Release 4.14 arch/x86/kernel/cpu/mcheck/mce-severity.c
/*
* MCE grading rules.
* Copyright 2008, 2009 Intel Corporation.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; version 2
* of the License.
*
* Author: Andi Kleen
*/
#include <linux/kernel.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/debugfs.h>
#include <asm/mce.h>
#include <linux/uaccess.h>
#include "mce-internal.h"
/*
* Grade an mce by severity. In general the most severe ones are processed
* first. Since there are quite a lot of combinations test the bits in a
* table-driven way. The rules are simply processed in order, first
* match wins.
*
* Note this is only used for machine check exceptions, the corrected
* errors use much simpler rules. The exceptions still check for the corrected
* errors, but only to leave them alone for the CMCI handler (except for
* panic situations)
*/
enum context { IN_KERNEL = 1, IN_USER = 2, IN_KERNEL_RECOV = 3 };
enum ser { SER_REQUIRED = 1, NO_SER = 2 };
enum exception { EXCP_CONTEXT = 1, NO_EXCP = 2 };
static struct severity {
u64 mask;
u64 result;
unsigned char sev;
unsigned char mcgmask;
unsigned char mcgres;
unsigned char ser;
unsigned char context;
unsigned char excp;
unsigned char covered;
char *msg;
} severities[] = {
#define MCESEV(s, m, c...) { .sev = MCE_ ## s ## _SEVERITY, .msg = m, ## c }
#define KERNEL .context = IN_KERNEL
#define USER .context = IN_USER
#define KERNEL_RECOV .context = IN_KERNEL_RECOV
#define SER .ser = SER_REQUIRED
#define NOSER .ser = NO_SER
#define EXCP .excp = EXCP_CONTEXT
#define NOEXCP .excp = NO_EXCP
#define BITCLR(x) .mask = x, .result = 0
#define BITSET(x) .mask = x, .result = x
#define MCGMASK(x, y) .mcgmask = x, .mcgres = y
#define MASK(x, y) .mask = x, .result = y
#define MCI_UC_S (MCI_STATUS_UC|MCI_STATUS_S)
#define MCI_UC_SAR (MCI_STATUS_UC|MCI_STATUS_S|MCI_STATUS_AR)
#define MCI_ADDR (MCI_STATUS_ADDRV|MCI_STATUS_MISCV)
MCESEV(
NO, "Invalid",
BITCLR(MCI_STATUS_VAL)
),
MCESEV(
NO, "Not enabled",
EXCP, BITCLR(MCI_STATUS_EN)
),
MCESEV(
PANIC, "Processor context corrupt",
BITSET(MCI_STATUS_PCC)
),
/* When MCIP is not set something is very confused */
MCESEV(
PANIC, "MCIP not set in MCA handler",
EXCP, MCGMASK(MCG_STATUS_MCIP, 0)
),
/* Neither return not error IP -- no chance to recover -> PANIC */
MCESEV(
PANIC, "Neither restart nor error IP",
EXCP, MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0)
),
MCESEV(
PANIC, "In kernel and no restart IP",
EXCP, KERNEL, MCGMASK(MCG_STATUS_RIPV, 0)
),
MCESEV(
PANIC, "In kernel and no restart IP",
EXCP, KERNEL_RECOV, MCGMASK(MCG_STATUS_RIPV, 0)
),
MCESEV(
DEFERRED, "Deferred error",
NOSER, MASK(MCI_STATUS_UC|MCI_STATUS_DEFERRED|MCI_STATUS_POISON, MCI_STATUS_DEFERRED)
),
MCESEV(
KEEP, "Corrected error",
NOSER, BITCLR(MCI_STATUS_UC)
),
/* ignore OVER for UCNA */
MCESEV(
UCNA, "Uncorrected no action required",
SER, MASK(MCI_UC_SAR, MCI_STATUS_UC)
),
MCESEV(
PANIC, "Illegal combination (UCNA with AR=1)",
SER,
MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_UC|MCI_STATUS_AR)
),
MCESEV(
KEEP, "Non signalled machine check",
SER, BITCLR(MCI_STATUS_S)
),
MCESEV(
PANIC, "Action required with lost events",
SER, BITSET(MCI_STATUS_OVER|MCI_UC_SAR)
),
/* known AR MCACODs: */
#ifdef CONFIG_MEMORY_FAILURE
MCESEV(
KEEP, "Action required but unaffected thread is continuable",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR, MCI_UC_SAR|MCI_ADDR),
MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, MCG_STATUS_RIPV)
),
MCESEV(
AR, "Action required: data load in error recoverable area of kernel",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_DATA),
KERNEL_RECOV
),
MCESEV(
AR, "Action required: data load error in a user process",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_DATA),
USER
),
MCESEV(
AR, "Action required: instruction fetch error in a user process",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_INSTR),
USER
),
#endif
MCESEV(
PANIC, "Action required: unknown MCACOD",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_SAR)
),
/* known AO MCACODs: */
MCESEV(
AO, "Action optional: memory scrubbing error",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD_SCRUBMSK, MCI_UC_S|MCACOD_SCRUB)
),
MCESEV(
AO, "Action optional: last level cache writeback error",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCACOD, MCI_UC_S|MCACOD_L3WB)
),
MCESEV(
SOME, "Action optional: unknown MCACOD",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_UC_S)
),
MCESEV(
SOME, "Action optional with lost events",
SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR, MCI_STATUS_OVER|MCI_UC_S)
),
MCESEV(
PANIC, "Overflowed uncorrected",
BITSET(MCI_STATUS_OVER|MCI_STATUS_UC)
),
MCESEV(
UC, "Uncorrected",
BITSET(MCI_STATUS_UC)
),
MCESEV(
SOME, "No match",
BITSET(0)
) /* always matches. keep at end */
};
#define mc_recoverable(mcg) (((mcg) & (MCG_STATUS_RIPV|MCG_STATUS_EIPV)) == \
(MCG_STATUS_RIPV|MCG_STATUS_EIPV))
/*
* If mcgstatus indicated that ip/cs on the stack were
* no good, then "m->cs" will be zero and we will have
* to assume the worst case (IN_KERNEL) as we actually
* have no idea what we were executing when the machine
* check hit.
