X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;ds=sidebyside;f=kernel%2Fprintk.c;h=13ced0f7828f477d6edc6356dcdfd7e8617cb567;hb=8d58d773b745950ac912e028b3c81f4902fbf91d;hp=290a07ce2c8a8029089d24304ea216bf8b937ade;hpb=d59745ce3e7aa13856bca16d3bcbb95041775ff6;p=safe%2Fjmp%2Flinux-2.6 diff --git a/kernel/printk.c b/kernel/printk.c index 290a07c..13ced0f 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -10,8 +10,8 @@ * elsewhere, in preparation for a serial line console (someday). * Ted Ts'o, 2/11/93. * Modified for sysctl support, 1/8/97, Chris Horn. - * Fixed SMP synchronization, 08/08/99, Manfred Spraul - * manfreds@colorfullife.com + * Fixed SMP synchronization, 08/08/99, Manfred Spraul + * manfred@colorfullife.com * Rewrote bits to get rid of console_lock * 01Mar01 Andrew Morton */ @@ -148,7 +148,7 @@ static int __init console_setup(char *str) if (!strcmp(str, "ttyb")) strcpy(name, "ttyS1"); #endif - for(s = name; *s; s++) + for (s = name; *s; s++) if ((*s >= '0' && *s <= '9') || *s == ',') break; idx = simple_strtoul(s, NULL, 10); @@ -160,42 +160,6 @@ static int __init console_setup(char *str) __setup("console=", console_setup); -/** - * add_preferred_console - add a device to the list of preferred consoles. - * - * The last preferred console added will be used for kernel messages - * and stdin/out/err for init. Normally this is used by console_setup - * above to handle user-supplied console arguments; however it can also - * be used by arch-specific code either to override the user or more - * 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) -{ - 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) { - selected_console = i; - return 0; - } - 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; -} - static int __init log_buf_len_setup(char *str) { unsigned long size = memparse(str, &str); @@ -205,11 +169,11 @@ static int __init log_buf_len_setup(char *str) size = roundup_pow_of_two(size); if (size > log_buf_len) { unsigned long start, dest_idx, offset; - char * new_log_buf; + char *new_log_buf; new_log_buf = alloc_bootmem(size); if (!new_log_buf) { - printk("log_buf_len: allocation failed\n"); + printk(KERN_WARNING "log_buf_len: allocation failed\n"); goto out; } @@ -229,10 +193,9 @@ static int __init log_buf_len_setup(char *str) log_end -= offset; spin_unlock_irqrestore(&logbuf_lock, flags); - printk("log_buf_len: %d\n", log_buf_len); + printk(KERN_NOTICE "log_buf_len: %d\n", log_buf_len); } out: - return 1; } @@ -253,7 +216,7 @@ __setup("log_buf_len=", log_buf_len_setup); * 9 -- Return number of unread characters in the log buffer * 10 -- Return size of the log buffer */ -int do_syslog(int type, char __user * buf, int len) +int do_syslog(int type, char __user *buf, int len) { unsigned long i, j, limit, count; int do_clear = 0; @@ -280,7 +243,8 @@ int do_syslog(int type, char __user * buf, int len) error = -EFAULT; goto out; } - error = wait_event_interruptible(log_wait, (log_start - log_end)); + error = wait_event_interruptible(log_wait, + (log_start - log_end)); if (error) goto out; i = 0; @@ -300,7 +264,7 @@ int do_syslog(int type, char __user * buf, int len) error = i; break; case 4: /* Read/clear last kernel messages */ - do_clear = 1; + do_clear = 1; /* FALL THRU */ case 3: /* Read last kernel messages */ error = -EINVAL; @@ -324,11 +288,11 @@ int do_syslog(int type, char __user * buf, int len) limit = log_end; /* * __put_user() could sleep, and while we sleep - * printk() could overwrite the messages + * printk() could overwrite the messages * we try to copy to user space. Therefore * the messages are copied in reverse. */ - for(i = 0; i < count && !error; i++) { + for (i = 0; i < count && !error; i++) { j = limit-1-i; if (j + log_buf_len < log_end) break; @@ -342,10 +306,10 @@ int do_syslog(int type, char __user * buf, int len) if (error) break; error = i; - if(i != count) { + if (i != count) { int offset = count-error; /* buffer overflow during copy, correct user buffer. */ - for(i=0;i 2) && - LOG_BUF(cur_index + 0) == '<' && - LOG_BUF(cur_index + 1) >= '0' && - LOG_BUF(cur_index + 1) <= '7' && - LOG_BUF(cur_index + 2) == '>') - { + if (msg_level < 0 && ((end - cur_index) > 2) && + LOG_BUF(cur_index + 0) == '<' && + LOG_BUF(cur_index + 1) >= '0' && + LOG_BUF(cur_index + 1) <= '7' && + LOG_BUF(cur_index + 2) == '>') { msg_level = LOG_BUF(cur_index + 