X-Git-Url: https://git.kernelconcepts.de/?a=blobdiff_plain;f=kernel%2Fprintk.c;h=3cb9708209bcb94a9d30a4c807f760ae485bf0c4;hb=bec7c458b372251617e0fdc6bf8ce4df06bab430;hp=5092397fac29926bfab6da75fc273882b14e905d;hpb=f45727d52d1581e9ff4df9d1a12a60789ad2d1eb;p=karo-tx-linux.git diff --git a/kernel/printk.c b/kernel/printk.c index 5092397fac29..3cb9708209bc 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -10,7 +10,7 @@ * 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 + * Fixed SMP synchronization, 08/08/99, Manfred Spraul * manfreds@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); @@ -169,11 +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; } @@ -193,10 +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; } @@ -217,7 +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; @@ -244,7 +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; @@ -264,7 +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; @@ -288,11 +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; @@ -306,10 +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) { /* @@ -461,7 +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; @@ -488,9 +486,14 @@ static int __init printk_time_setup(char *str) __setup("time", printk_time_setup); +__attribute__((weak)) unsigned long long printk_clock(void) +{ + return sched_clock(); +} + /* * 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 @@ -514,6 +517,9 @@ 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; @@ -522,11 +528,15 @@ 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); @@ -558,7 +568,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) loglev_char = default_message_loglevel + '0'; } - t = sched_clock(); + t = printk_clock(); nanosec_rem = do_div(t, 1000000000); tlen = sprintf(tbuf, "<%c>[%5lu.%06lu] ", @@ -595,6 +605,7 @@ asmlinkage int vprintk(const char *fmt, va_list args) * 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; } @@ -604,6 +615,7 @@ 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(); @@ -613,9 +625,11 @@ 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); @@ -623,13 +637,19 @@ 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 @@ -835,9 +855,9 @@ 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) @@ -862,7 +882,8 @@ 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 && @@ -917,9 +938,9 @@ 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(); @@ -933,10 +954,10 @@ int unregister_console(struct console * 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. @@ -978,7 +999,7 @@ 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; @@ -991,6 +1012,7 @@ 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); @@ -1005,7 +1027,7 @@ 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;