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 X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1B98C433E9 for ; Mon, 1 Mar 2021 16:48:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DDBA64FA1 for ; Mon, 1 Mar 2021 16:48:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233119AbhCAQra (ORCPT ); Mon, 1 Mar 2021 11:47:30 -0500 Received: from mail.kernel.org ([198.145.29.99]:41536 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234021AbhCAQjC (ORCPT ); Mon, 1 Mar 2021 11:39:02 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0BCA764F87; Mon, 1 Mar 2021 16:28:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614616097; bh=VzcM2zK0CXIH9uHqMj0F35NuxWY5WDsoXlYHg6auVLU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iT1J/IORtXVOAo9Nn0yapmBdtlua8mmOxCbosQmJCD+ouRKctFhx7jAAHEo6yqb+f e6AL4Q9OnXxFspSkcnUaS8q9kJe6oBk0FiedMo8stOxQdUDNva5R8JcUwoILtv+kNs thzyjpkt7PaNIurrqJnmtCmjwcTd6KwZR2wDeR8o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sumit Garg , Daniel Thompson Subject: [PATCH 4.14 009/176] kdb: Make memory allocations more robust Date: Mon, 1 Mar 2021 17:11:22 +0100 Message-Id: <20210301161021.416348129@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161020.931630716@linuxfoundation.org> References: <20210301161020.931630716@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sumit Garg commit 93f7a6d818deef69d0ba652d46bae6fbabbf365c upstream. Currently kdb uses in_interrupt() to determine whether its library code has been called from the kgdb trap handler or from a saner calling context such as driver init. This approach is broken because in_interrupt() alone isn't able to determine kgdb trap handler entry from normal task context. This can happen during normal use of basic features such as breakpoints and can also be trivially reproduced using: echo g > /proc/sysrq-trigger We can improve this by adding check for in_dbg_master() instead which explicitly determines if we are running in debugger context. Cc: stable@vger.kernel.org Signed-off-by: Sumit Garg Link: https://lore.kernel.org/r/1611313556-4004-1-git-send-email-sumit.garg@linaro.org Signed-off-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman --- kernel/debug/kdb/kdb_private.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/debug/kdb/kdb_private.h +++ b/kernel/debug/kdb/kdb_private.h @@ -233,7 +233,7 @@ extern struct task_struct *kdb_curr_task #define kdb_do_each_thread(g, p) do_each_thread(g, p) #define kdb_while_each_thread(g, p) while_each_thread(g, p) -#define GFP_KDB (in_interrupt() ? GFP_ATOMIC : GFP_KERNEL) +#define GFP_KDB (in_dbg_master() ? GFP_ATOMIC : GFP_KERNEL) extern void *debug_kmalloc(size_t size, gfp_t flags); extern void debug_kfree(void *);