1) - '0'; cur_index += 3; start_print = cur_index; } while (cur_index != end) { char c = LOG_BUF(cur_index); - cur_index++; + cur_index++; if (c == '\n') { if (msg_level < 0) { /* @@ -497,7 +459,7 @@ static void zap_locks(void) static unsigned long oops_timestamp; if (time_after_eq(jiffies, oops_timestamp) && - !time_after(jiffies, oops_timestamp + 30*HZ)) + !time_after(jiffies, oops_timestamp + 30 * HZ)) return; oops_timestamp = jiffies; @@ -524,9 +486,17 @@ static int __init printk_time_setup(char *str) __setup("time", printk_time_setup); -/* +__attribute__((weak)) unsigned long long printk_clock(void) +{ + return sched_clock(); +} + +/** + * printk - print a kernel message + * @fmt: format string + * * This is printk. It can be called from any context. We want it to work. - * + * * We try to grab the console_sem. If we succeed, it's easy - we log the output and * call the console drivers. If we fail to get the semaphore we place the output * into the log buffer and return. The current holder of the console_sem will @@ -536,6 +506,9 @@ __setup("time", printk_time_setup); * One effect of this deferred printing is that code which calls printk() and * then changes console_loglevel may break. This is because console_loglevel * is inspected when the actual printing occurs. + * + * See also: + * printf(3) */ asmlinkage int printk(const char *fmt, ...) @@ -550,6 +523,9 @@ asmlinkage int printk(const char *fmt, ...) return r; } +/* cpu currently holding logbuf_lock */ +static volatile unsigned int printk_cpu = UINT_MAX; + asmlinkage int vprintk(const char *fmt, va_list args) { unsigned long flags; @@ -558,11 +534,15 @@ asmlinkage int vprintk(const char *fmt, va_list args) static char printk_buf[1024]; static int log_level_unknown = 1; - if (unlikely(oops_in_progress)) + 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 */ zap_locks(); /* This stops the holder of console_sem just where we want him */ spin_lock_irqsave(&logbuf_lock, flags); + printk_cpu = smp_processor_id(); /* Emit the output into the temporary buffer */ printed_len = vscnprintf(printk_buf, sizeof(printk_buf), fmt, args); @@ -589,12 +569,12 @@ asmlinkage int vprintk(const char *fmt, va_list args) p[1] <= '7' && p[2] == '>') { loglev_char = p[1]; p += 3; - printed_len += 3; + printed_len -= 3; } else { loglev_char = default_message_loglevel + '0'; } - t = sched_clock(); + t = printk_clock(); nanosec_rem = do_div(t, 1000000000); tlen = sprintf(tbuf, "<%c>[%5lu.%06lu] ", @@ -604,7 +584,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) for (tp = tbuf; tp < tbuf + tlen; tp++) emit_log_char(*tp); - printed_len += tlen - 3; + printed_len += tlen; } else { if (p[0] != '<' || p[1] < '0' || p[1] > '7' || p[2] != '>') { @@ -612,8 +592,8 @@ asmlinkage int vprintk(const char *fmt, va_list args) emit_log_char(default_message_loglevel + '0'); emit_log_char('>'); + printed_len += 3; } - printed_len += 3; } log_level_unknown = 0; if (!*p) @@ -624,14 +604,14 @@ asmlinkage int vprintk(const char *fmt, va_list args) log_level_unknown = 1; } - if (!cpu_online(smp_processor_id()) && - system_state != SYSTEM_RUNNING) { + if (!cpu_online(smp_processor_id())) { /* * Some console drivers may assume that per-cpu resources have * been allocated. So don't allow them to be called by this * CPU until it is officially up. We shouldn't be calling into * random console drivers on a CPU which doesn't exist yet.. */ + printk_cpu = UINT_MAX; spin_unlock_irqrestore(&logbuf_lock, flags); goto out; } @@ -641,6 +621,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) * We own the drivers. We can drop the spinlock and let * release_console_sem() print the text */ + printk_cpu = UINT_MAX; spin_unlock_irqrestore(&logbuf_lock, flags); console_may_schedule = 0; release_console_sem(); @@ -650,9 +631,11 @@ asmlinkage int vprintk(const char *fmt, va_list args) * 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_irqrestore(&logbuf_lock, flags); } out: + preempt_enable(); return printed_len; } EXPORT_SYMBOL(printk); @@ -660,17 +643,62 @@ EXPORT_SYMBOL(vprintk); #else -asmlinkage long sys_syslog(int type, char __user * buf, int len) +asmlinkage long sys_syslog(int type, char __user *buf, int len) { return 0; } -int do_syslog(int type, char __user * buf, int len) { return 0; } -static void call_console_drivers(unsigned long start, unsigned long end) {} +int do_syslog(int