#include <linux/device.h>
#include <linux/module.h>
#include <linux/cpu.h>
+#include <linux/string.h>
+#include <linux/uaccess.h>
#include <asm/mce.h>
#include "mce_amd.h"
static struct mce i_mce;
static struct dentry *dfs_inj;
+static u8 n_banks;
+
+#define MAX_FLAG_OPT_SIZE 3
+
+enum injection_type {
+ SW_INJ = 0, /* SW injection, simply decode the error */
+ HW_INJ, /* Trigger a #MC */
+ N_INJ_TYPES,
+};
+
+static const char * const flags_options[] = {
+ [SW_INJ] = "sw",
+ [HW_INJ] = "hw",
+ NULL
+};
+
+/* Set default injection to SW_INJ */
+static enum injection_type inj_type = SW_INJ;
+
#define MCE_INJECT_SET(reg) \
static int inj_##reg##_set(void *data, u64 val) \
{ \
return err;
}
-static int flags_get(void *data, u64 *val)
+static int __set_inj(const char *buf)
{
- struct mce *m = (struct mce *)data;
+ int i;
- *val = m->inject_flags;
+ for (i = 0; i < N_INJ_TYPES; i++) {
+ if (!strncmp(flags_options[i], buf, strlen(flags_options[i]))) {
+ inj_type = i;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
- return 0;
+static ssize_t flags_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ char buf[MAX_FLAG_OPT_SIZE];
+ int n;
+
+ n = sprintf(buf, "%s\n", flags_options[inj_type]);
+
+ return simple_read_from_buffer(ubuf, cnt, ppos, buf, n);
}
-static int flags_set(void *data, u64 val)
+static ssize_t flags_write(struct file *filp, const char __user *ubuf,
+ size_t cnt, loff_t *ppos)
{
- struct mce *m = (struct mce *)data;
+ char buf[MAX_FLAG_OPT_SIZE], *__buf;
+ int err;
+ size_t ret;
- m->inject_flags = (u8)val;
- return 0;
+ if (cnt > MAX_FLAG_OPT_SIZE)
+ cnt = MAX_FLAG_OPT_SIZE;
+
+ ret = cnt;
+
+ if (copy_from_user(&buf, ubuf, cnt))
+ return -EFAULT;
+
+ buf[cnt - 1] = 0;
+
+ /* strip whitespace */
+ __buf = strstrip(buf);
+
+ err = __set_inj(__buf);
+ if (err) {
+ pr_err("%s: Invalid flags value: %s\n", __func__, __buf);
+ return err;
+ }
+
+ *ppos += ret;
+
+ return ret;
}
-DEFINE_SIMPLE_ATTRIBUTE(flags_fops, flags_get, flags_set, "%llu\n");
+static const struct file_operations flags_fops = {
+ .read = flags_read,
+ .write = flags_write,
+ .llseek = generic_file_llseek,
+};
/*
* On which CPU to inject?
unsigned int cpu = i_mce.extcpu;
u8 b = i_mce.bank;
- if (!(i_mce.inject_flags & MCJ_EXCEPTION)) {
+ if (i_mce.misc)
+ i_mce.status |= MCI_STATUS_MISCV;
+
+ if (inj_type == SW_INJ) {
amd_decode_mce(NULL, 0, &i_mce);
return;
}
- get_online_cpus();
- if (!cpu_online(cpu))
- goto err;
-
/* prep MCE global settings for the injection */
mcg_status = MCG_STATUS_MCIP | MCG_STATUS_EIPV;
if (!(i_mce.status & MCI_STATUS_PCC))
mcg_status |= MCG_STATUS_RIPV;
+ get_online_cpus();
+ if (!cpu_online(cpu))
+ goto err;
+
toggle_hw_mce_inject(cpu, true);
wrmsr_on_cpu(cpu, MSR_IA32_MCG_STATUS,
{
struct mce *m = (struct mce *)data;
- if (val > 5) {
- if (boot_cpu_data.x86 != 0x15 || val > 6) {
- pr_err("Non-existent MCE bank: %llu\n", val);
- return -EINVAL;
- }
+ if (val >= n_banks) {
+ pr_err("Non-existent MCE bank: %llu\n", val);
+ return -EINVAL;
}
m->bank = val;
return 0;
}
-static int inj_bank_get(void *data, u64 *val)
-{
- struct mce *m = (struct mce *)data;
+MCE_INJECT_GET(bank);
- *val = m->bank;
- return 0;
+DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");
+
+static const char readme_msg[] =
+"Description of the files and their usages:\n"
+"\n"
+"Note1: i refers to the bank number below.\n"
+"Note2: See respective BKDGs for the exact bit definitions of the files below\n"
+"as they mirror the hardware registers.\n"
+"\n"
+"status:\t Set MCi_STATUS: the bits in that MSR control the error type and\n"
+"\t attributes of the error which caused the MCE.\n"
+"\n"
+"misc:\t Set MCi_MISC: provide auxiliary info about the error. It is mostly\n"
+"\t used for error thresholding purposes and its validity is indicated by\n"
+"\t MCi_STATUS[MiscV].\n"
+"\n"
+"addr:\t Error address value to be written to MCi_ADDR. Log address information\n"
+"\t associated with the error.\n"
+"\n"
+"cpu:\t The CPU to inject the error on.\n"
+"\n"
+"bank:\t Specify the bank you want to inject the error into: the number of\n"
+"\t banks in a processor varies and is family/model-specific, therefore, the\n"
+"\t supplied value is sanity-checked. Setting the bank value also triggers the\n"
+"\t injection.\n"
+"\n"
+"flags:\t Injection type to be performed. Writing to this file will trigger a\n"
+"\t real machine check, an APIC interrupt or invoke the error decoder routines\n"
+"\t for AMD processors.\n"
+"\n"
+"\t Allowed error injection types:\n"
+"\t - \"sw\": Software error injection. Decode error to a human-readable \n"
+"\t format only. Safe to use.\n"
+"\t - \"hw\": Hardware error injection. Causes the #MC exception handler to \n"
+"\t handle the error. Be warned: might cause system panic if MCi_STATUS[PCC] \n"
+"\t is set. Therefore, consider setting (debugfs_mountpoint)/mce/fake_panic \n"
+"\t before injecting.\n"
+"\n";
+
+static ssize_t
+inj_readme_read(struct file *filp, char __user *ubuf,
+ size_t cnt, loff_t *ppos)
+{
+ return simple_read_from_buffer(ubuf, cnt, ppos,
+ readme_msg, strlen(readme_msg));
}
-DEFINE_SIMPLE_ATTRIBUTE(bank_fops, inj_bank_get, inj_bank_set, "%llu\n");
+static const struct file_operations readme_fops = {
+ .read = inj_readme_read,
+};
static struct dfs_node {
char *name;
struct dentry *d;
const struct file_operations *fops;
+ umode_t perm;
} dfs_fls[] = {
- { .name = "status", .fops = &status_fops },
- { .name = "misc", .fops = &misc_fops },
- { .name = "addr", .fops = &addr_fops },
- { .name = "bank", .fops = &bank_fops },
- { .name = "flags", .fops = &flags_fops },
- { .name = "cpu", .fops = &extcpu_fops },
+ { .name = "status", .fops = &status_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "misc", .fops = &misc_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "addr", .fops = &addr_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "bank", .fops = &bank_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "flags", .fops = &flags_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "cpu", .fops = &extcpu_fops, .perm = S_IRUSR | S_IWUSR },
+ { .name = "README", .fops = &readme_fops, .perm = S_IRUSR | S_IRGRP | S_IROTH },
};
static int __init init_mce_inject(void)
{
int i;
+ u64 cap;
+
+ rdmsrl(MSR_IA32_MCG_CAP, cap);
+ n_banks = cap & MCG_BANKCNT_MASK;
dfs_inj = debugfs_create_dir("mce-inject", NULL);
if (!dfs_inj)
for (i = 0; i < ARRAY_SIZE(dfs_fls); i++) {
dfs_fls[i].d = debugfs_create_file(dfs_fls[i].name,
- S_IRUSR | S_IWUSR,
+ dfs_fls[i].perm,
dfs_inj,
&i_mce,
dfs_fls[i].fops);
projects / deliverable / linux.git / blobdiff