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Date:   Wed, 16 Jun 2021 21:02:17 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        Michael Schmitz <schmitzmic@gmail.com>,
        linux-arch <linux-arch@vger.kernel.org>,
        Jens Axboe <axboe@kernel.dk>, Oleg Nesterov <oleg@redhat.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Richard Henderson <rth@twiddle.net>,
        Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
        Matt Turner <mattst88@gmail.com>,
        alpha <linux-alpha@vger.kernel.org>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        linux-m68k <linux-m68k@lists.linux-m68k.org>,
        Arnd Bergmann <arnd@kernel.org>,
        Ley Foon Tan <ley.foon.tan@intel.com>,
        Tejun Heo <tj@kernel.org>, Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH 1/2] alpha/ptrace: Record and handle the absence of
 switch_stack
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On Wed, Jun 16, 2021 at 03:57:19PM -0500, Eric W. Biederman wrote:
 
> Do you know if struct switch_stack or pt_regs is ever exposeed to
> usespace?  They are both defined in arch/alpha/include/uapi/asm/ptrace.h
> which makes me think userspace must see those definitions somewhere.

	They are exposed, but why mess with those in the first
place?  thread_info->status is strictly thread-synchronous, so just
use it and be done with that...