From: Steven Rostedt <rostedt@goodmis.org>
To: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Alexander Popov <alex.popov@linux.com>,
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Shuah Khan <shuah@kernel.org>
Subject: Re: [PATCH v2 0/2] Introduce the pkill_on_warn parameter
Date: Mon, 15 Nov 2021 11:06:49 -0500 [thread overview]
Message-ID: <20211115110649.4f9cb390@gandalf.local.home> (raw)
In-Reply-To: <CAKXUXMx5Oi-dNVKB+8E-pdrz+ooELMZf=oT_oGXKFrNWejz=fg@mail.gmail.com>
On Mon, 15 Nov 2021 14:59:57 +0100
Lukas Bulwahn <lukas.bulwahn@gmail.com> wrote:
> 1. Allow a reasonably configured kernel to boot and run with
> panic_on_warn set. Warnings should only be raised when something is
> not configured as the developers expect it or the kernel is put into a
> state that generally is _unexpected_ and has been exposed little to
> the critical thought of the developer, to testing efforts and use in
> other systems in the wild. Warnings should not be used for something
> informative, which still allows the kernel to continue running in a
> proper way in a generally expected environment. Up to my knowledge,
> there are some kernels in production that run with panic_on_warn; so,
> IMHO, this requirement is generally accepted (we might of course
To me, WARN*() is the same as BUG*(). If it gets hit, it's a bug in the
kernel and needs to be fixed. I have several WARN*() calls in my code, and
it's all because the algorithms used is expected to prevent the condition
in the warning from happening. If the warning triggers, it means either that
the algorithm is wrong or my assumption about the algorithm is wrong. In
either case, the kernel needs to be updated. All my tests fail if a WARN*()
gets hit (anywhere in the kernel, not just my own).
After reading all the replies and thinking about this more, I find the
pkill_on_warning actually worse than not doing anything. If you are
concerned about exploits from warnings, the only real solution is a
panic_on_warning. Yes, it brings down the system, but really, it has to be
brought down anyway, because it is in need of a kernel update.
-- Steve
next prev parent reply other threads:[~2021-11-15 16:07 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-27 23:32 [PATCH v2 0/2] Introduce the pkill_on_warn parameter Alexander Popov
2021-10-27 23:32 ` [PATCH v2 1/2] bug: do refactoring allowing to add a warning handling action Alexander Popov
2021-10-27 23:32 ` [PATCH v2 2/2] sysctl: introduce kernel.pkill_on_warn Alexander Popov
2021-11-12 21:24 ` Steven Rostedt
2021-11-12 18:52 ` [PATCH v2 0/2] Introduce the pkill_on_warn parameter Alexander Popov
2021-11-12 21:26 ` Linus Torvalds
2021-11-13 18:14 ` Alexander Popov
2021-11-13 19:58 ` Linus Torvalds
2021-11-14 14:21 ` Marco Elver
2021-11-15 13:59 ` Lukas Bulwahn
2021-11-15 15:51 ` [ELISA Safety Architecture WG] " Gabriele Paoloni
2021-11-16 7:52 ` Alexander Popov
2021-11-16 8:01 ` Lukas Bulwahn
2021-11-16 8:41 ` Petr Mladek
2021-11-16 9:19 ` Lukas Bulwahn
2021-11-16 13:20 ` James Bottomley
2021-11-15 16:06 ` Steven Rostedt [this message]
2021-11-15 22:06 ` Kees Cook
2021-11-16 9:12 ` Alexander Popov
2021-11-16 18:41 ` Kees Cook
2021-11-16 19:00 ` Casey Schaufler
2021-11-18 17:32 ` Kees Cook
2021-11-18 18:30 ` Casey Schaufler
2021-11-18 20:29 ` Kees Cook
2021-11-16 13:07 ` James Bottomley
2021-11-20 12:17 ` Marco Elver
2021-11-22 16:21 ` Steven Rostedt
2021-11-16 6:37 ` Christophe Leroy
2021-11-16 8:34 ` Alexander Popov
2021-11-16 8:57 ` Lukas Bulwahn
2021-11-15 8:12 ` Kaiwan N Billimoria
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