#include <linux/security.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
+#include <linux/aio.h>
#include <linux/syscalls.h>
#include <linux/kexec.h>
#include <linux/kdb.h>
#include <linux/notifier.h>
#include <linux/rculist.h>
#include <linux/poll.h>
+#include <linux/irq_work.h>
+#include <linux/utsname.h>
#include <asm/uaccess.h>
#define CREATE_TRACE_POINTS
#include <trace/events/printk.h>
-/*
- * Architectures can override it:
- */
-void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...)
-{
-}
+#include "console_cmdline.h"
+#include "braille.h"
/* printk's without a loglevel use this.. */
#define DEFAULT_MESSAGE_LOGLEVEL CONFIG_DEFAULT_MESSAGE_LOGLEVEL
#define MINIMUM_CONSOLE_LOGLEVEL 1 /* Minimum loglevel we let people use */
#define DEFAULT_CONSOLE_LOGLEVEL 7 /* anything MORE serious than KERN_DEBUG */
-DECLARE_WAIT_QUEUE_HEAD(log_wait);
-
int console_printk[4] = {
DEFAULT_CONSOLE_LOGLEVEL, /* console_loglevel */
DEFAULT_MESSAGE_LOGLEVEL, /* default_message_loglevel */
struct console *console_drivers;
EXPORT_SYMBOL_GPL(console_drivers);
+#ifdef CONFIG_LOCKDEP
+static struct lockdep_map console_lock_dep_map = {
+ .name = "console_lock"
+};
+#endif
+
/*
* This is used for debugging the mess that is the VT code by
* keeping track if we have the console semaphore held. It's
/*
* Array of consoles built from command line options (console=)
*/
-struct console_cmdline
-{
- char name[8]; /* Name of the driver */
- int index; /* Minor dev. to use */
- char *options; /* Options for the driver */
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
- char *brl_options; /* Options for braille driver */
-#endif
-};
#define MAX_CMDLINECONSOLES 8
static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
+
static int selected_console = -1;
static int preferred_console = -1;
int console_set_on_cmdline;
* 67 "g"
* 0032 00 00 00 padding to next message header
*
- * The 'struct log' buffer header must never be directly exported to
+ * The 'struct printk_log' buffer header must never be directly exported to
* userspace, it is a kernel-private implementation detail that might
* need to be changed in the future, when the requirements change.
*
LOG_CONT = 8, /* text is a fragment of a continuation line */
};
-struct log {
+struct printk_log {
u64 ts_nsec; /* timestamp in nanoseconds */
u16 len; /* length of entire record */
u16 text_len; /* length of text buffer */
static DEFINE_RAW_SPINLOCK(logbuf_lock);
#ifdef CONFIG_PRINTK
+DECLARE_WAIT_QUEUE_HEAD(log_wait);
/* the next printk record to read by syslog(READ) or /proc/kmsg */
static u64 syslog_seq;
static u32 syslog_idx;
#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)
#define LOG_ALIGN 4
#else
-#define LOG_ALIGN __alignof__(struct log)
+#define LOG_ALIGN __alignof__(struct printk_log)
#endif
#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN);
static volatile unsigned int logbuf_cpu = UINT_MAX;
/* human readable text of the record */
-static char *log_text(const struct log *msg)
+static char *log_text(const struct printk_log *msg)
{
- return (char *)msg + sizeof(struct log);
+ return (char *)msg + sizeof(struct printk_log);
}
/* optional key/value pair dictionary attached to the record */
-static char *log_dict(const struct log *msg)
+static char *log_dict(const struct printk_log *msg)
{
- return (char *)msg + sizeof(struct log) + msg->text_len;
+ return (char *)msg + sizeof(struct printk_log) + msg->text_len;
}
/* get record by index; idx must point to valid msg */
-static struct log *log_from_idx(u32 idx)
+static struct printk_log *log_from_idx(u32 idx)
{
- struct log *msg = (struct log *)(log_buf + idx);
+ struct printk_log *msg = (struct printk_log *)(log_buf + idx);
/*
* A length == 0 record is the end of buffer marker. Wrap around and
* read the message at the start of the buffer.
