Contributors: 92
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Kees Cook |
308 |
11.94% |
14 |
7.29% |
| Andi Kleen |
305 |
11.83% |
11 |
5.73% |
| Andrew Morton |
254 |
9.85% |
4 |
2.08% |
| Linus Torvalds (pre-git) |
183 |
7.10% |
20 |
10.42% |
| Arjan van de Ven |
135 |
5.23% |
7 |
3.65% |
| Feng Tang |
129 |
5.00% |
4 |
2.08% |
| Hidehiro Kawai |
127 |
4.92% |
6 |
3.12% |
| Rafael Aquini |
111 |
4.30% |
1 |
0.52% |
| Tamuki Shoichi |
95 |
3.68% |
1 |
0.52% |
| Linus Torvalds |
74 |
2.87% |
6 |
3.12% |
| Guilherme G. Piccoli |
71 |
2.75% |
4 |
2.08% |
| Petr Mladek |
45 |
1.74% |
1 |
0.52% |
| Rusty Russell |
41 |
1.59% |
3 |
1.56% |
| tangmeng |
39 |
1.51% |
1 |
0.52% |
| Borislav Petkov |
36 |
1.40% |
4 |
2.08% |
| Ingo Molnar |
33 |
1.28% |
6 |
3.12% |
| Ben Hutchings |
33 |
1.28% |
3 |
1.56% |
| Peter Zijlstra |
32 |
1.24% |
2 |
1.04% |
| Uros Bizjak |
30 |
1.16% |
1 |
0.52% |
| Josh Poimboeuf |
30 |
1.16% |
3 |
1.56% |
| Prarit Bhargava |
28 |
1.09% |
1 |
0.52% |
| Baoquan He |
21 |
0.81% |
1 |
0.52% |
| Michael Holzheu |
21 |
0.81% |
1 |
0.52% |
| Masami Hiramatsu |
18 |
0.70% |
1 |
0.52% |
| Arnaldo Carvalho de Melo |
18 |
0.70% |
1 |
0.52% |
| Alex Thorlton |
17 |
0.66% |
1 |
0.52% |
| Andy Shevchenko |
16 |
0.62% |
2 |
1.04% |
| Anton Blanchard |
16 |
0.62% |
2 |
1.04% |
| Marco Elver |
14 |
0.54% |
1 |
0.52% |
| Simon Kågström |
13 |
0.50% |
1 |
0.52% |
| Thomas Gleixner |
13 |
0.50% |
4 |
2.08% |
| David Gow |
12 |
0.47% |
1 |
0.52% |
| Art Haas |
12 |
0.47% |
1 |
0.52% |
| Matt Mackall |
11 |
0.43% |
3 |
1.56% |
| Fabian Frederick |
11 |
0.43% |
1 |
0.52% |
| Aaro Koskinen |
11 |
0.43% |
2 |
1.04% |
| Steven Rostedt |
11 |
0.43% |
4 |
2.08% |
| Christoph Hellwig |
11 |
0.43% |
1 |
0.52% |
| Alexander van Heukelum |
10 |
0.39% |
1 |
0.52% |
| Jason Wessel |
10 |
0.39% |
2 |
1.04% |
| Olaf Hering |
9 |
0.35% |
1 |
0.52% |
| Mel Gorman |
9 |
0.35% |
1 |
0.52% |
| Vitaly Kuznetsov |
9 |
0.35% |
2 |
1.04% |
| Hugh Dickins |
8 |
0.31% |
1 |
0.52% |
| Eric W. Biedermann |
8 |
0.31% |
2 |
1.04% |
| Joshua Hunt |
6 |
0.23% |
1 |
0.52% |
| Eric Dumazet |
6 |
0.23% |
1 |
0.52% |
| Doug Anderson |
6 |
0.23% |
1 |
0.52% |
| Heiko Carstens |
5 |
0.19% |
2 |
1.04% |
| Sergey Senozhatsky |
5 |
0.19% |
1 |
0.52% |
| Alan Stern |
5 |
0.19% |
1 |
0.52% |
| Frédéric Weisbecker |
5 |
0.19% |
1 |
0.52% |
| Christophe Leroy |
5 |
0.19% |
1 |
0.52% |
| Seth Jennings |
5 |
0.19% |
1 |
0.52% |
| Mathieu Desnoyers |
5 |
0.19% |
1 |
0.52% |
| Huang Ying |
5 |
0.19% |
1 |
0.52% |
| Jeremy Fitzhardinge |
