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[209.85.208.52]) by smtp.gmail.com with ESMTPSA id j16sm4845144edw.23.2021.10.02.09.59.23 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 02 Oct 2021 09:59:23 -0700 (PDT) Received: by mail-ed1-f52.google.com with SMTP id b8so12237308edk.2 for ; Sat, 02 Oct 2021 09:59:23 -0700 (PDT) X-Received: by 2002:a2e:3309:: with SMTP id d9mr4559712ljc.249.1633193585297; Sat, 02 Oct 2021 09:53:05 -0700 (PDT) MIME-Version: 1.0 References: <20210929185823.499268-1-alex.popov@linux.com> <20210929194924.GA880162@paulmck-ThinkPad-P17-Gen-1> In-Reply-To: From: Linus Torvalds Date: Sat, 2 Oct 2021 09:52:49 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] Introduce the pkill_on_warn boot parameter To: Alexander Popov Cc: Petr Mladek , "Paul E. McKenney" , Jonathan Corbet , Andrew Morton , Thomas Gleixner , Peter Zijlstra , Joerg Roedel , Maciej Rozycki , Muchun Song , Viresh Kumar , Robin Murphy , Randy Dunlap , Lu Baolu , Kees Cook , Luis Chamberlain , Wei Liu , John Ogness , Andy Shevchenko , Alexey Kardashevskiy , Christophe Leroy , Jann Horn , Greg Kroah-Hartman , Mark Rutland , Andy Lutomirski , Dave Hansen , Steven Rostedt , Will Deacon , David S Miller , Borislav Petkov , Kernel Hardening , linux-hardening@vger.kernel.org, "open list:DOCUMENTATION" , Linux Kernel Mailing List , notify@kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 2, 2021 at 4:41 AM Alexander Popov wrote: > > And what do you think about the proposed pkill_on_warn? Honestly, I don't see the point. If you can reliably trigger the WARN_ON some way, you can probably cause more problems by fooling some other process to trigger it. And if it's unintentional, then what does the signal help? So rather than a "rationale" that makes little sense, I'd like to hear of an actual _use_ case. That's different. That's somebody actually _using_ that pkill to good effect for some particular load. That said, I don't much care in the end. But it sounds like a pointless option to just introduce yet another behavior to something that should never happen anyway, and where the actual honest-to-goodness reason for WARN_ON() existing is already being fulfilled (ie syzbot has been very effective at flushing things like that out). Linus