*/
if (!msg->len)
- return (struct log *)log_buf;
+ return (struct printk_log *)log_buf;
return msg;
}
/* get next record; idx must point to valid msg */
static u32 log_next(u32 idx)
{
- struct log *msg = (struct log *)(log_buf + idx);
+ struct printk_log *msg = (struct printk_log *)(log_buf + idx);
/* length == 0 indicates the end of the buffer; wrap */
/*
* return the one after that.
*/
if (!msg->len) {
- msg = (struct log *)log_buf;
+ msg = (struct printk_log *)log_buf;
return msg->len;
}
return idx + msg->len;
const char *dict, u16 dict_len,
const char *text, u16 text_len)
{
- struct log *msg;
+ struct printk_log *msg;
u32 size, pad_len;
/* number of '\0' padding bytes to next message */
- size = sizeof(struct log) + text_len + dict_len;
+ size = sizeof(struct printk_log) + text_len + dict_len;
pad_len = (-size) & (LOG_ALIGN - 1);
size += pad_len;
else
free = log_first_idx - log_next_idx;
- if (free > size + sizeof(struct log))
+ if (free > size + sizeof(struct printk_log))
break;
/* drop old messages until we have enough contiuous space */
log_first_seq++;
}
- if (log_next_idx + size + sizeof(struct log) >= log_buf_len) {
+ if (log_next_idx + size + sizeof(struct printk_log) >= log_buf_len) {
/*
* This message + an additional empty header does not fit
* at the end of the buffer. Add an empty header with len == 0
* to signify a wrap around.
*/
- memset(log_buf + log_next_idx, 0, sizeof(struct log));
+ memset(log_buf + log_next_idx, 0, sizeof(struct printk_log));
log_next_idx = 0;
}
/* fill message */
- msg = (struct log *)(log_buf + log_next_idx);
+ msg = (struct printk_log *)(log_buf + log_next_idx);
memcpy(log_text(msg), text, text_len);
msg->text_len = text_len;
memcpy(log_dict(msg), dict, dict_len);
else
msg->ts_nsec = local_clock();
memset(log_dict(msg) + dict_len, 0, pad_len);
- msg->len = sizeof(struct log) + text_len + dict_len + pad_len;
+ msg->len = sizeof(struct printk_log) + text_len + dict_len + pad_len;
/* insert message */
log_next_idx += msg->len;
log_next_seq++;
}
+#ifdef CONFIG_SECURITY_DMESG_RESTRICT
+int dmesg_restrict = 1;
+#else
+int dmesg_restrict;
+#endif
+
+static int syslog_action_restricted(int type)
+{
+ if (dmesg_restrict)
+ return 1;
+ /*
+ * Unless restricted, we allow "read all" and "get buffer size"
+ * for everybody.
+ */
+ return type != SYSLOG_ACTION_READ_ALL &&
+ type != SYSLOG_ACTION_SIZE_BUFFER;
+}
+
+static int check_syslog_permissions(int type, bool from_file)
+{
+ /*
+ * If this is from /proc/kmsg and we've already opened it, then we've
+ * already done the capabilities checks at open time.
+ */
+ if (from_file && type != SYSLOG_ACTION_OPEN)
+ return 0;
+
+ if (syslog_action_restricted(type)) {
+ if (capable(CAP_SYSLOG))
+ return 0;
+ /*
+ * For historical reasons, accept CAP_SYS_ADMIN too, with
+ * a warning.
+ */
+ if (capable(CAP_SYS_ADMIN)) {
+ pr_warn_once("%s (%d): Attempt to access syslog with "
+ "CAP_SYS_ADMIN but no CAP_SYSLOG "
+ "(deprecated).\n",
+ current->comm, task_pid_nr(current));
+ return 0;
+ }
+ return -EPERM;
+ }
+ return security_syslog(type);
+}
+
+
/* /dev/kmsg - userspace message inject/listen interface */
struct devkmsg_user {
u64 seq;
size_t count, loff_t *ppos)
{
struct devkmsg_user *user = file->private_data;
- struct log *msg;
+ struct printk_log *msg;
u64 ts_usec;
size_t i;
char cont = '-';
/* return error when data has vanished underneath us */
if (user->seq < log_first_seq)
ret = POLLIN|POLLRDNORM|POLLERR|POLLPRI;
- ret = POLLIN|POLLRDNORM;
+ else
+ ret = POLLIN|POLLRDNORM;
}
raw_spin_unlock_irq(&logbuf_lock);
if ((file->f_flags & O_ACCMODE) == O_WRONLY)
return 0;
- err = security_syslog(SYSLOG_ACTION_READ_ALL);
+ err = check_syslog_permissions(SYSLOG_ACTION_READ_ALL,
+ SYSLOG_FROM_READER);
if (err)
return err;
VMCOREINFO_SYMBOL(log_first_idx);
VMCOREINFO_SYMBOL(log_next_idx);
/*
- * Export struct log size and field offsets. User space tools can
+ * Export struct printk_log size and field offsets. User space tools can
* parse it and detect any changes to structure down the line.
