* Fixed SMP synchronization, 08/08/99, Manfred Spraul
* manfred@colorfullife.com
* Rewrote bits to get rid of console_lock
- * 01Mar01 Andrew Morton <andrewm@uow.edu.au>
+ * 01Mar01 Andrew Morton
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
-#include <linux/smp_lock.h>
#include <linux/console.h>
#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/nmi.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/interrupt.h> /* For in_interrupt() */
#include <linux/security.h>
#include <linux/bootmem.h>
#include <linux/syscalls.h>
-#include <linux/jiffies.h>
+#include <linux/kexec.h>
+#include <linux/ratelimit.h>
#include <asm/uaccess.h>
+/*
+ * for_each_console() allows you to iterate on each console
+ */
+#define for_each_console(con) \
+ for (con = console_drivers; con != NULL; con = con->next)
+
+/*
+ * Architectures can override it:
+ */
+void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...)
+{
+}
+
#define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT)
/* printk's without a loglevel use this.. */
DEFAULT_CONSOLE_LOGLEVEL, /* default_console_loglevel */
};
+static int saved_console_loglevel = -1;
+
/*
- * Low lever drivers may need that to know if they can schedule in
+ * Low level drivers may need that to know if they can schedule in
* their unblank() callback or not. So let's export it.
*/
int oops_in_progress;
* driver system.
*/
static DECLARE_MUTEX(console_sem);
-static DECLARE_MUTEX(secondary_console_sem);
struct console *console_drivers;
+EXPORT_SYMBOL_GPL(console_drivers);
+
/*
* This is used for debugging the mess that is the VT code by
* keeping track if we have the console semaphore held. It's
*/
static DEFINE_SPINLOCK(logbuf_lock);
-#define LOG_BUF_MASK (log_buf_len-1)
+#define LOG_BUF_MASK (log_buf_len-1)
#define LOG_BUF(idx) (log_buf[(idx) & LOG_BUF_MASK])
/*
* The indices into log_buf are not constrained to log_buf_len - they
* must be masked before subscripting
*/
-static unsigned long log_start; /* Index into log_buf: next char to be read by syslog() */
-static unsigned long con_start; /* Index into log_buf: next char to be sent to consoles */
-static unsigned long log_end; /* Index into log_buf: most-recently-written-char + 1 */
+static unsigned log_start; /* Index into log_buf: next char to be read by syslog() */
+static unsigned con_start; /* Index into log_buf: next char to be sent to consoles */
+static unsigned log_end; /* Index into log_buf: most-recently-written-char + 1 */
/*
* Array of consoles built from command line options (console=)
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;
+EXPORT_SYMBOL(console_set_on_cmdline);
/* Flag: console code may call schedule() */
static int console_may_schedule;
static char __log_buf[__LOG_BUF_LEN];
static char *log_buf = __log_buf;
static int log_buf_len = __LOG_BUF_LEN;
-static unsigned long logged_chars; /* Number of chars produced since last read+clear operation */
+static unsigned logged_chars; /* Number of chars produced since last read+clear operation */
+
+#ifdef CONFIG_KEXEC
+/*
+ * This appends the listed symbols to /proc/vmcoreinfo
+ *
+ * /proc/vmcoreinfo is used by various utiilties, like crash and makedumpfile to
+ * obtain access to symbols that are otherwise very difficult to locate. These
+ * symbols are specifically used so that utilities can access and extract the
+ * dmesg log from a vmcore file after a crash.
