- (/noshow0 "at head of WITH-ALIEN")
- (let ((context (nth-interrupt-context index)))
- (/noshow0 "got CONTEXT")
- (when (= (sap-int frame-pointer)
- (sb!vm:context-register context sb!vm::cfp-offset))
- (without-gcing
- (/noshow0 "in WITHOUT-GCING")
- (let* ((component-ptr (component-ptr-from-pc
- (sb!vm:context-pc context)))
- (code (unless (sap= component-ptr (int-sap #x0))
- (component-from-component-ptr component-ptr))))
- (/noshow0 "got CODE")
- (when (null code)
- (return (values code 0 context)))
- (let* ((code-header-len (* (get-header-data code)
- sb!vm:n-word-bytes))
- (pc-offset
+ (let* ((context (nth-interrupt-context index))
+ (cfp (int-sap (sb!vm:context-register context sb!vm::cfp-offset))))
+ (/noshow0 "got CONTEXT")
+ (unless (control-stack-pointer-valid-p cfp)
+ (return (values nil nil nil t)))
+ (when (sap= frame-pointer cfp)
+ (without-gcing
+ (/noshow0 "in WITHOUT-GCING")
+ (let* ((component-ptr (component-ptr-from-pc
+ (sb!vm:context-pc context)))
+ (code (unless (sap= component-ptr (int-sap #x0))
+ (component-from-component-ptr component-ptr))))
+ (/noshow0 "got CODE")
+ (when (null code)
+ ;; KLUDGE: Detect undefined functions by a range-check
+ ;; against the trampoline address and the following
+ ;; function in the runtime.
+ (if (< (foreign-symbol-address "undefined_tramp")
+ (sap-int (sb!vm:context-pc context))
+ (foreign-symbol-address #!+x86 "closure_tramp"
+ #!+x86-64 "alloc_tramp"))
+ (return (values :undefined-function 0 context))
+ (return (values code 0 context))))
+ (let* ((code-header-len (* (get-header-data code)
+ sb!vm:n-word-bytes))
+ (pc-offset