4 |
0.16% |
1 |
0.52% |
| Nicholas Piggin |
4 |
0.16% |
2 |
1.04% |
| Don Zickus |
3 |
0.12% |
1 |
0.52% |
| Jan Beulich |
3 |
0.12% |
1 |
0.52% |
| Daisuke Hatayama |
3 |
0.12% |
1 |
0.52% |
| Vikram Mulukutla |
3 |
0.12% |
1 |
0.52% |
| Alexander Nyberg |
3 |
0.12% |
1 |
0.52% |
| Eduardo Pereira Habkost |
3 |
0.12% |
1 |
0.52% |
| Will Deacon |
3 |
0.12% |
1 |
0.52% |
| Nur Hussein |
3 |
0.12% |
1 |
0.52% |
| Yue haibing |
2 |
0.08% |
1 |
0.52% |
| Matteo Croce |
2 |
0.08% |
1 |
0.52% |
| Tejun Heo |
2 |
0.08% |
1 |
0.52% |
| Prasanna S. Panchamukhi |
2 |
0.08% |
1 |
0.52% |
| Kyle McMartin |
2 |
0.08% |
1 |
0.52% |
| Pavel Emelyanov |
2 |
0.08% |
1 |
0.52% |
| Éric Piel |
2 |
0.08% |
1 |
0.52% |
| Jason Baron |
2 |
0.08% |
1 |
0.52% |
| Martin Schwidefsky |
2 |
0.08% |
2 |
1.04% |
| Dave Jones |
2 |
0.08% |
1 |
0.52% |
| Vijay Kumar |
2 |
0.08% |
1 |
0.52% |
| Theodore Y. Ts'o |
2 |
0.08% |
1 |
0.52% |
| Vineet Gupta |
2 |
0.08% |
1 |
0.52% |
| Tiezhu Yang |
2 |
0.08% |
2 |
1.04% |
| Larry Finger |
2 |
0.08% |
1 |
0.52% |
| Sebastian Andrzej Siewior |
1 |
0.04% |
1 |
0.52% |
| Kefeng Wang |
1 |
0.04% |
1 |
0.52% |
| Mauro Carvalho Chehab |
1 |
0.04% |
1 |
0.52% |
| Yue Hu |
1 |
0.04% |
1 |
0.52% |
| Christian Bornträger |
1 |
0.04% |
1 |
0.52% |
| Octavian Purdila |
1 |
0.04% |
1 |
0.52% |
| Greg Kroah-Hartman |
1 |
0.04% |
1 |
0.52% |
| Jiri Slaby |
1 |
0.04% |
1 |
0.52% |
| John Ogness |
1 |
0.04% |
1 |
0.52% |
| Tom 'spot' Callaway |
1 |
0.04% |
1 |
0.52% |
| Jeff Dike |
1 |
0.04% |
1 |
0.52% |
| Total |
2579 |
|
192 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* 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/debug_locks.h>
#include <linux/sched/debug.h>
#include <linux/interrupt.h>
#include <linux/kgdb.h>
#include <linux/kmsg_dump.h>
#include <linux/kallsyms.h>
#include <linux/notifier.h>
#include <linux/vt_kern.h>
#include <linux/module.h>
#include <linux/random.h>
#include <linux/ftrace.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/kexec.h>
#include <linux/panic_notifier.h>
#include <linux/sched.h>
#include <linux/string_helpers.h>
#include <linux/sysrq.h>
#include <linux/init.h>
#include <linux/nmi.h>
#include <linux/console.h>
#include <linux/bug.h>
#include <linux/ratelimit.h>
#include <linux/debugfs.h>
#include <linux/sysfs.h>
#include <linux/context_tracking.h>
#include <trace/events/error_report.h>
#include <asm/sections.h>
#define PANIC_TIMER_STEP 100
#define PANIC_BLINK_SPD 18
#ifdef CONFIG_SMP
/*
* Should we dump all CPUs backtraces in an oops event?
