Hi.
As always Jakub provided my very nice hint how to fix the issue.
It's about adding representative of a stack partitioning into
asan_handled_variables when another variable of the partition
lies in asan_handled_variables.
Patch survives testing on ppc64le-linux-gnu.
Ready for trunk?
gcc/ChangeLog:
2018-09-21 Martin Liska <mli...@suse.cz>
PR sanitizer/85774
* asan.c: Make asan_handled_variables extern.
* asan.h: Likewise.
* cfgexpand.c (expand_stack_vars): Make sure
a representative is unpoison if another
variable in the partition is handled by
use-after-scope sanitization.
gcc/testsuite/ChangeLog:
2018-09-21 Martin Liska <mli...@suse.cz>
PR sanitizer/85774
* g++.dg/asan/pr85774.C: New test.
---
gcc/asan.c | 2 +-
gcc/asan.h | 2 ++
gcc/cfgexpand.c | 14 ++++++++
gcc/testsuite/g++.dg/asan/pr85774.C | 51 +++++++++++++++++++++++++++++
4 files changed, 68 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/g++.dg/asan/pr85774.C
diff --git a/gcc/asan.c b/gcc/asan.c
index e71ab2cc710..235e219479d 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -253,7 +253,7 @@ static tree last_alloca_addr;
/* Set of variable declarations that are going to be guarded by
use-after-scope sanitizer. */
-static hash_set<tree> *asan_handled_variables = NULL;
+hash_set<tree> *asan_handled_variables = NULL;
hash_set <tree> *asan_used_labels = NULL;
diff --git a/gcc/asan.h b/gcc/asan.h
index 412af220597..2f431b4f938 100644
--- a/gcc/asan.h
+++ b/gcc/asan.h
@@ -110,6 +110,8 @@ extern bool asan_sanitize_stack_p (void);
extern bool asan_sanitize_allocas_p (void);
+extern hash_set<tree> *asan_handled_variables;
+
/* Return TRUE if builtin with given FCODE will be intercepted by
libasan. */
diff --git a/gcc/cfgexpand.c b/gcc/cfgexpand.c
index c8d7805308c..35ca276e4ad 100644
--- a/gcc/cfgexpand.c
+++ b/gcc/cfgexpand.c
@@ -1155,6 +1155,20 @@ expand_stack_vars (bool (*pred) (size_t), struct stack_vars_data *data)
if (repr_decl == NULL_TREE)
repr_decl = stack_vars[i].decl;
data->asan_decl_vec.safe_push (repr_decl);
+
+ /* Make sure a representative is unpoison if another
+ variable in the partition is handled by
+ use-after-scope sanitization. */
+ if (asan_handled_variables != NULL
+ && !asan_handled_variables->contains (repr_decl))
+ {
+ for (j = i; j != EOC; j = stack_vars[j].next)
+ if (asan_handled_variables->contains (stack_vars[j].decl))
+ break;
+ if (j != EOC)
+ asan_handled_variables->add (repr_decl);
+ }
+
data->asan_alignb = MAX (data->asan_alignb, alignb);
if (data->asan_base == NULL)
data->asan_base = gen_reg_rtx (Pmode);
diff --git a/gcc/testsuite/g++.dg/asan/pr85774.C b/gcc/testsuite/g++.dg/asan/pr85774.C
new file mode 100644
index 00000000000..c033abfd69b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/asan/pr85774.C
@@ -0,0 +1,51 @@
+/* PR sanitizer/85774 */
+/* { dg-do run } */
+
+#include <functional>
+
+void
+DoSomething ()
+{
+}
+
+void
+DoFunc (const std::function<void(void)> &func)
+{
+ func ();
+}
+
+void
+Setup ()
+{
+ switch (1)
+ {
+ case 1:
+ {
+ DoFunc ([]() {});
+ break;
+ }
+ case 2:
+ {
+ DoFunc ([]() {});
+ break;
+ }
+ default:
+ break;
+ }
+
+ DoSomething ();
+}
+
+void
+DemostrateBadPoisoning ()
+{
+ DoFunc ([]() {});
+}
+
+int
+main ()
+{
+ Setup ();
+ DemostrateBadPoisoning ();
+ return 0;
+}