*/
- VMCOREINFO_STRUCT_SIZE(log);
- VMCOREINFO_OFFSET(log, ts_nsec);
- VMCOREINFO_OFFSET(log, len);
- VMCOREINFO_OFFSET(log, text_len);
- VMCOREINFO_OFFSET(log, dict_len);
+ VMCOREINFO_STRUCT_SIZE(printk_log);
+ VMCOREINFO_OFFSET(printk_log, ts_nsec);
+ VMCOREINFO_OFFSET(printk_log, len);
+ VMCOREINFO_OFFSET(printk_log, text_len);
+ VMCOREINFO_OFFSET(printk_log, dict_len);
}
#endif
}
#endif
-#ifdef CONFIG_SECURITY_DMESG_RESTRICT
-int dmesg_restrict = 1;
-#else
-int dmesg_restrict;
-#endif
-
-static int syslog_action_restricted(int type)
-{
- if (dmesg_restrict)
- return 1;
- /* Unless restricted, we allow "read all" and "get buffer size" for everybody */
- return type != SYSLOG_ACTION_READ_ALL && type != SYSLOG_ACTION_SIZE_BUFFER;
-}
-
-static int check_syslog_permissions(int type, bool from_file)
-{
- /*
- * If this is from /proc/kmsg and we've already opened it, then we've
- * already done the capabilities checks at open time.
- */
- if (from_file && type != SYSLOG_ACTION_OPEN)
- return 0;
-
- if (syslog_action_restricted(type)) {
- if (capable(CAP_SYSLOG))
- return 0;
- /* For historical reasons, accept CAP_SYS_ADMIN too, with a warning */
- if (capable(CAP_SYS_ADMIN)) {
- printk_once(KERN_WARNING "%s (%d): "
- "Attempt to access syslog with CAP_SYS_ADMIN "
- "but no CAP_SYSLOG (deprecated).\n",
- current->comm, task_pid_nr(current));
- return 0;
- }
- return -EPERM;
- }
- return 0;
-}
-
#if defined(CONFIG_PRINTK_TIME)
static bool printk_time = 1;
#else
(unsigned long)ts, rem_nsec / 1000);
}
-static size_t print_prefix(const struct log *msg, bool syslog, char *buf)
+static size_t print_prefix(const struct printk_log *msg, bool syslog, char *buf)
{
size_t len = 0;
unsigned int prefix = (msg->facility << 3) | msg->level;
return len;
}
-static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
bool syslog, char *buf, size_t size)
{
const char *text = log_text(msg);
static int syslog_print(char __user *buf, int size)
{
char *text;
- struct log *msg;
+ struct printk_log *msg;
int len = 0;
text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
idx = clear_idx;
prev = 0;
while (seq < log_next_seq) {
- struct log *msg = log_from_idx(idx);
+ struct printk_log *msg = log_from_idx(idx);
len += msg_print_text(msg, prev, true, NULL, 0);
prev = msg->flags;
idx = clear_idx;
prev = 0;
while (len > size && seq < log_next_seq) {
- struct log *msg = log_from_idx(idx);
+ struct printk_log *msg = log_from_idx(idx);
len -= msg_print_text(msg, prev, true, NULL, 0);
prev = msg->flags;
len = 0;
prev = 0;
while (len >= 0 && seq < next_seq) {
- struct log *msg = log_from_idx(idx);
+ struct printk_log *msg = log_from_idx(idx);
int textlen;
textlen = msg_print_text(msg, prev, true, text,
error = 0;
while (seq < log_next_seq) {
- struct log *msg = log_from_idx(idx);
+ struct printk_log *msg = log_from_idx(idx);
error += msg_print_text(msg, prev, true, NULL, 0);
idx = log_next(idx);
SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
{
- return do_syslog(type, buf, len, SYSLOG_FROM_CALL);
+ return do_syslog(type, buf, len, SYSLOG_FROM_READER);
}
/*
{
struct console *con;
- trace_console(text, 0, len, len);
+ trace_console(text, len);
if (!console_drivers)
return;
}
}
logbuf_cpu = UINT_MAX;
+ raw_spin_unlock(&logbuf_lock);
