286 lines
7.1 KiB
C
286 lines
7.1 KiB
C
/*
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* MCE grading rules.
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* Copyright 2008, 2009 Intel Corporation.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; version 2
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* of the License.
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*
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* Author: Andi Kleen
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*/
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#include <linux/kernel.h>
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#include <linux/seq_file.h>
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#include <linux/init.h>
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#include <linux/debugfs.h>
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#include <asm/mce.h>
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#include "mce-internal.h"
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/*
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* Grade an mce by severity. In general the most severe ones are processed
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* first. Since there are quite a lot of combinations test the bits in a
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* table-driven way. The rules are simply processed in order, first
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* match wins.
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*
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* Note this is only used for machine check exceptions, the corrected
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* errors use much simpler rules. The exceptions still check for the corrected
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* errors, but only to leave them alone for the CMCI handler (except for
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* panic situations)
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*/
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enum context { IN_KERNEL = 1, IN_USER = 2 };
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enum ser { SER_REQUIRED = 1, NO_SER = 2 };
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static struct severity {
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u64 mask;
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u64 result;
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unsigned char sev;
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unsigned char mcgmask;
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unsigned char mcgres;
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unsigned char ser;
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unsigned char context;
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unsigned char covered;
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char *msg;
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} severities[] = {
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#define MCESEV(s, m, c...) { .sev = MCE_ ## s ## _SEVERITY, .msg = m, ## c }
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#define KERNEL .context = IN_KERNEL
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#define USER .context = IN_USER
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#define SER .ser = SER_REQUIRED
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#define NOSER .ser = NO_SER
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#define BITCLR(x) .mask = x, .result = 0
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#define BITSET(x) .mask = x, .result = x
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#define MCGMASK(x, y) .mcgmask = x, .mcgres = y
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#define MASK(x, y) .mask = x, .result = y
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#define MCI_UC_S (MCI_STATUS_UC|MCI_STATUS_S)
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#define MCI_UC_SAR (MCI_STATUS_UC|MCI_STATUS_S|MCI_STATUS_AR)
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#define MCI_ADDR (MCI_STATUS_ADDRV|MCI_STATUS_MISCV)
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#define MCACOD 0xffff
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/* Architecturally defined codes from SDM Vol. 3B Chapter 15 */
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#define MCACOD_SCRUB 0x00C0 /* 0xC0-0xCF Memory Scrubbing */
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#define MCACOD_SCRUBMSK 0xfff0
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#define MCACOD_L3WB 0x017A /* L3 Explicit Writeback */
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#define MCACOD_DATA 0x0134 /* Data Load */
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#define MCACOD_INSTR 0x0150 /* Instruction Fetch */
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MCESEV(
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NO, "Invalid",
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BITCLR(MCI_STATUS_VAL)
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),
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MCESEV(
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NO, "Not enabled",
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BITCLR(MCI_STATUS_EN)
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),
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MCESEV(
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PANIC, "Processor context corrupt",
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BITSET(MCI_STATUS_PCC)
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),
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/* When MCIP is not set something is very confused */
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MCESEV(
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PANIC, "MCIP not set in MCA handler",
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MCGMASK(MCG_STATUS_MCIP, 0)
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),
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/* Neither return not error IP -- no chance to recover -> PANIC */
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MCESEV(
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PANIC, "Neither restart nor error IP",
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MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0)
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),
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MCESEV(
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PANIC, "In kernel and no restart IP",
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KERNEL, MCGMASK(MCG_STATUS_RIPV, 0)
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),
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MCESEV(
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KEEP, "Corrected error",
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NOSER, BITCLR(MCI_STATUS_UC)
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),
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/* ignore OVER for UCNA */
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MCESEV(
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KEEP, "Uncorrected no action required",
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SER, MASK(MCI_UC_SAR, MCI_STATUS_UC)
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),
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MCESEV(
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PANIC, "Illegal combination (UCNA with AR=1)",
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SER,
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MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_UC|MCI_STATUS_AR)
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),
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MCESEV(
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KEEP, "Non signalled machine check",
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SER, BITCLR(MCI_STATUS_S)
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),
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MCESEV(
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PANIC, "Action required with lost events",
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SER, BITSET(MCI_STATUS_OVER|MCI_UC_SAR)
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),
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/* known AR MCACODs: */
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#ifdef CONFIG_MEMORY_FAILURE
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MCESEV(
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KEEP, "HT thread notices Action required: data load error",
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SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_DATA),
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MCGMASK(MCG_STATUS_EIPV, 0)
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),
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MCESEV(
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AR, "Action required: data load error",
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SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_DATA),
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USER
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),
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#endif
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MCESEV(
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PANIC, "Action required: unknown MCACOD",
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SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_SAR)
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),
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/* known AO MCACODs: */
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MCESEV(
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AO, "Action optional: memory scrubbing error",
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SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD_SCRUBMSK, MCI_UC_S|MCACOD_SCRUB)
