From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH V7 04/10] arm64: exception: handle Synchronous External Abort Date: Mon, 16 Jan 2017 11:53:10 +0000 Message-ID: <20170116115309.GE1510@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 Return-path: Received: from foss.arm.com ([217.140.101.70]:51112 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750907AbdAPLxM (ORCPT ); Mon, 16 Jan 2017 06:53:12 -0500 Content-Disposition: inline In-Reply-To: <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org 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, 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, james.morse@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, S On Thu, Jan 12, 2017 at 11:15:18AM -0700, 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. > > Signed-off-by: Tyler Baicar > Signed-off-by: Jonathan (Zhixiong) Zhang > Signed-off-by: Naveen Kaje > --- > arch/arm64/include/asm/system_misc.h | 13 ++++++++ > arch/arm64/mm/fault.c | 58 +++++++++++++++++++++++++++++------- > 2 files changed, 61 insertions(+), 10 deletions(-) > > diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h > index 57f110b..e7f3440 100644 > --- a/arch/arm64/include/asm/system_misc.h > +++ b/arch/arm64/include/asm/system_misc.h > @@ -64,4 +64,17 @@ extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); > > #endif /* __ASSEMBLY__ */ > > +/* > + * The functions below are used to register and unregister callbacks > + * that are to be invoked when a Synchronous External Abort (SEA) > + * occurs. An SEA is raised by certain fault status codes that have > + * either data or instruction abort as the exception class, and > + * callbacks may be registered to parse or handle such hardware errors. > + * > + * Registered callbacks are run in an interrupt/atomic context. They > + * are not allowed to block or sleep. > + */ > +int register_sea_notifier(struct notifier_block *nb); > +void unregister_sea_notifier(struct notifier_block *nb); I still don't understand why you need notifiers for this. You register precisely one hook in the series. > #endif /* __ASM_SYSTEM_MISC_H */ > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 05d2bd7..81039c7 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -39,6 +39,22 @@ > #include > #include > > +/* > + * GHES SEA handler code may register a notifier call here to > + * handle HW error record passed from platform. > + */ > +static ATOMIC_NOTIFIER_HEAD(sea_handler_chain); > + > +int register_sea_notifier(struct notifier_block *nb) > +{ > + return atomic_notifier_chain_register(&sea_handler_chain, nb); > +} > + > +void unregister_sea_notifier(struct notifier_block *nb) > +{ > + atomic_notifier_chain_unregister(&sea_handler_chain, nb); > +} > + > static const char *fault_name(unsigned int esr); > > #ifdef CONFIG_KPROBES > @@ -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; > + info.si_addr = (void __user *)addr; > + 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; > @@ -502,22 +540,22 @@ static const struct fault_info { > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, > - { do_bad, SIGBUS, 0, "synchronous external abort" }, > + { do_sea, SIGBUS, 0, "synchronous external abort" }, > { do_bad, SIGBUS, 0, "unknown 17" }, > { do_bad, SIGBUS, 0, "unknown 18" }, > { do_bad, SIGBUS, 0, "unknown 19" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous parity error" }, > + { do_sea, SIGBUS, 0, "level 0 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 1 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 2 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 3 SEA (translation table walk)" }, Perhaps I wasn't clear enough in my previous review, but please expand the acronym for strings and comments. > + { do_sea, SIGBUS, 0, "synchronous parity or ECC err" }, s/err/error/ Will From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751095AbdAPLxO (ORCPT ); Mon, 16 Jan 2017 06:53:14 -0500 Received: from foss.arm.com ([217.140.101.70]:51112 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750907AbdAPLxM (ORCPT ); Mon, 16 Jan 2017 06:53:12 -0500 Date: Mon, 16 Jan 2017 11:53:10 +0000 From: Will Deacon 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, 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, james.morse@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 Message-ID: <20170116115309.GE1510@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-Disposition: inline In-Reply-To: <1484244924-24786-5-git-send-email-tbaicar@codeaurora.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 12, 2017 at 11:15:18AM -0700, 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. > > Signed-off-by: Tyler Baicar > Signed-off-by: Jonathan (Zhixiong) Zhang > Signed-off-by: Naveen Kaje > --- > arch/arm64/include/asm/system_misc.h | 13 ++++++++ > arch/arm64/mm/fault.c | 58 +++++++++++++++++++++++++++++------- > 2 files changed, 61 insertions(+), 10 deletions(-) > > diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h > index 57f110b..e7f3440 100644 > --- a/arch/arm64/include/asm/system_misc.h > +++ b/arch/arm64/include/asm/system_misc.h > @@ -64,4 +64,17 @@ extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); > > #endif /* __ASSEMBLY__ */ > > +/* > + * The functions below are used to register and unregister callbacks > + * that are to be invoked when a Synchronous External Abort (SEA) > + * occurs. An SEA is raised by certain fault status codes that have > + * either data or instruction abort as the exception class, and > + * callbacks may be registered to parse or handle such hardware errors. > + * > + * Registered callbacks are run in an interrupt/atomic context. They > + * are not allowed to block or sleep. > + */ > +int register_sea_notifier(struct notifier_block *nb); > +void unregister_sea_notifier(struct notifier_block *nb); I still don't understand why you need notifiers for this. You register precisely one hook in the series. > #endif /* __ASM_SYSTEM_MISC_H */ > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 05d2bd7..81039c7 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -39,6 +39,22 @@ > #include > #include > > +/* > + * GHES SEA handler code may register a notifier call here to > + * handle HW error record passed from platform. > + */ > +static ATOMIC_NOTIFIER_HEAD(sea_handler_chain); > + > +int register_sea_notifier(struct notifier_block *nb) > +{ > + return atomic_notifier_chain_register(&sea_handler_chain, nb); > +} > + > +void unregister_sea_notifier(struct notifier_block *nb) > +{ > + atomic_notifier_chain_unregister(&sea_handler_chain, nb); > +} > + > static const char *fault_name(unsigned int esr); > > #ifdef CONFIG_KPROBES > @@ -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; > + info.si_addr = (void __user *)addr; > + 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; > @@ -502,22 +540,22 @@ static const struct fault_info { > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, > - { do_bad, SIGBUS, 0, "synchronous external abort" }, > + { do_sea, SIGBUS, 0, "synchronous external abort" }, > { do_bad, SIGBUS, 0, "unknown 17" }, > { do_bad, SIGBUS, 0, "unknown 18" }, > { do_bad, SIGBUS, 0, "unknown 19" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous parity error" }, > + { do_sea, SIGBUS, 0, "level 0 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 1 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 2 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 3 SEA (translation table walk)" }, Perhaps I wasn't clear enough in my previous review, but please expand the acronym for strings and comments. > + { do_sea, SIGBUS, 0, "synchronous parity or ECC err" }, s/err/error/ Will From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Mon, 16 Jan 2017 11:53:10 +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: <20170116115309.GE1510@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jan 12, 2017 at 11:15:18AM -0700, 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. > > Signed-off-by: Tyler Baicar > Signed-off-by: Jonathan (Zhixiong) Zhang > Signed-off-by: Naveen Kaje > --- > arch/arm64/include/asm/system_misc.h | 13 ++++++++ > arch/arm64/mm/fault.c | 58 +++++++++++++++++++++++++++++------- > 2 files changed, 61 insertions(+), 10 deletions(-) > > diff --git a/arch/arm64/include/asm/system_misc.h b/arch/arm64/include/asm/system_misc.h > index 57f110b..e7f3440 100644 > --- a/arch/arm64/include/asm/system_misc.h > +++ b/arch/arm64/include/asm/system_misc.h > @@ -64,4 +64,17 @@ extern void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); > > #endif /* __ASSEMBLY__ */ > > +/* > + * The functions below are used to register and unregister callbacks > + * that are to be invoked when a Synchronous External Abort (SEA) > + * occurs. An SEA is raised by certain fault status codes that have > + * either data or instruction abort as the exception class, and > + * callbacks may be registered to parse or handle such hardware errors. > + * > + * Registered callbacks are run in an interrupt/atomic context. They > + * are not allowed to block or sleep. > + */ > +int register_sea_notifier(struct notifier_block *nb); > +void unregister_sea_notifier(struct notifier_block *nb); I still don't understand why you need notifiers for this. You register precisely one hook in the series. > #endif /* __ASM_SYSTEM_MISC_H */ > diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c > index 05d2bd7..81039c7 100644 > --- a/arch/arm64/mm/fault.c > +++ b/arch/arm64/mm/fault.c > @@ -39,6 +39,22 @@ > #include > #include > > +/* > + * GHES SEA handler code may register a notifier call here to > + * handle HW error record passed from platform. > + */ > +static ATOMIC_NOTIFIER_HEAD(sea_handler_chain); > + > +int register_sea_notifier(struct notifier_block *nb) > +{ > + return atomic_notifier_chain_register(&sea_handler_chain, nb); > +} > + > +void unregister_sea_notifier(struct notifier_block *nb) > +{ > + atomic_notifier_chain_unregister(&sea_handler_chain, nb); > +} > + > static const char *fault_name(unsigned int esr); > > #ifdef CONFIG_KPROBES > @@ -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; > + info.si_addr = (void __user *)addr; > + 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; > @@ -502,22 +540,22 @@ static const struct fault_info { > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 1 permission fault" }, > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 2 permission fault" }, > { do_page_fault, SIGSEGV, SEGV_ACCERR, "level 3 permission fault" }, > - { do_bad, SIGBUS, 0, "synchronous external abort" }, > + { do_sea, SIGBUS, 0, "synchronous external abort" }, > { do_bad, SIGBUS, 0, "unknown 17" }, > { do_bad, SIGBUS, 0, "unknown 18" }, > { do_bad, SIGBUS, 0, "unknown 19" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous abort (translation table walk)" }, > - { do_bad, SIGBUS, 0, "synchronous parity error" }, > + { do_sea, SIGBUS, 0, "level 0 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 1 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 2 SEA (translation table walk)" }, > + { do_sea, SIGBUS, 0, "level 3 SEA (translation table walk)" }, Perhaps I wasn't clear enough in my previous review, but please expand the acronym for strings and comments. > + { do_sea, SIGBUS, 0, "synchronous parity or ECC err" }, s/err/error/ Will