pr_cat.patch

diff --git a/kernel/printk.c b/kernel/printk.c
index 177fa49..0f4df08 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -48,6 +48,40 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/printk.h>
 
+#define CATSTR_INIT(name)		\
+	name##_len = 0
+
+#define CATSTR_DEFINE(name, max)	\
+	char name[max];			\
+	size_t name##_len = 0;		\
+	size_t name##_max = max
+
+#define pr_cat(name, fmt, ...)		\
+	_pr_cat(name, &name##_len, name##_max, fmt, ##__VA_ARGS__)
+
+bool _pr_cat(char *s, size_t *len, size_t size, const char *fmt, ...)
+{
+	va_list args;
+	size_t r;
+
+	if (*len == size)
+		return false;
+
+	va_start(args, fmt);
+	r = vsnprintf(s + *len, size - *len, fmt, args);
+	va_end(args);
+
+	if (r + 1 >= size - *len) {
+		s[*len] = '\0';
+		*len = size;
+		return false;
+	}
+
+	*len += r;
+	s[*len] = '\0';
+	return true;
+}
+
 /*
  * Architectures can override it:
  */
@@ -587,6 +621,11 @@ static int devkmsg_open(struct inode *inode, struct file *file)
 	struct devkmsg_user *user;
 	int err;
 
+	console_lock();
+	print_modules();
+	print_modules();
+	console_unlock();
+
 	/* write-only does not need any file context */
 	if ((file->f_flags & O_ACCMODE) == O_WRONLY)
 		return 0;
@@ -671,6 +710,59 @@ void __init setup_log_buf(int early)
 	unsigned long flags;
 	char *new_log_buf;
 	int free;
+	int i;
+
+	CATSTR_DEFINE(line, 64);
+	CATSTR_DEFINE(line2, 16);
+	CATSTR_DEFINE(line3, 12);
+
+	pr_cat(line, "1:");
+	pr_cat(line, "-%i ", 12);
+	pr_cat(line, "-%i ", 34);
+	pr_cat(line, "-%i ", 56);
+	pr_cat(line, "-%i ", 78);
+	pr_info("%s-%i\n", line, 90);
+
+	pr_cat(line2, "2:");
+	pr_cat(line2, "-%i ", 12);
+	pr_cat(line2, "-%i ", 34);
+	pr_cat(line2, "-%i ", 56);
+	pr_cat(line2, "-%i ", 78);
+	pr_info("%s-%i\n", line2, 90);
+
+	pr_cat(line3, "3:");
+	pr_cat(line3, "-%i ", 12);
+	pr_cat(line3, "-%i ", 34);
+	pr_cat(line3, "-%i ", 56);
+	pr_cat(line3, "-%i ", 78);
+	pr_info("%s-%i\n", line3, 90);
+
+	CATSTR_INIT(line3);
+	pr_cat(line3, "4:");
+	pr_cat(line3, "+%i ", 12);
+	pr_cat(line3, "+%i ", 34);
+	pr_cat(line3, "+%i ", 56);
+	pr_cat(line3, "+%i ", 78);
+	pr_info("%s-%i\n", line3, 90);
+
+	CATSTR_INIT(line3);
+	pr_cat(line3, "5:");
+	pr_cat(line3, "~%i ", 12);
+	pr_cat(line3, "~%i ", 34);
+	pr_cat(line3, "~%i ", 56);
+	pr_cat(line3, "~%i ", 78);
+	pr_info("%s-%i\n", line3, 90);
+
+	CATSTR_INIT(line);
+	pr_cat(line, "foo:");
+	for (i = 0; i < 50; i++) {
+		if (!pr_cat(line, " #%i", i)) {
+			pr_info("%s #%i\n", line, i);
+			CATSTR_INIT(line);
+			pr_cat(line, "foo+:");
+		}
+	}
+	pr_info("%s\n", line);
 
 	if (!new_log_buf_len)
 		return;