377 lines
8.6 KiB
C
377 lines
8.6 KiB
C
/*
|
|
* linux/kernel/panic.c
|
|
*
|
|
* Copyright (C) 1991, 1992 Linus Torvalds
|
|
*/
|
|
|
|
/*
|
|
* This function is used through-out the kernel (including mm and fs)
|
|
* to indicate a major problem.
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/reboot.h>
|
|
#include <linux/notifier.h>
|
|
#include <linux/init.h>
|
|
#include <linux/sysrq.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/nmi.h>
|
|
#include <linux/kexec.h>
|
|
#include <linux/debug_locks.h>
|
|
#include <linux/random.h>
|
|
#include <linux/kallsyms.h>
|
|
|
|
int panic_on_oops;
|
|
static unsigned long tainted_mask;
|
|
static int pause_on_oops;
|
|
static int pause_on_oops_flag;
|
|
static DEFINE_SPINLOCK(pause_on_oops_lock);
|
|
|
|
int panic_timeout;
|
|
|
|
ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
|
|
|
|
EXPORT_SYMBOL(panic_notifier_list);
|
|
|
|
static long no_blink(long time)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/* Returns how long it waited in ms */
|
|
long (*panic_blink)(long time);
|
|
EXPORT_SYMBOL(panic_blink);
|
|
|
|
/**
|
|
* panic - halt the system
|
|
* @fmt: The text string to print
|
|
*
|
|
* Display a message, then perform cleanups.
|
|
*
|
|
* This function never returns.
|
|
*/
|
|
|
|
NORET_TYPE void panic(const char * fmt, ...)
|
|
{
|
|
long i;
|
|
static char buf[1024];
|
|
va_list args;
|
|
#if defined(CONFIG_S390)
|
|
unsigned long caller = (unsigned long) __builtin_return_address(0);
|
|
#endif
|
|
|
|
/*
|
|
* It's possible to come here directly from a panic-assertion and not
|
|
* have preempt disabled. Some functions called from here want
|
|
* preempt to be disabled. No point enabling it later though...
|
|
*/
|
|
preempt_disable();
|
|
|
|
bust_spinlocks(1);
|
|
va_start(args, fmt);
|
|
vsnprintf(buf, sizeof(buf), fmt, args);
|
|
va_end(args);
|
|
printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
|
|
bust_spinlocks(0);
|
|
|
|
/*
|
|
* If we have crashed and we have a crash kernel loaded let it handle
|
|
* everything else.
|
|
* Do we want to call this before we try to display a message?
|
|
*/
|
|
crash_kexec(NULL);
|
|
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* Note smp_send_stop is the usual smp shutdown function, which
|
|
* unfortunately means it may not be hardened to work in a panic
|
|
* situation.
|
|
*/
|
|
smp_send_stop();
|
|
#endif
|
|
|
|
atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
|
|
|
|
if (!panic_blink)
|
|
panic_blink = no_blink;
|
|
|
|
if (panic_timeout > 0) {
|
|
/*
|
|
* Delay timeout seconds before rebooting the machine.
|
|
* We can't use the "normal" timers since we just panicked..
|
|
*/
|
|
printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout);
|
|
for (i = 0; i < panic_timeout*1000; ) {
|
|
touch_nmi_watchdog();
|
|
i += panic_blink(i);
|
|
mdelay(1);
|
|
i++;
|
|
}
|
|
/* This will not be a clean reboot, with everything
|
|
* shutting down. But if there is a chance of
|
|
* rebooting the system it will be rebooted.