* If we do have a good "m->cs" (or a faked one in the
* case we were executing in VM86 mode) we can use it to
* distinguish an exception taken in user from from one
* taken in the kernel.
*/
static int error_context(struct mce *m)
{
if ((m->cs & 3) == 3)
return IN_USER;
if (mc_recoverable(m->mcgstatus) && ex_has_fault_handler(m->ip))
return IN_KERNEL_RECOV;
return IN_KERNEL;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Tony Luck | 25 | 52.08% | 1 | 50.00% |
| Andi Kleen | 23 | 47.92% | 1 | 50.00% |
| Total | 48 | 100.00% | 2 | 100.00% |
static int mce_severity_amd_smca(struct mce *m, int err_ctx)
{
u32 addr = MSR_AMD64_SMCA_MCx_CONFIG(m->bank);
u32 low, high;
/*
* We need to look at the following bits:
* - "succor" bit (data poisoning support), and
* - TCC bit (Task Context Corrupt)
* in MCi_STATUS to determine error severity.
*/
if (!mce_flags.succor)
return MCE_PANIC_SEVERITY;
if (rdmsr_safe(addr, &low, &high))
return MCE_PANIC_SEVERITY;
/* TCC (Task context corrupt). If set and if IN_KERNEL, panic. */
if ((low & MCI_CONFIG_MCAX) &&
(m->status & MCI_STATUS_TCC) &&
(err_ctx == IN_KERNEL))
return MCE_PANIC_SEVERITY;
/* ...otherwise invoke hwpoison handler. */
return MCE_AR_SEVERITY;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Aravind Gopalakrishnan | 86 | 100.00% | 1 | 100.00% |
| Total | 86 | 100.00% | 1 | 100.00% |
/*
* See AMD Error Scope Hierarchy table in a newer BKDG. For example
* 49125_15h_Models_30h-3Fh_BKDG.pdf, section "RAS Features"
*/
static int mce_severity_amd(struct mce *m, int tolerant, char **msg, bool is_excp)
{
enum context ctx = error_context(m);
/* Processor Context Corrupt, no need to fumble too much, die! */
if (m->status & MCI_STATUS_PCC)
return MCE_PANIC_SEVERITY;
if (m->status & MCI_STATUS_UC) {
/*
* On older systems where overflow_recov flag is not present, we
* should simply panic if an error overflow occurs. If
* overflow_recov flag is present and set, then software can try
* to at least kill process to prolong system operation.
*/
if (mce_flags.overflow_recov) {
if (mce_flags.smca)
return mce_severity_amd_smca(m, ctx);
/* software can try to contain */
if (!(m->mcgstatus & MCG_STATUS_RIPV) && (ctx == IN_KERNEL))
return MCE_PANIC_SEVERITY;
/* kill current process */
return MCE_AR_SEVERITY;
} else {
/* at least one error was not logged */
if (m->status & MCI_STATUS_OVER)
return MCE_PANIC_SEVERITY;
}
/*
* For any other case, return MCE_UC_SEVERITY so that we log the
* error and exit #MC handler.
*/
return MCE_UC_SEVERITY;
}
/*
* deferred error: poll handler catches these and adds to mce_ring so
* memory-failure can take recovery actions.