* Defaults to 0, can be changed via sysctl.
*/
static unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
#else
#define sysctl_oops_all_cpu_backtrace 0
#endif /* CONFIG_SMP */
int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
static unsigned long tainted_mask =
IS_ENABLED(CONFIG_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
static int pause_on_oops;
static int pause_on_oops_flag;
static DEFINE_SPINLOCK(pause_on_oops_lock);
bool crash_kexec_post_notifiers;
int panic_on_warn __read_mostly;
unsigned long panic_on_taint;
bool panic_on_taint_nousertaint = false;
static unsigned int warn_limit __read_mostly;
int panic_timeout = CONFIG_PANIC_TIMEOUT;
EXPORT_SYMBOL_GPL(panic_timeout);
#define PANIC_PRINT_TASK_INFO 0x00000001
#define PANIC_PRINT_MEM_INFO 0x00000002
#define PANIC_PRINT_TIMER_INFO 0x00000004
#define PANIC_PRINT_LOCK_INFO 0x00000008
#define PANIC_PRINT_FTRACE_INFO 0x00000010
#define PANIC_PRINT_ALL_PRINTK_MSG 0x00000020
#define PANIC_PRINT_ALL_CPU_BT 0x00000040
#define PANIC_PRINT_BLOCKED_TASKS 0x00000080
unsigned long panic_print;
ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
EXPORT_SYMBOL(panic_notifier_list);
#ifdef CONFIG_SYSCTL
static struct ctl_table kern_panic_table[] = {
#ifdef CONFIG_SMP
{
.procname = "oops_all_cpu_backtrace",
.data = &sysctl_oops_all_cpu_backtrace,
.maxlen = sizeof(int),
.mode = 0644,
.proc_handler = proc_dointvec_minmax,
.extra1 = SYSCTL_ZERO,
.extra2 = SYSCTL_ONE,
},
#endif
{
.procname = "warn_limit",
.data = &warn_limit,
.maxlen = sizeof(warn_limit),
.mode = 0644,
.proc_handler = proc_douintvec,
},
{ }
};
static __init int kernel_panic_sysctls_init(void)
{
register_sysctl_init("kernel", kern_panic_table);
return 0;
}
late_initcall(kernel_panic_sysctls_init);
#endif
static atomic_t warn_count = ATOMIC_INIT(0);
#ifdef CONFIG_SYSFS
static ssize_t warn_count_show(struct kobject *kobj, struct kobj_attribute *attr,
char *page)
{
return sysfs_emit(page, "%d\n", atomic_read(&warn_count));
}
static struct kobj_attribute warn_count_attr = __ATTR_RO(warn_count);
static __init int kernel_panic_sysfs_init(void)
{
sysfs_add_file_to_group(kernel_kobj, &warn_count_attr.attr, NULL);
return 0;
}
late_initcall(kernel_panic_sysfs_init);
#endif
static long no_blink(int state)
{
return 0;
}
/* Returns how long it waited in ms */
long (*panic_blink)(int state);
EXPORT_SYMBOL(panic_blink);
/*
* Stop ourself in panic -- architecture code may override this
*/
void __weak __noreturn panic_smp_self_stop(void)
{
while (1)
cpu_relax();
}
/*
* Stop ourselves in NMI context if another CPU has already panicked. Arch code
* may override this to prepare for crash dumping, e.g. save regs info.
*/
void __weak __noreturn nmi_panic_self_stop(struct pt_regs *regs)
{
panic_smp_self_stop();
}
/*
* Stop other CPUs in panic. Architecture dependent code may override this
* with more suitable version. For example, if the architecture supports
* crash dump, it should save registers of each stopped CPU and disable
* per-CPU features such as virtualization extensions.
*/
void __weak crash_smp_send_stop(void)
{
static int cpus_stopped;
/*
* This function can be called twice in panic path, but obviously
* we execute this only once.