+ */
+void log_buf_kexec_setup(void)
+{
+ VMCOREINFO_SYMBOL(log_buf);
+ VMCOREINFO_SYMBOL(log_end);
+ VMCOREINFO_SYMBOL(log_buf_len);
+ VMCOREINFO_SYMBOL(logged_chars);
+}
+#endif
static int __init log_buf_len_setup(char *str)
{
- unsigned long size = memparse(str, &str);
+ unsigned size = memparse(str, &str);
unsigned long flags;
if (size)
size = roundup_pow_of_two(size);
if (size > log_buf_len) {
- unsigned long start, dest_idx, offset;
+ unsigned start, dest_idx, offset;
char *new_log_buf;
new_log_buf = alloc_bootmem(size);
__setup("log_buf_len=", log_buf_len_setup);
+#ifdef CONFIG_BOOT_PRINTK_DELAY
+
+static unsigned int boot_delay; /* msecs delay after each printk during bootup */
+static unsigned long long loops_per_msec; /* based on boot_delay */
+
+static int __init boot_delay_setup(char *str)
+{
+ unsigned long lpj;
+
+ lpj = preset_lpj ? preset_lpj : 1000000; /* some guess */
+ loops_per_msec = (unsigned long long)lpj / 1000 * HZ;
+
+ get_option(&str, &boot_delay);
+ if (boot_delay > 10 * 1000)
+ boot_delay = 0;
+
+ pr_debug("boot_delay: %u, preset_lpj: %ld, lpj: %lu, "
+ "HZ: %d, loops_per_msec: %llu\n",
+ boot_delay, preset_lpj, lpj, HZ, loops_per_msec);
+ return 1;
+}
+__setup("boot_delay=", boot_delay_setup);
+
+static void boot_delay_msec(void)
+{
+ unsigned long long k;
+ unsigned long timeout;
+
+ if (boot_delay == 0 || system_state != SYSTEM_BOOTING)
+ return;
+
+ k = (unsigned long long)loops_per_msec * boot_delay;
+
+ timeout = jiffies + msecs_to_jiffies(boot_delay);
+ while (k) {
+ k--;
+ cpu_relax();
+ /*
+ * use (volatile) jiffies to prevent
+ * compiler reduction; loop termination via jiffies
+ * is secondary and may or may not happen.
+ */
+ if (time_after(jiffies, timeout))
+ break;
+ touch_nmi_watchdog();
+ }
+}
+#else
+static inline void boot_delay_msec(void)
+{
+}
+#endif
+
/*
* Commands to do_syslog:
*
*/
int do_syslog(int type, char __user *buf, int len)
{
- unsigned long i, j, limit, count;
+ unsigned i, j, limit, count;
int do_clear = 0;
char c;
int error = 0;
logged_chars = 0;
break;
case 6: /* Disable logging to console */
+ if (saved_console_loglevel == -1)
+ saved_console_loglevel = console_loglevel;
console_loglevel = minimum_console_loglevel;
break;
case 7: /* Enable logging to console */
- console_loglevel = default_console_loglevel;
+ if (saved_console_loglevel != -1) {
+ console_loglevel = saved_console_loglevel;
+ saved_console_loglevel = -1;
+ }
break;
case 8: /* Set level of messages printed to console */
error = -EINVAL;
if (len < minimum_console_loglevel)
len = minimum_console_loglevel;
console_loglevel = len;
+ /* Implicitly re-enable logging to console */
+ saved_console_loglevel = -1;
error = 0;
break;
case 9: /* Number of chars in the log buffer */
return error;
}
-asmlinkage long sys_syslog(int type, char __user *buf, int len)
+SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
{
return do_syslog(type, buf, len);
}
/*
* Call the console drivers on a range of log_buf
*/
-static void __call_console_drivers(unsigned long start, unsigned long end)
+static void __call_console_drivers(unsigned start, unsigned end)
{
struct console *con;
- for (con = console_drivers; con; con = con->next) {
+ for_each_console(con) {
if ((con->flags & CON_ENABLED) && con->write &&
(cpu_online(smp_processor_id()) ||
(con->flags & CON_ANYTIME)))
ignore_loglevel = 1;
printk(KERN_INFO "debug: ignoring loglevel setting.\n");
- return 1;
+ return 0;
}
-__setup("ignore_loglevel", ignore_loglevel_setup);
+early_param("ignore_loglevel", ignore_loglevel_setup);
/*
* Write out chars from start to end - 1 inclusive
*/
-static void _call_console_drivers(unsigned long start,
- unsigned long end, int msg_log_level)
+static void _call_console_drivers(unsigned start,
+ unsigned end, int msg_log_level)
{
if ((msg_log_level < console_loglevel || ignore_loglevel) &&
console_drivers && start != end) {
* log_buf[start] to log_buf[end - 1].
* The console_sem must be held.