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),
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MCESEV(
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AO, "Action optional: last level cache writeback error",
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SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD, MCI_UC_S|MCACOD_L3WB)
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),
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MCESEV(
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SOME, "Action optional: unknown MCACOD",
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SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S)
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),
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MCESEV(
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SOME, "Action optional with lost events",
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SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_OVER|MCI_UC_S)
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),
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MCESEV(
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PANIC, "Overflowed uncorrected",
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BITSET(MCI_STATUS_OVER|MCI_STATUS_UC)
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),
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MCESEV(
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UC, "Uncorrected",
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BITSET(MCI_STATUS_UC)
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),
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MCESEV(
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SOME, "No match",
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BITSET(0)
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) /* always matches. keep at end */
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};
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/*
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* If mcgstatus indicated that ip/cs on the stack were
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* no good, then "m->cs" will be zero and we will have
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* to assume the worst case (IN_KERNEL) as we actually
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* have no idea what we were executing when the machine
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* check hit.
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* If we do have a good "m->cs" (or a faked one in the
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* case we were executing in VM86 mode) we can use it to
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* distinguish an exception taken in user from from one
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* taken in the kernel.
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*/
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static int error_context(struct mce *m)
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{
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return ((m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
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}
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int mce_severity(struct mce *m, int tolerant, char **msg)
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{
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enum context ctx = error_context(m);
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struct severity *s;
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for (s = severities;; s++) {
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if ((m->status & s->mask) != s->result)
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continue;
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if ((m->mcgstatus & s->mcgmask) != s->mcgres)
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continue;
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if (s->ser == SER_REQUIRED && !mce_ser)
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continue;
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if (s->ser == NO_SER && mce_ser)
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continue;
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if (s->context && ctx != s->context)
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continue;
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if (msg)
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*msg = s->msg;
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s->covered = 1;
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if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
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if (panic_on_oops || tolerant < 1)
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return MCE_PANIC_SEVERITY;
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}
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return s->sev;
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}
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}
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#ifdef CONFIG_DEBUG_FS
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static void *s_start(struct seq_file *f, loff_t *pos)
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{
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if (*pos >= ARRAY_SIZE(severities))
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return NULL;
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return &severities[*pos];
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}
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static void *s_next(struct seq_file *f, void *data, loff_t *pos)
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{
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if (++(*pos) >= ARRAY_SIZE(severities))
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return NULL;
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return &severities[*pos];
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}
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static void s_stop(struct seq_file *f, void *data)
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{
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}
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static int s_show(struct seq_file *f, void *data)
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{
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struct severity *ser = data;
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seq_printf(f, "%d\t%s\n", ser->covered, ser->msg);
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return 0;
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}
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static const struct seq_operations severities_seq_ops = {
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.start = s_start,
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.next = s_next,
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.stop = s_stop,
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.show = s_show,
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};
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static int severities_coverage_open(struct inode *inode, struct file *file)
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{
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return seq_open(file, &severities_seq_ops);
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}
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static ssize_t severities_coverage_write(struct file *file,
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const char __user *ubuf,
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size_t count, loff_t *ppos)
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{
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int i;
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for (i = 0; i < ARRAY_SIZE(severities); i++)
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severities[i].covered = 0;
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return count;
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}
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static const struct file_operations severities_coverage_fops = {
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.open = severities_coverage_open,
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.release = seq_release,
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.read = seq_read,
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.write = severities_coverage_write,
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.llseek = seq_lseek,
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};
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static int __init severities_debugfs_init(void)
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{
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struct dentry *dmce, *fsev;
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dmce = mce_get_debugfs_dir();
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if (!dmce)
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goto err_out;
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fsev = debugfs_create_file("severities-coverage", 0444, dmce, NULL,
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&severities_coverage_fops);
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if (!fsev)
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goto err_out;
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return 0;
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err_out:
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return -ENOMEM;
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}
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late_initcall(severities_debugfs_init);
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#endif /* CONFIG_DEBUG_FS */
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