[5/12] arm: Implement target feature macros for PACBTI
Commit Message
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
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.
@@ -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)
{
new file mode 100644
@@ -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;
+}
new file mode 100644
@@ -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;
+}
new file mode 100644
@@ -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;
+}