From 0ade5611df9f981005eed32b369d1e699e520221 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?V=C3=ADt=20Ondruch?= Date: Thu, 10 Feb 2022 13:26:44 +0100 Subject: [PATCH] Don't query `RubyVM::FrozenCore` for class path. The `RubyVM::FrozenCore` class path is corrupted during GC cycle and returns random garbage, which might result in segfault. But since it is easy to detect the `RubyVM::FrozenCore`, just provide the class path explicitly as a workaround. Other possibility would be to ignore `RubyVM::FrozenCore` simlarly as TracePoint API does: https://github.com/ruby/ruby/blob/46f6575157d4c2f6bbd5693896e26a65037e5552/vm_trace.c#L411 --- vm.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/vm.c b/vm.c index 8ce8b279d4..3d189fa63a 100644 --- a/vm.c +++ b/vm.c @@ -547,7 +547,15 @@ rb_dtrace_setup(rb_execution_context_t *ec, VALUE klass, ID id, } type = BUILTIN_TYPE(klass); if (type == T_CLASS || type == T_ICLASS || type == T_MODULE) { - VALUE name = rb_class_path(klass); + VALUE name = Qnil; + /* + * Special treatment for rb_mRubyVMFrozenCore wchi is broken by GC. + * https://bugs.ruby-lang.org/issues/18257 + */ + if (klass == rb_mRubyVMFrozenCore) + name = rb_str_new_cstr("RubyVM::FrozenCore"); + else + name = rb_class_path(klass); const char *classname, *filename; const char *methodname = rb_id2name(id); if (methodname && (filename = rb_source_location_cstr(&args->line_no)) != 0) {