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-rw-r--r--Documentation/ABI/removed/sysfs-mce37
-rw-r--r--Documentation/ABI/testing/sysfs-mce32
-rw-r--r--Documentation/vm/hwpoison.rst2
-rw-r--r--Documentation/x86/x86_64/boot-options.rst9
-rw-r--r--arch/x86/kernel/cpu/mce/core.c53
-rw-r--r--arch/x86/kernel/cpu/mce/internal.h3
-rw-r--r--arch/x86/kernel/cpu/mce/severity.c21
7 files changed, 68 insertions, 89 deletions
diff --git a/Documentation/ABI/removed/sysfs-mce b/Documentation/ABI/removed/sysfs-mce
new file mode 100644
index 000000000000..ef5dd2a80918
--- /dev/null
+++ b/Documentation/ABI/removed/sysfs-mce
@@ -0,0 +1,37 @@
+What: /sys/devices/system/machinecheck/machinecheckX/tolerant
+Contact: Borislav Petkov <bp@suse.de>
+Date: Dec, 2021
+Description:
+ Unused and obsolete after the advent of recoverable machine
+ checks (see last sentence below) and those are present since
+ 2010 (Nehalem).
+
+ Original description:
+
+ The entries appear for each CPU, but they are truly shared
+ between all CPUs.
+
+ Tolerance level. When a machine check exception occurs for a
+ non corrected machine check the kernel can take different
+ actions.
+
+ Since machine check exceptions can happen any time it is
+ sometimes risky for the kernel to kill a process because it
+ defies normal kernel locking rules. The tolerance level
+ configures how hard the kernel tries to recover even at some
+ risk of deadlock. Higher tolerant values trade potentially
+ better uptime with the risk of a crash or even corruption
+ (for tolerant >= 3).
+
+ == ===========================================================
+ 0 always panic on uncorrected errors, log corrected errors
+ 1 panic or SIGBUS on uncorrected errors, log corrected errors
+ 2 SIGBUS or log uncorrected errors, log corrected errors
+ 3 never panic or SIGBUS, log all errors (for testing only)
+ == ===========================================================
+
+ Default: 1
+
+ Note this only makes a difference if the CPU allows recovery
+ from a machine check exception. Current x86 CPUs generally
+ do not.
diff --git a/Documentation/ABI/testing/sysfs-mce b/Documentation/ABI/testing/sysfs-mce
index c8cd989034b4..83172f50e27c 100644
--- a/Documentation/ABI/testing/sysfs-mce
+++ b/Documentation/ABI/testing/sysfs-mce
@@ -53,38 +53,6 @@ Description:
(but some corrected errors might be still reported
in other ways)
-What: /sys/devices/system/machinecheck/machinecheckX/tolerant
-Contact: Andi Kleen <ak@linux.intel.com>
-Date: Feb, 2007
-Description:
- The entries appear for each CPU, but they are truly shared
- between all CPUs.
-
- Tolerance level. When a machine check exception occurs for a
- non corrected machine check the kernel can take different
- actions.
-
- Since machine check exceptions can happen any time it is
- sometimes risky for the kernel to kill a process because it
- defies normal kernel locking rules. The tolerance level
- configures how hard the kernel tries to recover even at some
- risk of deadlock. Higher tolerant values trade potentially
- better uptime with the risk of a crash or even corruption
- (for tolerant >= 3).
-
- == ===========================================================
- 0 always panic on uncorrected errors, log corrected errors
- 1 panic or SIGBUS on uncorrected errors, log corrected errors
- 2 SIGBUS or log uncorrected errors, log corrected errors
- 3 never panic or SIGBUS, log all errors (for testing only)
- == ===========================================================
-
- Default: 1
-
- Note this only makes a difference if the CPU allows recovery
- from a machine check exception. Current x86 CPUs generally
- do not.
-
What: /sys/devices/system/machinecheck/machinecheckX/trigger
Contact: Andi Kleen <ak@linux.intel.com>
Date: Feb, 2007
diff --git a/Documentation/vm/hwpoison.rst b/Documentation/vm/hwpoison.rst
index 89b5f7a52077..c742de1769d1 100644
--- a/Documentation/vm/hwpoison.rst
+++ b/Documentation/vm/hwpoison.rst
@@ -60,8 +60,6 @@ There are two (actually three) modes memory failure recovery can be in:
vm.memory_failure_recovery sysctl set to zero:
All memory failures cause a panic. Do not attempt recovery.
