[PATCH] stack-protector: Check stack canary for noreturn function

[H.J. Lu via Gcc-patches]

Check stack canary for noreturn function to catch stack corruption
before calling noreturn function.  For C++, check stack canary when
throwing exception or resuming stack unwind to avoid corrupted stack.

gcc/

        PR middle-end/58245
        * calls.cc (expand_call): Check stack canary for noreturn
        function.

gcc/testsuite/

        PR middle-end/58245
        * c-c++-common/pr58245-1.c: New test.
        * g++.dg/pr58245-1.C: Likewise.
        * g++.dg/fstack-protector-strong.C: Adjusted.
---
 gcc/calls.cc                                   |  7 ++++++-
 gcc/testsuite/c-c++-common/pr58245-1.c         | 12 ++++++++++++
 gcc/testsuite/g++.dg/fstack-protector-strong.C |  2 +-
 gcc/testsuite/g++.dg/pr58245-1.C               | 10 ++++++++++
 4 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/c-c++-common/pr58245-1.c
 create mode 100644 gcc/testsuite/g++.dg/pr58245-1.C

diff --git a/gcc/calls.cc b/gcc/calls.cc
index bc96aff38f0..7816c2c8d99 100644
--- a/gcc/calls.cc
+++ b/gcc/calls.cc
@@ -3154,7 +3154,12 @@ 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.  */
+      if ((pass == 0
+          || ((flags & ECF_NORETURN) != 0
+              && (fndecl
+                  != get_callee_fndecl (targetm.stack_protect_fail ()))))
          && crtl->stack_protect_guard
          && targetm.stack_protect_runtime_enabled_p ())
        stack_protect_epilogue ();
diff --git a/gcc/testsuite/c-c++-common/pr58245-1.c 
b/gcc/testsuite/c-c++-common/pr58245-1.c
new file mode 100644
index 00000000000..945acc53004
--- /dev/null
+++ b/gcc/testsuite/c-c++-common/pr58245-1.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target i?86-*-* x86_64-*-* rs6000-*-* s390x-*-* } } */
+/* { dg-options "-O2 -fstack-protector-all" } */
+
+extern void foo (void) __attribute__ ((noreturn));
+
+void
+bar (void)
+{
+  foo ();
+}
+
+/* { dg-final { scan-assembler-times "stack_chk_fail" 1 } } */
diff --git a/gcc/testsuite/g++.dg/fstack-protector-strong.C 
b/gcc/testsuite/g++.dg/fstack-protector-strong.C
index ae6d2fdb8df..034af2ce9ab 100644
--- a/gcc/testsuite/g++.dg/fstack-protector-strong.C
+++ b/gcc/testsuite/g++.dg/fstack-protector-strong.C
@@ -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 } } */
diff --git a/gcc/testsuite/g++.dg/pr58245-1.C b/gcc/testsuite/g++.dg/pr58245-1.C
new file mode 100644
index 00000000000..1439bc62e71
--- /dev/null
+++ b/gcc/testsuite/g++.dg/pr58245-1.C
@@ -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 } } */
-- 
2.36.1