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Enable addressable params sanitization with --param asan-stack=1.

Message ID a06613df-6f36-fd85-f569-666a47dca8f6@suse.cz
State New
Headers show

Commit Message

Martin Liška July 4, 2017, 10:52 a.m. UTC 
On 07/04/2017 09:59 AM, Jakub Jelinek wrote:
> On Tue, Jul 04, 2017 at 09:47:29AM +0200, Martin Liška wrote:
>> As mentioned in https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81040#c15, the sanitization is
>> done only when one uses use-after-scope. That's caused by fact that I decorated the newly
>> created auto variables with DECL_ARTIFICIAL = 1. Because of that
>>
>> static inline bool
>> asan_protect_stack_decl (tree decl)
>> {
>>   return DECL_P (decl)
>>     && (!DECL_ARTIFICIAL (decl)
>> 	|| (asan_sanitize_use_after_scope () && TREE_ADDRESSABLE (decl)));
>> }
>>
>> returns false. I hope not marking the variable as DECL_ARTIFICIAL will work fine?
>> Or am I missing something?
> 
> Well, you should make sure the debug info is correct.
> Which means ideally that there is just one DW_TAG_formal_parameter and no
> DW_TAG_variable for the parameter.
> For the addressable parameters I hope the corresponding artificial
> vars just live in memory for the whole rest of the scope, at least for the
> case where you emit a debug bind (hope it is after the assignment to the
> artificial var) I think it should be fine to set DECL_IGNORED_P on the
> artificial var instead of DECL_ARTIFICIAL.
> For the other case where there is DECL_VALUE_EXPR, perhaps try it too and
> see what you get.
> 
> 	Jakub
> 

Using DECL_IGNORED_P works for me.
Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.

I'm going to install the patch.
Martin
diff mbox

Patch

From 20d69fbf4076add09df363ffb9d03cd243f8190d Mon Sep 17 00:00:00 2001
From: marxin <mliska@suse.cz>
Date: Tue, 4 Jul 2017 09:22:23 +0200
Subject: [PATCH] Enable addressable params sanitization with --param
 asan-stack=1.

gcc/ChangeLog:

2017-07-04  Martin Liska  <mliska@suse.cz>

	PR sanitizer/81040
	* sanopt.c (sanitize_rewrite_addressable_params): Mark the
	newly created variable as DECL_IGNORED_P.

gcc/testsuite/ChangeLog:

2017-07-04  Martin Liska  <mliska@suse.cz>

	PR sanitizer/81040
	* g++.dg/asan/function-argument-1.C: Run the test-case w/o
	use-after-scope sanitization.
---
 gcc/sanopt.c                                    | 2 +-
 gcc/testsuite/g++.dg/asan/function-argument-1.C | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/gcc/sanopt.c b/gcc/sanopt.c
index 7692f6a9db7..b7740741d43 100644
--- a/gcc/sanopt.c
+++ b/gcc/sanopt.c
@@ -905,7 +905,7 @@  sanitize_rewrite_addressable_params (function *fun)
 	  tree var = build_decl (DECL_SOURCE_LOCATION (arg),
 				 VAR_DECL, DECL_NAME (arg), type);
 	  TREE_ADDRESSABLE (var) = 1;
-	  DECL_ARTIFICIAL (var) = 1;
+	  DECL_IGNORED_P (var) = 1;
 
 	  gimple_add_tmp_var (var);
 
diff --git a/gcc/testsuite/g++.dg/asan/function-argument-1.C b/gcc/testsuite/g++.dg/asan/function-argument-1.C
index 148c4628316..bdbb37a44a4 100644
--- a/gcc/testsuite/g++.dg/asan/function-argument-1.C
+++ b/gcc/testsuite/g++.dg/asan/function-argument-1.C
@@ -1,5 +1,6 @@ 
 // { dg-do run }
 // { dg-shouldfail "asan" }
+// { dg-options "-fsanitize=address -fno-sanitize-address-use-after-scope" }
 
 struct A
 {
-- 
2.13.2