*/
-static void call_console_drivers(unsigned long start, unsigned long end)
+static void call_console_drivers(unsigned start, unsigned end)
{
- unsigned long cur_index, start_print;
+ unsigned cur_index, start_print;
static int msg_level = -1;
- BUG_ON(((long)(start - end)) > 0);
+ BUG_ON(((int)(start - end)) > 0);
cur_index = start;
start_print = start;
#else
static int printk_time = 0;
#endif
-module_param(printk_time, int, S_IRUGO | S_IWUSR);
-
-static int __init printk_time_setup(char *str)
-{
- if (*str)
- return 0;
- printk_time = 1;
- return 1;
-}
-
-__setup("time", printk_time_setup);
-
-__attribute__((weak)) unsigned long long printk_clock(void)
-{
- return sched_clock();
-}
+module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
/* Check if we have any console registered that can be called early in boot. */
static int have_callable_console(void)
{
struct console *con;
- for (con = console_drivers; con; con = con->next)
+ for_each_console(con)
if (con->flags & CON_ANYTIME)
return 1;
*
* See also:
* printf(3)
+ *
+ * See the vsnprintf() documentation for format string extensions over C99.
*/
asmlinkage int printk(const char *fmt, ...)
/* cpu currently holding logbuf_lock */
static volatile unsigned int printk_cpu = UINT_MAX;
+/*
+ * Can we actually use the console at this time on this cpu?
+ *
+ * Console drivers may assume that per-cpu resources have
+ * been allocated. So unless they're explicitly marked as
+ * being able to cope (CON_ANYTIME) don't call them until
+ * this CPU is officially up.
+ */
+static inline int can_use_console(unsigned int cpu)
+{
+ return cpu_online(cpu) || have_callable_console();
+}
+
+/*
+ * Try to get console ownership to actually show the kernel
+ * messages from a 'printk'. Return true (and with the
+ * console_semaphore held, and 'console_locked' set) if it
+ * is successful, false otherwise.
+ *
+ * This gets called with the 'logbuf_lock' spinlock held and
+ * interrupts disabled. It should return with 'lockbuf_lock'
+ * released but interrupts still disabled.
+ */
+static int acquire_console_semaphore_for_printk(unsigned int cpu)
+{
+ int retval = 0;
+
+ if (!try_acquire_console_sem()) {
+ retval = 1;
+
+ /*
+ * If we can't use the console, we need to release
+ * the console semaphore by hand to avoid flushing
+ * the buffer. We need to hold the console semaphore
+ * in order to do this test safely.
+ */
+ if (!can_use_console(cpu)) {
+ console_locked = 0;
+ up(&console_sem);
+ retval = 0;
+ }
+ }
+ printk_cpu = UINT_MAX;
+ spin_unlock(&logbuf_lock);
+ return retval;
+}
+static const char recursion_bug_msg [] =
+ KERN_CRIT "BUG: recent printk recursion!\n";
+static int recursion_bug;
+static int new_text_line = 1;
+static char printk_buf[1024];
+
+int printk_delay_msec __read_mostly;
+
+static inline void printk_delay(void)
+{
+ if (unlikely(printk_delay_msec)) {
+ int m = printk_delay_msec;
+
+ while (m--) {
+ mdelay(1);
+ touch_nmi_watchdog();
+ }
+ }
+}
+
asmlinkage int vprintk(const char *fmt, va_list args)
{
+ int printed_len = 0;
+ int current_log_level = default_message_loglevel;
unsigned long flags;
- int printed_len;
+ int this_cpu;
char *p;
- static char printk_buf[1024];
- static int log_level_unknown = 1;
+
+ boot_delay_msec();
+ printk_delay();
preempt_disable();
- if (unlikely(oops_in_progress) && printk_cpu == smp_processor_id())
- /* If a crash is occurring during printk() on this CPU,
- * make sure we can't deadlock */
+ /* This stops the holder of console_sem just where we want him */
+ raw_local_irq_save(flags);
+ this_cpu = smp_processor_id();
+
+ /*
+ * Ouch, printk recursed into itself!
