Re: [PATCH] Linux: Add execveat system call wrapper

[Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org>]

On 27/11/2020 14:32, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
> 
>>> +{
>>> +  /* Avoid implicit array coercion in syscall macros.  */
>>> +  INLINE_SYSCALL_CALL (execveat, dirfd, path, &argv[0], &envp[0], flags);
>>> +#ifndef __ASSUME_EXECVEAT
>>> +  if (errno != ENOSYS)
>>> +    return -1;
>>
>> You need get the INLINE_SYSCALL_CALL and check if it was sucessful as well,
>> instead of just check for the errno value. Also, this implementation always 
>> return '-1' (as below):
>>
>>     int r = INLINE_SYSCALL_CALL (execveat, dirfd, path, &argv[0], &envp[0],
>>                                  flags);
>>   #if __ASSUME_EXECVEAT
>>     return r;
>>   #else
>>     if (r == 0 || errno != ENOSYS)
>>       return r;
>>     [...]
> 
>>> +  return -1;
>>> +}
>>
>> This will make the function always return -1.  Hasn't it shown in
>> testing?
> 
> This is the expected behavior for execve and execveat.  It does not
> return successfully, which is why it is not necessary to check the value
> of the INLINE_SYSCALL_CALL macro, either.

Right, forgot about the non return in case of success. So please ignore
that part of the review.