[PATCH] gcc: xtensa: enable address sanitizer

[PATCH] gcc: xtensa: enable address sanitizer

[Max Filippov]

gcc/
2017-12-04  Max Filippov  <jcmvbkbc@gmail.com>

	* config/xtensa/xtensa.c (xtensa_asan_shadow_offset): New
	function.
	(TARGET_ASAN_SHADOW_OFFSET): New macro definition.
	* config/xtensa/xtensa.h (FRAME_GROWS_DOWNWARD): Set to 1 if
	ASAN is enabled.
---
 gcc/config/xtensa/xtensa.c | 12 ++++++++++++
 gcc/config/xtensa/xtensa.h |  3 ++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/gcc/config/xtensa/xtensa.c b/gcc/config/xtensa/xtensa.c
index 1e73b2f4405d..92b9a600df82 100644
--- a/gcc/config/xtensa/xtensa.c
+++ b/gcc/config/xtensa/xtensa.c
@@ -183,6 +183,7 @@ static bool xtensa_hard_regno_mode_ok (unsigned int, machine_mode);
 static bool xtensa_modes_tieable_p (machine_mode, machine_mode);
 static HOST_WIDE_INT xtensa_constant_alignment (const_tree, HOST_WIDE_INT);
 static HOST_WIDE_INT xtensa_starting_frame_offset (void);
+static unsigned HOST_WIDE_INT xtensa_asan_shadow_offset (void);
 
 \f
 
@@ -325,6 +326,9 @@ static HOST_WIDE_INT xtensa_starting_frame_offset (void);
 #undef TARGET_STARTING_FRAME_OFFSET
 #define TARGET_STARTING_FRAME_OFFSET xtensa_starting_frame_offset
 
+#undef TARGET_ASAN_SHADOW_OFFSET
+#define TARGET_ASAN_SHADOW_OFFSET xtensa_asan_shadow_offset
+
 struct gcc_target targetm = TARGET_INITIALIZER;
 
 \f
@@ -4413,4 +4417,12 @@ xtensa_starting_frame_offset (void)
   return crtl->outgoing_args_size;
 }
 
+/* Implement TARGET_ASAN_SHADOW_OFFSET.  */
+
+static unsigned HOST_WIDE_INT
+xtensa_asan_shadow_offset (void)
+{
+  return HOST_WIDE_INT_UC (0x10000000);
+}
+
 #include "gt-xtensa.h"
diff --git a/gcc/config/xtensa/xtensa.h b/gcc/config/xtensa/xtensa.h
index b4cf53708b3e..1602fae3d9ea 100644
--- a/gcc/config/xtensa/xtensa.h
+++ b/gcc/config/xtensa/xtensa.h
@@ -430,7 +430,8 @@ enum reg_class
 
 #define STACK_GROWS_DOWNWARD 1
 
-#define FRAME_GROWS_DOWNWARD flag_stack_protect
+#define FRAME_GROWS_DOWNWARD (flag_stack_protect \
+			      || (flag_sanitize & SANITIZE_ADDRESS) != 0)
 
 /* The ARG_POINTER and FRAME_POINTER are not real Xtensa registers, so
    they are eliminated to either the stack pointer or hard frame pointer.  */
-- 
2.1.4

Re: [PATCH] gcc: xtensa: enable address sanitizer

[Jakub Jelinek]

On Mon, Dec 04, 2017 at 01:28:53PM -0800, Max Filippov wrote:
> gcc/
> 2017-12-04  Max Filippov  <jcmvbkbc@gmail.com>
> 
> 	* config/xtensa/xtensa.c (xtensa_asan_shadow_offset): New
> 	function.
> 	(TARGET_ASAN_SHADOW_OFFSET): New macro definition.
> 	* config/xtensa/xtensa.h (FRAME_GROWS_DOWNWARD): Set to 1 if
> 	ASAN is enabled.

Is this just for -fsanitize=kernel-address ?  Because I don't see any
libsanitizer/ changes (and those would need to go upstream first anyway).

	Jakub

Re: [PATCH] gcc: xtensa: enable address sanitizer

[Max Filippov]

On Mon, Dec 4, 2017 at 1:31 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Mon, Dec 04, 2017 at 01:28:53PM -0800, Max Filippov wrote:
>> gcc/
>> 2017-12-04  Max Filippov  <jcmvbkbc@gmail.com>
>>
>>       * config/xtensa/xtensa.c (xtensa_asan_shadow_offset): New
>>       function.
>>       (TARGET_ASAN_SHADOW_OFFSET): New macro definition.
>>       * config/xtensa/xtensa.h (FRAME_GROWS_DOWNWARD): Set to 1 if
>>       ASAN is enabled.
>
> Is this just for -fsanitize=kernel-address ?  Because I don't see any
> libsanitizer/ changes (and those would need to go upstream first anyway).

Yes, it's for the -fsanitize=kernel-address. I'll port libsanitizer later.

-- 
Thanks.
-- Max

Re: [PATCH] gcc: xtensa: enable address sanitizer

[augustine.sterling]

On Mon, Dec 4, 2017 at 1:28 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
> gcc/
> 2017-12-04  Max Filippov  <jcmvbkbc@gmail.com>
>
>         * config/xtensa/xtensa.c (xtensa_asan_shadow_offset): New
>         function.
>         (TARGET_ASAN_SHADOW_OFFSET): New macro definition.
>         * config/xtensa/xtensa.h (FRAME_GROWS_DOWNWARD): Set to 1 if
>         ASAN is enabled.

This is OK.

Re: [PATCH] gcc: xtensa: enable address sanitizer

[Max Filippov]

On Mon, Dec 4, 2017 at 9:37 PM, augustine.sterling@gmail.com
<augustine.sterling@gmail.com> wrote:
> On Mon, Dec 4, 2017 at 1:28 PM, Max Filippov <jcmvbkbc@gmail.com> wrote:
>> gcc/
>> 2017-12-04  Max Filippov  <jcmvbkbc@gmail.com>
>>
>>         * config/xtensa/xtensa.c (xtensa_asan_shadow_offset): New
>>         function.
>>         (TARGET_ASAN_SHADOW_OFFSET): New macro definition.
>>         * config/xtensa/xtensa.h (FRAME_GROWS_DOWNWARD): Set to 1 if
>>         ASAN is enabled.
>
> This is OK.

Thanks! Applied to trunk and backported to gcc-7-branch.

-- Max