大家来帮我看看这个代码，为什么invalid address alignment？？__origarg_0xffffffff_argv_fake_argv_char_

当前位置: 技术问答>linux和unix

大家来帮我看看这个代码，为什么invalid address alignment？？

来源: 互联网发布时间：2017-02-23

本文导语: $ cat test.c #include static struct { int argc; char **argv; int len; } origarg; static int get_arglen(int argc, char **argv) { char *s = argv[0]; return 0; } void ruby_sysinit(int *argc, char ***argv) { ...

$ cat test.c
#include
static struct {
    int argc;
    char **argv;
    int len;
} origarg;

static int get_arglen(int argc, char **argv)
{
    char *s = argv[0];
        return 0;
}

  void
ruby_sysinit(int *argc, char ***argv)
{
    origarg.argc = *argc;
    origarg.argv = *argv;
    origarg.len = get_arglen(origarg.argc, origarg.argv);

}

int main()
{
        int fake_argc = 0;
        char* fake_argv[1] = { "" };

        ruby_sysinit(&fake_argc, (char ***)&fake_argv);
        return 0;
}

$ CC -m64 test.c // 去掉-m64就没问题了
$ ./a.out
Bus Error(coredump)

$ CC -V
CC: Sun C++ 5.11 SunOS_sparc 2010/08/13

$ dbx a.out core
t@1 (l@1) program terminated by signal BUS (invalid address alignment)
0x0000000100000a98: get_arglen+0x0008:  ldx      [%i1], %o0
(dbx) where -h
current thread: t@1
=>[1] get_arglen(0x0, 0x100000d2c, 0xffffffff7ee48240, 0xffffffff7ee49e44, 0xffffffff7eb00200, 0x4), at 0x100000a98
  [2] ruby_sysinit(0xffffffff7ffff154, 0xffffffff7ffff148, 0x1f053c, 0xffffffff7f1085a4, 0xffffffff7ee00700, 0xffffffff7eb00200), at 0x100000af8
  [3] main(0x1, 0xffffffff7ffff218, 0xffffffff7ffff228, 0xffffffff7ec4bb50, 0xffffffff7ee00680, 0xffffffff7eb00200), at 0x100000b60

(dbx) frame 1
Current function is get_arglen
   11       char *s = argv[0];

(dbx) print argv[0]
argv[0] = 0x1 ""

(dbx) frame 3
Current function is main
   29                       ruby_sysinit(&fake_argc, (char ***)&fake_argv);

(dbx) print &fake_argv
&fake_argv = 0xffffffff7ffff068

(dbx) print (char **)fake_argv
dbx: Cannot cast an array
(dbx) print fake_argv
fake_argv = (0x100000db4 "")

大家来帮我看看啊，这为什么会coredump啊？

  void
ruby_sysinit(int *argc, char ***argv)
{
  origarg.argc = *argc;
  origarg.argv = *argv;
  origarg.len = get_arglen(origarg.argc, origarg.argv);

}

int main()
{
  int fake_argc = 0;
  char* fake_argv[1] = { "" };

  ruby_sysinit(&fake_argc, (char ***)&fake_argv);
  return 0;
}

楼主这指针学的，一看就不会指针。你以为多&一下就是多一个*啊 =，=

#include 

static struct {

          int argc;

            char **argv;

                  int len;

} origarg;



static int get_arglen(int argc, char* *argv)

{

          char *s = argv[0];

            return 0;

}



  void

  ruby_sysinit(int *argc, char* *argv)

{

          origarg.argc = *argc;

            origarg.argv = argv;

                  origarg.len = get_arglen(origarg.argc, origarg.argv);



}



int main()

{

          int fake_argc = 0;

            char* fake_argv[1] = { "" };



                  ruby_sysinit(&fake_argc, fake_argv);

                    return 0;

}

只是给你改对了，都不理解为什么要传int的地址，蛋疼。

char* fake_argv[1] 不能转换成三级指针。。。
加个-xmemalign来忽略这个sigbus

您可能感兴趣的文章:

本站(WWW.)旨在分享和传播互联网科技相关的资讯和技术，将尽最大努力为读者提供更好的信息聚合和浏览方式。
本站(WWW.)站内文章除注明原创外，均为转载、整理或搜集自网络。欢迎任何形式的转载，转载请注明出处。