tests/win32-stack-unwind.c

   1 /* Compiled and loaded by win32-foreign-stack-unwind.impure.lisp
   2  *
   3  * establish_return_frame(callback_ptr) establishes an SEH frame
   4  * that will cause an unwind to itself followed by a return on
   5  * any exception, and then calls the callback_ptr.
   6  *
   7  * perform_test_unwind() does an unwind to the SEH frame
   8  * established by establish_return_frame().
   9  *
  10  * The name of the game for the tests is to establish a callback
  11  * that establishes something with a dynamic contour and
  12  * possibly a control transfer semantic (such as a binding or an
  13  * unwind-protect) and then call perform_test_unwind() or cause
  14  * an exception that should be handled by SBCL and see what
  15  * breaks.
  16  */
  17
  18 /* This software is part of the SBCL system. See the README file for
  19  * more information.
  20  *
  21  * While most of SBCL is derived from the CMU CL system, the test
  22  * files (like this one) were written from scratch after the fork
  23  * from CMU CL.
  24  *
  25  * This software is in the public domain and is provided with
  26  * absolutely no warranty. See the COPYING and CREDITS files for
  27  * more information.
  28  */
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32
  33 #define WIN32_LEAN_AND_MEAN
  34 #include <windows.h>
  35 #include <excpt.h>
  36
  37
  38 /* The "public" API */
  39
  40 typedef void (*callback_ptr)(void);
  41
  42 void establish_return_frame(callback_ptr callback);
  43 void perform_test_unwind(void);
  44
  45
  46 /* The implementation */
  47
  48 static
  49 void **saved_exception_frame;
  50
  51 static
  52 DWORD saved_ebp;
  53
  54 static void *get_seh_frame(void)
  55 {
  56     void* retval;
  57     asm volatile ("movl %%fs:0,%0": "=r" (retval));
  58     return retval;
  59 }
  60
  61 static void set_seh_frame(void *frame)
  62 {
  63     asm volatile ("movl %0,%%fs:0": : "r" (frame));
  64 }
  65
  66
  67 static
  68 EXCEPTION_DISPOSITION handle_exception(EXCEPTION_RECORD *exception_record,
  69                                        void **exception_frame,
  70                                        CONTEXT *context,
  71                                        void *dc)
  72 {
  73     /* If an exception occurs and is passed to us to handle, just
  74      * unwind.  One or more test cases check for SBCL handling
  75      * breakpoint exceptions properly.  This makes sure that it
  76      * doesn't unless a new exception frame is estabished when a
  77      * callback occurs. */
  78     if (!(exception_record->ExceptionFlags
  79           & (EH_UNWINDING | EH_EXIT_UNWIND))) {
  80         perform_test_unwind();
  81     }
  82
  83     return ExceptionContinueSearch;
  84 }
  85
  86 static void invoke_callback(callback_ptr callback, DWORD *unwind_token);
  87
  88 asm("_invoke_callback:"
  89     "pushl %ebp; movl %esp, %ebp;"
  90     "movl 12(%ebp), %eax;"
  91     "movl %ebp, (%eax);"
  92     "call *8(%ebp);"
  93     "movl %ebp, %esp; popl %ebp; ret");
  94
  95 static void do_unwind(void *target_frame, DWORD unwind_token);
  96 asm("_do_unwind:"
  97     "pushl $target; pushl %ebp; movl %esp, %ebp;"
  98     "pushl $0xcafe; pushl $0; pushl $-1; pushl 12(%ebp); call _RtlUnwind@16;"
  99     "target:"
 100     "movl 16(%ebp), %esp; popl %ebp; ret");
 101
 102
 103 void establish_return_frame(callback_ptr callback)
 104 {
 105     void *exception_frame[2];
 106
 107     saved_exception_frame = exception_frame;
 108     exception_frame[0] = get_seh_frame();
 109     exception_frame[1] = handle_exception;
 110     set_seh_frame(exception_frame);
 111
 112     invoke_callback(callback, &saved_ebp);
 113
 114     if (exception_frame != get_seh_frame()) {
 115         /* It is never good for this to happen. */
 116         printf("exception frame mismatch on callback return.\n");
 117     }
 118
 119     set_seh_frame(exception_frame[0]);
 120 }
 121
 122 void perform_test_unwind(void)
 123 {
 124     do_unwind(saved_exception_frame, saved_ebp);
 125 }
 126
 127 /* EOF */