*/
if (m->status & MCI_STATUS_DEFERRED)
return MCE_DEFERRED_SEVERITY;
/*
* corrected error: poll handler catches these and passes responsibility
* of decoding the error to EDAC
*/
return MCE_KEEP_SEVERITY;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Aravind Gopalakrishnan | 136 | 100.00% | 4 | 100.00% |
| Total | 136 | 100.00% | 4 | 100.00% |
static int mce_severity_intel(struct mce *m, int tolerant, char **msg, bool is_excp)
{
enum exception excp = (is_excp ? EXCP_CONTEXT : NO_EXCP);
enum context ctx = error_context(m);
struct severity *s;
for (s = severities;; s++) {
if ((m->status & s->mask) != s->result)
continue;
if ((m->mcgstatus & s->mcgmask) != s->mcgres)
continue;
if (s->ser == SER_REQUIRED && !mca_cfg.ser)
continue;
if (s->ser == NO_SER && mca_cfg.ser)
continue;
if (s->context && ctx != s->context)
continue;
if (s->excp && excp != s->excp)
continue;
if (msg)
*msg = s->msg;
s->covered = 1;
if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
if (tolerant < 1)
return MCE_PANIC_SEVERITY;
}
return s->sev;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Andi Kleen | 146 | 76.04% | 2 | 28.57% |
| Chen Yucong | 28 | 14.58% | 1 | 14.29% |
| Borislav Petkov | 6 | 3.12% | 1 | 14.29% |
| Huang Ying | 6 | 3.12% | 1 | 14.29% |
| Hidetoshi Seto | 4 | 2.08% | 1 | 14.29% |
| Aravind Gopalakrishnan | 2 | 1.04% | 1 | 14.29% |
| Total | 192 | 100.00% | 7 | 100.00% |
/* Default to mce_severity_intel */
int (*mce_severity)(struct mce *m, int tolerant, char **msg, bool is_excp) =
mce_severity_intel;
void __init mcheck_vendor_init_severity(void)
{
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
mce_severity = mce_severity_amd;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Aravind Gopalakrishnan | 20 | 100.00% | 1 | 100.00% |
| Total | 20 | 100.00% | 1 | 100.00% |
#ifdef CONFIG_DEBUG_FS
static void *s_start(struct seq_file *f, loff_t *pos)
{
if (*pos >= ARRAY_SIZE(severities))
return NULL;
return &severities[*pos];
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Huang Ying | 37 | 100.00% | 1 | 100.00% |
| Total | 37 | 100.00% | 1 | 100.00% |
static void *s_next(struct seq_file *f, void *data, loff_t *pos)
{
if (++(*pos) >= ARRAY_SIZE(severities))
return NULL;
return &severities[*pos];
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Huang Ying | 44 | 100.00% | 1 | 100.00% |
| Total | 44 | 100.00% | 1 | 100.00% |
static void s_stop(struct seq_file *f, void *data)
{
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Huang Ying | 14 | 100.00% | 1 | 100.00% |
| Total | 14 | 100.00% | 1 | 100.00% |
static int s_show(struct seq_file *f, void *data)
{
struct severity *ser = data;
seq_printf(f, "%d\t%s\n", ser->covered, ser->msg);
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Huang Ying | 40 | 100.00% | 1 | 100.00% |
| Total | 40 | 100.00% | 1 | 100.00% |
static const struct seq_operations severities_seq_ops = {
.start = s_start,
.next = s_next,
.stop = s_stop,
.show = s_show,
};
static int severities_coverage_open(struct inode *inode, struct file *file)
{
return seq_open(file, &severities_seq_ops);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Huang Ying | 25 | 100.00% | 1 | 100.00% |
| Total | 25 | 100.00% | 1 | 100.00% |
static ssize_t severities_coverage_write(struct file *file,
const char __user *ubuf,
size_t count, loff_t *ppos)
{
int i;
for (i = 0; i < ARRAY_SIZE(severities); i++)
severities[i].covered = 0;
return count;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Huang Ying | 55 | 100.00% | 1 | 100.00% |
| Total | 55 | 100.00% | 1 | 100.00% |
static const struct file_operations severities_coverage_fops = {
.open = severities_coverage_open,
.release = seq_release,
.read = seq_read,
.write = severities_coverage_write,
.llseek = seq_lseek,
};
static int __init severities_debugfs_init(void)
{
struct dentry *dmce, *fsev;
dmce = mce_get_debugfs_dir();
if (!dmce)
goto err_out;
fsev = debugfs_create_file("severities-coverage", 0444, dmce, NULL,
&severities_coverage_fops);
if (!fsev)
goto err_out;
return 0;
err_out:
return -ENOMEM;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Huang Ying | 58 | 92.06% | 2 | 66.67% |
| Hidetoshi Seto | 5 | 7.94% | 1 | 33.33% |
| Total | 63 | 100.00% | 3 | 100.00% |
late_initcall(severities_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Andi Kleen | 457 | 29.81% | 3 | 13.64% |
| Huang Ying | 353 | 23.03% | 2 | 9.09% |
| Aravind Gopalakrishnan | 271 | 17.68% | 4 | 18.18% |
| Tony Luck | 184 | 12.00% | 6 | 27.27% |
| Hidetoshi Seto | 170 | 11.09% | 2 | 9.09% |
| Chen Yucong | 81 | 5.28% | 1 | 4.55% |
| Borislav Petkov | 6 | 0.39% | 1 | 4.55% |
| Arnd Bergmann | 5 | 0.33% | 1 | 4.55% |
| Chen Gong | 5 | 0.33% | 1 | 4.55% |
| Linus Torvalds | 1 | 0.07% | 1 | 4.55% |
| Total | 1533 | 100.00% | 22 | 100.00% |
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