if (wake)
up(&console_sem);
- raw_spin_unlock(&logbuf_lock);
return retval;
}
u8 level;
bool flushed:1;
} cont;
-static struct log *log_from_idx(u32 idx) { return NULL; }
+static struct printk_log *log_from_idx(u32 idx) { return NULL; }
static u32 log_next(u32 idx) { return 0; }
static void call_console_drivers(int level, const char *text, size_t len) {}
-static size_t msg_print_text(const struct log *msg, enum log_flags prev,
+static size_t msg_print_text(const struct printk_log *msg, enum log_flags prev,
bool syslog, char *buf, size_t size) { return 0; }
static size_t cont_print_text(char *text, size_t size) { return 0; }
#endif /* CONFIG_PRINTK */
+#ifdef CONFIG_EARLY_PRINTK
+struct console *early_console;
+
+void early_vprintk(const char *fmt, va_list ap)
+{
+ if (early_console) {
+ char buf[512];
+ int n = vscnprintf(buf, sizeof(buf), fmt, ap);
+
+ early_console->write(early_console, buf, n);
+ }
+}
+
+asmlinkage void early_printk(const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start(ap, fmt);
+ early_vprintk(fmt, ap);
+ va_end(ap);
+}
+#endif
+
static int __add_preferred_console(char *name, int idx, char *options,
char *brl_options)
{
* See if this tty is not yet registered, and
* if we have a slot free.
*/
- for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
- if (strcmp(console_cmdline[i].name, name) == 0 &&
- console_cmdline[i].index == idx) {
- if (!brl_options)
- selected_console = i;
- return 0;
+ for (i = 0, c = console_cmdline;
+ i < MAX_CMDLINECONSOLES && c->name[0];
+ i++, c++) {
+ if (strcmp(c->name, name) == 0 && c->index == idx) {
+ if (!brl_options)
+ selected_console = i;
+ return 0;
}
+ }
if (i == MAX_CMDLINECONSOLES)
return -E2BIG;
if (!brl_options)
selected_console = i;
- c = &console_cmdline[i];
strlcpy(c->name, name, sizeof(c->name));
c->options = options;
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
- c->brl_options = brl_options;
-#endif
+ braille_set_options(c, brl_options);
+
c->index = idx;
return 0;
}
char *s, *options, *brl_options = NULL;
int idx;
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
- if (!memcmp(str, "brl,", 4)) {
- brl_options = "";
- str += 4;
- } else if (!memcmp(str, "brl=", 4)) {
- brl_options = str + 4;
- str = strchr(brl_options, ',');
- if (!str) {
- printk(KERN_ERR "need port name after brl=\n");
- return 1;
- }
- *(str++) = 0;
- }
-#endif
+ if (_braille_console_setup(&str, &brl_options))
+ return 1;
/*
* Decode str into name, index, options.
struct console_cmdline *c;
int i;
- for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
- if (strcmp(console_cmdline[i].name, name) == 0 &&
- console_cmdline[i].index == idx) {
- c = &console_cmdline[i];
- strlcpy(c->name, name_new, sizeof(c->name));
- c->name[sizeof(c->name) - 1] = 0;
- c->options = options;
- c->index = idx_new;
- return i;
+ for (i = 0, c = console_cmdline;
+ i < MAX_CMDLINECONSOLES && c->name[0];
+ i++, c++)
+ if (strcmp(c->name, name) == 0 && c->index == idx) {
+ strlcpy(c->name, name_new, sizeof(c->name));
+ c->name[sizeof(c->name) - 1] = 0;
+ c->options = options;
+ c->index = idx_new;
+ return i;
}
/* not found */
return -1;
* called when a new CPU comes online (or fails to come up), and ensures
* that any such output gets printed.
