ABI: Update dev-kmsg documentation to match current kernel behaviour

Commit 5aa068ea4082 ("printk: remove games with previous record flags")
abolished the practice of setting the log flag to 'c' for the first
continuation line and '+' for subsequent lines. Now all continuation
lines are flagged with 'c' and '+' is never used.

Update the 'dev-kmsg' documentation to remove the reference to the
obsolete '+' flag. In addition, state explicitly that only 8 bits of the
<N> syslog prefix are used for the facility number when writing to
/dev/kmsg.

Link: http://lkml.kernel.org/r/0102016cf1b26630-8e9b337b-da49-43c6-b028-4250c2fac3ef-000000@eu-west-1.amazonses.com
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: James Byrne <james.byrne@origamienergy.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg
index fff817e..f307506 100644 (file)
--- a/Documentation/ABI/testing/dev-kmsg
+++ b/Documentation/ABI/testing/dev-kmsg
@@ -12,7 +12,7 @@ Description:  The /dev/kmsg character device node provides userspace access
                The logged line can be prefixed with a <N> syslog prefix, which
                carries the syslog priority and facility. The single decimal
                prefix number is composed of the 3 lowest bits being the syslog
-               priority and the higher bits the syslog facility number.
+               priority and the next 8 bits the syslog facility number.
 
                If no prefix is given, the priority number is the default kernel
                log priority and the facility number is set to LOG_USER (1). It
@@ -90,13 +90,12 @@ Description:        The /dev/kmsg character device node provides userspace access
                  +sound:card0 - subsystem:devname
 
                The flags field carries '-' by default. A 'c' indicates a
-               fragment of a line. All following fragments are flagged with
-               '+'. Note, that these hints about continuation lines are not
-               necessarily correct, and the stream could be interleaved with
-               unrelated messages, but merging the lines in the output
-               usually produces better human readable results. A similar
-               logic is used internally when messages are printed to the
-               console, /proc/kmsg or the syslog() syscall.
+               fragment of a line. Note, that these hints about continuation
+               lines are not necessarily correct, and the stream could be
+               interleaved with unrelated messages, but merging the lines in
+               the output usually produces better human readable results. A
+               similar logic is used internally when messages are printed to
+               the console, /proc/kmsg or the syslog() syscall.
 
                By default, kernel tries to avoid fragments by concatenating
                when it can and fragments are rare; however, when extended