|
|
*/
|
|
emergency_restart();
|
|
}
|
|
#ifdef __sparc__
|
|
{
|
|
extern int stop_a_enabled;
|
|
/* Make sure the user can actually press Stop-A (L1-A) */
|
|
stop_a_enabled = 1;
|
|
printk(KERN_EMERG "Press Stop-A (L1-A) to return to the boot prom\n");
|
|
}
|
|
#endif
|
|
#if defined(CONFIG_S390)
|
|
disabled_wait(caller);
|
|
#endif
|
|
local_irq_enable();
|
|
for (i = 0;;) {
|
|
touch_softlockup_watchdog();
|
|
i += panic_blink(i);
|
|
mdelay(1);
|
|
i++;
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL(panic);
|
|
|
|
|
|
struct tnt {
|
|
u8 bit;
|
|
char true;
|
|
char false;
|
|
};
|
|
|
|
static const struct tnt tnts[] = {
|
|
{ TAINT_PROPRIETARY_MODULE, 'P', 'G' },
|
|
{ TAINT_FORCED_MODULE, 'F', ' ' },
|
|
{ TAINT_UNSAFE_SMP, 'S', ' ' },
|
|
{ TAINT_FORCED_RMMOD, 'R', ' ' },
|
|
{ TAINT_MACHINE_CHECK, 'M', ' ' },
|
|
{ TAINT_BAD_PAGE, 'B', ' ' },
|
|
{ TAINT_USER, 'U', ' ' },
|
|
{ TAINT_DIE, 'D', ' ' },
|
|
{ TAINT_OVERRIDDEN_ACPI_TABLE, 'A', ' ' },
|
|
{ TAINT_WARN, 'W', ' ' },
|
|
{ TAINT_CRAP, 'C', ' ' },
|
|
};
|
|
|
|
/**
|
|
* print_tainted - return a string to represent the kernel taint state.
|
|
*
|
|
* 'P' - Proprietary module has been loaded.
|
|
* 'F' - Module has been forcibly loaded.
|
|
* 'S' - SMP with CPUs not designed for SMP.
|
|
* 'R' - User forced a module unload.
|
|
* 'M' - System experienced a machine check exception.
|
|
* 'B' - System has hit bad_page.
|
|
* 'U' - Userspace-defined naughtiness.
|
|
* 'D' - Kernel has oopsed before
|
|
* 'A' - ACPI table overridden.
|
|
* 'W' - Taint on warning.
|
|
* 'C' - modules from drivers/staging are loaded.
|
|
*
|
|
* The string is overwritten by the next call to print_taint().
|
|
*/
|
|
const char *print_tainted(void)
|
|
{
|
|
static char buf[ARRAY_SIZE(tnts) + sizeof("Tainted: ") + 1];
|
|
|
|
if (tainted_mask) {
|
|
char *s;
|
|
int i;
|
|
|
|
s = buf + sprintf(buf, "Tainted: ");
|
|
for (i = 0; i < ARRAY_SIZE(tnts); i++) {
|
|
const struct tnt *t = &tnts[i];
|
|
*s++ = test_bit(t->bit, &tainted_mask) ?
|
|
t->true : t->false;
|
|
}
|
|
*s = 0;
|
|
} else
|
|
snprintf(buf, sizeof(buf), "Not tainted");
|
|
return(buf);
|
|
}
|
|
|
|
int test_taint(unsigned flag)
|
|
{
|
|
return test_bit(flag, &tainted_mask);
|
|
}
|
|
EXPORT_SYMBOL(test_taint);
|
|
|
|
unsigned long get_taint(void)
|
|
{
|
|
return tainted_mask;
|
|
}
|
|
|
|
void add_taint(unsigned flag)
|
|
{
|
|
debug_locks = 0; /* can't trust the integrity of the kernel anymore */
|
|
set_bit(flag, &tainted_mask);
|
|
}
|
|
EXPORT_SYMBOL(add_taint);
|
|
|
|
static void spin_msec(int msecs)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < msecs; i++) {
|
|
touch_nmi_watchdog();
|
|
mdelay(1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* It just happens that oops_enter() and oops_exit() are identically
|
|
* implemented...
|
|
*/
|
|
static void do_oops_enter_exit(void)
|
|
{
|
|
unsigned long flags;
|
|
static int spin_counter;
|
|
|
|
if (!pause_on_oops)
|
|
return;
|
|
|
|
spin_lock_irqsave(&pause_on_oops_lock, flags);
|
|
if (pause_on_oops_flag == 0) {
|
|
/* This CPU may now print the oops message */
|
|
pause_on_oops_flag = 1;
|
|
} else {
|
|
/* We need to stall this CPU */
|
|
if (!spin_counter) {
|
|
/* This CPU gets to do the counting */
|
|
spin_counter = pause_on_oops;
|
|
do {
|
|
spin_unlock(&pause_on_oops_lock);
|
|
spin_msec(MSEC_PER_SEC);
|
|
spin_lock(&pause_on_oops_lock);
|
|
} while (--spin_counter);
|
|
pause_on_oops_flag = 0;
|
|
} else {
|
|
/* This CPU waits for a different one */
|
|
while (spin_counter) {
|
|
spin_unlock(&pause_on_oops_lock);
|
|
spin_msec(1);
|
|
spin_lock(&pause_on_oops_lock);
|
|
}
|
|
}
|
|
}
|
|
spin_unlock_irqrestore(&pause_on_oops_lock, flags);
|
|
}
|
|
|
|
/*
|
|
* Return true if the calling CPU is allowed to print oops-related info. This
|
|
* is a bit racy..
