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 A9B88C433DB for ; Fri, 22 Jan 2021 09:46:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59D2520E65 for ; Fri, 22 Jan 2021 09:46:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727658AbhAVJqb (ORCPT ); Fri, 22 Jan 2021 04:46:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46068 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727336AbhAVJje (ORCPT ); Fri, 22 Jan 2021 04:39:34 -0500 Received: from mail-pg1-x52c.google.com (mail-pg1-x52c.google.com [IPv6:2607:f8b0:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9349C06174A for ; Fri, 22 Jan 2021 01:38:53 -0800 (PST) Received: by mail-pg1-x52c.google.com with SMTP id c132so3353519pga.3 for ; Fri, 22 Jan 2021 01:38:53 -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=5XkfPIeaOJLsy0Tv+oZGNxT8cNyK2rUePBRvJsE8fKA=; b=hh6PmUhwxLRoyQ/oYOx+tc2FT99ESSRDcHrUQuCUnmt1POfYLRkHJzzroCEVrCArrH Ogk0tzqX+rO/FTJA86Lx9TT5HAM+RBM3Th9/Wk4W9cjBhTNNAkkt8oOJdUghNuNSIl7F 3GWARhehbMK/YFBoecnfuxZIZCwGm9SNDuLNxW2Uy1tP+GuN4xe5/e2xcoN4KH5qaAJQ Mgy3eknMBe5cYRzlPkw4/FvlgXWHNuT8Sf1RBkoBQ3KFHchAqLYYnYxVEDGRPC3gJ0xa 0nTukggDzea0NV8Jpiuatf9HaEzcf4hPgqPBzN5mhr8MXkM9c+53Nk0SfdjjMhgNI5mi s0YA== 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=5XkfPIeaOJLsy0Tv+oZGNxT8cNyK2rUePBRvJsE8fKA=; b=M4hi2Z8tfP9uGnsL5ZaAXKaKTy4Ggz5Umafv5/KDu4cN61rzAT76DY8+vAb7XOzfMj sSopRcousKx9RiPc65SA1pQWAg8F91/GNxf9szJI+t0KoheoSyfp7adxp++lAlK3aYUG xf8ilz3cN/YNQP+uUjBgsgFWF0CoMFU1MLJZsFgyV+93T+XXe8FFjXJEmwGyY+ols/Pr t9eCQeMlbdZGAaDtuRQxSMV7vmKcWtEm2o282WZs9mtr3abH8RGBWsbN1xcmEYTu1mAI 87tQZXTCQk6UT69o7KYDew6BIIfch63HUmeY9Mkk8B9Fn2WmgOrNXJWy40qLvWSSBCOV cL7Q== X-Gm-Message-State: AOAM532xIE79e+AjDuQ+fiAxIR6xDCmWBUkQV1xaB0Zm88+biTXYCgdx FFQSd0D48XIs9thQYaxJJ+J0USa1XFAEqw== X-Google-Smtp-Source: ABdhPJzvUWzsIHNQPvEPrBlano9vEd2rYgUsgOyBcrkbE0eYZBzSqTClmrX9Cd7jS7BLSBuAklpNrw== X-Received: by 2002:a62:5b07:0:b029:1ae:177d:69e1 with SMTP id p7-20020a625b070000b02901ae177d69e1mr3853738pfb.25.1611308333324; Fri, 22 Jan 2021 01:38:53 -0800 (PST) Received: from localhost.localdomain ([122.173.53.31]) by smtp.gmail.com with ESMTPSA id y26sm8543616pgk.42.2021.01.22.01.38.49 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 22 Jan 2021 01:38:52 -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] kdb: Make memory allocations more robust Date: Fri, 22 Jan 2021 15:08:31 +0530 Message-Id: <1611308311-2530-1-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() which explicitly determines if we are running in debugger context. Also, use in_atomic() instead of in_interrupt() as the former is more appropriate to know atomic context and moreover the later one is deprecated. [1] $ echo g > /proc/sysrq-trigger Signed-off-by: Sumit Garg --- 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..7a9ebd9 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_atomic() || 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