From: nobu@...
Date: 2014-10-16T05:22:07+00:00
Subject: [ruby-core:65752] [ruby-trunk - Bug #10290] segfault when calling a lambda recursively after rescuing SystemStackError

Issue #10290 has been updated by Nobuyoshi Nakada.

Description updated

I could reproduce it with gcc-4.9 on either Linux and OS X.
On Linux, SIGSEGV seems masked after the first stack overflow occurred, and it seems working by enabling interrupts.

~~~diff
diff --git c/eval.c i/eval.c
index 3e4ea16..6bd6ac9 100644
--- c/eval.c
+++ i/eval.c
@@ -500,7 +500,6 @@ setup_exception(rb_thread_t *th, int tag, volatile VALUE mesg, VALUE cause)
     if (cause == Qundef) {
 	cause = nocause ? Qnil : get_thread_errinfo(th);
     }
-    exc_setup_cause(mesg, cause);
 
     file = rb_sourcefile();
     if (file) line = rb_sourceline();
@@ -526,6 +525,7 @@ setup_exception(rb_thread_t *th, int tag, volatile VALUE mesg, VALUE cause)
 	    set_backtrace(mesg, at);
 	}
     }
+    exc_setup_cause(mesg, cause);
 
     if (!NIL_P(mesg)) {
 	th->errinfo = mesg;
diff --git c/signal.c i/signal.c
index d3c7cb8..b939930 100644
--- c/signal.c
+++ i/signal.c
@@ -767,6 +767,7 @@ check_stack_overflow(const uintptr_t addr, const ucontext_t *ctx)
 	     * place. */
 	    th->tag = th->tag->prev;
 	}
+	rb_enable_interrupt();
 	ruby_thread_stack_overflow(th);
     }
 }
~~~

However, on OS X it makes the second stack overflow SIGILL, with no outputs.
I have no idea what happens there.

----------------------------------------
Bug #10290: segfault when calling a lambda recursively after rescuing SystemStackError
https://bugs.ruby-lang.org/issues/10290#change-49485

* Author: Jack Nagel
* Status: Feedback
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
* ruby -v: ruby 2.1.3p242 (2014-09-19 revision 47629) [x86_64-darwin13.0]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
The following code segfaults on Ruby 2.1.3:

```ruby
l = -> { l.() }

begin
  l.()
rescue SystemStackError
  l.() # segfault
end
```

the issue does not occur on trunk.

---Files--------------------------------
ruby_2014-09-25-000925_haswell.log (46.4 KB)
ruby_2014-09-25-001644_haswell.log (46.8 KB)


-- 
https://bugs.ruby-lang.org/