[PATCH] better output

[Petr Mladek]

---
 fs/seq_file.c            | 21 +++++++++++++++++++++
 include/linux/seq_file.h |  1 +
 kernel/printk/printk.c   | 20 ++++++++++++++------
 3 files changed, 36 insertions(+), 6 deletions(-)

diff --git a/fs/seq_file.c b/fs/seq_file.c
index 03a369ccd28c..364587eff9d2 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -376,6 +376,27 @@ void seq_escape(struct seq_file *m, const char *s, const char *esc)
 }
 EXPORT_SYMBOL(seq_escape);
 
+/**
+ *	seq_escape+printf_format - print string into buffer, escaping
+ *		characters that are escaped in printf format,
+ *	@m:	target buffer
+ *	@s:	string
+ *
+ *	Puts string into buffer and escape characters that are
+ *	escaped in printf format.
+ *	Use seq_has_overflowed() to check for errors.
+ */
+void seq_escape_printf_format(struct seq_file *m, const char *s)
+{
+	char *buf;
+	size_t size = seq_get_buf(m, &buf);
+	int ret;
+
+	ret = string_escape_str(s, buf, size, ESCAPE_SPACE | ESCAPE_SPECIAL, NULL);
+	seq_commit(m, ret < size ? ret : -1);
+}
+EXPORT_SYMBOL(seq_escape_printf_format);
+
 void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz)
 {
 	char *buf;
diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h
index b83b3ae3c877..cfc504a30429 100644
--- a/include/linux/seq_file.h
+++ b/include/linux/seq_file.h
@@ -127,6 +127,7 @@ void seq_put_hex_ll(struct seq_file *m, const char *delimiter,
 		    unsigned long long v, unsigned int width);
 
 void seq_escape(struct seq_file *m, const char *s, const char *esc);
+void seq_escape_printf_format(struct seq_file *m, const char *s);
 void seq_escape_mem_ascii(struct seq_file *m, const char *src, size_t isz);
 
 void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type,
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index adf545ba9eb9..77a43b483b7b 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -783,6 +783,8 @@ static const char *ps_get_module_name(const struct printk_fmt_sec *ps)
 }
 #endif /* CONFIG_MODULES */
 
+static u16 parse_prefix(const char *text, int *level, enum log_flags *lflags);
+
 static int debugfs_pf_show(struct seq_file *s, void *v)
 {
 	struct module *mod = s->file->f_inode->i_private;
@@ -804,11 +806,17 @@ static int debugfs_pf_show(struct seq_file *s, void *v)
 	}
 
 	for (fptr = ps->start; fptr < ps->end; fptr++) {
-		/* For callsites without KERN_SOH + level preamble. */
-		if (unlikely(*fptr[0] != KERN_SOH_ASCII))
-			seq_printf(s, "%c%d", KERN_SOH_ASCII,
-				   MESSAGE_LOGLEVEL_DEFAULT);
-		seq_printf(s, "%s%c", *fptr, '\0');
+		int level;
+		u16 prefix_len;
+		const char *fmt;
+
+		level = LOGLEVEL_DEFAULT;
+		prefix_len = parse_prefix(fptr[0], &level, NULL);
+		fmt = fptr[0] + prefix_len;
+
+		seq_printf(s, "<%d> ", level);
+		seq_escape_printf_format(s, fmt);
+		seq_printf(s, "\n");
 	}
 
 out_unlock:
@@ -2113,7 +2121,7 @@ static inline u32 printk_caller_id(void)
  *
  * Return: The length of the parsed level and control flags.
  */
-static u16 parse_prefix(char *text, int *level, enum log_flags *lflags)
+static u16 parse_prefix(const char *text, int *level, enum log_flags *lflags)
 {
 	u16 prefix_len = 0;
 	int kern_level;
-- 
2.26.2