Prevent segfaults running with SystemTap.

Resolves: rhbz#2015441

ruby-3.1.0-Don-t-query-RubyVM-FrozenCore-for-class-path.patch

@@ -0,0 +1,43 @@
+From 0ade5611df9f981005eed32b369d1e699e520221 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?V=C3=ADt=20Ondruch?= <vondruch@redhat.com>
+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
+@@ -446,7 +446,15 @@ 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) {
+-- 
+2.34.1
+

ruby.spec

@@ -138,6 +138,12 @@ Patch5: ruby-1.9.3-mkmf-verbose.patch
 # https://lists.fedoraproject.org/archives/list/ruby-sig@lists.fedoraproject.org/message/LH6L6YJOYQT4Y5ZNOO4SLIPTUWZ5V45Q/
 # For now, load the ABRT hook via this simple patch:
 Patch6: ruby-2.7.0-Initialize-ABRT-hook.patch
+# Prevent segfaults running with SystemTap due to `RubyVM::FrozenCore` being
+# corrupted by GC.
+# https://bugzilla.redhat.com/show_bug.cgi?id=2015441
+# https://bugzilla.redhat.com/show_bug.cgi?id=1986206
+# https://bugs.ruby-lang.org/issues/18257
+Patch7: ruby-3.1.0-Don-t-query-RubyVM-FrozenCore-for-class-path.patch
 # Fix DWARF5 support.
 # https://bugzilla.redhat.com/show_bug.cgi?id=1920533
 # https://bugs.ruby-lang.org/issues/17585
@@ -676,6 +682,7 @@ rm -rf ext/fiddle/libffi*
 %patch4 -p1
 %patch5 -p1
 %patch6 -p1
+%patch7 -p1
 %patch15 -p1
 %patch16 -p1
 %patch17 -p1
@@ -1459,6 +1466,10 @@ mv test/fiddle/test_import.rb{,.disable}
 
 
 %changelog
+* Thu Feb 10 2022 Vít Ondruch <vondruch@redhat.com> - 3.0.3-159
+- Prevent segfaults running with SystemTap.
+  Resolves: rhbz#2015441
+
 * Tue Jan 25 2022 Vít Ondruch <vondruch@redhat.com> - 3.0.3-159
 - Update OpenSSL 3 compatibility patches.
   Resolves: rhbz#1952925