*/
-static int __cpuinit console_cpu_notify(struct notifier_block *self,
+static int console_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
switch (action) {
return;
console_locked = 1;
console_may_schedule = 1;
+ mutex_acquire(&console_lock_dep_map, 0, 0, _RET_IP_);
}
EXPORT_SYMBOL(console_lock);
}
console_locked = 1;
console_may_schedule = 0;
+ mutex_acquire(&console_lock_dep_map, 0, 1, _RET_IP_);
return 1;
}
EXPORT_SYMBOL(console_trylock);
return console_locked;
}
-/*
- * Delayed printk version, for scheduler-internal messages:
- */
-#define PRINTK_BUF_SIZE 512
-
-#define PRINTK_PENDING_WAKEUP 0x01
-#define PRINTK_PENDING_SCHED 0x02
-
-static DEFINE_PER_CPU(int, printk_pending);
-static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
-
-void printk_tick(void)
-{
- if (__this_cpu_read(printk_pending)) {
- int pending = __this_cpu_xchg(printk_pending, 0);
- if (pending & PRINTK_PENDING_SCHED) {
- char *buf = __get_cpu_var(printk_sched_buf);
- printk(KERN_WARNING "[sched_delayed] %s", buf);
- }
- if (pending & PRINTK_PENDING_WAKEUP)
- wake_up_interruptible(&log_wait);
- }
-}
-
-int printk_needs_cpu(int cpu)
-{
- if (cpu_is_offline(cpu))
- printk_tick();
- return __this_cpu_read(printk_pending);
-}
-
-void wake_up_klogd(void)
-{
- if (waitqueue_active(&log_wait))
- this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
-}
-
static void console_cont_flush(char *text, size_t size)
{
unsigned long flags;
console_cont_flush(text, sizeof(text));
again:
for (;;) {
- struct log *msg;
+ struct printk_log *msg;
size_t len;
int level;
local_irq_restore(flags);
}
console_locked = 0;
+ mutex_release(&console_lock_dep_map, 1, _RET_IP_);
/* Release the exclusive_console once it is used */
if (unlikely(exclusive_console))
int i;
unsigned long flags;
struct console *bcon = NULL;
+ struct console_cmdline *c;
/*
* before we register a new CON_BOOT console, make sure we don't
* See if this console matches one we selected on
* the command line.
*/
- for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
- i++) {
- if (strcmp(console_cmdline[i].name, newcon->name) != 0)
+ for (i = 0, c = console_cmdline;
+ i < MAX_CMDLINECONSOLES && c->name[0];
+ i++, c++) {
+ if (strcmp(c->name, newcon->name) != 0)
continue;
if (newcon->index >= 0 &&
- newcon->index != console_cmdline[i].index)
+ newcon->index != c->index)
continue;
if (newcon->index < 0)
- newcon->index = console_cmdline[i].index;
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
- if (console_cmdline[i].brl_options) {
- newcon->flags |= CON_BRL;
- braille_register_console(newcon,
- console_cmdline[i].index,
- console_cmdline[i].options,
- console_cmdline[i].brl_options);
+ newcon->index = c->index;
+
+ if (_braille_register_console(newcon, c))
return;
- }
-#endif
+
if (newcon->setup &&
newcon->setup(newcon, console_cmdline[i].options) != 0)
break;
newcon->flags |= CON_ENABLED;
- newcon->index = console_cmdline[i].index;
+ newcon->index = c->index;
if (i == selected_console) {
newcon->flags |= CON_CONSDEV;
preferred_console = selected_console;
int unregister_console(struct console *console)
{
struct console *a, *b;
- int res = 1;
+ int res;
-#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
- if (console->flags & CON_BRL)
- return braille_unregister_console(console);
-#endif
+ res = _braille_unregister_console(console);
+ if (res)
+ return res;
+ res = 1;
console_lock();
if (console_drivers == console) {
console_drivers=console->next;
late_initcall(printk_late_init);
#if defined CONFIG_PRINTK
+/*
+ * Delayed printk version, for scheduler-internal messages:
+ */
+#define PRINTK_BUF_SIZE 512
+
+#define PRINTK_PENDING_WAKEUP 0x01
+#define PRINTK_PENDING_SCHED 0x02
+
+static DEFINE_PER_CPU(int, printk_pending);
+static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
+
+static void wake_up_klogd_work_func(struct irq_work *irq_work)
+{
+ int pending = __this_cpu_xchg(printk_pending, 0);
+
+ if (pending & PRINTK_PENDING_SCHED) {
+ char *buf = __get_cpu_var(printk_sched_buf);
+ printk(KERN_WARNING "[sched_delayed] %s", buf);
+ }
+
+ if (pending & PRINTK_PENDING_WAKEUP)
+ wake_up_interruptible(&log_wait);
+}
+
+static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = {
+ .func = wake_up_klogd_work_func,
+ .flags = IRQ_WORK_LAZY,
+};
+
+void wake_up_klogd(void)
+{
+ preempt_disable();
+ if (waitqueue_active(&log_wait)) {
+ this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
+ irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+ }
+ preempt_enable();
+}
int printk_sched(const char *fmt, ...)