*/
if (cpus_stopped)
return;
/*
* 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();
cpus_stopped = 1;
}
atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
/*
* A variant of panic() called from NMI context. We return if we've already
* panicked on this CPU. If another CPU already panicked, loop in
* nmi_panic_self_stop() which can provide architecture dependent code such
* as saving register state for crash dump.
*/
void nmi_panic(struct pt_regs *regs, const char *msg)
{
int old_cpu, this_cpu;
old_cpu = PANIC_CPU_INVALID;
this_cpu = raw_smp_processor_id();
/* atomic_try_cmpxchg updates old_cpu on failure */
if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu))
panic("%s", msg);
else if (old_cpu != this_cpu)
nmi_panic_self_stop(regs);
}
EXPORT_SYMBOL(nmi_panic);
static void panic_print_sys_info(bool console_flush)
{
if (console_flush) {
if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
console_flush_on_panic(CONSOLE_REPLAY_ALL);
return;
}
if (panic_print & PANIC_PRINT_TASK_INFO)
show_state();
if (panic_print & PANIC_PRINT_MEM_INFO)
show_mem();
if (panic_print & PANIC_PRINT_TIMER_INFO)
sysrq_timer_list_show();
if (panic_print & PANIC_PRINT_LOCK_INFO)
debug_show_all_locks();
if (panic_print & PANIC_PRINT_FTRACE_INFO)
ftrace_dump(DUMP_ALL);
if (panic_print & PANIC_PRINT_BLOCKED_TASKS)
show_state_filter(TASK_UNINTERRUPTIBLE);
}
void check_panic_on_warn(const char *origin)
{
unsigned int limit;
if (panic_on_warn)
panic("%s: panic_on_warn set ...\n", origin);
limit = READ_ONCE(warn_limit);
if (atomic_inc_return(&warn_count) >= limit && limit)
panic("%s: system warned too often (kernel.warn_limit is %d)",
origin, limit);
}
/*
* Helper that triggers the NMI backtrace (if set in panic_print)
* and then performs the secondary CPUs shutdown - we cannot have
* the NMI backtrace after the CPUs are off!
*/
static void panic_other_cpus_shutdown(bool crash_kexec)
{
if (panic_print & PANIC_PRINT_ALL_CPU_BT)
trigger_all_cpu_backtrace();
/*
* Note that smp_send_stop() is the usual SMP shutdown function,
* which unfortunately may not be hardened to work in a panic
* situation. If we want to do crash dump after notifier calls
* and kmsg_dump, we will need architecture dependent extra
* bits in addition to stopping other CPUs, hence we rely on
* crash_smp_send_stop() for that.
*/
if (!crash_kexec)
smp_send_stop();
else
crash_smp_send_stop();
}
/**
* panic - halt the system
* @fmt: The text string to print
*
* Display a message, then perform cleanups.
*
* This function never returns.
*/
void panic(const char *fmt, ...)
{
static char buf[1024];
va_list args;
long i, i_next = 0, len;
int state = 0;
int old_cpu, this_cpu;
bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
if (panic_on_warn) {
/*
* This thread may hit another WARN() in the panic path.
* Resetting this prevents additional WARN() from panicking the
* system on this thread. Other threads are blocked by the
* panic_mutex in panic().
*/
panic_on_warn = 0;
}
/*
* Disable local interrupts. This will prevent panic_smp_self_stop
* from deadlocking the first cpu that invokes the panic, since
* there is nothing to prevent an interrupt handler (that runs
* after setting panic_cpu) from invoking panic() again.
*/
local_irq_disable();
preempt_disable_notrace();
/*
* 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...
*
* Only one CPU is allowed to execute the panic code from here. For
* multiple parallel invocations of panic, all other CPUs either
* stop themself or will wait until they are stopped by the 1st CPU
* with smp_send_stop().
*
* cmpxchg success means this is the 1st CPU which comes here,
* so go ahead.
* `old_cpu == this_cpu' means we came from nmi_panic() which sets
* panic_cpu to this CPU. In this case, this is also the 1st CPU.
