From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Morse Subject: Re: [PATCH V7 04/10] arm64: exception: handle Synchronous External Abort Date: Tue, 17 Jan 2017 10:31:21 +0000 Message-ID: <587DF279.1010402@arm.com> References: <1484244924-24786-1-git-send-email-tbaicar@codeaurora.org> <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Tyler Baicar Cc: linux-efi@vger.kernel.org, kvm@vger.kernel.org, matt@codeblueprint.co.uk, catalin.marinas@arm.com, will.deacon@arm.com, robert.moore@intel.com, paul.gortmaker@windriver.com, lv.zheng@intel.com, kvmarm@lists.cs.columbia.edu, fu.wei@linaro.org, zjzhang@codeaurora.org, linux@armlinux.org.uk, linux-acpi@vger.kernel.org, eun.taik.lee@samsung.com, shijie.huang@arm.com, labbott@redhat.com, lenb@kernel.org, harba@codeaurora.org, john.garry@huawei.com, marc.zyngier@arm.com, punit.agrawal@arm.com, rostedt@goodmis.org, nkaje@codeaurora.org, sandeepa.s.prabhu@gmail.com, linux-arm-kernel@lists.infradead.org, devel@acpica.org, rjw@rjwysocki.net, rruigrok@codeaurora.org, linux-kernel@vger.kernel.org, astone@redhat.com, hanjun.guo@linaro.org, pbonzini@redhat.com, akpm@linux-foundation.org, bristot@redhat.com, shiju.jose@huawei.com List-Id: linux-acpi@vger.kernel.org Hi Tyler, On 12/01/17 18:15, Tyler Baicar wrote: > SEA exceptions are often caused by an uncorrected hardware > error, and are handled when data abort and instruction abort > exception classes have specific values for their Fault Status > Code. > When SEA occurs, before killing the process, go through > the handlers registered in the notification list. > Update fault_info[] with specific SEA faults so that the > new SEA handler is used. > @@ -480,6 +496,28 @@ static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) > return 1; > } > > +/* > + * This abort handler deals with Synchronous External Abort. > + * It calls notifiers, and then returns "fault". > + */ > +static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) > +{ > + struct siginfo info; > + > + atomic_notifier_call_chain(&sea_handler_chain, 0, NULL); > + > + pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n", > + fault_name(esr), esr, addr); > + > + info.si_signo = SIGBUS; > + info.si_errno = 0; > + info.si_code = 0; Half of the other do_*() functions in this file read the signo and code from the fault_info table. > + info.si_addr = (void __user *)addr; addr here was read from FAR_EL1, but for some of the classes of exception you have listed below this register isn't updated with the faulting address. The ARM-ARM version 'k' in D1.10.5 "Summary of registers on faults taken to an Exception level that is using Aarch64" has: > The architecture permits that the FAR_ELx is UNKNOWN for Synchronous External > Aborts other than Synchronous External Aborts on Translation Table Walks. In > this case, the ISS.FnV bit returned in ESR_ELx indicates whether FAR_ELx is > valid. This is a problem if we get 'synchronous external abort' or 'synchronous parity error' while a user space process was running. > + arm64_notify_die("", regs, &info, esr); > + > + return 0; > +} > + > static const struct fault_info { > int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); > int sig; Thanks, James From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751538AbdAQKeh (ORCPT ); Tue, 17 Jan 2017 05:34:37 -0500 Received: from foss.arm.com ([217.140.101.70]:46660 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751213AbdAQKde (ORCPT ); Tue, 17 Jan 2017 05:33:34 -0500 Message-ID: <587DF279.1010402@arm.com> Date: Tue, 17 Jan 2017 10:31:21 +0000 From: James Morse User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.6.0 MIME-Version: 1.0 To: Tyler Baicar CC: christoffer.dall@linaro.org, marc.zyngier@arm.com, pbonzini@redhat.com, rkrcmar@redhat.com, linux@armlinux.org.uk, catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, matt@codeblueprint.co.uk, robert.moore@intel.com, lv.zheng@intel.com, nkaje@codeaurora.org, zjzhang@codeaurora.org, mark.rutland@arm.com, akpm@linux-foundation.org, eun.taik.lee@samsung.com, sandeepa.s.prabhu@gmail.com, labbott@redhat.com, shijie.huang@arm.com, rruigrok@codeaurora.org, paul.gortmaker@windriver.com, tn@semihalf.com, fu.wei@linaro.org, rostedt@goodmis.org, bristot@redhat.