- (on x86 this can be also affected by the tolerant level of the
- MCE subsystem)
early kill
(can be controlled globally and per process)
diff --git a/Documentation/x86/x86_64/boot-options.rst b/Documentation/x86/x86_64/boot-options.rst
index ccb7e86bf8d9..07aa0007f346 100644
--- a/Documentation/x86/x86_64/boot-options.rst
+++ b/Documentation/x86/x86_64/boot-options.rst
@@ -47,14 +47,7 @@ Please see Documentation/x86/x86_64/machinecheck.rst for sysfs runtime tunables.
in a reboot. On Intel systems it is enabled by default.
mce=nobootlog
Disable boot machine check logging.
- mce=tolerancelevel[,monarchtimeout] (number,number)
- tolerance levels:
- 0: always panic on uncorrected errors, log corrected errors
- 1: panic or SIGBUS on uncorrected errors, log corrected errors
- 2: SIGBUS or log uncorrected errors, log corrected errors
- 3: never panic or SIGBUS, log all errors (for testing only)
- Default is 1
- Can be also set using sysfs which is preferable.
+ mce=monarchtimeout (number)
monarchtimeout:
Sets the time in us to wait for other CPUs on machine checks. 0
to disable.
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 3d766e6247bc..6c9b5dac38fd 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -86,14 +86,6 @@ struct mce_vendor_flags mce_flags __read_mostly;
struct mca_config mca_cfg __read_mostly = {
.bootlog = -1,
- /*
- * Tolerant levels:
- * 0: always panic on uncorrected errors, log corrected errors
- * 1: panic or SIGBUS on uncorrected errors, log corrected errors
- * 2: SIGBUS or log uncorrected errors (if possible), log corr. errors
- * 3: never panic or SIGBUS, log all errors (for testing only)
- */
- .tolerant = 1,
.monarch_timeout = -1
};
@@ -753,7 +745,7 @@ log_it:
goto clear_it;
mce_read_aux(&m, i);
- m.severity = mce_severity(&m, NULL, mca_cfg.tolerant, NULL, false);
+ m.severity = mce_severity(&m, NULL, NULL, false);
/*
* Don't get the IP here because it's unlikely to
* have anything to do with the actual error location.
@@ -887,7 +879,7 @@ static __always_inline int mce_no_way_out(struct mce *m, char **msg, unsigned lo
quirk_sandybridge_ifu(i, m, regs);
m->bank = i;
- if (mce_severity(m, regs, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) {
+ if (mce_severity(m, regs, &tmp, true) >= MCE_PANIC_SEVERITY) {
mce_read_aux(m, i);
*msg = tmp;
return 1;
@@ -935,12 +927,11 @@ static noinstr int mce_timed_out(u64 *t, const char *msg)
if (!mca_cfg.monarch_timeout)
goto out;
if ((s64)*t < SPINUNIT) {
- if (mca_cfg.tolerant <= 1) {
- if (cpumask_and(&mce_missing_cpus, cpu_online_mask, &mce_missing_cpus))
- pr_emerg("CPUs not responding to MCE broadcast (may include false positives): %*pbl\n",
- cpumask_pr_args(&mce_missing_cpus));
- mce_panic(msg, NULL, NULL);
- }
+ if (cpumask_and(&mce_missing_cpus, cpu_online_mask, &mce_missing_cpus))
+ pr_emerg("CPUs not responding to MCE broadcast (may include false positives): %*pbl\n",
+ cpumask_pr_args(&mce_missing_cpus));
+ mce_panic(msg, NULL, NULL);
+
ret = 1;
goto out;
}
@@ -1004,9 +995,9 @@ static void mce_reign(void)
* This dumps all the mces in the log buffer and stops the
* other CPUs.
*/
- if (m && global_worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) {
+ if (m && global_worst >= MCE_PANIC_SEVERITY) {
/* call mce_severity() to get "msg" for panic */
- mce_severity(m, NULL, mca_cfg.tolerant, &msg, true);
+ mce_severity(m, NULL, &msg, true);
mce_panic("Fatal machine check", m, msg);
}
@@ -1020,7 +1011,7 @@ static void mce_reign(void)
* No machine check event found. Must be some external
* source or one CPU is hung. Panic.
*/
- if (global_worst <= MCE_KEEP_SEVERITY && mca_cfg.tolerant < 3)
+ if (global_worst <= MCE_KEEP_SEVERITY)
mce_panic("Fatal machine check from unknown source", NULL, NULL);
/*
@@ -1267,7 +1258,7 @@ __mc_scan_banks(struct mce *m, struct pt_regs *regs, struct mce *final,
/* Set taint even when machine check was not enabled. */
taint++;
- severity = mce_severity(m, regs, cfg->tolerant, NULL, true);
+ severity = mce_severity(m, regs, NULL, true);
/*
* When machine check was for corrected/deferred handler don't
@@ -1425,7 +1416,6 @@ noinstr void do_machine_check(struct pt_regs *regs)
int worst = 0, order, no_way_out, kill_current_task, lmce, taint = 0;
DECLARE_BITMAP(valid_banks, MAX_NR_BANKS) = { 0 };
DECLARE_BITMAP(toclear, MAX_NR_BANKS) = { 0 };
- struct mca_config *cfg = &mca_cfg;
struct mce m, *final;
char *msg = NULL;
@@ -1447,7 +1437,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
/*
* If no_way_out gets set, there is no safe way to recover from this
- * MCE. If mca_cfg.tolerant is cranked up, we'll try anyway.
+ * MCE.
*/
no_way_out = 0;
@@ -1481,7 +1471,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
* severity is MCE_AR_SEVERITY we have other options.
*/
if (!(m.mcgstatus & MCG_STATUS_RIPV))
- kill_current_task = (cfg->tolerant == 3) ? 0 : 1;
+ kill_current_task = 1;
/*
* Check if this MCE is signaled to only this logical processor,
* on Intel, Zhaoxin only.
@@ -1498,7 +1488,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
* to see it will clear it.
*/
if (lmce) {
- if (no_way_out && cfg->tolerant < 3)
+ if (no_way_out)
mce_panic("Fatal local machine check", &m, msg);
} else {
order = mce_start(&no_way_out);
@@ -1518,7 +1508,7 @@ noinstr void do_machine_check(struct pt_regs *regs)
if (!no_way_out)
no_way_out = worst >= MCE_PANIC_SEVERITY;
- if (no_way_out && cfg->tolerant < 3)
+ if (no_way_out)
mce_panic("Fatal machine check on current CPU", &m, msg);
}
} else {
@@ -1530,8 +1520,8 @@ noinstr void do_machine_check(struct pt_regs *regs)
* fatal error. We call "mce_severity()" again to
* make sure we have the right "msg".
