Re: [linux-stable-rc:linux-4.14.y 9981/9999] arch/x86/kernel/ptrace.c:659:22: warning: ISO C90 forbids mixing declarations and code

[Nathan Chancellor <natechancellor@gmail.com>]

On Sun, Jul 14, 2019 at 06:55:15AM +0800, kbuild test robot wrote:
> CC: kbuild-all@01.org
> TO: Dianzhang Chen <dianzhangchen0@gmail.com>
> CC: "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>
> CC: Thomas Gleixner <tglx@linutronix.de>
> 
> tree:   https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.14.y
> head:   728f3eef5bdde0f9516277b4c4519fa5436e7e5d
> commit: 55ac552ebd34f9687cc1bdcb07006bf7f104dc99 [9981/9999] x86/ptrace: Fix possible spectre-v1 in ptrace_get_debugreg()
> config: x86_64-rhel-7.2 (attached as .config)
> compiler: clang version 9.0.0 (git://gitmirror/llvm_project 87856e739c8e55f3b4e0f37baaf93308ec2dbd47)
> reproduce:
>         git checkout 55ac552ebd34f9687cc1bdcb07006bf7f104dc99
>         # save the attached .config to linux build tree
>         make ARCH=x86_64 
> 
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp@intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
> >> arch/x86/kernel/ptrace.c:659:22: warning: ISO C90 forbids mixing declarations and code [-Wdeclaration-after-statement]
>                    struct perf_event *bp = thread->ptrace_bps[index];
>                                       ^
>    1 warning generated.
> 
> vim +659 arch/x86/kernel/ptrace.c
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Hi Greg and Sasha,

I was going to reply to this on the GCC version of the thread but I
don't really see a way to get the original message or the message ID
from the web archive since I'm not subscribed to that list :(

https://lists.01.org/pipermail/kbuild-all/2019-July/062379.html

This is not an issue in Linus' tree because he fixed it manually during
the merge:

https://lore.kernel.org/lkml/CAHk-=whhq5RQYNKzHOLqC+gzSjmcEGNJjbC=Psc_vQaCx4TCKg@mail.gmail.com/

I would say that it isn't unreasonable to fold that fixup into the
original patch, with a note that it came from Linus' merge upstream:

223cea6a4f05 ("Merge branch 'x86-pti-for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip").

Cheers,
Nathan