{
va_end(args);
__this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
+ irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
local_irq_restore(flags);
return r;
bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
char *line, size_t size, size_t *len)
{
- struct log *msg;
+ struct printk_log *msg;
size_t l = 0;
bool ret = false;
idx = dumper->cur_idx;
prev = 0;
while (seq < dumper->next_seq) {
- struct log *msg = log_from_idx(idx);
+ struct printk_log *msg = log_from_idx(idx);
l += msg_print_text(msg, prev, true, NULL, 0);
idx = log_next(idx);
idx = dumper->cur_idx;
prev = 0;
while (l > size && seq < dumper->next_seq) {
- struct log *msg = log_from_idx(idx);
+ struct printk_log *msg = log_from_idx(idx);
l -= msg_print_text(msg, prev, true, NULL, 0);
idx = log_next(idx);
l = 0;
prev = 0;
while (seq < dumper->next_seq) {
- struct log *msg = log_from_idx(idx);
+ struct printk_log *msg = log_from_idx(idx);
l += msg_print_text(msg, prev, syslog, buf + l, size - l);
idx = log_next(idx);
raw_spin_unlock_irqrestore(&logbuf_lock, flags);
}
EXPORT_SYMBOL_GPL(kmsg_dump_rewind);
+
+static char dump_stack_arch_desc_str[128];
+
+/**
+ * dump_stack_set_arch_desc - set arch-specific str to show with task dumps
+ * @fmt: printf-style format string
+ * @...: arguments for the format string
+ *
+ * The configured string will be printed right after utsname during task
+ * dumps. Usually used to add arch-specific system identifiers. If an
+ * arch wants to make use of such an ID string, it should initialize this
+ * as soon as possible during boot.
+ */
+void __init dump_stack_set_arch_desc(const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ vsnprintf(dump_stack_arch_desc_str, sizeof(dump_stack_arch_desc_str),
+ fmt, args);
+ va_end(args);
+}
+
+/**
+ * dump_stack_print_info - print generic debug info for dump_stack()
+ * @log_lvl: log level
+ *
+ * Arch-specific dump_stack() implementations can use this function to
+ * print out the same debug information as the generic dump_stack().
+ */
+void dump_stack_print_info(const char *log_lvl)
+{
+ printk("%sCPU: %d PID: %d Comm: %.20s %s %s %.*s\n",
+ log_lvl, raw_smp_processor_id(), current->pid, current->comm,
+ print_tainted(), init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
+
+ if (dump_stack_arch_desc_str[0] != '\0')
+ printk("%sHardware name: %s\n",
+ log_lvl, dump_stack_arch_desc_str);
+
+ print_worker_info(log_lvl, current);
+}
+
+/**
+ * show_regs_print_info - print generic debug info for show_regs()
+ * @log_lvl: log level
+ *
+ * show_regs() implementations can use this function to print out generic
+ * debug information.
+ */
+void show_regs_print_info(const char *log_lvl)
+{
+ dump_stack_print_info(log_lvl);
+
+ printk("%stask: %p ti: %p task.ti: %p\n",
+ log_lvl, current, current_thread_info(),
+ task_thread_info(current));
+}
+
#endif