Memory leak on darwin x86

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When executing the following code:

(defun foo (array x y) (aref array x y))

(let ((a (make-array '(128 128))))
  (dotimes (i 1000000)
    (handler-case
       (foo a -1 -1)
     (type-error () 0))))

Memory usage goes up quickly until exhausted. Follows a stream of mmap: Cannot allocate memory and sbcl finally crashes.

It repros on sbcl darwin x86 1.0.22.? 1.0.24.24 and 1.0.25.9. However the bug does not seem to affect linux builds.

[Paul Khuong (pvk)]

The leak comes from signal_emulation_wrapper in x86-64-darwin-os.c:199. The (posix) handler function does not always return. Since our stuff isn't allocated on the stack, it doesn't get freed implicitly by unwinds. We don't allocate on the stack like on other platforms to avoid confusing the debugger's backtrace logic. It might be preferable to make the backtracer smarter, or track SP/IP around foreign stack frames.

[Stas Boukarev (stassats)]

Fixed in f723f68aa847501d7f30e1403f79a678f7da2fe2