+ */
+ if (unlikely(printk_cpu == this_cpu)) {
+ /*
+ * If a crash is occurring during printk() on this CPU,
+ * then try to get the crash message out but make sure
+ * we can't deadlock. Otherwise just return to avoid the
+ * recursion and return - but flag the recursion so that
+ * it can be printed at the next appropriate moment:
+ */
+ if (!oops_in_progress) {
+ recursion_bug = 1;
+ goto out_restore_irqs;
+ }
zap_locks();
+ }
- /* This stops the holder of console_sem just where we want him */
- local_irq_save(flags);
lockdep_off();
spin_lock(&logbuf_lock);
- printk_cpu = smp_processor_id();
+ printk_cpu = this_cpu;
+ if (recursion_bug) {
+ recursion_bug = 0;
+ strcpy(printk_buf, recursion_bug_msg);
+ printed_len = strlen(recursion_bug_msg);
+ }
/* Emit the output into the temporary buffer */
- printed_len = vscnprintf(printk_buf, sizeof(printk_buf), fmt, args);
+ printed_len += vscnprintf(printk_buf + printed_len,
+ sizeof(printk_buf) - printed_len, fmt, args);
+
+
+ p = printk_buf;
+
+ /* Do we have a loglevel in the string? */
+ if (p[0] == '<') {
+ unsigned char c = p[1];
+ if (c && p[2] == '>') {
+ switch (c) {
+ case '0' ... '7': /* loglevel */
+ current_log_level = c - '0';
+ /* Fallthrough - make sure we're on a new line */
+ case 'd': /* KERN_DEFAULT */
+ if (!new_text_line) {
+ emit_log_char('\n');
+ new_text_line = 1;
+ }
+ /* Fallthrough - skip the loglevel */
+ case 'c': /* KERN_CONT */
+ p += 3;
+ break;
+ }
+ }
+ }
/*
* Copy the output into log_buf. If the caller didn't provide
* appropriate log level tags, we insert them here
*/
- for (p = printk_buf; *p; p++) {
- if (log_level_unknown) {
- /* log_level_unknown signals the start of a new line */
+ for ( ; *p; p++) {
+ if (new_text_line) {
+ /* Always output the token */
+ emit_log_char('<');
+ emit_log_char(current_log_level + '0');
+ emit_log_char('>');
+ printed_len += 3;
+ new_text_line = 0;
+
if (printk_time) {
- int loglev_char;
+ /* Follow the token with the time */
char tbuf[50], *tp;
unsigned tlen;
unsigned long long t;
unsigned long nanosec_rem;
- /*
- * force the log level token to be
- * before the time output.
- */
- if (p[0] == '<' && p[1] >='0' &&
- p[1] <= '7' && p[2] == '>') {
- loglev_char = p[1];
- p += 3;
- printed_len -= 3;
- } else {
- loglev_char = default_message_loglevel
- + '0';
- }
- t = printk_clock();
+ t = cpu_clock(printk_cpu);
nanosec_rem = do_div(t, 1000000000);
- tlen = sprintf(tbuf,
- "<%c>[%5lu.%06lu] ",
- loglev_char,
- (unsigned long)t,
- nanosec_rem/1000);
+ tlen = sprintf(tbuf, "[%5lu.%06lu] ",
+ (unsigned long) t,
+ nanosec_rem / 1000);
for (tp = tbuf; tp < tbuf + tlen; tp++)
emit_log_char(*tp);
printed_len += tlen;
- } else {
- if (p[0] != '<' || p[1] < '0' ||
- p[1] > '7' || p[2] != '>') {
- emit_log_char('<');
- emit_log_char(default_message_loglevel
- + '0');
- emit_log_char('>');
- printed_len += 3;
- }
}
- log_level_unknown = 0;
+
if (!*p)
break;
}
+
emit_log_char(*p);
if (*p == '\n')
- log_level_unknown = 1;
+ new_text_line = 1;
}
- if (!down_trylock(&console_sem)) {
- /*
- * We own the drivers. We can drop the spinlock and
- * let release_console_sem() print the text, maybe ...
- */
- console_locked = 1;
- printk_cpu = UINT_MAX;
- spin_unlock(&logbuf_lock);
+ /*
+ * Try to acquire and then immediately release the
+ * console semaphore. The release will do all the
+ * actual magic (print out buffers, wake up klogd,
+ * etc).
+ *
+ * The acquire_console_semaphore_for_printk() function
+ * will release 'logbuf_lock' regardless of whether it
+ * actually gets the semaphore or not.
+ */
+ if (acquire_console_semaphore_for_printk(this_cpu))
+ release_console_sem();
- /*
- * Console drivers may assume that per-cpu resources have
- * been allocated. So unless they're explicitly marked as
- * being able to cope (CON_ANYTIME) don't call them until
- * this CPU is officially up.
- */
- if (cpu_online(smp_processor_id()) || have_callable_console()) {
- console_may_schedule = 0;
- release_console_sem();
- } else {
- /* Release by hand to avoid flushing the buffer. */
- console_locked = 0;
- up(&console_sem);
- }
- lockdep_on();
- local_irq_restore(flags);
- } else {
- /*
- * Someone else owns the drivers. We drop the spinlock, which
- * allows the semaphore holder to proceed and to call the
- * console drivers with the output which we just produced.
