lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 16 Jan 2017 13:09:22 -0700 From: "Baicar, Tyler" <tbaicar@...eaurora.org> To: Will Deacon <will.deacon@....com> Cc: christoffer.dall@...aro.org, marc.zyngier@....com, pbonzini@...hat.com, rkrcmar@...hat.com, linux@...linux.org.uk, catalin.marinas@....com, rjw@...ysocki.net, lenb@...nel.org, matt@...eblueprint.co.uk, robert.moore@...el.com, lv.zheng@...el.com, nkaje@...eaurora.org, zjzhang@...eaurora.org, mark.rutland@....com, james.morse@....com, akpm@...ux-foundation.org, eun.taik.lee@...sung.com, sandeepa.s.prabhu@...il.com, labbott@...hat.com, shijie.huang@....com, rruigrok@...eaurora.org, paul.gortmaker@...driver.com, tn@...ihalf.com, fu.wei@...aro.org, rostedt@...dmis.org, bristot@...hat.com, linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.cs.columbia.edu, kvm@...r.kernel.org, linux-kernel@...r.kernel.org, linux-acpi@...r.kernel.org, linux-efi@...r.kernel.org, devel@...ica.org, Suzuki.Poulose@....com, punit.agrawal@....com, astone@...hat.com, harba@...eaurora.org, hanjun.guo@...aro.org, john.garry@...wei.com, shiju.jose@...wei.com Subject: Re: [PATCH V7 04/10] arm64: exception: handle Synchronous External Abort Hello Will, On 1/16/2017 4:53 AM, Will Deacon wrote: > 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 <tbaicar@...eaurora.org> >> Signed-off-by: Jonathan (Zhixiong) Zhang <zjzhang@...eaurora.org> >> Signed-off-by: Naveen Kaje <nkaje@...eaurora.org> >> --- >> 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. I didn't see a response to my last comment on the previous series so I just left it in for this series. The notifier usage is consistent with the GHES code for SCI errors which are also only used a single time in the code. If you think making the call directly is a better option I will remove the notifiers. >> #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 <asm/pgtable.h> >> #include <asm/tlbflush.h> >> >> +/* >> + * 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. Sorry, I will expand these. >> + { do_sea, SIGBUS, 0, "synchronous parity or ECC err" }, > s/err/error/ > > Will Thanks, Tyler -- Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
Powered by blists - more mailing lists