Re: [PATCH] Locate executables on remote stubs without multiprocess extensions

[Pedro Alves <palves at redhat dot com>]

On 05/06/2015 06:16 PM, Gary Benson wrote:
> Gary Benson wrote:

> @@ -11718,7 +11719,15 @@ remote_pid_to_exec_file (struct target_ops *self, int pid)
>    if (filename != NULL)
>      xfree (filename);
>
> -  xsnprintf (annex, sizeof (annex), "%x", pid);
> +  inf = find_inferior_pid (pid);
> +  if (inf != NULL && !inf->fake_pid_p)

This will silently do the wrong thing (retrieve the exec file
of the server's current thread/process) if this method is ever
used to try to fetch the exec out of a process that we're
_not_ currently attached to.  Maybe this should be:

  if (inf == NULL)
    internal_error (__FILE__, __LINE__,
                    "attempt to retrieve exec-file of not-debugged process");
  if (!inf->fake_pid_p)

>> diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
>> index d2e20d9..516a311 100644
>> --- a/gdb/gdbserver/server.c
>> +++ b/gdb/gdbserver/server.c
>> @@ -1144,17 +1144,32 @@ handle_qxfer_exec_file (const char *const_annex,
>>  			gdb_byte *readbuf, const gdb_byte *writebuf,
>>  			ULONGEST offset, LONGEST len)
>>  {
>> -  char *annex, *file;
>> +  char *file;
>>    ULONGEST pid;
>>    int total_len;
>>  
>>    if (the_target->pid_to_exec_file == NULL || writebuf != NULL)
>>      return -2;
>>  
>> -  annex = alloca (strlen (const_annex) + 1);
>> -  strcpy (annex, const_annex);
>> -  annex = unpack_varlen_hex (annex, &pid);
>> -  if (annex[0] != '\0' || pid == 0)
>> +  if (const_annex[0] == '\0')
>> +    {
>> +      if (current_thread == NULL)
>> +	return -1;
>> +
>> +      pid = pid_of (current_thread);
>> +    }
>> +  else
>> +    {
>> +      char *annex = alloca (strlen (const_annex) + 1);
>> +
>> +      strcpy (annex, const_annex);
>> +      annex = unpack_varlen_hex (annex, &pid);
>> +
>> +      if (annex[0] != '\0')
>> +	return -1;
>> +    }
>> +
>> +  if (pid < 0)
>>      return -1;
> 
> Oops, this should be "<=".

This is OK with that change and the point above addressed.

Thanks,
Pedro Alves