type, char __user *buf, int len) +{ + return 0; +} + +static void call_console_drivers(unsigned long start, unsigned long end) +{ +} #endif /** + * add_preferred_console - add a device to the list of preferred consoles. + * @name: device name + * @idx: device index + * @options: options for this console + * + * The last preferred console added will be used for kernel messages + * and stdin/out/err for init. Normally this is used by console_setup + * above to handle user-supplied console arguments; however it can also + * be used by arch-specific code either to override the user or more + * 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) +{ + 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) { + selected_console = i; + return 0; + } + 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; +} + +/** * acquire_console_sem - lock the console system for exclusive use. * * Acquires a semaphore which guarantees that the caller has @@ -745,7 +773,8 @@ void release_console_sem(void) } EXPORT_SYMBOL(release_console_sem); -/** console_conditional_schedule - yield the CPU if required +/** + * console_conditional_schedule - yield the CPU if required * * If the console code is currently allowed to sleep, and * if this CPU should yield the CPU to another task, do @@ -787,7 +816,6 @@ void console_unblank(void) c->unblank(); release_console_sem(); } -EXPORT_SYMBOL(console_unblank); /* * Return the console tty driver structure and its associated index @@ -836,9 +864,9 @@ EXPORT_SYMBOL(console_start); * print any messages that were printed by the kernel before the * console driver was initialized. */ -void register_console(struct console * console) +void register_console(struct console *console) { - int i; + int i; unsigned long flags; if (preferred_console < 0) @@ -863,7 +891,8 @@ void register_console(struct console * console) * See if this console matches one we selected on * the command line. */ - 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, console->name) != 0) continue; if (console->index >= 0 && @@ -876,8 +905,10 @@ void register_console(struct console * console) break; console->flags |= CON_ENABLED; console->index = console_cmdline[i].index; - if (i == preferred_console) + if (i == selected_console) { console->flags |= CON_CONSDEV; + preferred_console = selected_console; + } break; } @@ -897,6 +928,8 @@ void register_console(struct console * console) if ((console->flags & CON_CONSDEV) || console_drivers == NULL) { console->next = console_drivers; console_drivers = console; + if (console->next) + console->next->flags &= ~CON_CONSDEV; } else { console->next = console_drivers->next; console_drivers->next = console; @@ -914,33 +947,37 @@ void register_console(struct console * console) } EXPORT_SYMBOL(register_console); -int unregister_console(struct console * console) +int unregister_console(struct console *console) { - struct console *a,*b; + struct console *a, *b; int res = 1; acquire_console_sem(); if (console_drivers == console) { console_drivers=console->next; res = 0; - } else { + } else if (console_drivers) { for (a=console_drivers->next, b=console_drivers ; a; b=a, a=b->next) { if (a == console) { b->next = a->next; res = 0; break; - } + } } } - + /* 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) + console_drivers->flags |= CON_CONSDEV; release_console_sem(); return res; @@ -949,6 +986,8 @@ 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 @@ -971,7 +1010,7 @@ void tty_write_message(struct tty_struct *tty, char *msg) int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst) { static DEFINE_SPINLOCK(ratelimit_lock); - static unsigned long toks = 10*5*HZ; + static unsigned long toks = 10 * 5 * HZ; static unsigned long last_msg; static int missed; unsigned long flags; @@ -984,6 +1023,7 @@ int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst) toks = ratelimit_burst * ratelimit_jiffies; if (toks >= ratelimit_jiffies) { int lost = missed; + missed = 0; toks -= ratelimit_jiffies; spin_unlock_irqrestore(&ratelimit_lock, flags); @@ -998,7 +1038,7 @@ int __printk_ratelimit(int ratelimit_jiffies, int ratelimit_burst) EXPORT_SYMBOL(__printk_ratelimit); /* minimum time in jiffies between messages */ -int printk_ratelimit_jiffies = 5*HZ; +int printk_ratelimit_jiffies = 5 * HZ; /* number of messages we send before ratelimiting */ int printk_ratelimit_burst = 10;