1 files changed, 79 insertions, 6 deletions

diff --git a/kernel/printk.c b/kernel/printk.c
index ebce88c..c461698 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -4,28 +4,101 @@
  *  (C) 1991  Linus Torvalds
  */
 
-/*
- * When in kernel-mode, we cannot use printf, as fs is liable to
- * point to 'interesting' things. Make a printf with fs-saving, and
- * all is well.
- */
 #include <stdarg.h>
 #include <stddef.h>
+#include <errno.h>
 
+#include <asm/segment.h>
+#include <asm/system.h>
+
+#include <linux/sched.h>
 #include <linux/kernel.h>
 
 static char buf[1024];
 
 extern int vsprintf(char * buf, const char * fmt, va_list args);
+extern void console_print(const char *);
+
+static unsigned long log_page = 0;
+static unsigned long log_start = 0;
+static unsigned long log_size = 0;
+static struct task_struct * log_wait = NULL;
+
+int sys_syslog(int type, char * buf, int len)
+{
+	unsigned long i;
+	char c;
+
+	if (!suser())
+		return -EPERM;
+	switch (type) {
+		case 0:
+			i = log_page;
+			log_page = 0;
+			free_page(i);
+			wake_up(&log_wait);
+			return 0;
+		case 1:
+			i = get_free_page();
+			if (log_page) {
+				free_page(i);
+				return 0;
+			} else if (log_page = i) {
+				log_start = log_size = 0;
+				return 0;
+			}
+			return -ENOMEM;
+		case 2:
+			if (!buf || len < 0)
+				return -EINVAL;
+			if (!len)
+				return 0;
+			verify_area(buf,len);
+			while (!log_size) {
+				if (!log_page)
+					return -EIO;
+				if (current->signal & ~current->blocked)
+					return -ERESTARTSYS;
+				cli();
+				if (!log_size)
+					interruptible_sleep_on(&log_wait);
+				sti();
+			}
+			i = 0;
+			while (log_size && len) {
+				c = *((char *) log_page+log_start);
+				log_start++;
+				log_size--;
+				log_start &= 4095;
+				put_fs_byte(c,buf);
+				buf++;
+				i++;
+			}
+			return i;
+	}
+	return -EINVAL;
+}
+			
 
 int printk(const char *fmt, ...)
 {
 	va_list args;
-	int i;
+	int i,j;
+	char * p;
 
 	va_start(args, fmt);
 	i=vsprintf(buf,fmt,args);
 	va_end(args);
+	for (j = 0; j < i && log_page ; j++) {
+		p = (char *) log_page + (4095 & (log_start+log_size));
+		*p = buf[j];
+		if (log_size < 4096)
+			log_size++;
+		else
+			log_start++;
+	}
+	if (log_page)
+		wake_up(&log_wait);
 	console_print(buf);
 	return i;
 }