libgo/misc/cgo/test/sigaltstack.go

   1 // Copyright 2015 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // +build !windows,!android
   6
   7 // Test that the Go runtime still works if C code changes the signal stack.
   8
   9 package cgotest
  10
  11 /*
  12 #include <signal.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16
  17 static stack_t oss;
  18 static char signalStack[SIGSTKSZ];
  19
  20 static void changeSignalStack(void) {
  21         stack_t ss;
  22         memset(&ss, 0, sizeof ss);
  23         ss.ss_sp = signalStack;
  24         ss.ss_flags = 0;
  25         ss.ss_size = SIGSTKSZ;
  26         if (sigaltstack(&ss, &oss) < 0) {
  27                 perror("sigaltstack");
  28                 abort();
  29         }
  30 }
  31
  32 static void restoreSignalStack(void) {
  33 #if (defined(__x86_64__) || defined(__i386__)) && defined(__APPLE__)
  34         // The Darwin C library enforces a minimum that the kernel does not.
  35         // This is OK since we allocated this much space in mpreinit,
  36         // it was just removed from the buffer by stackalloc.
  37         oss.ss_size = MINSIGSTKSZ;
  38 #endif
  39         if (sigaltstack(&oss, NULL) < 0) {
  40                 perror("sigaltstack restore");
  41                 abort();
  42         }
  43 }
  44
  45 static int zero(void) {
  46         return 0;
  47 }
  48 */
  49 import "C"
  50
  51 import (
  52         "runtime"
  53         "testing"
  54 )
  55
  56 func testSigaltstack(t *testing.T) {
  57         switch {
  58         case runtime.GOOS == "solaris", runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64"):
  59                 t.Skipf("switching signal stack not implemented on %s/%s", runtime.GOOS, runtime.GOARCH)
  60         case runtime.GOOS == "darwin" && runtime.GOARCH == "386":
  61                 t.Skipf("sigaltstack fails on darwin/386")
  62         }
  63
  64         C.changeSignalStack()
  65         defer C.restoreSignalStack()
  66         defer func() {
  67                 if recover() == nil {
  68                         t.Error("did not see expected panic")
  69                 }
  70         }()
  71         v := 1 / int(C.zero())
  72         t.Errorf("unexpected success of division by zero == %d", v)
  73 }