Disable TSAN for rb_gc_mark_machine_context

Previously this was listed as a suppression, but we actually want this
permanently unsanitized. This should be faster and more reliable since
TASN won't have to match against symbolicated backtraces.

Author: jhawthorn

configure.ac

@@ -1372,6 +1372,7 @@ AC_CHECK_HEADERS(process.h)
 AC_CHECK_HEADERS(pwd.h)
 AC_CHECK_HEADERS(sanitizer/asan_interface.h)
 AC_CHECK_HEADERS(sanitizer/msan_interface.h)
+AC_CHECK_HEADERS(sanitizer/tsan_interface.h)
 AC_CHECK_HEADERS(setjmpex.h)
 AC_CHECK_HEADERS(stdalign.h)
 AC_CHECK_HEADERS(stdio.h)

internal/sanitizers.h

@@ -29,6 +29,13 @@
 # endif
 #endif
 
+#ifdef HAVE_SANITIZER_TSAN_INTERFACE_H
+# if __has_feature(thread_sanitizer) || defined(__SANITIZE_THREAD__)
+#  define RUBY_TSAN_ENABLED
+#  include <sanitizer/tsan_interface.h>
+# endif
+#endif
+
 #include "ruby/internal/stdbool.h"     /* for bool */
 #include "ruby/ruby.h"          /* for VALUE */
 
@@ -42,6 +49,9 @@
 #elif defined(RUBY_MSAN_ENABLED)
     # define ATTRIBUTE_NO_ADDRESS_SAFETY_ANALYSIS(x) \
     __attribute__((__no_sanitize__("memory"), __noinline__)) x
+#elif defined(RUBY_TSAN_ENABLED)
+# define ATTRIBUTE_NO_ADDRESS_SAFETY_ANALYSIS(x) \
+    __attribute__((__no_sanitize__("thread"), __noinline__)) x
 #elif defined(NO_SANITIZE_ADDRESS)
 # define ATTRIBUTE_NO_ADDRESS_SAFETY_ANALYSIS(x) \
     NO_SANITIZE_ADDRESS(NOINLINE(x))

misc/tsan_suppressions.txt

@@ -104,10 +104,6 @@ race_top:encoded_iseq_trace_instrument
 race:rb_iseq_trace_set_all
 race:rb_tracepoint_enable
 
-# We walk the machine stack looking for markable objects, a thread with the GVL
-# released could by mutating the stack with non-Ruby-objects
-race:rb_gc_mark_machine_context
-
 # GC enable/disable flag modifications race with object allocation flag reads
 race_top:rb_gc_impl_gc_disable
 race_top:rb_gc_impl_gc_enable