Hi, Eugene!
On 9/12/21 12:24 AM, Eugene Syromyatnikov wrote:
On Sat, Sep 11, 2021 at 8:40 PM Alejandro Colomar (man-pages)
<alx.manpages@xxxxxxxxx> wrote:
Hi Eugene,
On 9/11/21 8:29 PM, Eugene Syromyatnikov wrote:
On Sat, Sep 11, 2021 at 6:01 PM Alejandro Colomar
<alx.manpages@xxxxxxxxx> wrote:
Alejandro Colomar (45):
_exit.2: Add LIBRARY section
keyctl.2: Add LIBRARY section
...
socketcall.2: Add LIBRARY section
sigwaitinfo.2: Add LIBRARY section
I'm not sure about these, my understanding is that the primary purpose
of section 2 is syscalls, userspace-kernel interface, and not their
libc wrappers. Even intro(2) states that it is Linux-specific:
“Section 2 of the manual describes the Linux system calls. A system
call is an entry point into the Linux kernel.” Tying it to libc feels
like a bit of a stretch, even though it is the exceedingly common
interface for invoking them.
Thanks for pointing that out. I had some doubts about this in the
beginning. I started writing something like "Linux kernel - GNU C
library" meaning that it's not only a thing of glibc but also the
kernel. But no one replied my RFCs... :/
Apologies on my part—I read the list only occasionally.
No need to apologize. We're doing this for free :)
In the end I simplified it to Standard C library (as FreeBSD does),
The issue here is that FreeBSD has a bit of a different approach,
where libc and kernel are parts of the whole operating systems and
quite tied together, so there's no (assumption about) multiple libc
implementations like in Linux (it is possible, but meaningless—libc is
a part of OS already, after all), so calling syscalls without libc is
much more unusual than in Linux (where it is sometimes even required,
for example, to do weird stuff on x32, for which libc, and even its
syscall() implementation, could stand in the way).
Yes, that was my first thought...
because I wasn't convinced of the syntax I had used. And also, since a
man page being in section 2 already implies that it is implemented in
the kernel, I didn't want to be repetitive, and just point what the user
has to link to to make a program work.
There are some system calls that are wrapped by other libraries, such as
keyctl(2) by libkeyutils, and those get a different LIBRARY (you can
check patch 02/45).
But if you think there's a better way to express this, please propose it.
After some thinking, I think it's okay; I re-read some “C
library/kernel differences”, and those are clearly written with the
assumption that the described call is invoked via its libc wrapper;
notes about the absence of a glibc wrapper for some other syscalls
hint at the same expectation.
but as you say, man-pages already assume use of the glibc (or other
libraries') wrappers almost everywhere; and I think doing otherwise
would overcomplicate it.
Thanks for reviewing my patches!!
Cheers,
Alex
--
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
http://www.alejandro-colomar.es/
