Mark asan fake stacks during machine stack marking

ASAN leaves a pointer to the fake frame on the stack; we can use the
__asan_addr_is_in_fake_stack API to work out the extent of the fake
stack and thus mark any VALUEs contained therein.

[Bug #20001]

1 files changed, 5 insertions, 0 deletions

diff --git a/vm_core.h b/vm_core.h
index 91cfae77e9..9557004dbc 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -94,6 +94,7 @@ extern int ruby_assert_critical_section_entered;
 #include "internal.h"
 #include "internal/array.h"
 #include "internal/basic_operators.h"
+#include "internal/sanitizers.h"
 #include "internal/serial.h"
 #include "internal/vm.h"
 #include "method.h"
@@ -1155,6 +1156,10 @@ typedef struct rb_thread_struct {
     void **specific_storage;
 
     struct rb_ext_config ext_config;
+
+#ifdef RUBY_ASAN_ENABLED
+    void *asan_fake_stack_handle;
+#endif
 } rb_thread_t;
 
 static inline unsigned int