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=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,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 7910EC2D0A3 for ; Thu, 29 Oct 2020 14:58:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0FFFD206E9 for ; Thu, 29 Oct 2020 14:58:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="kj3iNPCN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727988AbgJ2O6z (ORCPT ); Thu, 29 Oct 2020 10:58:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41512 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727839AbgJ2O6y (ORCPT ); Thu, 29 Oct 2020 10:58:54 -0400 Received: from mail-pf1-x443.google.com (mail-pf1-x443.google.com [IPv6:2607:f8b0:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC078C0613CF for ; Thu, 29 Oct 2020 07:58:54 -0700 (PDT) Received: by mail-pf1-x443.google.com with SMTP id j18so2559638pfa.0 for ; Thu, 29 Oct 2020 07:58:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=63fCD7b9c39BMwHAue5Fl+YEtHFG3eKfVilw8x2/rAA=; b=kj3iNPCNr2+M9wcLse6ZQ21oBMHYl72Qc/zJOgpvoUZZqUK4+1MCHZUsaeGS6ui0Cw NKMYgFNZDZEEj26ihm97tZCqaNTMiwt8L2gI8RVYyN+frDClvcpXVMJFqKb05BxLkC7G pA0NV8O4+fz/AgT5Lsyvp1Hiy6smYo9cDdacpYTYMV336wKhX1U6gCN05GCtvtBbrP3+ +32FuTSbVwYNzjs7SVRxQFtex1r2DZw/dc7+kq04dEPh84eVNDJmESv2i2upZTMFosJ/ ALonraRZR/qVAXbwtRieM5V+r2Zwg6rgyGAGcYRou7223Z1UXYNR9wAKUSLXL6Mjz2if g6MA== 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:in-reply-to :references; bh=63fCD7b9c39BMwHAue5Fl+YEtHFG3eKfVilw8x2/rAA=; b=mtTmSz1Chj102psRM+9qXbiPbpY+wXfexkQfRwwv1pwaIimlbXg+n91I25S1uHTF11 +xBFVIC6/EBZm191+BGOEOwaXnaFWWM0RNosYTtZ3HtTp3cKyxmg142Lt1vAx7csS61s 0zkVLz2pDrr/XgKcO8FPpoq45aBPNepYY0OnAKwh1Dbb5WGttIE27FLgslERYXwHC3e6 l5dUs81QLszuDAqxNgXDjklrVxPsPaQo1EKaODI+enoy71hI8riUqiSK7M65ZeSRrTg3 ObCCY/rmjkdqgRsl0cRT6RDn1BklVoKHC1rOHdw8L/Q5ekMia/NyTevkTwiuwwQnBfnX vEWA== X-Gm-Message-State: AOAM532U9dt9pF6FZSxwVnQsB9vS/DtgYujQURUXKybx8vMamNtUAYpM tpTvgS1HjZ+BpamyduPm0OlvbQ== X-Google-Smtp-Source: ABdhPJw17SGDkWifbE7fvN8UeDKNxr6nOnVarhxUncUj/mUYxJzpJE6WxXsesAZ4m34FfWUD2Yt8kQ== X-Received: by 2002:a17:90a:b30b:: with SMTP id d11mr152257pjr.163.1603983534301; Thu, 29 Oct 2020 07:58:54 -0700 (PDT) Received: from localhost.localdomain ([117.252.71.231]) by smtp.gmail.com with ESMTPSA id j11sm3085082pfc.64.2020.10.29.07.58.44 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 29 Oct 2020 07:58:53 -0700 (PDT) From: Sumit Garg To: maz@kernel.org, catalin.marinas@arm.com, will@kernel.org Cc: linux-arm-kernel@lists.infradead.org, tglx@linutronix.de, jason@lakedaemon.net, linux@armlinux.org.uk, tsbogend@alpha.franken.de, mpe@ellerman.id.au, davem@davemloft.net, mingo@redhat.com, bp@alien8.de, x86@kernel.org, mark.rutland@arm.com, julien.thierry.kdev@gmail.com, dianders@chromium.org, daniel.thompson@linaro.org, jason.wessel@windriver.com, msys.mizuma@gmail.com, ito-yuichi@fujitsu.com, kgdb-bugreport@lists.sourceforge.net, linux-kernel@vger.kernel.org, Sumit Garg Subject: [PATCH v6 5/7] arm64: ipi_nmi: Add support for NMI backtrace Date: Thu, 29 Oct 2020 20:26:25 +0530 Message-Id: <1603983387-8738-6-git-send-email-sumit.garg@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1603983387-8738-1-git-send-email-sumit.garg@linaro.org> References: <1603983387-8738-1-git-send-email-sumit.garg@linaro.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Enable NMI backtrace support on arm64 using IPI turned as an NMI leveraging pseudo NMIs support. It is now possible for users to get a backtrace of a CPU stuck in hard-lockup using magic SYSRQ. Signed-off-by: Sumit Garg --- arch/arm64/include/asm/irq.h | 6 ++++++ arch/arm64/kernel/ipi_nmi.c | 18 ++++++++++++++++-- 2 files changed, 22 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h index b2b0c64..ef018a8 100644 --- a/arch/arm64/include/asm/irq.h +++ b/arch/arm64/include/asm/irq.h @@ -6,6 +6,12 @@ #include +#ifdef CONFIG_SMP +extern bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, + bool exclude_self); +#define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace +#endif + struct pt_regs; static inline int nr_legacy_irqs(void) diff --git a/arch/arm64/kernel/ipi_nmi.c b/arch/arm64/kernel/ipi_nmi.c index a945dcf..597dcf7 100644 --- a/arch/arm64/kernel/ipi_nmi.c +++ b/arch/arm64/kernel/ipi_nmi.c @@ -8,6 +8,7 @@ #include #include +#include #include #include @@ -31,11 +32,24 @@ void arm64_send_nmi(cpumask_t *mask) __ipi_send_mask(ipi_nmi_desc, mask); } +bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) +{ + if (!ipi_nmi_desc) + return false; + + nmi_trigger_cpumask_backtrace(mask, exclude_self, arm64_send_nmi); + + return true; +} + static irqreturn_t ipi_nmi_handler(int irq, void *data) { - /* nop, NMI handlers for special features can be added here. */ + irqreturn_t ret = IRQ_NONE; + + if (nmi_cpu_backtrace(get_irq_regs())) + ret = IRQ_HANDLED; - return IRQ_NONE; + return ret; } void dynamic_ipi_setup(int cpu) -- 2.7.4