From patchwork Tue Jan 24 19:29:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 13114693 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71C01C61DA0 for ; Tue, 24 Jan 2023 19:35:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234329AbjAXTfY (ORCPT ); Tue, 24 Jan 2023 14:35:24 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39092 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233558AbjAXTfU (ORCPT ); Tue, 24 Jan 2023 14:35:20 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 69AB74EF7; Tue, 24 Jan 2023 11:35:19 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 114DBB816D5; Tue, 24 Jan 2023 19:35:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4A311C433A4; Tue, 24 Jan 2023 19:35:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1674588916; bh=jnlzHwyIKm111Hgt2bT1SNx3+PzVjlKrJId4SKTZuz8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lsC6dQs0j3a3o0JmgEA8ug7xy8LjBCRKobbwU/VK1NYCtc+g5dyX1owPEkNVnu7s3 lQSzjhlYn+zseYArnq+Cu6bUU6uiCPbMiLM6P/I+hZchrQPwKK7SinALNOLgcE3LrF ZEJE2XQLsk6j1rwjYiG3Veng4DWMyHCbgp1R65Qm/iZa9fcIgHBNSdLujdhBanCtJN mOwkK8SyGLfiCi2FhkbiK7Q7ucjDA4Guhr3fOM4qIw5i/z5aOML8WmAFL0e/EJicU7 RcvKI9Z6uDPpJF2TW2UNcR/n++4MNIDthEEEIbgzFntJwtBP4E5H6/42K7lPJY4X3C Z//fxzzx+S1fg== From: Eric Biggers To: stable@vger.kernel.org, Greg Kroah-Hartman Cc: Kees Cook , SeongJae Park , Seth Jenkins , Jann Horn , "Eric W . Biederman" , linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, Andrey Ryabinin , Baoquan He , Jonathan Corbet , Xuefeng Li , Tiezhu Yang , Marco Elver , Andrew Morton , Linus Torvalds Subject: [PATCH 5.10 03/20] panic: unset panic_on_warn inside panic() Date: Tue, 24 Jan 2023 11:29:47 -0800 Message-Id: <20230124193004.206841-4-ebiggers@kernel.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230124193004.206841-1-ebiggers@kernel.org> References: <20230124193004.206841-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org From: Tiezhu Yang commit 1a2383e8b84c0451fd9b1eec3b9aab16f30b597c upstream. In the current code, the following three places need to unset panic_on_warn before calling panic() to avoid recursive panics: kernel/kcsan/report.c: print_report() kernel/sched/core.c: __schedule_bug() mm/kfence/report.c: kfence_report_error() In order to avoid copy-pasting "panic_on_warn = 0" all over the places, it is better to move it inside panic() and then remove it from the other places. Link: https://lkml.kernel.org/r/1644324666-15947-4-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Tiezhu Yang Reviewed-by: Marco Elver Cc: Andrey Ryabinin Cc: Baoquan He Cc: Jonathan Corbet Cc: Xuefeng Li Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Eric Biggers --- kernel/panic.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/kernel/panic.c b/kernel/panic.c index f567195d45d9d..960c2be2759cb 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -207,6 +207,16 @@ void panic(const char *fmt, ...) int old_cpu, this_cpu; bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers; + if (panic_on_warn) { + /* + * This thread may hit another WARN() in the panic path. + * Resetting this prevents additional WARN() from panicking the + * system on this thread. Other threads are blocked by the + * panic_mutex in panic(). + */ + panic_on_warn = 0; + } + /* * Disable local interrupts. This will prevent panic_smp_self_stop * from deadlocking the first cpu that invokes the panic, since @@ -618,16 +628,8 @@ void __warn(const char *file, int line, void *caller, unsigned taint, if (regs) show_regs(regs); - if (panic_on_warn) { - /* - * This thread may hit another WARN() in the panic path. - * Resetting this prevents additional WARN() from panicking the - * system on this thread. Other threads are blocked by the - * panic_mutex in panic(). - */ - panic_on_warn = 0; + if (panic_on_warn) panic("panic_on_warn set ...\n"); - } if (!regs) dump_stack();