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From: Arnd Bergmann <arnd@arndb.de>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Palmer Dabbelt <palmer@sifive.com>, Guo Ren <ren_guo@c-sky.com>,
	linux-arch <linux-arch@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Jason Cooper <jason@lakedaemon.net>,
	DTML <devicetree@vger.kernel.org>,
	andrea.parri@amarulasolutions.com,
	Peter Zijlstra <peterz@infradead.org>,
	c-sky_gcc_upstream@c-sky.com, gnu-csky@mentor.com,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	wbx@uclibc-ng.org, Greentime Hu <green.hu@gmail.com>,
	Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: [PATCH V4 00/27] C-SKY(csky) Linux Kernel Port
Date: Mon, 24 Sep 2018 10:47:09 +0200	[thread overview]
Message-ID: <CAK8P3a0AVPL3nYF4HTM_jD8-vFn_ScSTnLMUku9vRdbwZQeD4g@mail.gmail.com> (raw)
In-Reply-To: <CAMuHMdVV0QWXCkkL8dq4UMLaANGMHu7ePhQ83FiFDtynpJzbLA@mail.gmail.com>

On Mon, Sep 24, 2018 at 9:21 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> Hi Arnd,
>
> On Fri, Sep 21, 2018 at 7:19 AM Arnd Bergmann <arnd@arndb.de> wrote:
> > On Thu, Sep 20, 2018 at 10:52 AM Palmer Dabbelt <palmer@sifive.com> wrote:
> > > On Fri, 14 Sep 2018 07:37:20 PDT (-0700), ren_guo@c-sky.com wrote:
> > > > On Wed, Sep 12, 2018 at 04:30:36PM +0200, Arnd Bergmann wrote:
> > > >> On Wed, Sep 12, 2018 at 3:25 PM Guo Ren <ren_guo@c-sky.com> wrote:
> > My plan was to get that all into 4.20, and then have a conversation about the
> > actual syscall table changes in 4.21. If we need it for both csky and rv32,
> > we might just change the generic syscall table that way in 4.21 without
> > changing all the other ones along with them. I don't want to drag things out
> > over too many merge windows though, and my plan was to do all architectures
> > together to simplify the version checks in the libc code to only have to check
> > for a single version.
>
> What happens with the version checks if it is backported to stable?

They end up as dead code.

The way these version checks are done in glibc, we always try the new
interface first before falling back to the old version, but don't check the
kernel version at runtime.

The compile-time check optimizes out the fallback if glibc is built for
a recent-enough minimum kernel version that is guaranteed to have
the new version.

      Arnd

  reply	other threads:[~2018-09-24  8:47 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-12 13:24 [PATCH V4 00/27] C-SKY(csky) Linux Kernel Port Guo Ren
2018-09-12 13:24 ` [PATCH V3 01/27] csky: Build infrastructure Guo Ren
2018-09-12 13:24 ` [PATCH V3 02/27] csky: defconfig Guo Ren
2018-09-12 13:24 ` [PATCH V3 03/27] csky: Kernel booting Guo Ren
2018-09-12 13:24 ` [PATCH V3 04/27] csky: Exception handling Guo Ren
2018-09-12 13:24 ` [PATCH V3 05/27] csky: System Call Guo Ren
2018-09-12 13:24 ` [PATCH V3 06/27] csky: Cache and TLB routines Guo Ren
2018-09-12 13:24 ` [PATCH V3 07/27] csky: MMU and page table management Guo Ren
2018-09-12 13:24 ` [PATCH V3 08/27] csky: Process management and Signal Guo Ren
2018-09-12 13:24 ` [PATCH V3 09/27] csky: VDSO and rt_sigreturn Guo Ren
2018-09-12 13:24 ` [PATCH V3 10/27] csky: IRQ handling Guo Ren
2018-09-12 13:24 ` [PATCH V3 12/27] csky: ELF and module probe Guo Ren
2018-09-12 13:24 ` [PATCH V3 13/27] csky: Library functions Guo Ren
2018-09-12 13:24 ` [PATCH V3 14/27] csky: User access Guo Ren
2018-09-12 13:24 ` [PATCH V3 15/27] csky: Debug and Ptrace GDB Guo Ren
2018-09-12 13:24 ` [PATCH V3 16/27] csky: SMP support Guo Ren
2018-09-12 13:24 ` [PATCH V3 18/27] dt-bindings: csky CPU Bindings Guo Ren
2018-09-12 13:24 ` [PATCH V3 19/27] dt-bindings: timer: gx6605s SOC timer Guo Ren
2018-09-12 13:24 ` [PATCH V3 20/27] dt-bindings: timer: C-SKY Multi-processor timer Guo Ren
2018-09-12 13:24 ` [PATCH V3 22/27] dt-bindings: interrupt-controller: C-SKY SMP intc Guo Ren
2018-09-12 13:24 ` [PATCH V3 23/27] clocksource: add gx6605s SOC system timer Guo Ren
     [not found] ` <abb46d366b513b814f7af234d560306a818b7324.1536757532.git.ren_guo@c-sky.com>
2018-09-12 14:22   ` [PATCH V3 17/27] csky: Misc headers Arnd Bergmann
2018-09-12 14:30 ` [PATCH V4 00/27] C-SKY(csky) Linux Kernel Port Arnd Bergmann
2018-09-14 14:37   ` Guo Ren
2018-09-14 14:46     ` Arnd Bergmann
2018-09-14 16:02       ` Guo Ren
2018-09-14 16:09         ` Arnd Bergmann
2018-09-14 23:28           ` Guo Ren
2018-09-20 17:52     ` Palmer Dabbelt
2018-09-21  5:18       ` Arnd Bergmann
2018-09-21 23:48         ` Guo Ren
2018-09-24  7:21         ` Geert Uytterhoeven
2018-09-24  8:47           ` Arnd Bergmann [this message]
2018-09-16  1:07   ` Guo Ren
2018-09-16  4:53   ` Guo Ren
2018-09-17 11:54     ` Stephen Rothwell
2018-09-17 12:03       ` Stephen Rothwell
2018-09-17 14:50         ` Guo Ren
2018-09-17 14:37       ` Guo Ren
     [not found] ` <93e8b592e429c156ad4d4ca5d85ef48fd0ab8b70.1536757532.git.ren_guo@c-sky.com>
2018-09-12 15:55   ` [PATCH V3 11/27] csky: Atomic operations Peter Zijlstra
2018-09-15 14:55     ` Guo Ren
2018-09-17  8:17       ` Peter Zijlstra
2018-09-17 15:05         ` Guo Ren

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