From: Kees Cook <keescook@chromium.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>,
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Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
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Subject: Re: [PATCH] selftests: proc: Make sure wchan works when it exists
Date: Thu, 21 Oct 2021 13:12:29 -0700 [thread overview]
Message-ID: <202110211310.634B74A@keescook> (raw)
In-Reply-To: <f4b83c21-4e73-45b6-ae3a-17659be512c0@www.fastmail.com>
On Thu, Oct 21, 2021 at 01:03:33PM -0700, Andy Lutomirski wrote:
>
>
> On Fri, Oct 8, 2021, at 4:55 PM, Kees Cook wrote:
> > This makes sure that wchan contains a sensible symbol when a process is
> > blocked. Specifically this calls the sleep() syscall, and expects the
> > architecture to have called schedule() from a function that has "sleep"
> > somewhere in its name. For example, on the architectures I tested
> > (x86_64, arm64, arm, mips, and powerpc) this is "hrtimer_nanosleep":
>
> Is this really better than admitting that the whole mechanism is nonsense and disabling it?
>
> We could have a fixed string for each task state and call it a day.
I consider this to be "future work". In earlier discussions it came up,
but there wasn't an obvious clean cost-free way to do this, so instead
we're just fixing the broken corner and keeping the mostly working rest
of it while cleaning up the weird edges. :)
--
Kees Cook
next prev parent reply other threads:[~2021-10-21 20:12 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-08 23:55 [PATCH] selftests: proc: Make sure wchan works when it exists Kees Cook
2021-10-09 12:52 ` Alexey Dobriyan
2021-10-11 17:42 ` Kees Cook
2021-10-21 17:09 ` Kees Cook
2021-10-21 19:30 ` Peter Zijlstra
2021-10-21 20:10 ` Kees Cook
2021-10-21 20:03 ` Andy Lutomirski
2021-10-21 20:12 ` Kees Cook [this message]
2021-10-22 0:39 ` Andy Lutomirski
2021-10-22 3:35 ` Kees Cook
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