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Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOJI6-0004FE-CS; Tue, 14 Apr 2020 10:59:42 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jOJI3-0004Ee-0e for linux-arm-kernel@lists.infradead.org; Tue, 14 Apr 2020 10:59:40 +0000 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 71FBB1FB; Tue, 14 Apr 2020 03:59:38 -0700 (PDT) Received: from C02TD0UTHF1T.local (unknown [10.57.30.4]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 413B03F6C4; Tue, 14 Apr 2020 03:59:36 -0700 (PDT) Date: Tue, 14 Apr 2020 11:59:23 +0100 From: Mark Rutland To: Xie XiuQi Subject: Re: [PATCH] arm64: panic on synchronous external abort in kernel context Message-ID: <20200414105923.GA2486@C02TD0UTHF1T.local> References: <20200410015245.23230-1-xiexiuqi@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200410015245.23230-1-xiexiuqi@huawei.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200414_035939_100145_1F26B8AB X-CRM114-Status: GOOD ( 15.79 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: catalin.marinas@arm.com, linux-kernel@vger.kernel.org, tanxiaofei@huawei.com, james.morse@arm.com, tglx@linutronix.de, will@kernel.org, wangxiongfeng2@huawei.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Apr 10, 2020 at 09:52:45AM +0800, Xie XiuQi wrote: > We should panic even panic_on_oops is not set, when we can't recover > from synchronous external abort in kernel context. > > Othervise, there are two issues: > 1) fallback to do_exit() in exception context, cause this core hung up. > do_sea() > -> arm64_notify_die > -> die > -> do_exit > 2) errors may propagated. > > Signed-off-by: Xie XiuQi > Cc: Xiaofei Tan > --- > arch/arm64/include/asm/esr.h | 12 ++++++++++++ > arch/arm64/kernel/traps.c | 2 ++ > 2 files changed, 14 insertions(+) > > diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h > index cb29253ae86b..acfc71c6d148 100644 > --- a/arch/arm64/include/asm/esr.h > +++ b/arch/arm64/include/asm/esr.h > @@ -326,6 +326,18 @@ static inline bool esr_is_data_abort(u32 esr) > return ec == ESR_ELx_EC_DABT_LOW || ec == ESR_ELx_EC_DABT_CUR; > } > > +static inline bool esr_is_inst_abort(u32 esr) > +{ > + const u32 ec = ESR_ELx_EC(esr); > + > + return ec == ESR_ELx_EC_IABT_LOW || ec == ESR_ELx_EC_IABT_CUR; > +} > + > +static inline bool esr_is_ext_abort(u32 esr) > +{ > + return esr_is_data_abort(esr) || esr_is_inst_abort(esr); > +} A data abort or an intstruction abort are not necessarily synchronus external aborts, so this isn't right. What exactly are you trying to catch here? If you are seeing a problem in practice, can you please share your log from a crash? Thanks, Mark. > + > const char *esr_get_class_string(u32 esr); > #endif /* __ASSEMBLY */ > > diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c > index cf402be5c573..08f7f7688d5b 100644 > --- a/arch/arm64/kernel/traps.c > +++ b/arch/arm64/kernel/traps.c > @@ -202,6 +202,8 @@ void die(const char *str, struct pt_regs *regs, int err) > panic("Fatal exception in interrupt"); > if (panic_on_oops) > panic("Fatal exception"); > + if (esr_is_ext_abort(err)) > + panic("Synchronous external abort in kernel context"); > > raw_spin_unlock_irqrestore(&die_lock, flags); > > -- > 2.20.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel