Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 | /*
* Machine check injection support.
* Copyright 2008 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.
*
* Authors:
* Andi Kleen
* Ying Huang
*/
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/timer.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/fs.h>
#include <linux/preempt.h>
#include <linux/smp.h>
#include <linux/notifier.h>
#include <linux/kdebug.h>
#include <linux/cpu.h>
#include <linux/sched.h>
#include <linux/gfp.h>
#include <asm/mce.h>
#include <asm/apic.h>
#include <asm/nmi.h>
/* Update fake mce registers on current CPU. */
static void inject_mce(struct mce *m)
{
struct mce *i = &per_cpu(injectm, m->extcpu);
/* Make sure no one reads partially written injectm */
i->finished = 0;
mb();
m->finished = 0;
/* First set the fields after finished */
i->extcpu = m->extcpu;
mb();
/* Now write record in order, finished last (except above) */
memcpy(i, m, sizeof(struct mce));
/* Finally activate it */
mb();
i->finished = 1;
}
static void raise_poll(struct mce *m)
{
unsigned long flags;
mce_banks_t b;
memset(&b, 0xff, sizeof(mce_banks_t));
local_irq_save(flags);
machine_check_poll(0, &b);
local_irq_restore(flags);
m->finished = 0;
}
static void raise_exception(struct mce *m, struct pt_regs *pregs)
{
struct pt_regs regs;
unsigned long flags;
if (!pregs) {
memset(®s, 0, sizeof(struct pt_regs));
regs.ip = m->ip;
regs.cs = m->cs;
pregs = ®s;
}
/* in mcheck exeception handler, irq will be disabled */
local_irq_save(flags);
do_machine_check(pregs, 0);
local_irq_restore(flags);
m->finished = 0;
}
static cpumask_var_t mce_inject_cpumask;
static DEFINE_MUTEX(mce_inject_mutex);
static int mce_raise_notify(unsigned int cmd, struct pt_regs *regs)
{
int cpu = smp_processor_id();
struct mce *m = &__get_cpu_var(injectm);
if (!cpumask_test_cpu(cpu, mce_inject_cpumask))
return NMI_DONE;
cpumask_clear_cpu(cpu, mce_inject_cpumask);
if (m->inject_flags & MCJ_EXCEPTION)
raise_exception(m, regs);
else if (m->status)
raise_poll(m);
return NMI_HANDLED;
}
static void mce_irq_ipi(void *info)
{
int cpu = smp_processor_id();
struct mce *m = &__get_cpu_var(injectm);
if (cpumask_test_cpu(cpu, mce_inject_cpumask) &&
m->inject_flags & MCJ_EXCEPTION) {
cpumask_clear_cpu(cpu, mce_inject_cpumask);
raise_exception(m, NULL);
}
}
/* Inject mce on current CPU */
static int raise_local(void)
{
struct mce *m = &__get_cpu_var(injectm);
int context = MCJ_CTX(m->inject_flags);
int ret = 0;
int cpu = m->extcpu;
if (m->inject_flags & MCJ_EXCEPTION) {
printk(KERN_INFO "Triggering MCE exception on CPU %d\n", cpu);
switch (context) {
case MCJ_CTX_IRQ:
/*
* Could do more to fake interrupts like
* calling irq_enter, but the necessary
* machinery isn't exported currently.
*/
/*FALL THROUGH*/
case MCJ_CTX_PROCESS:
raise_exception(m, NULL);
break;
default:
printk(KERN_INFO "Invalid MCE context\n");
ret = -EINVAL;
}
printk(KERN_INFO "MCE exception done on CPU %d\n", cpu);
} else if (m->status) {
printk(KERN_INFO "Starting machine check poll CPU %d\n", cpu);
raise_poll(m);
mce_notify_irq();
printk(KERN_INFO "Machine check poll done on CPU %d\n", cpu);
} else
m->finished = 0;
return ret;
}
static void raise_mce(struct mce *m)
{
int context = MCJ_CTX(m->inject_flags);
inject_mce(m);
if (context == MCJ_CTX_RANDOM)
return;
#ifdef CONFIG_X86_LOCAL_APIC
if (m->inject_flags & (MCJ_IRQ_BRAODCAST | MCJ_NMI_BROADCAST)) {
unsigned long start;
int cpu;
get_online_cpus();
cpumask_copy(mce_inject_cpumask, cpu_online_mask);
cpumask_clear_cpu(get_cpu(), mce_inject_cpumask);
for_each_online_cpu(cpu) {
struct mce *mcpu = &per_cpu(injectm, cpu);
if (!mcpu->finished ||
MCJ_CTX(mcpu->inject_flags) != MCJ_CTX_RANDOM)
cpumask_clear_cpu(cpu, mce_inject_cpumask);
}
if (!cpumask_empty(mce_inject_cpumask)) {
if (m->inject_flags & MCJ_IRQ_BRAODCAST) {
/*
* don't wait because mce_irq_ipi is necessary
* to be sync with following raise_local
*/
preempt_disable();
smp_call_function_many(mce_inject_cpumask,
mce_irq_ipi, NULL, 0);
preempt_enable();
} else if (m->inject_flags & MCJ_NMI_BROADCAST)
apic->send_IPI_mask(mce_inject_cpumask,
NMI_VECTOR);
}
start = jiffies;
while (!cpumask_empty(mce_inject_cpumask)) {
if (!time_before(jiffies, start + 2*HZ)) {
printk(KERN_ERR
"Timeout waiting for mce inject %lx\n",
*cpumask_bits(mce_inject_cpumask));
break;
}
cpu_relax();
}
raise_local();
put_cpu();
put_online_cpus();
} else
#endif
{
preempt_disable();
raise_local();
preempt_enable();
}
}
/* Error injection interface */
static ssize_t mce_write(struct file *filp, const char __user *ubuf,
size_t usize, loff_t *off)
{
struct mce m;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
/*
* There are some cases where real MSR reads could slip
* through.
*/
if (!boot_cpu_has(X86_FEATURE_MCE) || !boot_cpu_has(X86_FEATURE_MCA))
return -EIO;
if ((unsigned long)usize > sizeof(struct mce))
usize = sizeof(struct mce);
if (copy_from_user(&m, ubuf, usize))
return -EFAULT;
if (m.extcpu >= num_possible_cpus() || !cpu_online(m.extcpu))
return -EINVAL;
/*
* Need to give user space some time to set everything up,
* so do it a jiffie or two later everywhere.
*/
schedule_timeout(2);
mutex_lock(&mce_inject_mutex);
raise_mce(&m);
mutex_unlock(&mce_inject_mutex);
return usize;
}
static int inject_init(void)
{
if (!alloc_cpumask_var(&mce_inject_cpumask, GFP_KERNEL))
return -ENOMEM;
printk(KERN_INFO "Machine check injector initialized\n");
register_mce_write_callback(mce_write);
register_nmi_handler(NMI_LOCAL, mce_raise_notify, 0,
"mce_notify");
return 0;
}
module_init(inject_init);
/*
* Cannot tolerate unloading currently because we cannot
* guarantee all openers of mce_chrdev will get a reference to us.
*/
MODULE_LICENSE("GPL");
|