On 5/20/21 12:55 PM, Marco Elver wrote:
I think this came up with other no_sanitize [1] based on what I had
written to you last year [2].
[1]https://gcc.gnu.org/pipermail/gcc-patches/2020-June/547618.html
[2]https://lore.kernel.org/lkml/canpmjnnrz5ovkb6pe7k6gjfogbht_zhypkng9ad+kjndzk7...@mail.gmail.com/
Ah, you're right. I've just updated the patch to address that.
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
Ready to be installed?
Thanks,
Martin
>From b7f9f6c9722e7cb1b81b96ec646cadb5706b1038 Mon Sep 17 00:00:00 2001
From: Martin Liska <mli...@suse.cz>
Date: Thu, 20 May 2021 09:32:29 +0200
Subject: [PATCH] Add no_sanitize_coverage attribute.
gcc/ChangeLog:
* asan.h (sanitize_coverage_p): New function.
* doc/extend.texi: Document it.
* fold-const.c (fold_range_test): Use sanitize_flags_p
instead of flag_sanitize_coverage.
(fold_truth_andor): Likewise.
* sancov.c: Likewise.
* tree-ssa-ifcombine.c (ifcombine_ifandif): Likewise.
* ipa-inline.c (sanitize_attrs_match_for_inline_p): Handle
-fsanitize-coverage when inlining.
gcc/c-family/ChangeLog:
* c-attribs.c (handle_no_sanitize_coverage_attribute): New.
gcc/testsuite/ChangeLog:
* gcc.dg/sancov/attribute.c: New test.
---
gcc/asan.h | 10 ++++++++++
gcc/c-family/c-attribs.c | 20 ++++++++++++++++++++
gcc/doc/extend.texi | 6 ++++++
gcc/fold-const.c | 4 ++--
gcc/ipa-inline.c | 3 +++
gcc/sancov.c | 4 ++--
gcc/testsuite/gcc.dg/sancov/attribute.c | 15 +++++++++++++++
gcc/tree-ssa-ifcombine.c | 4 +++-
8 files changed, 61 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/sancov/attribute.c
diff --git a/gcc/asan.h b/gcc/asan.h
index f110f1db563..8c0b2baf170 100644
--- a/gcc/asan.h
+++ b/gcc/asan.h
@@ -249,4 +249,14 @@ sanitize_flags_p (unsigned int flag, const_tree fn = current_function_decl)
return result_flags;
}
+/* Return true when coverage sanitization should happend for FN function. */
+
+static inline bool
+sanitize_coverage_p (const_tree fn = current_function_decl)
+{
+ return (flag_sanitize_coverage
+ && lookup_attribute ("no_sanitize_coverage",
+ DECL_ATTRIBUTES (fn)) == NULL_TREE);
+}
+
#endif /* TREE_ASAN */
diff --git a/gcc/c-family/c-attribs.c b/gcc/c-family/c-attribs.c
index ccf9e4ccf0b..671b27c3200 100644
--- a/gcc/c-family/c-attribs.c
+++ b/gcc/c-family/c-attribs.c
@@ -62,6 +62,8 @@ static tree handle_no_address_safety_analysis_attribute (tree *, tree, tree,
int, bool *);
static tree handle_no_sanitize_undefined_attribute (tree *, tree, tree, int,
bool *);
+static tree handle_no_sanitize_coverage_attribute (tree *, tree, tree, int,
+ bool *);
static tree handle_asan_odr_indicator_attribute (tree *, tree, tree, int,
bool *);
static tree handle_stack_protect_attribute (tree *, tree, tree, int, bool *);
@@ -449,6 +451,8 @@ const struct attribute_spec c_common_attribute_table[] =
handle_no_sanitize_thread_attribute, NULL },
{ "no_sanitize_undefined", 0, 0, true, false, false, false,
handle_no_sanitize_undefined_attribute, NULL },
+ { "no_sanitize_coverage", 0, 0, true, false, false, false,
+ handle_no_sanitize_coverage_attribute, NULL },
{ "asan odr indicator", 0, 0, true, false, false, false,
handle_asan_odr_indicator_attribute, NULL },
{ "warning", 1, 1, true, false, false, false,
@@ -1211,6 +1215,22 @@ handle_no_sanitize_undefined_attribute (tree *node, tree name, tree, int,
return NULL_TREE;
}
+/* Handle a "no_sanitize_coverage" attribute; arguments as in
+ struct attribute_spec.handler. */
+
+static tree
+handle_no_sanitize_coverage_attribute (tree *node, tree name, tree, int,
+ bool *no_add_attrs)
+{
+ if (TREE_CODE (*node) != FUNCTION_DECL)
+ {
+ warning (OPT_Wattributes, "%qE attribute ignored", name);
+ *no_add_attrs = true;
+ }
+
+ return NULL_TREE;
+}
+
/* Handle an "asan odr indicator" attribute; arguments as in
struct attribute_spec.handler. */
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 826804e6149..3ddeb0dee3a 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -3415,6 +3415,12 @@ The @code{no_sanitize_undefined} attribute on functions is used
to inform the compiler that it should not check for undefined behavior
in the function when compiling with the @option{-fsanitize=undefined} option.