*/
old_cpu = PANIC_CPU_INVALID;
this_cpu = raw_smp_processor_id();
/* atomic_try_cmpxchg updates old_cpu on failure */
if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu)) {
/* go ahead */
} else if (old_cpu != this_cpu)
panic_smp_self_stop();
console_verbose();
bust_spinlocks(1);
va_start(args, fmt);
len = vscnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
if (len && buf[len - 1] == '\n')
buf[len - 1] = '\0';
pr_emerg("Kernel panic - not syncing: %s\n", buf);
#ifdef CONFIG_DEBUG_BUGVERBOSE
/*
* Avoid nested stack-dumping if a panic occurs during oops processing
*/
if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
dump_stack();
#endif
/*
* If kgdb is enabled, give it a chance to run before we stop all
* the other CPUs or else we won't be able to debug processes left
* running on them.
*/
kgdb_panic(buf);
/*
* If we have crashed and we have a crash kernel loaded let it handle
* everything else.
* If we want to run this after calling panic_notifiers, pass
* the "crash_kexec_post_notifiers" option to the kernel.
*
* Bypass the panic_cpu check and call __crash_kexec directly.
*/
if (!_crash_kexec_post_notifiers)
__crash_kexec(NULL);
panic_other_cpus_shutdown(_crash_kexec_post_notifiers);
/*
* Run any panic handlers, including those that might need to
* add information to the kmsg dump output.
*/
atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
panic_print_sys_info(false);
kmsg_dump(KMSG_DUMP_PANIC);
/*
* If you doubt kdump always works fine in any situation,
* "crash_kexec_post_notifiers" offers you a chance to run
* panic_notifiers and dumping kmsg before kdump.
* Note: since some panic_notifiers can make crashed kernel
* more unstable, it can increase risks of the kdump failure too.
*
* Bypass the panic_cpu check and call __crash_kexec directly.
*/
if (_crash_kexec_post_notifiers)
__crash_kexec(NULL);
console_unblank();
/*
* We may have ended up stopping the CPU holding the lock (in
* smp_send_stop()) while still having some valuable data in the console
* buffer. Try to acquire the lock then release it regardless of the
* result. The release will also print the buffers out. Locks debug
* should be disabled to avoid reporting bad unlock balance when
* panic() is not being callled from OOPS.
*/
debug_locks_off();
console_flush_on_panic(CONSOLE_FLUSH_PENDING);
panic_print_sys_info(true);
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.
*/
pr_emerg("Rebooting in %d seconds..\n", panic_timeout);
for (i = 0; i < panic_timeout * 1000; i += PANIC_TIMER_STEP) {
touch_nmi_watchdog();
if (i >= i_next) {
i += panic_blink(state ^= 1);
i_next = i + 3600 / PANIC_BLINK_SPD;
}
mdelay(PANIC_TIMER_STEP);
}
}
if (panic_timeout != 0) {
/*
* 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.
*/
if (panic_reboot_mode != REBOOT_UNDEFINED)
reboot_mode = panic_reboot_mode;
emergency_restart();
}
#ifdef __sparc__
{
extern int stop_a_enabled;
/* Make sure the user can actually press Stop-A (L1-A) */
stop_a_enabled = 1;
pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n"
"twice on console to return to the boot prom\n");
}
#endif
#if defined(CONFIG_S390)
disabled_wait();
#endif
pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf);
/* Do not scroll important messages printed above */
suppress_printk = 1;
/*
* The final messages may not have been printed if in a context that
* defers printing (such as NMI) and irq_work is not available.
* Explicitly flush the kernel log buffer one last time.
*/
console_flush_on_panic(CONSOLE_FLUSH_PENDING);
local_irq_enable();
for (i = 0; ; i += PANIC_TIMER_STEP) {
touch_softlockup_watchdog();
if (i >= i_next) {
i += panic_blink(state ^= 1);
i_next = i + 3600 / PANIC_BLINK_SPD;
}
mdelay(PANIC_TIMER_STEP);
}
}
EXPORT_SYMBOL(panic);
/*
* TAINT_FORCED_RMMOD could be a per-module flag but the module
* is being removed anyway.
