Re: BUG: /proc/self/exe reports relative paths, should always return absolute paths?

[Samuel Thibault]

Hello,

Svante Signell, on ven. 22 sept. 2017 16:24:11 +0200, wrote:
> Final version?

Almost there :)

> -/* Replace the current process, executing FILE_NAME with arguments ARGV and
> -   environment ENVP.  ARGV and ENVP are terminated by NULL pointers.  */
> +/* Replace the current process, executing ABS_NAME, a canonicalized
> +   absolute path name of FILE_NAME, with arguments ARGV and
> +   environment ENVP.  ARGV and ENVP are terminated by NULL
> +   pointers.  */
>  int
>  __execve (const char *file_name, char *const argv[], char *const envp[])
>  {
>    error_t err;
> -  file_t file = __file_name_lookup (file_name, O_EXEC, 0);
> +  char *cwd = NULL, *concat_name = NULL;
> +  const char *abs_name;
>  
> +  file_t file = __file_name_lookup (file_name, O_EXEC, 0);

This creates a file_t, so return paths have to deallocate it (just like
it is done at the end of the function).

>    if (file == MACH_PORT_NULL)
>      return -1;
>  
> +  /* Absolute path */
> +  if (file_name[0] == '/')
> +    {
> +      abs_name = file_name;
> +    }
> +  /* Relative path */
> +  else
> +    {
> +      cwd = getcwd (NULL, 0);
> +      if (cwd == NULL)

Here

> +     return -1;
> +      int res = asprintf (&concat_name, "%s/%s", cwd, file_name);
> +      if (res == -1)
> +     {

and there

> +       free (cwd);
> +       return -1;
> +     }
> +      abs_name = concat_name;
> +      free (cwd);
> +    }

Along the way, you could move the declaration f the char *cwd variable
on the cwd = getcwd() line, it'll be just a little bit better :)

Samuel