- */
- printk_cpu = UINT_MAX;
- spin_unlock(&logbuf_lock);
- lockdep_on();
- local_irq_restore(flags);
- }
+ lockdep_on();
+out_restore_irqs:
+ raw_local_irq_restore(flags);
preempt_enable();
return printed_len;
#else
-asmlinkage long sys_syslog(int type, char __user *buf, int len)
+static void call_console_drivers(unsigned start, unsigned end)
{
- return -ENOSYS;
}
-static void call_console_drivers(unsigned long start, unsigned long end)
+#endif
+
+static int __add_preferred_console(char *name, int idx, char *options,
+ char *brl_options)
{
-}
+ struct console_cmdline *c;
+ int i;
+ /*
+ * 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;
+ }
+ 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
-
+ c->index = idx;
+ return 0;
+}
/*
* Set up a list of consoles. Called from init/main.c
*/
static int __init console_setup(char *str)
{
- char name[sizeof(console_cmdline[0].name)];
- char *s, *options;
+ char buf[sizeof(console_cmdline[0].name) + 4]; /* 4 for index */
+ 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
+
/*
* Decode str into name, index, options.
*/
if (str[0] >= '0' && str[0] <= '9') {
- strcpy(name, "ttyS");
- strncpy(name + 4, str, sizeof(name) - 5);
+ strcpy(buf, "ttyS");
+ strncpy(buf + 4, str, sizeof(buf) - 5);
} else {
- strncpy(name, str, sizeof(name) - 1);
+ strncpy(buf, str, sizeof(buf) - 1);
}
- name[sizeof(name) - 1] = 0;
+ buf[sizeof(buf) - 1] = 0;
if ((options = strchr(str, ',')) != NULL)
*(options++) = 0;
#ifdef __sparc__
if (!strcmp(str, "ttya"))
- strcpy(name, "ttyS0");
+ strcpy(buf, "ttyS0");
if (!strcmp(str, "ttyb"))
- strcpy(name, "ttyS1");
+ strcpy(buf, "ttyS1");
#endif
- for (s = name; *s; s++)
+ for (s = buf; *s; s++)
if ((*s >= '0' && *s <= '9') || *s == ',')
break;
idx = simple_strtoul(s, NULL, 10);
*s = 0;
- add_preferred_console(name, idx, options);
+ __add_preferred_console(buf, idx, options, brl_options);
+ console_set_on_cmdline = 1;
return 1;
}
__setup("console=", console_setup);
* commonly to provide a default console (ie from PROM variables) when
* the user has not supplied one.
*/
-int __init add_preferred_console(char *name, int idx, char *options)
+int add_preferred_console(char *name, int idx, char *options)
+{
+ return __add_preferred_console(name, idx, options, NULL);
+}
+
+int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, char *options)
{
struct console_cmdline *c;
int i;
- /*
- * 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++)
+ 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) {
- selected_console = i;
- return 0;
+ 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;
}
- if (i == MAX_CMDLINECONSOLES)
- return -E2BIG;
- selected_console = i;
- c = &console_cmdline[i];
- memcpy(c->name, name, sizeof(c->name));
- c->name[sizeof(c->name) - 1] = 0;
- c->options = options;
- c->index = idx;
- return 0;
+ /* not found */
+ return -1;
+}
+
+int console_suspend_enabled = 1;
+EXPORT_SYMBOL(console_suspend_enabled);
+
+static int __init console_suspend_disable(char *str)
+{
+ console_suspend_enabled = 0;
+ return 1;
}
+__setup("no_console_suspend", console_suspend_disable);
-#ifndef CONFIG_DISABLE_CONSOLE_SUSPEND
/**
* suspend_console - suspend the console subsystem
*
*/
void suspend_console(void)
{
- printk("Suspending console(s)\n");
+ if (!console_suspend_enabled)
+ return;
+ printk("Suspending console(s) (use no_console_suspend to debug)\n");
acquire_console_sem();
console_suspended = 1;
+ up(&console_sem);
}
void resume_console(void)
{
+ if (!console_suspend_enabled)
+ return;
+ down(&console_sem);
console_suspended = 0;
release_console_sem();
}
-#endif /* CONFIG_DISABLE_CONSOLE_SUSPEND */
/**
* acquire_console_sem - lock the console system for exclusive use.