*/
const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
[ TAINT_PROPRIETARY_MODULE ] = { 'P', 'G', true },
[ TAINT_FORCED_MODULE ] = { 'F', ' ', true },
[ TAINT_CPU_OUT_OF_SPEC ] = { 'S', ' ', false },
[ TAINT_FORCED_RMMOD ] = { 'R', ' ', false },
[ TAINT_MACHINE_CHECK ] = { 'M', ' ', false },
[ TAINT_BAD_PAGE ] = { 'B', ' ', false },
[ TAINT_USER ] = { 'U', ' ', false },
[ TAINT_DIE ] = { 'D', ' ', false },
[ TAINT_OVERRIDDEN_ACPI_TABLE ] = { 'A', ' ', false },
[ TAINT_WARN ] = { 'W', ' ', false },
[ TAINT_CRAP ] = { 'C', ' ', true },
[ TAINT_FIRMWARE_WORKAROUND ] = { 'I', ' ', false },
[ TAINT_OOT_MODULE ] = { 'O', ' ', true },
[ TAINT_UNSIGNED_MODULE ] = { 'E', ' ', true },
[ TAINT_SOFTLOCKUP ] = { 'L', ' ', false },
[ TAINT_LIVEPATCH ] = { 'K', ' ', true },
[ TAINT_AUX ] = { 'X', ' ', true },
[ TAINT_RANDSTRUCT ] = { 'T', ' ', true },
[ TAINT_TEST ] = { 'N', ' ', true },
};
/**
* print_tainted - return a string to represent the kernel taint state.
*
* For individual taint flag meanings, see Documentation/admin-guide/sysctl/kernel.rst
*
* The string is overwritten by the next call to print_tainted(),
* but is always NULL terminated.
*/
const char *print_tainted(void)
{
static char buf[TAINT_FLAGS_COUNT + sizeof("Tainted: ")];
BUILD_BUG_ON(ARRAY_SIZE(taint_flags) != TAINT_FLAGS_COUNT);
if (tainted_mask) {
char *s;
int i;
s = buf + sprintf(buf, "Tainted: ");
for (i = 0; i < TAINT_FLAGS_COUNT; i++) {
const struct taint_flag *t = &taint_flags[i];
*s++ = test_bit(i, &tainted_mask) ?
t->c_true : t->c_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;
}
/**
* add_taint: add a taint flag if not already set.
* @flag: one of the TAINT_* constants.
* @lockdep_ok: whether lock debugging is still OK.
*
* If something bad has gone wrong, you'll want @lockdebug_ok = false, but for
* some notewortht-but-not-corrupting cases, it can be set to true.
*/
void add_taint(unsigned flag, enum lockdep_ok lockdep_ok)
{
if (lockdep_ok == LOCKDEP_NOW_UNRELIABLE && __debug_locks_off())
pr_warn("Disabling lock debugging due to kernel taint\n");
set_bit(flag, &tainted_mask);
if (tainted_mask & panic_on_taint) {
panic_on_taint = 0;
panic("panic_on_taint set ...");
}
}
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..
*/
bool 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)
{
tracing_off();
/* can't trust the integrity of the kernel anymore: */
debug_locks_off();
do_oops_enter_exit();
if (sysctl_oops_all_cpu_backtrace)
trigger_all_cpu_backtrace();
}
static void print_oops_end_marker(void)
{
pr_warn("---[ end trace %016llx ]---\n", 0ULL);
}
/*
* Called when the architecture exits its oops handler, after printing
* everything.
