From: Florian Weimer <fweimer@redhat.com>
To: Andreas Schwab <schwab@suse.de>
Cc: GNU C Library <libc-alpha@sourceware.org>
Subject: Re: [PATCH] <bits/syscall.h>: Use an arch-independent system call list on Linux
Date: Thu, 06 Apr 2017 09:47:00 -0000 [thread overview]
Message-ID: <652ab8b9-fbf1-00f3-ff65-faff202cfc07@redhat.com> (raw)
In-Reply-To: <mvmmvbtewly.fsf@suse.de>
On 04/06/2017 11:03 AM, Andreas Schwab wrote:
> On Apr 06 2017, Florian Weimer <fweimer@redhat.com> wrote:
>
>> On 04/06/2017 10:00 AM, Andreas Schwab wrote:
>>> On Apr 05 2017, Florian Weimer <fweimer@redhat.com> wrote:
>>>
>>>> Downstream, we have the problem that we need to deliver our glibc packages
>>>> before the kernel team finishes backporting system calls. This means that
>>>> the final glibc build before a release does not contain all the SYS_*
>>>> macros supported by the kernel headers.
>>>
>>> Why can't you just patch the kernel headers package?
>>
>> Wasn't this rejected on this list because that would lead to a namespace
>> violation?
>
> I don't understand. The kernel uapi headers fully respect namespace,
> at least those used by glibc.
I think the argument was that __NR_* should come from the kernel, and
SYS_* should come from glibc, and that the kernel has no business
defining SYS_* macros, purely based on namespace concerns.
>> The system call list is generated in an architecture-specific manner.
>
> Sure, but the commits that add the syscalls are easily separable. All
> you need is to update the files underneath asm/unistd.h, which are
> pretty regular.
Not sure if we are talking about the same thing. Our kernel-headers
package comes from the kernel sources, 3.10 era. Maybe you have
frozen/explicit <asm/unistd.h> header in the sources. We don't, we only
have what upstream offers, which is Â… quite dynamic and heavily
automated on some architectures.
>> I looked into this, most architectures use some construct which is
>> rather impenetrable. It's also very brittle in the sense that you can
>> easily change the userspace ABI by accident, and nothing in the kernel
>> build will tell you that you just did.
>
> You only need to patch the kernel headers package, which is hopefully
> separate from the kernel.
Well, I see how this can simplify things. This is not the case for us.
I don't know the rationale behind the tight integration with the kernel
package. I'll ask around.
Anyway, I think for those who don't have separately maintained uapi
headers (because they are building from upstream kernel sources), I
think the relaxing of the build order requirement my proposed patch
provides is still valuable.
Thanks,
Florian
next prev parent reply other threads:[~2017-04-06 9:47 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-05 19:40 Florian Weimer
2017-04-06 8:00 ` Andreas Schwab
2017-04-06 8:52 ` Florian Weimer
2017-04-06 9:03 ` Andreas Schwab
2017-04-06 9:47 ` Florian Weimer [this message]
2017-04-06 10:07 ` Andreas Schwab
2017-04-06 10:12 ` Florian Weimer
2017-04-06 12:29 ` Andreas Schwab
2017-04-06 12:32 ` Florian Weimer
2017-04-06 12:49 ` Andreas Schwab
2017-04-06 13:24 ` Florian Weimer
2017-04-06 13:44 ` Andreas Schwab
2017-04-06 14:22 ` Florian Weimer
2017-04-06 14:37 ` Dmitry V. Levin
2017-04-21 10:06 ` Florian Weimer
2017-04-21 12:27 ` Andreas Schwab
2017-04-21 12:37 ` Florian Weimer
2017-04-21 18:31 ` Carlos O'Donell
2017-04-21 18:02 ` Andreas Schwab
2017-04-21 18:46 ` Florian Weimer
2017-04-21 19:08 ` Andreas Schwab
2017-04-21 19:15 ` Florian Weimer
2017-04-21 19:34 ` Andreas Schwab
2017-04-21 19:37 ` Florian Weimer
2017-04-21 19:40 ` Andreas Schwab
2017-04-21 19:57 ` Florian Weimer
2017-04-22 9:38 ` Andreas Schwab
2017-04-22 11:59 ` Florian Weimer
2017-04-22 13:45 ` Andreas Schwab
2017-04-22 14:22 ` Florian Weimer
2017-04-22 15:08 ` Andreas Schwab
2017-04-22 15:27 ` Florian Weimer
2017-04-22 15:37 ` Andreas Schwab
2017-04-22 15:51 ` Florian Weimer
2017-04-22 17:27 ` Andreas Schwab
2017-08-24 14:35 ` Carlos O'Donell
2017-08-24 15:15 ` Joseph Myers
2017-08-24 16:08 ` Carlos O'Donell
2017-08-24 18:49 ` Florian Weimer
2017-08-24 20:28 ` Joseph Myers
2017-08-25 14:30 ` Florian Weimer
2017-08-25 15:40 ` Joseph Myers
2017-08-25 15:57 ` Florian Weimer
2017-08-28 11:36 ` Joseph Myers
2017-08-28 12:35 ` Florian Weimer
2017-08-28 12:43 ` Joseph Myers
2017-04-23 0:35 ` synchronizing kernel UAPI and libc headers Dmitry V. Levin
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