void acquire_console_sem(void)
{
BUG_ON(in_interrupt());
- if (console_suspended) {
- down(&secondary_console_sem);
- return;
- }
down(&console_sem);
+ if (console_suspended)
+ return;
console_locked = 1;
console_may_schedule = 1;
}
{
if (down_trylock(&console_sem))
return -1;
+ if (console_suspended) {
+ up(&console_sem);
+ return -1;
+ }
console_locked = 1;
console_may_schedule = 0;
return 0;
return console_locked;
}
+static DEFINE_PER_CPU(int, printk_pending);
+
+void printk_tick(void)
+{
+ if (__get_cpu_var(printk_pending)) {
+ __get_cpu_var(printk_pending) = 0;
+ wake_up_interruptible(&log_wait);
+ }
+}
+
+int printk_needs_cpu(int cpu)
+{
+ return per_cpu(printk_pending, cpu);
+}
+
+void wake_up_klogd(void)
+{
+ if (waitqueue_active(&log_wait))
+ __raw_get_cpu_var(printk_pending) = 1;
+}
+
/**
* release_console_sem - unlock the console system
*
void release_console_sem(void)
{
unsigned long flags;
- unsigned long _con_start, _log_end;
- unsigned long wake_klogd = 0;
+ unsigned _con_start, _log_end;
+ unsigned wake_klogd = 0;
if (console_suspended) {
- up(&secondary_console_sem);
+ up(&console_sem);
return;
}
_log_end = log_end;
con_start = log_end; /* Flush */
spin_unlock(&logbuf_lock);
+ stop_critical_timings(); /* don't trace print latency */
call_console_drivers(_con_start, _log_end);
+ start_critical_timings();
local_irq_restore(flags);
}
console_locked = 0;
up(&console_sem);
spin_unlock_irqrestore(&logbuf_lock, flags);
- if (wake_klogd && !oops_in_progress && waitqueue_active(&log_wait))
- wake_up_interruptible(&log_wait);
+ if (wake_klogd)
+ wake_up_klogd();
}
EXPORT_SYMBOL(release_console_sem);
}
EXPORT_SYMBOL(console_conditional_schedule);
-void console_print(const char *s)
-{
- printk(KERN_EMERG "%s", s);
-}
-EXPORT_SYMBOL(console_print);
-
void console_unblank(void)
{
struct console *c;
console_locked = 1;
console_may_schedule = 0;
- for (c = console_drivers; c != NULL; c = c->next)
+ for_each_console(c)
if ((c->flags & CON_ENABLED) && c->unblank)
c->unblank();
release_console_sem();
struct tty_driver *driver = NULL;
acquire_console_sem();
- for (c = console_drivers; c != NULL; c = c->next) {
+ for_each_console(c) {
if (!c->device)
continue;
driver = c->device(c, index);
* to register the console printing procedure with printk() and to
* print any messages that were printed by the kernel before the
* console driver was initialized.
+ *
+ * This can happen pretty early during the boot process (because of
+ * early_printk) - sometimes before setup_arch() completes - be careful
+ * of what kernel features are used - they may not be initialised yet.
+ *
+ * There are two types of consoles - bootconsoles (early_printk) and
+ * "real" consoles (everything which is not a bootconsole) which are
+ * handled differently.
+ * - Any number of bootconsoles can be registered at any time.
+ * - As soon as a "real" console is registered, all bootconsoles
+ * will be unregistered automatically.
+ * - Once a "real" console is registered, any attempt to register a
+ * bootconsoles will be rejected
*/
-void register_console(struct console *console)
+void register_console(struct console *newcon)
{
int i;
unsigned long flags;
+ struct console *bcon = NULL;
- if (preferred_console < 0)
+ /*
+ * before we register a new CON_BOOT console, make sure we don't
+ * already have a valid console
+ */
+ if (console_drivers && newcon->flags & CON_BOOT) {
+ /* find the last or real console */
+ for_each_console(bcon) {
+ if (!(bcon->flags & CON_BOOT)) {
+ printk(KERN_INFO "Too late to register bootconsole %s%d\n",
+ newcon->name, newcon->index);
+ return;
+ }
+ }
+ }
+
+ if (console_drivers && console_drivers->flags & CON_BOOT)
+ bcon = console_drivers;
+
+ if (preferred_console < 0 || bcon || !console_drivers)
preferred_console = selected_console;
+ if (newcon->early_setup)
+ newcon->early_setup();
+
/*
* See if we want to use this console driver. If we
* didn't select a console we take the first one
* that registers here.
