asan.h (asan_sanitize_allocas_p): Declare.

gcc/
	* asan.h (asan_sanitize_allocas_p): Declare.
	* asan.c (asan_sanitize_allocas_p): New function.
	(handle_builtin_stack_restore): Bail out if !asan_sanitize_allocas_p.
	(handle_builtin_alloca): Likewise.
	* cfgexpand.c (expand_used_vars): Do not add allocas unpoisoning stuff
	if !asan_sanitize_allocas_p.
	* params.def (asan-instrument-allocas): Add new option.
	* params.h (ASAN_PROTECT_ALLOCAS): Define.
	* opts.c (common_handle_option): Disable allocas sanitization for
	KASan by default.

gcc/testsuite/
	* c-c++-common/asan/kasan-alloca-1.c: New test.
	* c-c++-common/asan/kasan-alloca-2.c: Likewise.

From-SVN: r250032

1 files changed, 8 insertions, 2 deletions

diff --git a/gcc/asan.c b/gcc/asan.c
index 252e59f..95004d7 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -310,6 +310,12 @@ asan_sanitize_stack_p (void)
   return (sanitize_flags_p (SANITIZE_ADDRESS) && ASAN_STACK);
 }
 
+bool
+asan_sanitize_allocas_p (void)
+{
+  return (asan_sanitize_stack_p () && ASAN_PROTECT_ALLOCAS);
+}
+
 /* Checks whether section SEC should be sanitized.  */
 
 static bool
@@ -569,7 +575,7 @@ get_last_alloca_addr ()
 static void
 handle_builtin_stack_restore (gcall *call, gimple_stmt_iterator *iter)
 {
-  if (!iter)
+  if (!iter || !asan_sanitize_allocas_p ())
     return;
 
   tree last_alloca = get_last_alloca_addr ();
@@ -607,7 +613,7 @@ handle_builtin_stack_restore (gcall *call, gimple_stmt_iterator *iter)
 static void
 handle_builtin_alloca (gcall *call, gimple_stmt_iterator *iter)
 {
-  if (!iter)
+  if (!iter || !asan_sanitize_allocas_p ())
     return;
 
   gassign *g;