+@item no_sanitize_coverage
+@cindex @code{no_sanitize_coverage} function attribute
+The @code{no_sanitize_coverage} attribute on functions is used
+to inform the compiler that it should not do coverage-guided
+fuzzing code instrumentation (@option{-fsanitize-coverage}).
+
@item no_split_stack
@cindex @code{no_split_stack} function attribute
@opindex fsplit-stack
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index 3be9c15e6b2..d088187a057 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -6016,7 +6016,7 @@ fold_range_test (location_t loc, enum tree_code code, tree type,
logical_op_non_short_circuit
= param_logical_op_non_short_circuit;
if (logical_op_non_short_circuit
- && !flag_sanitize_coverage
+ && !sanitize_coverage_p ()
&& lhs != 0 && rhs != 0
&& (code == TRUTH_ANDIF_EXPR || code == TRUTH_ORIF_EXPR)
&& operand_equal_p (lhs, rhs, 0))
@@ -9652,7 +9652,7 @@ fold_truth_andor (location_t loc, enum tree_code code, tree type,
logical_op_non_short_circuit
= param_logical_op_non_short_circuit;
if (logical_op_non_short_circuit
- && !flag_sanitize_coverage
+ && !sanitize_coverage_p ()
&& (code == TRUTH_AND_EXPR
|| code == TRUTH_ANDIF_EXPR
|| code == TRUTH_OR_EXPR
diff --git a/gcc/ipa-inline.c b/gcc/ipa-inline.c
index f15c4828958..9d896beb2ac 100644
--- a/gcc/ipa-inline.c
+++ b/gcc/ipa-inline.c
@@ -283,6 +283,9 @@ sanitize_attrs_match_for_inline_p (const_tree caller, const_tree callee)
!= sanitize_flags_p (codes[i], callee))
return false;
+ if (sanitize_coverage_p (caller) != sanitize_coverage_p (callee))
+ return false;
+
return true;
}
diff --git a/gcc/sancov.c b/gcc/sancov.c
index d656c37cae9..9cfbd425def 100644
--- a/gcc/sancov.c
+++ b/gcc/sancov.c
@@ -313,9 +313,9 @@ public:
return new pass_sancov<O0> (m_ctxt);
}
virtual bool
- gate (function *)
+ gate (function *fun)
{
- return flag_sanitize_coverage && (!O0 || !optimize);
+ return sanitize_coverage_p (fun->decl) && (!O0 || !optimize);
}
virtual unsigned int
execute (function *fun)
diff --git a/gcc/testsuite/gcc.dg/sancov/attribute.c b/gcc/testsuite/gcc.dg/sancov/attribute.c
new file mode 100644
index 00000000000..bf6dbd4bae7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/sancov/attribute.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-fsanitize-coverage=trace-pc -fdump-tree-optimized" } */
+
+void foo(void)
+{
+}
+
+void
+__attribute__((no_sanitize_coverage))
+bar(void)
+{
+}
+
+
+/* { dg-final { scan-tree-dump-times "__builtin___sanitizer_cov_trace_pc \\(\\)" 1 "optimized" } } */
diff --git a/gcc/tree-ssa-ifcombine.c b/gcc/tree-ssa-ifcombine.c
index 836a12d6b80..f93e04aa4df 100644
--- a/gcc/tree-ssa-ifcombine.c
+++ b/gcc/tree-ssa-ifcombine.c
@@ -40,6 +40,8 @@ along with GCC; see the file COPYING3. If not see
#include "gimplify-me.h"
#include "tree-cfg.h"
#include "tree-ssa.h"
+#include "attribs.h"
+#include "asan.h"
#ifndef LOGICAL_OP_NON_SHORT_CIRCUIT
#define LOGICAL_OP_NON_SHORT_CIRCUIT \
@@ -567,7 +569,7 @@ ifcombine_ifandif (basic_block inner_cond_bb, bool inner_inv,
if (param_logical_op_non_short_circuit != -1)
logical_op_non_short_circuit
= param_logical_op_non_short_circuit;
- if (!logical_op_non_short_circuit || flag_sanitize_coverage)
+ if (!logical_op_non_short_circuit || sanitize_coverage_p ())
return false;
/* Only do this optimization if the inner bb contains only the conditional. */
if (!gsi_one_before_end_p (gsi_start_nondebug_after_labels_bb (inner_cond_bb)))
--
2.31.1