*/
if (preferred_console < 0) {
- if (console->index < 0)
- console->index = 0;
- if (console->setup == NULL ||
- console->setup(console, NULL) == 0) {
- console->flags |= CON_ENABLED | CON_CONSDEV;
- preferred_console = 0;
+ if (newcon->index < 0)
+ newcon->index = 0;
+ if (newcon->setup == NULL ||
+ newcon->setup(newcon, NULL) == 0) {
+ newcon->flags |= CON_ENABLED;
+ if (newcon->device) {
+ newcon->flags |= CON_CONSDEV;
+ preferred_console = 0;
+ }
}
}
*/
for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
i++) {
- if (strcmp(console_cmdline[i].name, console->name) != 0)
+ if (strcmp(console_cmdline[i].name, newcon->name) != 0)
continue;
- if (console->index >= 0 &&
- console->index != console_cmdline[i].index)
+ if (newcon->index >= 0 &&
+ newcon->index != console_cmdline[i].index)
continue;
- if (console->index < 0)
- console->index = console_cmdline[i].index;
- if (console->setup &&
- console->setup(console, console_cmdline[i].options) != 0)
+ 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);
+ return;
+ }
+#endif
+ if (newcon->setup &&
+ newcon->setup(newcon, console_cmdline[i].options) != 0)
break;
- console->flags |= CON_ENABLED;
- console->index = console_cmdline[i].index;
+ newcon->flags |= CON_ENABLED;
+ newcon->index = console_cmdline[i].index;
if (i == selected_console) {
- console->flags |= CON_CONSDEV;
+ newcon->flags |= CON_CONSDEV;
preferred_console = selected_console;
}
break;
}
- if (!(console->flags & CON_ENABLED))
+ if (!(newcon->flags & CON_ENABLED))
return;
- if (console_drivers && (console_drivers->flags & CON_BOOT)) {
- unregister_console(console_drivers);
- console->flags &= ~CON_PRINTBUFFER;
- }
+ /*
+ * If we have a bootconsole, and are switching to a real console,
+ * don't print everything out again, since when the boot console, and
+ * the real console are the same physical device, it's annoying to
+ * see the beginning boot messages twice
+ */
+ if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV))
+ newcon->flags &= ~CON_PRINTBUFFER;
/*
* Put this console in the list - keep the
* preferred driver at the head of the list.
*/
acquire_console_sem();
- if ((console->flags & CON_CONSDEV) || console_drivers == NULL) {
- console->next = console_drivers;
- console_drivers = console;
- if (console->next)
- console->next->flags &= ~CON_CONSDEV;
+ if ((newcon->flags & CON_CONSDEV) || console_drivers == NULL) {
+ newcon->next = console_drivers;
+ console_drivers = newcon;
+ if (newcon->next)
+ newcon->next->flags &= ~CON_CONSDEV;
} else {
- console->next = console_drivers->next;
- console_drivers->next = console;
+ newcon->next = console_drivers->next;
+ console_drivers->next = newcon;
}
- if (console->flags & CON_PRINTBUFFER) {
+ if (newcon->flags & CON_PRINTBUFFER) {
/*
* release_console_sem() will print out the buffered messages
* for us.
spin_unlock_irqrestore(&logbuf_lock, flags);
}
release_console_sem();
+
+ /*
+ * By unregistering the bootconsoles after we enable the real console
+ * we get the "console xxx enabled" message on all the consoles -
+ * boot consoles, real consoles, etc - this is to ensure that end
+ * users know there might be something in the kernel's log buffer that
+ * went to the bootconsole (that they do not see on the real console)
+ */
+ if (bcon && ((newcon->flags & (CON_CONSDEV | CON_BOOT)) == CON_CONSDEV)) {
+ /* we need to iterate through twice, to make sure we print
+ * everything out, before we unregister the console(s)
+ */
+ printk(KERN_INFO "console [%s%d] enabled, bootconsole disabled\n",
+ newcon->name, newcon->index);
+ for_each_console(bcon)
+ if (bcon->flags & CON_BOOT)
+ unregister_console(bcon);
+ } else {
+ printk(KERN_INFO "%sconsole [%s%d] enabled\n",
+ (newcon->flags & CON_BOOT) ? "boot" : "" ,
+ newcon->name, newcon->index);
+ }
}
EXPORT_SYMBOL(register_console);
struct console *a, *b;
int res = 1;
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+ if (console->flags & CON_BRL)
+ return braille_unregister_console(console);
+#endif
+
acquire_console_sem();
if (console_drivers == console) {
console_drivers=console->next;
}
}
- /* If last console is removed, we re-enable picking the first
- * one that gets registered. Without that, pmac early boot console
- * would prevent fbcon from taking over.
