From d635711daa98be86d4c7fd01499c34f566b54ccb Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Fri, 10 Jun 2016 05:30:17 -0300 Subject: Linux-libre 4.6.2-gnu --- arch/x86/kernel/cpu/mcheck/mce.c | 85 +++++++++++++++++++++++----------------- 1 file changed, 50 insertions(+), 35 deletions(-) (limited to 'arch/x86/kernel/cpu/mcheck/mce.c') diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index a006f4cd7..f0c921b03 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -961,6 +961,20 @@ static void mce_clear_state(unsigned long *toclear) } } +static int do_memory_failure(struct mce *m) +{ + int flags = MF_ACTION_REQUIRED; + int ret; + + pr_err("Uncorrected hardware memory error in user-access at %llx", m->addr); + if (!(m->mcgstatus & MCG_STATUS_RIPV)) + flags |= MF_MUST_KILL; + ret = memory_failure(m->addr >> PAGE_SHIFT, MCE_VECTOR, flags); + if (ret) + pr_err("Memory error not recovered"); + return ret; +} + /* * The actual machine check handler. This only handles real * exceptions when something got corrupted coming in through int 18. @@ -998,8 +1012,6 @@ void do_machine_check(struct pt_regs *regs, long error_code) DECLARE_BITMAP(toclear, MAX_NR_BANKS); DECLARE_BITMAP(valid_banks, MAX_NR_BANKS); char *msg = "Unknown"; - u64 recover_paddr = ~0ull; - int flags = MF_ACTION_REQUIRED; int lmce = 0; /* If this CPU is offline, just bail out. */ @@ -1136,22 +1148,13 @@ void do_machine_check(struct pt_regs *regs, long error_code) } /* - * At insane "tolerant" levels we take no action. Otherwise - * we only die if we have no other choice. For less serious - * issues we try to recover, or limit damage to the current - * process. + * If tolerant is at an insane level we drop requests to kill + * processes and continue even when there is no way out. */ - if (cfg->tolerant < 3) { - if (no_way_out) - mce_panic("Fatal machine check on current CPU", &m, msg); - if (worst == MCE_AR_SEVERITY) { - recover_paddr = m.addr; - if (!(m.mcgstatus & MCG_STATUS_RIPV)) - flags |= MF_MUST_KILL; - } else if (kill_it) { - force_sig(SIGBUS, current); - } - } + if (cfg->tolerant == 3) + kill_it = 0; + else if (no_way_out) + mce_panic("Fatal machine check on current CPU", &m, msg); if (worst > 0) mce_report_event(regs); @@ -1159,25 +1162,24 @@ void do_machine_check(struct pt_regs *regs, long error_code) out: sync_core(); - if (recover_paddr == ~0ull) - goto done; + if (worst != MCE_AR_SEVERITY && !kill_it) + goto out_ist; - pr_err("Uncorrected hardware memory error in user-access at %llx", - recover_paddr); - /* - * We must call memory_failure() here even if the current process is - * doomed. We still need to mark the page as poisoned and alert any - * other users of the page. - */ - ist_begin_non_atomic(regs); - local_irq_enable(); - if (memory_failure(recover_paddr >> PAGE_SHIFT, MCE_VECTOR, flags) < 0) { - pr_err("Memory error not recovered"); - force_sig(SIGBUS, current); + /* Fault was in user mode and we need to take some action */ + if ((m.cs & 3) == 3) { + ist_begin_non_atomic(regs); + local_irq_enable(); + + if (kill_it || do_memory_failure(&m)) + force_sig(SIGBUS, current); + local_irq_disable(); + ist_end_non_atomic(); + } else { + if (!fixup_exception(regs, X86_TRAP_MC)) + mce_panic("Failed kernel mode recovery", &m, NULL); } - local_irq_disable(); - ist_end_non_atomic(); -done: + +out_ist: ist_exit(regs); } EXPORT_SYMBOL_GPL(do_machine_check); @@ -1576,6 +1578,17 @@ static int __mcheck_cpu_apply_quirks(struct cpuinfo_x86 *c) if (c->x86 == 6 && c->x86_model == 45) quirk_no_way_out = quirk_sandybridge_ifu; + /* + * MCG_CAP.MCG_SER_P is necessary but not sufficient to know + * whether this processor will actually generate recoverable + * machine checks. Check to see if this is an E7 model Xeon. + * We can't do a model number check because E5 and E7 use the + * same model number. E5 doesn't support recovery, E7 does. + */ + if (mca_cfg.recovery || (mca_cfg.ser && + !strncmp(c->x86_model_id, + "Intel(R) Xeon(R) CPU E7-", 24))) + set_cpu_cap(c, X86_FEATURE_MCE_RECOVERY); } if (cfg->monarch_timeout < 0) cfg->monarch_timeout = 0; @@ -1617,10 +1630,10 @@ static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c) case X86_VENDOR_AMD: { u32 ebx = cpuid_ebx(0x80000007); - mce_amd_feature_init(c); mce_flags.overflow_recov = !!(ebx & BIT(0)); mce_flags.succor = !!(ebx & BIT(1)); mce_flags.smca = !!(ebx & BIT(3)); + mce_amd_feature_init(c); break; } @@ -2028,6 +2041,8 @@ static int __init mcheck_enable(char *str) cfg->bootlog = (str[0] == 'b'); else if (!strcmp(str, "bios_cmci_threshold")) cfg->bios_cmci_threshold = true; + else if (!strcmp(str, "recovery")) + cfg->recovery = true; else if (isdigit(str[0])) { if (get_option(&str, &cfg->tolerant) == 2) get_option(&str, &(cfg->monarch_timeout)); -- cgit v1.2.3-54-g00ecf