From mboxrd@z Thu Jan 1 00:00:00 1970 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 6B236C433FE for ; Fri, 28 Jan 2022 11:42:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244242AbiA1Lmn (ORCPT ); Fri, 28 Jan 2022 06:42:43 -0500 Received: from mail.loongson.cn ([114.242.206.163]:40652 "EHLO loongson.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S236347AbiA1Lml (ORCPT ); Fri, 28 Jan 2022 06:42:41 -0500 Received: from linux.localdomain (unknown [113.200.148.30]) by mail.loongson.cn (Coremail) with SMTP id AQAAf9Dxb+Kh1vNhREgFAA--.17556S7; Fri, 28 Jan 2022 19:42:28 +0800 (CST) From: Tiezhu Yang To: Baoquan He , Jonathan Corbet , Andrew Morton , Peter Zijlstra , Marco Elver Cc: kexec@lists.infradead.org, linux-doc@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 5/5] kfence: unset panic_on_warn before calling panic() Date: Fri, 28 Jan 2022 19:42:25 +0800 Message-Id: <1643370145-26831-6-git-send-email-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1643370145-26831-1-git-send-email-yangtiezhu@loongson.cn> References: <1643370145-26831-1-git-send-email-yangtiezhu@loongson.cn> X-CM-TRANSID: AQAAf9Dxb+Kh1vNhREgFAA--.17556S7 X-Coremail-Antispam: 1UD129KBjvdXoW7Xw4kJF18Xr45GF1UXr1DZFb_yoWDGrX_C3 40gw1kKw4kJa90ya1UKwn8Xr9rK3y2vr409Fs7WrZ0k34UGryjqF4rXF1kJ3yFgF4UCrW3 tr1qqFyIkw4UCjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUIcSsGvfJTRUUUbgkYjsxI4VWkCwAYFVCjjxCrM7AC8VAFwI0_Wr0E3s1l1xkIjI8I 6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AEw4v_Jr0_Jr4l82xGYIkIc2x26280x7 IE14v26r126s0DM28IrcIa0xkI8VCY1x0267AKxVW5JVCq3wA2ocxC64kIII0Yj41l84x0 c7CEw4AK67xGY2AK021l84ACjcxK6xIIjxv20xvE14v26r4j6ryUM28EF7xvwVC0I7IYx2 IY6xkF7I0E14v26F4j6r4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280 aVCY1x0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzV Aqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S 6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7Mx kIecxEwVAFwVW8KwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s02 6c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw 0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUCVW8JwCI42IY6xIIjxv20xvE c7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67 AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuY vjxUxVyxDUUUU X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As done in the full WARN() handler, panic_on_warn needs to be cleared before calling panic() to avoid recursive panics. Signed-off-by: Tiezhu Yang --- mm/kfence/report.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/mm/kfence/report.c b/mm/kfence/report.c index f93a7b2..9d61a23 100644 --- a/mm/kfence/report.c +++ b/mm/kfence/report.c @@ -267,8 +267,16 @@ void kfence_report_error(unsigned long address, bool is_write, struct pt_regs *r lockdep_on(); - if (panic_on_warn) + 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; panic("panic_on_warn set ...\n"); + } /* We encountered a memory safety error, taint the kernel! */ add_taint(TAINT_BAD_PAGE, LOCKDEP_STILL_OK); -- 2.1.0