- *
+ /*
* If this isn't the last console and it has CON_CONSDEV set, we
* need to set it on the next preferred console.
*/
- if (console_drivers == NULL)
- preferred_console = selected_console;
- else if (console->flags & CON_CONSDEV)
+ if (console_drivers != NULL && console->flags & CON_CONSDEV)
console_drivers->flags |= CON_CONSDEV;
release_console_sem();
}
EXPORT_SYMBOL(unregister_console);
-/**
- * tty_write_message - write a message to a certain tty, not just the console.
- * @tty: the destination tty_struct
- * @msg: the message to write
- *
- * This is used for messages that need to be redirected to a specific tty.
- * We don't put it into the syslog queue right now maybe in the future if
- * really needed.
- */
-void tty_write_message(struct tty_struct *tty, char *msg)
+static int __init disable_boot_consoles(void)
{
- if (tty && tty->driver->write)
- tty->driver->write(tty, msg, strlen(msg));
- return;
-}
+ struct console *con;
-/*
- * printk rate limiting, lifted from the networking subsystem.
- *
- * This enforces a rate limit: not more than one kernel message
- * every printk_ratelimit_jiffies to make a denial-of-service
- * attack impossible.
- */
-int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst)
-{
- static DEFINE_SPINLOCK(ratelimit_lock);
- static unsigned long toks = 10 * 5 * HZ;
- static unsigned long last_msg;
- static int missed;
- unsigned long flags;
- unsigned long now = jiffies;
-
- spin_lock_irqsave(&ratelimit_lock, flags);
- toks += now - last_msg;
- last_msg = now;
- if (toks > (ratelimit_burst * ratelimit_jiffies))
- toks = ratelimit_burst * ratelimit_jiffies;
- if (toks >= ratelimit_jiffies) {
- int lost = missed;
-
- missed = 0;
- toks -= ratelimit_jiffies;
- spin_unlock_irqrestore(&ratelimit_lock, flags);
- if (lost)
- printk(KERN_WARNING "printk: %d messages suppressed.\n", lost);
- return 1;
+ for_each_console(con) {
+ if (con->flags & CON_BOOT) {
+ printk(KERN_INFO "turn off boot console %s%d\n",
+ con->name, con->index);
+ unregister_console(con);
+ }
}
- missed++;
- spin_unlock_irqrestore(&ratelimit_lock, flags);
return 0;
}
-EXPORT_SYMBOL(__printk_ratelimit);
+late_initcall(disable_boot_consoles);
-/* minimum time in jiffies between messages */
-int printk_ratelimit_jiffies = 5 * HZ;
+#if defined CONFIG_PRINTK
-/* number of messages we send before ratelimiting */
-int printk_ratelimit_burst = 10;
+/*
+ * printk rate limiting, lifted from the networking subsystem.
+ *
+ * This enforces a rate limit: not more than 10 kernel messages
+ * every 5s to make a denial-of-service attack impossible.
+ */
+DEFINE_RATELIMIT_STATE(printk_ratelimit_state, 5 * HZ, 10);
-int printk_ratelimit(void)
+int __printk_ratelimit(const char *func)
{
- return __printk_ratelimit(printk_ratelimit_jiffies,
- printk_ratelimit_burst);
+ return ___ratelimit(&printk_ratelimit_state, func);
}
-EXPORT_SYMBOL(printk_ratelimit);
+EXPORT_SYMBOL(__printk_ratelimit);
/**
* printk_timed_ratelimit - caller-controlled printk ratelimiting
bool printk_timed_ratelimit(unsigned long *caller_jiffies,
unsigned int interval_msecs)
{
- if (*caller_jiffies == 0 || time_after(jiffies, *caller_jiffies)) {
- *caller_jiffies = jiffies + msecs_to_jiffies(interval_msecs);
+ if (*caller_jiffies == 0
+ || !time_in_range(jiffies, *caller_jiffies,
+ *caller_jiffies
+ + msecs_to_jiffies(interval_msecs))) {
+ *caller_jiffies = jiffies;
return true;
}
return false;
}
EXPORT_SYMBOL(printk_timed_ratelimit);
+#endif
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff