From: Alexey Khoroshilov <khoroshilov@ispras.ru>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Petr Mladek <pmladek@suse.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Alexander Popov <alex.popov@linux.com>,
Jonathan Corbet <corbet@lwn.net>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Peter Zijlstra <peterz@infradead.org>,
Joerg Roedel <jroedel@suse.de>,
Maciej Rozycki <macro@orcam.me.uk>,
Muchun Song <songmuchun@bytedance.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
Robin Murphy <robin.murphy@arm.com>,
Randy Dunlap <rdunlap@infradead.org>,
Lu Baolu <baolu.lu@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
Luis Chamberlain <mcgrof@kernel.org>, Wei Liu <wl@xen.org>,
John Ogness <john.ogness@linutronix.de>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Alexey Kardashevskiy <aik@ozlabs.ru>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
Jann Horn <jannh@google.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Mark Rutland <mark.rutland@arm.com>,
Andy Lutomirski <luto@kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Steven Rostedt <rostedt@goodmis.org>,
Thomas Garnier <thgarnie@google.com>,
Will Deacon <will.deacon@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Laura Abbott <labbott@redhat.com>,
David S Miller <davem@davemloft.net>,
Borislav Petkov <bp@alien8.de>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
linux-hardening@vger.kernel.org,
"open list:DOCUMENTATION" <linux-doc@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
notify@kernel.org, ldv-project@linuxtesting.org
Subject: Re: [PATCH] Introduce the pkill_on_warn boot parameter
Date: Wed, 27 Jul 2022 20:47:41 +0300 [thread overview]
Message-ID: <64be87a7-bb1f-5578-a526-b7d064fcfea3@ispras.ru> (raw)
In-Reply-To: <CAHk-=wgSyNh2gZTnC-EoiGs5WNtVu99jcHXxLRUvwMabm37iKg@mail.gmail.com>
On 27.07.2022 19:42, Linus Torvalds wrote:
> On Wed, Jul 27, 2022 at 9:17 AM Alexey Khoroshilov
> <khoroshilov@ispras.ru> wrote:
>>
>> We see a number of cases where WARNING is used to inform userspace that
>> it is doing something wrong, e.g.
>> https://elixir.bootlin.com/linux/v5.19-rc8/source/net/can/j1939/socket.c#L181
>> https://elixir.bootlin.com/linux/v5.19-rc8/source/drivers/video/fbdev/core/fbmem.c#L1023
>
> That first case is entirely bogus.
>
> WARN_ON() should only be used for "This cannot happen, but if it does,
> I want to know how we got here".
>
> But the second case is fine: Using "pr_warn()" is fine. A kernel
> warning (without a backtrace) is a normal thing for something that is
> deprecated or questionable, and you want to tell the user that "this
> app is doing something wrong".
Agree with the only note that I like the requirement:
* Do not include "BUG"/"WARNING" in format strings manually to make
* these conditions distinguishable from kernel issues.
very much.
Thank you,
Alexey
next prev parent reply other threads:[~2022-07-27 18:53 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-29 18:58 Alexander Popov
2021-09-29 19:01 ` Alexander Popov
2021-09-29 19:49 ` Paul E. McKenney
2021-09-30 9:15 ` Petr Mladek
2021-09-30 15:05 ` Alexander Popov
2021-10-01 12:23 ` Petr Mladek
2021-09-30 16:59 ` Steven Rostedt
2021-10-01 12:09 ` Petr Mladek
2021-09-30 18:28 ` Kees Cook
2021-10-01 19:59 ` Linus Torvalds
2021-10-02 11:41 ` Alexander Popov
2021-10-02 12:13 ` Steven Rostedt
2021-10-02 16:33 ` Alexander Popov
2021-10-02 16:52 ` Linus Torvalds
2021-10-02 21:05 ` Alexander Popov
2021-10-05 19:48 ` Eric W. Biederman
2021-10-06 14:56 ` Alexander Popov
2021-10-22 17:30 ` Alexander Popov
2022-07-27 16:17 ` Alexey Khoroshilov
2022-07-27 16:30 ` Jann Horn
2022-07-27 16:43 ` Alexey Khoroshilov
2022-07-27 16:42 ` Linus Torvalds
2022-07-27 17:47 ` Alexey Khoroshilov [this message]
2021-09-29 23:31 ` Andrew Morton
2021-09-30 18:27 ` Alexander Popov
2021-09-30 18:36 ` Kees Cook
2021-09-29 19:03 ` Dave Hansen
2021-09-29 19:47 ` Peter Zijlstra
2021-09-29 20:06 ` Kees Cook
2021-09-30 13:55 ` Alexander Popov
2021-09-30 18:20 ` Kees Cook
2021-10-02 18:04 ` Al Viro
2021-10-02 18:31 ` Steven Rostedt
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