved here
> <https://gcc.gnu.org/pipermail/gcc-patches/2021-December/586334.html>.
> 
> gcc/ChangeLog:
> 
> 	* config/arm/arm-c.c (arm_cpu_builtins): Define
> 	__ARM_FEATURE_BTI_DEFAULT, __ARM_FEATURE_PAC_DEFAULT,
> 	__ARM_FEATURE_PAUTH and __ARM_FEATURE_BTI.

This bit is OK.

> 
> gcc/testsuite/ChangeLog:
> 
> 	* gcc.target/arm/acle/pacbti-m-predef-2.c: New test.
> 	* gcc.target/arm/acle/pacbti-m-predef-4.c: New test.
> 	* gcc.target/arm/acle/pacbti-m-predef-5.c: New test.
> 

These are all execution tests.  I think we also need some compile-only 
tests so that we get better coverage when the target does not directly 
support PACBTI.

We also need some tests for the defines when targetting armv8-m.main and 
some tests for checking __ARM_FEATURE_BTI and __ARM_FEATURE_PAC (the 
tests here check only the '..._DEFAULT' macros.

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

R.
diff mbox series

Patch

diff --git a/gcc/config/arm/arm-c.cc b/gcc/config/arm/arm-c.cc
index a8697b8c62f..190099b2c37 100644
--- a/gcc/config/arm/arm-c.cc
+++ b/gcc/config/arm/arm-c.cc
@@ -212,6 +212,24 @@  arm_cpu_builtins (struct cpp_reader* pfile)
   def_or_undef_macro (pfile, "__ARM_FEATURE_COMPLEX", TARGET_COMPLEX);
   def_or_undef_macro (pfile, "__ARM_32BIT_STATE", TARGET_32BIT);
 
+  def_or_undef_macro (pfile, "__ARM_FEATURE_PAUTH", TARGET_HAVE_PACBTI);
+  def_or_undef_macro (pfile, "__ARM_FEATURE_BTI", TARGET_HAVE_PACBTI);
+  def_or_undef_macro (pfile, "__ARM_FEATURE_BTI_DEFAULT",
+		      aarch_enable_bti == 1);
+
+  cpp_undef (pfile, "__ARM_FEATURE_PAC_DEFAULT");
+  if (aarch_ra_sign_scope != AARCH_FUNCTION_NONE)
+  {
+    unsigned int pac = 1;
+
+    gcc_assert (aarch_ra_sign_key == AARCH_KEY_A);
+
+    if (aarch_ra_sign_scope == AARCH_FUNCTION_ALL)
+      pac |= 0x4;
+
+    builtin_define_with_int_value ("__ARM_FEATURE_PAC_DEFAULT", pac);
+  }
+
   cpp_undef (pfile, "__ARM_FEATURE_MVE");
   if (TARGET_HAVE_MVE && TARGET_HAVE_MVE_FLOAT)
     {
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-2.c b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-2.c
new file mode 100644
index 00000000000..4394fd147d7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-2.c
@@ -0,0 +1,24 @@ 
+
+/* { dg-do run } */
+/* { dg-require-effective-target arm_pacbti_hw } */
+/* { dg-additional-options " -mbranch-protection=bti+pac-ret+leaf" } */
+
+#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
+
+int
+main()
+{
+  if (__ARM_FEATURE_BTI_DEFAULT != 1)
+    __builtin_abort ();
+
+  if (__ARM_FEATURE_PAC_DEFAULT != 5)
+    __builtin_abort ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-4.c b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-4.c
new file mode 100644
index 00000000000..90f0c724b9e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-4.c
@@ -0,0 +1,21 @@ 
+
+/* { dg-do run } */
+/* { dg-require-effective-target arm_pacbti_hw } */
+/* { dg-additional-options " -mbranch-protection=pac-ret" } */
+
+#if !defined (__ARM_FEATURE_PAC_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be defined."
+#endif
+
+#if defined (__ARM_FEATURE_BTI_DEFAULT)
+#error "Feature test macro __ARM_FEATURE_BTI_DEFAULT should be undefined."
+#endif
+
+int
+main()
+{
+  if (__ARM_FEATURE_PAC_DEFAULT != 1)
+    __builtin_abort ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-5.c b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-5.c
new file mode 100644
index 00000000000..c865809b8b0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-5.c
@@ -0,0 +1,24 @@ 
+
+/* { dg-do run } */
+/* { dg-require-effective-target arm_pacbti_hw } */
+/* { dg-additional-options " -mbranch-protection=bti+pac-ret" } */
+
+#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
+
+int
+main()
+{
+  if (__ARM_FEATURE_BTI_DEFAULT != 1)
+    __builtin_abort ();
+
+  if (__ARM_FEATURE_PAC_DEFAULT != 1)
+    __builtin_abort ();
+
+  return 0;
+}