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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 69214C49361 for ; Thu, 17 Jun 2021 11:46:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 406546140C for ; Thu, 17 Jun 2021 11:46:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232572AbhFQLsc (ORCPT ); Thu, 17 Jun 2021 07:48:32 -0400 Received: from foss.arm.com ([217.140.110.172]:52404 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232243AbhFQLsb (ORCPT ); Thu, 17 Jun 2021 07:48:31 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DE1EB11FB; Thu, 17 Jun 2021 04:46:23 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E0EC93F719; Thu, 17 Jun 2021 04:46:21 -0700 (PDT) Date: Thu, 17 Jun 2021 12:46:18 +0100 From: Mark Rutland To: Mikko Perttunen Cc: catalin.marinas@arm.com, will@kernel.org, thierry.reding@gmail.com, jonathanh@nvidia.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org Subject: Re: [PATCH 1/2] arm64: traps: Support for registering SError hooks Message-ID: <20210617114618.GC82133@C02TD0UTHF1T.local> References: <20210617104053.765434-1-mperttunen@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210617104053.765434-1-mperttunen@nvidia.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 17, 2021 at 01:40:52PM +0300, Mikko Perttunen wrote: > Add the ability for drivers to register SError hooks to be run > on a fatal SError interrupt. This allows printing of system-specific > error information to aid with debugging. > > Signed-off-by: Mikko Perttunen Can't you dump information unconditionally in a panic notifier? That wouldn't require any new infrastructure. Thanks, Mark. > --- > arch/arm64/include/asm/traps.h | 6 ++++++ > arch/arm64/kernel/traps.c | 20 ++++++++++++++++++++ > 2 files changed, 26 insertions(+) > > diff --git a/arch/arm64/include/asm/traps.h b/arch/arm64/include/asm/traps.h > index 54f32a0675df..054fecfa22f0 100644 > --- a/arch/arm64/include/asm/traps.h > +++ b/arch/arm64/include/asm/traps.h > @@ -22,8 +22,14 @@ struct undef_hook { > int (*fn)(struct pt_regs *regs, u32 instr); > }; > > +struct serror_hook { > + struct list_head node; > + void (*fn)(void); > +}; > + > void register_undef_hook(struct undef_hook *hook); > void unregister_undef_hook(struct undef_hook *hook); > +void register_serror_hook(struct serror_hook *hook); > void force_signal_inject(int signal, int code, unsigned long address, unsigned int err); > void arm64_notify_segfault(unsigned long addr); > void arm64_force_sig_fault(int signo, int code, unsigned long far, const char *str); > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index 273066279bb5..02dbaab71ea3 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -890,8 +890,23 @@ void panic_bad_stack(struct pt_regs *regs, unsigned int esr, unsigned long far) > } > #endif > > +static LIST_HEAD(serror_hook); > +static DEFINE_RAW_SPINLOCK(serror_lock); > + > +void register_serror_hook(struct serror_hook *hook) > +{ > + unsigned long flags; > + > + raw_spin_lock_irqsave(&serror_lock, flags); > + list_add(&hook->node, &serror_hook); > + raw_spin_unlock_irqrestore(&serror_lock, flags); > +} > + > void __noreturn arm64_serror_panic(struct pt_regs *regs, u32 esr) > { > + struct serror_hook *hook; > + unsigned long flags; > + > console_verbose(); > > pr_crit("SError Interrupt on CPU%d, code 0x%08x -- %s\n", > @@ -899,6 +914,11 @@ void __noreturn arm64_serror_panic(struct pt_regs *regs, u32 esr) > if (regs) > __show_regs(regs); > > + raw_spin_lock_irqsave(&serror_lock, flags); > + list_for_each_entry(hook, &serror_hook, node) > + hook->fn(); > + raw_spin_unlock_irqrestore(&serror_lock, flags); > + > nmi_panic(regs, "Asynchronous SError Interrupt"); > > cpu_park_loop(); > -- > 2.30.1 >