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,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 50FFBC433DB for ; Fri, 22 Jan 2021 10:30:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C653239D4 for ; Fri, 22 Jan 2021 10:30:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727863AbhAVK2b (ORCPT ); Fri, 22 Jan 2021 05:28:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727883AbhAVKVt (ORCPT ); Fri, 22 Jan 2021 05:21:49 -0500 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F0D1C0613D6 for ; Fri, 22 Jan 2021 02:21:07 -0800 (PST) Received: by mail-pj1-x1034.google.com with SMTP id g15so3466605pjd.2 for ; Fri, 22 Jan 2021 02:21:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=XoFMW3OnfJNPPFldVSvQQaSFejRFNATBngl33Eh4QXM=; b=ZSWzskGWJQHTWK8xCE0MwgJkMnc94cSw/xSZAitSkx1ocOp67NrLdmveru5Jfn5jJr AFQn+XTyax+ZDbHMFjPyaCHwhO9euQMT8ZoQ2dnOHNu51obRl8NO+pQ+XGYGMOtp1kVW 2/UUEQhJ9nrY0FuV0NDAqXBYBxDkWc/0HFLYHatQD6VnqJKIgpBVV02nsIVPY5I6Fjcl YqEyeZBDTn4B9uftmeR0SNIwjNXlUgZKkJ+9pHP7/Fa4SyDVHXXRuVpCzhx95mAPmAoA zD+qQ/8VdloWls+4lRhfzcxZiX+GuTS4WcV0XAQk+dMGGV3aDupkjx9Qo51hgWkhn0Xr ibJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=XoFMW3OnfJNPPFldVSvQQaSFejRFNATBngl33Eh4QXM=; b=UYgw3hnsORrtKJQ8a+cPGgYwk1PIuxYycZ0Q84QZCdyxf+gdUJHKrV2D8BQTeJG4Vt 1sz7kyBXdsLAZ4th+P9/1Cs2ca5vWXFKQwC0cQS1dll/zoZ7hlR0yByTN2p2scnnPwR3 BwMRQ/dEQZfc2d6xjYft1u8JdiVmDTPKLaTI+398w1OX+X36hbc1MlDnehLJsh9usOPo 5qPXqJHJlb80UmpRXNIGoGCyNOSuCUSk2Qv5oQU2weCN+HcldnuzM0ZvJoEVJcsUPdEb xs+yjmPHqYkKNNDP1lCCA0F9i9zd/bvqU+KZig4CHvz7+AtuzI+xTK3CwwxSFBjuQUDa qJXw== X-Gm-Message-State: AOAM532EXcYxI129+VSPIbAWZ9WZEOl/Bo33NxsDWT5gDvKXFYIWQvO2 2+5APLkL4zk5Zvr2axIcv11UyQ== X-Google-Smtp-Source: ABdhPJzRoAHA3V2OMWAaOdw8coCyBE2IHrTcMy8kprKt4kCmC5DwgsnYIdx2PH4Lqtn4pdxX8zUBjA== X-Received: by 2002:a17:902:bc41:b029:de:1ec2:dac1 with SMTP id t1-20020a170902bc41b02900de1ec2dac1mr4244934plz.9.1611310866648; Fri, 22 Jan 2021 02:21:06 -0800 (PST) Received: from localhost.localdomain ([122.173.53.31]) by smtp.gmail.com with ESMTPSA id ne6sm8487557pjb.44.2021.01.22.02.21.03 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Jan 2021 02:21:05 -0800 (PST) From: Sumit Garg To: kgdb-bugreport@lists.sourceforge.net Cc: jason.wessel@windriver.com, daniel.thompson@linaro.org, dianders@chromium.org, linux-kernel@vger.kernel.org, Sumit Garg Subject: [PATCH v2] kdb: Make memory allocations more robust Date: Fri, 22 Jan 2021 15:50:50 +0530 Message-Id: <1611310850-3339-1-git-send-email-sumit.garg@linaro.org> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Currently kdb uses in_interrupt() to determine whether it's 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 via normal task context such as [1]. We can improve this by adding check for in_dbg_master() instead which explicitly determines if we are running in debugger context. [1] $ echo g > /proc/sysrq-trigger Signed-off-by: Sumit Garg --- Changes in v2: - Get rid of redundant in_atomic() check. kernel/debug/kdb/kdb_private.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/debug/kdb/kdb_private.h b/kernel/debug/kdb/kdb_private.h index 7a4a181..344eb0d 100644 --- a/kernel/debug/kdb/kdb_private.h +++ b/kernel/debug/kdb/kdb_private.h @@ -231,7 +231,7 @@ extern struct task_struct *kdb_curr_task(int); #define kdb_task_has_cpu(p) (task_curr(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 *); -- 2.7.4