*/
void oops_exit(void)
{
do_oops_enter_exit();
print_oops_end_marker();
kmsg_dump(KMSG_DUMP_OOPS);
}
struct warn_args {
const char *fmt;
va_list args;
};
void __warn(const char *file, int line, void *caller, unsigned taint,
struct pt_regs *regs, struct warn_args *args)
{
disable_trace_on_warning();
if (file)
pr_warn("WARNING: CPU: %d PID: %d at %s:%d %pS\n",
raw_smp_processor_id(), current->pid, file, line,
caller);
else
pr_warn("WARNING: CPU: %d PID: %d at %pS\n",
raw_smp_processor_id(), current->pid, caller);
#pragma GCC diagnostic push
#ifndef __clang__
#pragma GCC diagnostic ignored "-Wsuggest-attribute=format"
#endif
if (args)
vprintk(args->fmt, args->args);
#pragma GCC diagnostic pop
print_modules();
if (regs)
show_regs(regs);
check_panic_on_warn("kernel");
if (!regs)
dump_stack();
print_irqtrace_events(current);
print_oops_end_marker();
trace_error_report_end(ERROR_DETECTOR_WARN, (unsigned long)caller);
/* Just a warning, don't kill lockdep. */
add_taint(taint, LOCKDEP_STILL_OK);
}
#ifdef CONFIG_BUG
#ifndef __WARN_FLAGS
void warn_slowpath_fmt(const char *file, int line, unsigned taint,
const char *fmt, ...)
{
bool rcu = warn_rcu_enter();
struct warn_args args;
pr_warn(CUT_HERE);
if (!fmt) {
__warn(file, line, __builtin_return_address(0), taint,
NULL, NULL);
warn_rcu_exit(rcu);
return;
}
args.fmt = fmt;
va_start(args.args, fmt);
__warn(file, line, __builtin_return_address(0), taint, NULL, &args);
va_end(args.args);
warn_rcu_exit(rcu);
}
EXPORT_SYMBOL(warn_slowpath_fmt);
#else
void __warn_printk(const char *fmt, ...)
{
bool rcu = warn_rcu_enter();
va_list args;
pr_warn(CUT_HERE);
va_start(args, fmt);
vprintk(fmt, args);
va_end(args);
warn_rcu_exit(rcu);
}
EXPORT_SYMBOL(__warn_printk);
#endif
/* Support resetting WARN*_ONCE state */
static int clear_warn_once_set(void *data, u64 val)
{
generic_bug_clear_once();
memset(__start_once, 0, __end_once - __start_once);
return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(clear_warn_once_fops, NULL, clear_warn_once_set,
"%lld\n");
static __init int register_warn_debugfs(void)
{
/* Don't care about failure */
debugfs_create_file_unsafe("clear_warn_once", 0200, NULL, NULL,
&clear_warn_once_fops);
return 0;
}
device_initcall(register_warn_debugfs);
#endif
#ifdef CONFIG_STACKPROTECTOR
/*
* Called when gcc's -fstack-protector feature is used, and
* gcc detects corruption of the on-stack canary value
*/
__visible noinstr void __stack_chk_fail(void)
{
instrumentation_begin();
panic("stack-protector: Kernel stack is corrupted in: %pB",
__builtin_return_address(0));
instrumentation_end();
}
EXPORT_SYMBOL(__stack_chk_fail);
#endif
core_param(panic, panic_timeout, int, 0644);
core_param(panic_print, panic_print, ulong, 0644);
core_param(pause_on_oops, pause_on_oops, int, 0644);
core_param(panic_on_warn, panic_on_warn, int, 0644);
core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
static int __init oops_setup(char *s)
{
if (!s)
return -EINVAL;
if (!strcmp(s, "panic"))
panic_on_oops = 1;
return 0;
}
early_param("oops", oops_setup);
static int __init panic_on_taint_setup(char *s)
{
char *taint_str;
if (!s)
return -EINVAL;
taint_str = strsep(&s, ",");
if (kstrtoul(taint_str, 16, &panic_on_taint))
return -EINVAL;
/* make sure panic_on_taint doesn't hold out-of-range TAINT flags */
panic_on_taint &= TAINT_FLAGS_MAX;
if (!panic_on_taint)
return -EINVAL;
if (s && !strcmp(s, "nousertaint"))
panic_on_taint_nousertaint = true;
pr_info("panic_on_taint: bitmask=0x%lx nousertaint_mode=%s\n",
panic_on_taint, str_enabled_disabled(panic_on_taint_nousertaint));
return 0;
}
early_param("panic_on_taint", panic_on_taint_setup);