Hello Florian,
On 9/23/19 10:41 PM, Florian Weimer wrote:
> * Michael Kerrisk:
>
>>>> static
>>>> int pidfd_open(pid_t pid, unsigned int flags)
>>>> {
>>>> return syscall(__NR_pidfd_open, pid, flags);
>>>> }
>>>
>>> Please call this function something else (not pidfd_open), so that the
>>> example continues to work if glibc provides the system call wrapper.
>>
>> I figured that if the syscall does get added to glibc, then I would
>> modify the example. In the meantime, this does seem the most natural
>> way of doing things, since the example then uses the real syscall
>> name as it would be used if there were a wrapper function.
>
> The problem is that programs do this as well, so they fail to build
> once they are built on a newer glibc version.
But isn't such a failure a good thing? I mean: it encourages
people to rid their programs of uses of syscall(2).
>> But, this leads to the question: what do you think the likelihood
>> is that this system call will land in glibc?
>
> Quite likely. It's easy enough to document, there are no P&C issues,
> and it doesn't need any new types.
Okay.
> pidfd_send_signal is slightly more difficult because we probably need
> to add rt_sigqueueinfo first, for consistency.
Okay. I see that's a little more problematic.
Cheers,
Michael
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