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-efi@vger.kernel.org, devel@acpica.org, Suzuki.Poulose@arm.com, punit.agrawal@arm.com, astone@redhat.com, harba@codeaurora.org, hanjun.guo@linaro.org, john.garry@huawei.com, shiju.jose@huawei.com Subject: Re: [PATCH V7 04/10] arm64: exception: handle Synchronous External Abort References: <1484244924-24786-1-git-send-email-tbaicar@codeaurora.org> <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> In-Reply-To: <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tyler, On 12/01/17 18:15, Tyler Baicar wrote: > SEA exceptions are often caused by an uncorrected hardware > error, and are handled when data abort and instruction abort > exception classes have specific values for their Fault Status > Code. > When SEA occurs, before killing the process, go through > the handlers registered in the notification list. > Update fault_info[] with specific SEA faults so that the > new SEA handler is used. > @@ -480,6 +496,28 @@ static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) > return 1; > } > > +/* > + * This abort handler deals with Synchronous External Abort. > + * It calls notifiers, and then returns "fault". > + */ > +static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) > +{ > + struct siginfo info; > + > + atomic_notifier_call_chain(&sea_handler_chain, 0, NULL); > + > + pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n", > + fault_name(esr), esr, addr); > + > + info.si_signo = SIGBUS; > + info.si_errno = 0; > + info.si_code = 0; Half of the other do_*() functions in this file read the signo and code from the fault_info table. > + info.si_addr = (void __user *)addr; addr here was read from FAR_EL1, but for some of the classes of exception you have listed below this register isn't updated with the faulting address. The ARM-ARM version 'k' in D1.10.5 "Summary of registers on faults taken to an Exception level that is using Aarch64" has: > The architecture permits that the FAR_ELx is UNKNOWN for Synchronous External > Aborts other than Synchronous External Aborts on Translation Table Walks. In > this case, the ISS.FnV bit returned in ESR_ELx indicates whether FAR_ELx is > valid. This is a problem if we get 'synchronous external abort' or 'synchronous parity error' while a user space process was running. > + arm64_notify_die("", regs, &info, esr); > + > + return 0; > +} > + > static const struct fault_info { > int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); > int sig; Thanks, James From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Tue, 17 Jan 2017 10:31:21 +0000 Subject: [PATCH V7 04/10] arm64: exception: handle Synchronous External Abort In-Reply-To: <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> References: <1484244924-24786-1-git-send-email-tbaicar@codeaurora.org> <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> Message-ID: <587DF279.1010402@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Tyler, On 12/01/17 18:15, Tyler Baicar wrote: > SEA exceptions are often caused by an uncorrected hardware > error, and are handled when data abort and instruction abort > exception classes have specific values for their Fault Status > Code. > When SEA occurs, before killing the process, go through > the handlers registered in the notification list. > Update fault_info[] with specific SEA faults so that the > new SEA handler is used. > @@ -480,6 +496,28 @@ static int do_bad(unsigned long addr, unsigned int esr, struct pt_regs *regs) > return 1; > } > > +/* > + * This abort handler deals with Synchronous External Abort. > + * It calls notifiers, and then returns "fault". > + */ > +static int do_sea(unsigned long addr, unsigned int esr, struct pt_regs *regs) > +{ > + struct siginfo info; > + > + atomic_notifier_call_chain(&sea_handler_chain, 0, NULL); > + > + pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n", > + fault_name(esr), esr, addr); > + > + info.si_signo = SIGBUS; > + info.si_errno = 0; > + info.si_code = 0; Half of the other do_*() functions in this file read the signo and code from the fault_info table. > + info.si_addr = (void __user *)addr; addr here was read from FAR_EL1, but for some of the classes of exception you have listed below this register isn't updated with the faulting address. The ARM-ARM version 'k' in D1.10.5 "Summary of registers on faults taken to an Exception level that is using Aarch64" has: > The architecture permits that the FAR_ELx is UNKNOWN for Synchronous External > Aborts other than Synchronous External Aborts on Translation Table Walks. In > this case, the ISS.FnV bit returned in ESR_ELx indicates whether FAR_ELx is > valid. This is a problem if we get 'synchronous external abort' or 'synchronous parity error' while a user space process was running. > + arm64_notify_die("", regs, &info, esr); > + > + return 0; > +} > + > static const struct fault_info { > int (*fn)(unsigned long addr, unsigned int esr, struct pt_regs *regs); > int sig; Thanks, James