Re: [PATCH][PR sanitizer/78651] Incorrect exception handling when catch clause uses local class and PIC and sanitizer are active

[Maxim Ostapenko]

On 03/19/2018 07:35 PM, Jakub Jelinek wrote:

On Mon, Mar 19, 2018 at 07:28:11PM +0300, Maxim Ostapenko wrote:

Yes, it works, attaching the patch.

Can you please add a short comment why we do this?  Also, the testcase
needs work, see below.  Ok for trunk with those changes and after a
while for affected release branches as well.

Ok, thanks, attaching the patch I'm going to apply.

-Maxim

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b5b5559..356e68c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2018-03-19  Maxim Ostapenko  <m.ostape...@samsung.com>
+
+	PR sanitizer/78651
+	* dwarf2asm.c (dw2_output_indirect_constant_1): Disable ASan before
+	calling assemble_variable.
+
 2018-03-19  Richard Biener  <rguent...@suse.de>
 
 	PR tree-optimization/84929
diff --git a/gcc/dwarf2asm.c b/gcc/dwarf2asm.c
index e9b18b8..2e108ac 100644
--- a/gcc/dwarf2asm.c
+++ b/gcc/dwarf2asm.c
@@ -967,7 +967,13 @@ dw2_output_indirect_constant_1 (const char *sym, tree id)
     }
 
   sym_ref = gen_rtx_SYMBOL_REF (Pmode, sym);
+  /* Disable ASan for decl because redzones cause ABI breakage between GCC and
+     libstdc++ for `.LDFCM*' variables.  See PR 78651 for details.  */
+  unsigned int save_flag_sanitize = flag_sanitize;
+  flag_sanitize &= ~(SANITIZE_ADDRESS | SANITIZE_USER_ADDRESS
+		     | SANITIZE_KERNEL_ADDRESS);
   assemble_variable (decl, 1, 1, 1);
+  flag_sanitize = save_flag_sanitize;
   assemble_integer (sym_ref, POINTER_SIZE_UNITS, POINTER_SIZE, 1);
 
   return 0;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 868d8e8..6ff9217 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2018-03-19  Maxim Ostapenko  <m.ostape...@samsung.com>
+
+	PR sanitizer/78651
+	* g++.dg/asan/pr78651.C: New test.
+
 2018-03-19  Richard Biener  <rguent...@suse.de>
 
 	PR tree-optimization/84929
diff --git a/gcc/testsuite/g++.dg/asan/pr78651.C b/gcc/testsuite/g++.dg/asan/pr78651.C
new file mode 100644
index 0000000..09f1be5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/asan/pr78651.C
@@ -0,0 +1,26 @@
+// PR sanitizer/78651
+// { dg-do run }
+// { dg-additional-options "-fpic" { target fpic } }
+
+struct A { };
+
+namespace {
+
+void thisThrows () {
+  throw A();
+}
+
+struct SomeRandomType {};
+}
+
+int main() {
+  try {
+    thisThrows();
+  }
+  catch (SomeRandomType) {
+    throw;
+  }
+  catch (A) {
+  }
+  return 0;
+}