本文共 3310 字，大约阅读时间需要 11 分钟。

1.源码

#include 
   
    #include 
    
     #include 
     
      int main(){  char *test1;  test1 = (char *)malloc(8);  printf("test1 addr is 0x%lx\n",test1);  strncpy(test1,"adbdefg",7);  //test1 = "adbdefg";  printf("test1 addr is 0x%lx\n",test1);  printf("test1 addr is 0x%lx\n",test1);  printf("test1 is %s\n",test1);  printf("test1 size is %d\n",sizeof(*test1));  printf("test1 addr size is %d\n",sizeof(test1));  free(test1);  test1 = NULL;  return 0;}
     
    
   

结果：

test1 addr is 0x255b010test1 addr is 0x255b010test1 addr is 0x255b010test1 is adbdefgtest1 size is 1test1 addr size is 8

test1 addr is 0x11cd010test1 addr is 0x400751test1 addr is 0x400751test1 is adbdefgtest1 size is 1test1 addr size is 8*** glibc detected *** ./testt: free(): invalid pointer: 0x0000000000400751 ***======= Backtrace: =========/lib/x86_64-linux-gnu/libc.so.6(+0x7ae16)[0x7fc54434ee16]/lib/x86_64-linux-gnu/libc.so.6(cfree+0x6c)[0x7fc5443530fc]./testt[0x400640]/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed)[0x7fc5442f530d]./testt[0x4004c9]======= Memory map: ========00400000-00401000 r-xp 00000000 08:07 21086431                           /home/lianxi/c++/testt00600000-00601000 r--p 00000000 08:07 21086431                           /home/lianxi/c++/testt00601000-00602000 rw-p 00001000 08:07 21086431                           /home/lianxi/c++/testt011cd000-011ee000 rw-p 00000000 00:00 0                                  [heap]7fc540000000-7fc540021000 rw-p 00000000 00:00 0 7fc540021000-7fc544000000 ---p 00000000 00:00 0 7fc5440be000-7fc5440d3000 r-xp 00000000 08:05 2050760                    /lib/x86_64-linux-gnu/libgcc_s.so.17fc5440d3000-7fc5442d2000 ---p 00015000 08:05 2050760                    /lib/x86_64-linux-gnu/libgcc_s.so.17fc5442d2000-7fc5442d3000 r--p 00014000 08:05 2050760                    /lib/x86_64-linux-gnu/libgcc_s.so.17fc5442d3000-7fc5442d4000 rw-p 00015000 08:05 2050760                    /lib/x86_64-linux-gnu/libgcc_s.so.17fc5442d4000-7fc54446d000 r-xp 00000000 08:05 2048322                    /lib/x86_64-linux-gnu/libc-2.13.so7fc54446d000-7fc54466c000 ---p 00199000 08:05 2048322                    /lib/x86_64-linux-gnu/libc-2.13.so7fc54466c000-7fc544670000 r--p 00198000 08:05 2048322                    /lib/x86_64-linux-gnu/libc-2.13.so7fc544670000-7fc544671000 rw-p 0019c000 08:05 2048322                    /lib/x86_64-linux-gnu/libc-2.13.so7fc544671000-7fc544677000 rw-p 00000000 00:00 0 7fc544677000-7fc544698000 r-xp 00000000 08:05 2048320                    /lib/x86_64-linux-gnu/ld-2.13.so7fc54486f000-7fc544872000 rw-p 00000000 00:00 0 7fc544894000-7fc544897000 rw-p 00000000 00:00 0 7fc544897000-7fc544898000 r--p 00020000 08:05 2048320                    /lib/x86_64-linux-gnu/ld-2.13.so7fc544898000-7fc54489a000 rw-p 00021000 08:05 2048320                    /lib/x86_64-linux-gnu/ld-2.13.so7fffd2e0f000-7fffd2e30000 rw-p 00000000 00:00 0                          [stack]7fffd2f54000-7fffd2f55000 r-xp 00000000 00:00 0                          [vdso]ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]已放弃

2.分析原因

char *test1;

test1 = (char *)malloc(8);//在堆中分配动态内存

test1 = "adbdefg";//"adbdefg"为常量，存储在TEXT存储区域；试图释放该内存会导致异常

free(test1);//使用free函数去释放一个TEXT只读区域内存，程序肯定异常

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