[v2] stack-protector: Check stack canary before throwing exception
Commit Message
Check stack canary before throwing exception to avoid stack corruption.
gcc/
PR middle-end/58245
* calls.cc: Include "tree-eh.h".
(expand_call): Check stack canary before throwing exception.
gcc/testsuite/
PR middle-end/58245
* g++.dg/fstack-protector-strong.C: Adjusted.
* g++.dg/pr58245-1.C: New test.
---
gcc/calls.cc | 6 +++++-
gcc/testsuite/g++.dg/fstack-protector-strong.C | 2 +-
gcc/testsuite/g++.dg/pr58245-1.C | 10 ++++++++++
3 files changed, 16 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/g++.dg/pr58245-1.C
Comments
On 8/17/22 16:18, H.J. Lu via Gcc-patches wrote:
> Check stack canary before throwing exception to avoid stack corruption.
>
> gcc/
>
> PR middle-end/58245
> * calls.cc: Include "tree-eh.h".
> (expand_call): Check stack canary before throwing exception.
>
> gcc/testsuite/
>
> PR middle-end/58245
> * g++.dg/fstack-protector-strong.C: Adjusted.
> * g++.dg/pr58245-1.C: New test.
OK.
Jeff
@@ -60,6 +60,7 @@ along with GCC; see the file COPYING3. If not see
#include "attr-fnspec.h"
#include "value-query.h"
#include "tree-pretty-print.h"
+#include "tree-eh.h"
/* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
#define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
@@ -3154,7 +3155,10 @@ expand_call (tree exp, rtx target, int ignore)
if (pass && (flags & ECF_MALLOC))
start_sequence ();
- if (pass == 0
+ /* Check the canary value for sibcall or function which doesn't
+ return and could throw. */
+ if ((pass == 0
+ || ((flags & ECF_NORETURN) != 0 && tree_could_throw_p (exp)))
&& crtl->stack_protect_guard
&& targetm.stack_protect_runtime_enabled_p ())
stack_protect_epilogue ();
@@ -85,4 +85,4 @@ int foo7 (B *p)
return p->return_slot ().a1;
}
-/* { dg-final { scan-assembler-times "stack_chk_fail" 7 } } */
+/* { dg-final { scan-assembler-times "stack_chk_fail" 8 } } */
new file mode 100644
@@ -0,0 +1,10 @@
+/* { dg-do compile { target i?86-*-* x86_64-*-* rs6000-*-* s390x-*-* } } */
+/* { dg-options "-O2 -fstack-protector-all" } */
+
+void
+bar (void)
+{
+ throw 1;
+}
+
+/* { dg-final { scan-assembler-times "stack_chk_fail" 1 } } */