#527: Segmentation fault when stack overflows -------------------------------------+-------------------------------------- Reporter: haruki.zaemon@… | Owner: lsansonetti@… Type: defect | Status: new Priority: major | Milestone: Component: MacRuby | Keywords: stack overflow segfault -------------------------------------+-------------------------------------- Description changed by lsansonetti@…: Old description:

irb --> def a(n); n == 0 ? "DONE" : b(n - 1); end irb --> def b(n); n == 0 ? "DONE" : a(n - 1); end irb --> a(10000) Segmentation fault

New description: {{{ irb --> def a(n); n == 0 ? "DONE" : b(n - 1); end irb --> def b(n); n == 0 ? "DONE" : a(n - 1); end irb --> a(10000) Segmentation fault }}} -- -- Ticket URL: <http://www.macruby.org/trac/ticket/527#comment:2> MacRuby <http://macruby.org/>

#527: Segmentation fault when stack overflows -------------------------------------+-------------------------------------- Reporter: haruki.zaemon@… | Owner: lsansonetti@… Type: defect | Status: new Priority: major | Milestone: Component: MacRuby | Keywords: stack overflow segfault -------------------------------------+-------------------------------------- Comment(by conradwt@…): Yes, I agree that MacRuby should generate an exception. For example, in Ruby 1.9.1/1.9.2, the following is generated: {{{ $ ruby stack-overflow.rb stack-overflow.rb:6:in `b': stack level too deep (SystemStackError) from stack-overflow.rb:2:in `a' from stack-overflow.rb:6:in `b' from stack-overflow.rb:2:in `a' from stack-overflow.rb:6:in `b' from stack-overflow.rb:2:in `a' from stack-overflow.rb:6:in `b' from stack-overflow.rb:2:in `a' from stack-overflow.rb:6:in `b' ... 8718 levels... from stack-overflow.rb:2:in `a' from stack-overflow.rb:6:in `b' from stack-overflow.rb:2:in `a' from stack-overflow.rb:9:in `<main>' }}} -- Ticket URL: <http://www.macruby.org/trac/ticket/527#comment:4> MacRuby <http://macruby.org/>

#527: Segmentation fault when stack overflows -------------------------------------+-------------------------------------- Reporter: haruki.zaemon@… | Owner: lsansonetti@… Type: defect | Status: new Priority: major | Milestone: Component: MacRuby | Keywords: stack overflow segfault -------------------------------------+-------------------------------------- Comment(by martinlagardette@…): Updating status of the bug following #822: It could be possible for MacRuby to handle stack overflow, by handling the stack overflow signal in an alternate stack (allocated with `sigaltstack`). The reasons it is not currently in MacRuby are - Handling the stack overflow signal (I believe it is SIGSEV) messes up the stack and is not good for crash trace analyzers (See r4077) - If we raise in the alt stack, I'm not sure there's a way to catch it in the main thread, meaning a SystemStackError would stop the program, and would not be catchable -- Ticket URL: <http://www.macruby.org/trac/ticket/527#comment:7> MacRuby <http://macruby.org/>

#527: Segmentation fault when stack overflows -------------------------------------+-------------------------------------- Reporter: haruki.zaemon@… | Owner: lsansonetti@… Type: defect | Status: new Priority: major | Milestone: Component: MacRuby | Keywords: stack overflow segfault -------------------------------------+-------------------------------------- Comment(by martinlagardette@…):

"Catching the signal wouldnt help here as I'm pretty sure it's already too late to do anything"

That's actually what `sigaltstack` is for, it allocates a stack just for handling the signal. But yeah, raising from there is likely to fail. And I also agree that it's not a critical issue at all, I just wanted to update the status of the bug so that people know why it's not fixed yet :-) -- Ticket URL: <http://www.macruby.org/trac/ticket/527#comment:9> MacRuby <http://macruby.org/>