Messages in this thread | | | Subject | Re: [PATCH V7 04/10] arm64: exception: handle Synchronous External Abort | From | "Baicar, Tyler" <> | Date | Wed, 18 Jan 2017 15:52:03 -0700 |
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On 1/17/2017 3:23 AM, James Morse wrote: > Hi Tyler, > > On 16/01/17 11:53, 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. >>> 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 >>> @@ -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. > > The 'SEA' in this user-string doesn't add anything. Now that these use do_sea() > instead of do_bad(), when they are printed won't it be: >> Synchronous External Abort: level 3 SEA (translation table walk) (...) at ....
Good point, yes they will:
+ pr_err("Synchronous External Abort: %s (0x%08x) at 0x%016lx\n", + fault_name(esr), esr, addr);
I can just remove SEA here then.
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.
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