|
|
*/
|
|
int oops_may_print(void)
|
|
{
|
|
return pause_on_oops_flag == 0;
|
|
}
|
|
|
|
/*
|
|
* Called when the architecture enters its oops handler, before it prints
|
|
* anything. If this is the first CPU to oops, and it's oopsing the first time
|
|
* then let it proceed.
|
|
*
|
|
* This is all enabled by the pause_on_oops kernel boot option. We do all this
|
|
* to ensure that oopses don't scroll off the screen. It has the side-effect
|
|
* of preventing later-oopsing CPUs from mucking up the display, too.
|
|
*
|
|
* It turns out that the CPU which is allowed to print ends up pausing for the
|
|
* right duration, whereas all the other CPUs pause for twice as long: once in
|
|
* oops_enter(), once in oops_exit().
|
|
*/
|
|
void oops_enter(void)
|
|
{
|
|
debug_locks_off(); /* can't trust the integrity of the kernel anymore */
|
|
do_oops_enter_exit();
|
|
}
|
|
|
|
/*
|
|
* 64-bit random ID for oopses:
|
|
*/
|
|
static u64 oops_id;
|
|
|
|
static int init_oops_id(void)
|
|
{
|
|
if (!oops_id)
|
|
get_random_bytes(&oops_id, sizeof(oops_id));
|
|
|
|
return 0;
|
|
}
|
|
late_initcall(init_oops_id);
|
|
|
|
static void print_oops_end_marker(void)
|
|
{
|
|
init_oops_id();
|
|
printk(KERN_WARNING "---[ end trace %016llx ]---\n",
|
|
(unsigned long long)oops_id);
|
|
}
|
|
|
|
/*
|
|
* Called when the architecture exits its oops handler, after printing
|
|
* everything.
|
|
*/
|
|
void oops_exit(void)
|
|
{
|
|
do_oops_enter_exit();
|
|
print_oops_end_marker();
|
|
}
|
|
|
|
#ifdef WANT_WARN_ON_SLOWPATH
|
|
void warn_on_slowpath(const char *file, int line)
|
|
{
|
|
char function[KSYM_SYMBOL_LEN];
|
|
unsigned long caller = (unsigned long) __builtin_return_address(0);
|
|
sprint_symbol(function, caller);
|
|
|
|
printk(KERN_WARNING "------------[ cut here ]------------\n");
|
|
printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
|
|
line, function);
|
|
print_modules();
|
|
dump_stack();
|
|
print_oops_end_marker();
|
|
add_taint(TAINT_WARN);
|
|
}
|
|
EXPORT_SYMBOL(warn_on_slowpath);
|
|
|
|
|
|
void warn_slowpath(const char *file, int line, const char *fmt, ...)
|
|
{
|
|
va_list args;
|
|
char function[KSYM_SYMBOL_LEN];
|
|
unsigned long caller = (unsigned long)__builtin_return_address(0);
|
|
sprint_symbol(function, caller);
|
|
|
|
printk(KERN_WARNING "------------[ cut here ]------------\n");
|
|
printk(KERN_WARNING "WARNING: at %s:%d %s()\n", file,
|
|
line, function);
|
|
va_start(args, fmt);
|
|
vprintk(fmt, args);
|
|
va_end(args);
|
|
|
|
print_modules();
|
|
dump_stack();
|
|
print_oops_end_marker();
|
|
add_taint(TAINT_WARN);
|
|
}
|
|
EXPORT_SYMBOL(warn_slowpath);
|
|
#endif
|
|
|
|
#ifdef CONFIG_CC_STACKPROTECTOR
|
|
/*
|
|
* Called when gcc's -fstack-protector feature is used, and
|
|
* gcc detects corruption of the on-stack canary value
|
|
*/
|
|
void __stack_chk_fail(void)
|
|
{
|
|
panic("stack-protector: Kernel stack is corrupted");
|
|
}
|
|
EXPORT_SYMBOL(__stack_chk_fail);
|
|
#endif
|
|
|
|
core_param(panic, panic_timeout, int, 0644);
|
|
core_param(pause_on_oops, pause_on_oops, int, 0644);
|