*/
- if (worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) {
- mce_severity(&m, regs, cfg->tolerant, &msg, true);
+ if (worst >= MCE_PANIC_SEVERITY) {
+ mce_severity(&m, regs, &msg, true);
mce_panic("Local fatal machine check!", &m, msg);
}
}
@@ -2267,10 +2257,9 @@ static int __init mcheck_enable(char *str)
cfg->bios_cmci_threshold = 1;
else if (!strcmp(str, "recovery"))
cfg->recovery = 1;
- else if (isdigit(str[0])) {
- if (get_option(&str, &cfg->tolerant) == 2)
- get_option(&str, &(cfg->monarch_timeout));
- } else {
+ else if (isdigit(str[0]))
+ get_option(&str, &(cfg->monarch_timeout));
+ else {
pr_info("mce argument %s ignored. Please use /sys\n", str);
return 0;
}
@@ -2520,7 +2509,6 @@ static ssize_t store_int_with_restart(struct device *s,
return ret;
}
-static DEVICE_INT_ATTR(tolerant, 0644, mca_cfg.tolerant);
static DEVICE_INT_ATTR(monarch_timeout, 0644, mca_cfg.monarch_timeout);
static DEVICE_BOOL_ATTR(dont_log_ce, 0644, mca_cfg.dont_log_ce);
static DEVICE_BOOL_ATTR(print_all, 0644, mca_cfg.print_all);
@@ -2541,7 +2529,6 @@ static struct dev_ext_attribute dev_attr_cmci_disabled = {
};
static struct device_attribute *mce_device_attrs[] = {
- &dev_attr_tolerant.attr,
&dev_attr_check_interval.attr,
#ifdef CONFIG_X86_MCELOG_LEGACY
&dev_attr_trigger,
diff --git a/arch/x86/kernel/cpu/mce/internal.h b/arch/x86/kernel/cpu/mce/internal.h
index 3efb5037c364..4ae0e603f7fa 100644
--- a/arch/x86/kernel/cpu/mce/internal.h
+++ b/arch/x86/kernel/cpu/mce/internal.h
@@ -35,7 +35,7 @@ int mce_gen_pool_add(struct mce *mce);
int mce_gen_pool_init(void);
struct llist_node *mce_gen_pool_prepare_records(void);
-int mce_severity(struct mce *a, struct pt_regs *regs, int tolerant, char **msg, bool is_excp);
+int mce_severity(struct mce *a, struct pt_regs *regs, char **msg, bool is_excp);
struct dentry *mce_get_debugfs_dir(void);
extern mce_banks_t mce_banks_ce_disabled;
@@ -127,7 +127,6 @@ struct mca_config {
bool ignore_ce;
bool print_all;
- int tolerant;
int monarch_timeout;
int panic_timeout;
u32 rip_msr;
diff --git a/arch/x86/kernel/cpu/mce/severity.c b/arch/x86/kernel/cpu/mce/severity.c
index ca0d775346fb..1add86935349 100644
--- a/arch/x86/kernel/cpu/mce/severity.c
+++ b/arch/x86/kernel/cpu/mce/severity.c
@@ -330,8 +330,7 @@ static __always_inline int mce_severity_amd_smca(struct mce *m, enum context err
* See AMD Error Scope Hierarchy table in a newer BKDG. For example
* 49125_15h_Models_30h-3Fh_BKDG.pdf, section "RAS Features"
*/
-static noinstr int mce_severity_amd(struct mce *m, struct pt_regs *regs, int tolerant,
- char **msg, bool is_excp)
+static noinstr int mce_severity_amd(struct mce *m, struct pt_regs *regs, char **msg, bool is_excp)
{
enum context ctx = error_context(m, regs);
@@ -383,8 +382,7 @@ static noinstr int mce_severity_amd(struct mce *m, struct pt_regs *regs, int tol
return MCE_KEEP_SEVERITY;
}
-static noinstr int mce_severity_intel(struct mce *m, struct pt_regs *regs,
- int tolerant, char **msg, bool is_excp)
+static noinstr int mce_severity_intel(struct mce *m, struct pt_regs *regs, char **msg, bool is_excp)
{
enum exception excp = (is_excp ? EXCP_CONTEXT : NO_EXCP);
enum context ctx = error_context(m, regs);
@@ -412,22 +410,21 @@ static noinstr int mce_severity_intel(struct mce *m, struct pt_regs *regs,
if (msg)
*msg = s->msg;
s->covered = 1;
- if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL) {
- if (tolerant < 1)
- return MCE_PANIC_SEVERITY;
- }
+
+ if (s->sev >= MCE_UC_SEVERITY && ctx == IN_KERNEL)
+ return MCE_PANIC_SEVERITY;
+
return s->sev;
}
}
-int noinstr mce_severity(struct mce *m, struct pt_regs *regs, int tolerant, char **msg,
- bool is_excp)
+int noinstr mce_severity(struct mce *m, struct pt_regs *regs, char **msg, bool is_excp)
{
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
- return mce_severity_amd(m, regs, tolerant, msg, is_excp);
+ return mce_severity_amd(m, regs, msg, is_excp);
else
- return mce_severity_intel(m, regs, tolerant, msg, is_excp);
+ return mce_severity_intel(m, regs, msg, is_excp);
}
#ifdef CONFIG_DEBUG_FS
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2025-01-15 00:45:13 +0000