diff mbox series

[7/15] arm: Emit build attributes for PACBTI target feature

Message ID gkrpmh5bhsf.fsf@arm.com
State New, archived
Headers
Series arm: Enables return address verification and branch target identification on Cortex-M |

Commit Message

Andrea Corallo Aug. 12, 2022, 3:30 p.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

Andrea Corallo Sept. 5, 2022, 4:53 p.m. UTC | #1 
Andrea Corallo via Gcc-patches <gcc-patches@gcc.gnu.org> writes:

> 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>

Ping

  Andrea
Kyrylo Tkachov Oct. 20, 2022, 2:47 p.m. UTC | #2 
Hi Andrea,

> -----Original Message-----
> From: Gcc-patches <gcc-patches-
> bounces+kyrylo.tkachov=arm.com@gcc.gnu.org> On Behalf Of Andrea
> Corallo via Gcc-patches
> Sent: Friday, August 12, 2022 4:31 PM
> To: Andrea Corallo via Gcc-patches <gcc-patches@gcc.gnu.org>
> Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>; nd <nd@arm.com>
> Subject: [PATCH 7/15] arm: Emit build attributes for PACBTI target feature
> 
> 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>

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);
+	}

This hunk will set both Tag_PAC_extension and Tag_BTI_extension if only one of pac or bti is on. Is that intended?
Would it makes sense to instead set the two Tag_*_extension tags individually as in the hunk below?
+
+      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();
     }

Thanks,
Kyrill
Richard Earnshaw Oct. 20, 2022, 3:15 p.m. UTC | #3 
On 20/10/2022 15:47, Kyrylo Tkachov via Gcc-patches wrote:
> Hi Andrea,
> 
>> -----Original Message-----
>> From: Gcc-patches <gcc-patches-
>> bounces+kyrylo.tkachov=arm.com@gcc.gnu.org> On Behalf Of Andrea
>> Corallo via Gcc-patches
>> Sent: Friday, August 12, 2022 4:31 PM
>> To: Andrea Corallo via Gcc-patches <gcc-patches@gcc.gnu.org>
>> Cc: Richard Earnshaw <Richard.Earnshaw@arm.com>; nd <nd@arm.com>
>> Subject: [PATCH 7/15] arm: Emit build attributes for PACBTI target feature
>>
>> 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>
> 
> 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);
> +	}
> 
> This hunk will set both Tag_PAC_extension and Tag_BTI_extension if only one of pac or bti is on. Is that intended?
> Would it makes sense to instead set the two Tag_*_extension tags individually as in the hunk below?

That's because they are one feature in armv8-m and these tags describe 
the presence of the feature in the architecture.

> +
> +      if (bti)
> +        arm_emit_eabi_attribute ("TAG_BTI_use", 74, 1);
> +      if (pac)
> +	arm_emit_eabi_attribute ("TAG_PACRET_use", 76, 1);
> +

But this describes /use/ by the code of each feature.

R.

>         if (arm_lang_output_object_attributes_hook)
>   	arm_lang_output_object_attributes_hook();
>       }
> 
> Thanks,
> Kyrill
>
Richard Earnshaw Oct. 21, 2022, 12:19 p.m. UTC | #4 
On 12/08/2022 16:30, 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.
> 
> 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>
> 

OK.

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..122f7a762a7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-1.c
@@ -0,0 +1,17 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target mbranch_protection_ok } */
+/* { dg-options "-march=armv8.1-m.main+fp -mbranch-protection=pac-ret+bti -mfloat-abi=hard --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..b94f3447ad9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-3.c
@@ -0,0 +1,17 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target mbranch_protection_ok } */
+/* { dg-options "-march=armv8.1-m.main+fp -mbranch-protection=pac-ret+leaf -mfloat-abi=hard --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..ed52afc83c5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-6.c
@@ -0,0 +1,16 @@ 
+/* { dg-do compile } */
+/* { dg-require-effective-target mbranch_protection_ok } */
+/* { dg-additional-options "-march=armv8.1-m.main+fp -mbranch-protection=bti -mfloat-abi=hard --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..1b25907635e
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/acle/pacbti-m-predef-7.c
@@ -0,0 +1,17 @@ 
+/* { dg-do compile } */
+/* { dg-skip-if "avoid conflicting multilib options" { *-*-* } { "-marm" "-mcpu=*" } } */
+/* { dg-additional-options "-march=armv8.1-m.main+pacbti+fp --save-temps -mfloat-abi=hard" } */
+
+#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" } } */