為什么使用信號處理程序在此代碼中出現分段錯誤？

Question

我在我的程序中編寫了一個信號處理程序，但是在這個文件結構中我遇到了分段錯誤。 但是，如果一切都在一個文件中，那么一切正常。 據我了解，它無法訪問返回地址。 我該如何解決？

“測試.h”

#ifndef TEST_H
#define TEST_H
#include <string.h>
#include <setjmp.h>
#include <signal.h>
static jmp_buf g_env;
void sig_handler(int sig);
endif TEST_H

“測試.c”

#include "test.h"
void sig_handler(int sig) {
  psignal(sig, "Signal");
  siglongjmp(g_env, 1);
}

“主要.c”

#include "test.h"
int main(void) {
  struct sigaction act;
  memset(&act, 0, sizeof(act));
  act.sa_handler = sig_handler;
  sigemptyset(&act.sa_mask);
  sigaddset(&act.sa_mask, SIGSEGV);
  sigaction(SIGSEGV, &act, 0);

  if (!sigsetjmp(g_env, 1)) {
    raise(SIGSEGV);
  }
  return (1);
}

“結果：”

Signal: Segmentation fault
Segmentation fault (core dumped)

“瓦爾格林德：”

==44698== Command: ./a.out
==44698==
Signal: Segmentation fault
==44698== Warning: client switching stacks?  SP change: 0x1ffeffee08 --> 0xf7c1f413060a2966
==44698==          to suppress, use: --max-stackframe=593925450715481250 or greater
==44698== Jump to the invalid address stated on the next line
==44698==    at 0xF7C1F413060A2966: ???
==44698==  Address 0xf7c1f413060a2966 is not stack'd, malloc'd or (recently) free'd
==44698==
==44698==
==44698== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==44698==  Bad permissions for mapped region at address 0xF7C1F413060A2966
==44698==    at 0xF7C1F413060A2966: ???
==44698== Invalid write of size 8
==44698==    at 0x482F120: _vgnU_freeres (vg_preloaded.c:59)
==44698==  Address 0xf7c1f413060a295e is not stack'd, malloc'd or (recently) free'd
==44698==
==44698==
==44698== Process terminating with default action of signal 11 (SIGSEGV)
==44698==  General Protection Fault
==44698==    at 0x482F120: _vgnU_freeres (vg_preloaded.c:59)

Answer 1

這是因為您有不同的g_env實例 - 每個翻譯單元都有不同的g_env 。 因此， sigsetjmp 中使用的g_env緩沖區與sigsetjmp中使用的siglongjmp 。

只需從以下位置刪除static ：

static jmp_buf g_env;

現在，將只有一個g_env的全局實例。