X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fprintk.c;h=11c6681ad944ea3b7bee4f67fe630ec6117c75a2;hb=c7b5ebbddf7bcd3651947760f423e3783bbe6573;hp=bb5ac824d4e19f12a34f3018f77d68d6637d8219;hpb=a8e794ca871505c8ea96cc102f4ad555c5231d7f;p=linux-2.6.git

diff --git a/kernel/printk.c b/kernel/printk.c
index bb5ac824d..11c6681ad 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -30,6 +30,7 @@
 #include <linux/smp.h>
 #include <linux/security.h>
 #include <linux/bootmem.h>
+#include <linux/vs_base.h>
 
 #include <asm/uaccess.h>
 
@@ -192,6 +193,8 @@ static int __init log_buf_len_setup(char *str)
 	unsigned long 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;
 		char * new_log_buf;
@@ -474,6 +477,27 @@ static void emit_log_char(char c)
 		logged_chars++;
 }
 
+/*
+ * Zap console related locks when oopsing. Only zap at most once
+ * every 10 seconds, to leave time for slow consoles to print a
+ * full oops.
+ */
+static void zap_locks(void)
+{
+	static unsigned long oops_timestamp;
+
+	if (time_after_eq(jiffies, oops_timestamp) &&
+			!time_after(jiffies, oops_timestamp + 30*HZ))
+		return;
+
+	oops_timestamp = jiffies;
+
+	/* If a crash is occurring, make sure we can't deadlock */
+	spin_lock_init(&logbuf_lock);
+	/* And make sure that we print immediately */
+	init_MUTEX(&console_sem);
+}
+
 /*
  * This is printk.  It can be called from any context.  We want it to work.
  * 
@@ -490,26 +514,34 @@ static void emit_log_char(char c)
 asmlinkage int printk(const char *fmt, ...)
 {
 	va_list args;
+	int r;
+
+	va_start(args, fmt);
+	r = vprintk(fmt, args);
+	va_end(args);
+
+	return r;
+}
+
+static volatile int printk_cpu = -1;
+
+asmlinkage int vprintk(const char *fmt, va_list args)
+{
 	unsigned long flags;
 	int printed_len;
 	char *p;
 	static char printk_buf[1024];
 	static int log_level_unknown = 1;
 
-	if (oops_in_progress) {
-		/* If a crash is occurring, make sure we can't deadlock */
-		spin_lock_init(&logbuf_lock);
-		/* And make sure that we print immediately */
-		init_MUTEX(&console_sem);
-	}
+	if (unlikely(oops_in_progress && printk_cpu == smp_processor_id()))
+		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 */
-	va_start(args, fmt);
 	printed_len = vscnprintf(printk_buf, sizeof(printk_buf), fmt, args);
-	va_end(args);
 
 	/*
 	 * Copy the output into log_buf.  If the caller didn't provide
@@ -561,6 +593,7 @@ out:
 	return printed_len;
 }
 EXPORT_SYMBOL(printk);
+EXPORT_SYMBOL(vprintk);
 
 /**
  * acquire_console_sem - lock the console system for exclusive use.
@@ -669,6 +702,47 @@ void console_unblank(void)
 }
 EXPORT_SYMBOL(console_unblank);
 
+/*
+ * Return the console tty driver structure and its associated index
+ */
+struct tty_driver *console_device(int *index)
+{
+	struct console *c;
+	struct tty_driver *driver = NULL;
+
+	acquire_console_sem();
+	for (c = console_drivers; c != NULL; c = c->next) {
+		if (!c->device)
+			continue;
+		driver = c->device(c, index);
+		if (driver)
+			break;
+	}
+	release_console_sem();
+	return driver;
+}
+
+/*
+ * Prevent further output on the passed console device so that (for example)
+ * serial drivers can disable console output before suspending a port, and can
+ * re-enable output afterwards.
+ */
+void console_stop(struct console *console)
+{
+	acquire_console_sem();
+	console->flags &= ~CON_ENABLED;
+	release_console_sem();
+}
+EXPORT_SYMBOL(console_stop);
+
+void console_start(struct console *console)
+{
+	acquire_console_sem();
+	console->flags |= CON_ENABLED;
+	release_console_sem();
+}
+EXPORT_SYMBOL(console_start);
+
 /*
  * The console driver calls this routine during kernel initialization
  * to register the console printing procedure with printk() and to