add changelog and documentation

1 files changed, 84 insertions, 2 deletions

diff --git a/kmsg-export-flags.patch b/kmsg-export-flags.patch
index 4989050..c817460 100644
--- a/kmsg-export-flags.patch
+++ b/kmsg-export-flags.patch
@@ -1,7 +1,89 @@
+From: Kay Sievers <kay@vrfy.org>
+Subject: kmsg - export "continuation record" flag to /dev/kmsg
+
+In some cases we are forced to store individual records for a continuation
+line print.
+
+Export a flag to allow the external re-construction of the line. The flag
+allows us to apply a similar logic externally which is used internally when
+the console, /proc/kmsg or the syslog() output is printed.
+
+  $ cat /dev/kmsg
+  4,165,0,-;Free swap  = 0kB
+  4,166,0,-;Total swap = 0kB
+  6,167,0,c;[
+  4,168,0,+;0 
+  4,169,0,+;1 
+  4,170,0,+;2 
+  4,171,0,+;3 
+  4,172,0,+;]
+  6,173,0,-;[0 1 2 3 ]
+  6,174,0,-;Console: colour VGA+ 80x25
+  6,175,0,-;console [tty0] enabled
+
+Signed-off-by: Kay Sievers <kay@vrfy.org>
 ---
- kernel/printk.c |   23 +++++++++++++++++++++--
- 1 file changed, 21 insertions(+), 2 deletions(-)
 
+ Documentation/ABI/testing/dev-kmsg |   29 ++++++++++++++++++++---------
+ kernel/printk.c                    |   23 +++++++++++++++++++++--
+ 2 files changed, 41 insertions(+), 11 deletions(-)
+
+--- a/Documentation/ABI/testing/dev-kmsg
++++ b/Documentation/ABI/testing/dev-kmsg
+@@ -58,16 +58,18 @@ Description:	The /dev/kmsg character dev
+ 
+ 		The output format consists of a prefix carrying the syslog
+ 		prefix including priority and facility, the 64 bit message
+-		sequence number and the monotonic timestamp in microseconds.
+-		The values are separated by a ','. Future extensions might
+-		add more comma separated values before the terminating ';'.
+-		Unknown values should be gracefully ignored.
++		sequence number and the monotonic timestamp in microseconds,
++		and a flag field. All fields are separated by a ','.
++
++		Future extensions might add more comma separated values before
++		the terminating ';'. Unknown fields and values should be
++		gracefully ignored.
+ 
+ 		The human readable text string starts directly after the ';'
+ 		and is terminated by a '\n'. Untrusted values derived from
+ 		hardware or other facilities are printed, therefore
+-		all non-printable characters in the log message are escaped
+-		by "\x00" C-style hex encoding.
++		all non-printable characters and '\' itself in the log message
++		are escaped by "\x00" C-style hex encoding.
+ 
+ 		A line starting with ' ', is a continuation line, adding
+ 		key/value pairs to the log message, which provide the machine
+@@ -75,11 +77,11 @@ Description:	The /dev/kmsg character dev
+ 		userspace.
+ 
+ 		Example:
+-		7,160,424069;pci_root PNP0A03:00: host bridge window [io  0x0000-0x0cf7] (ignored)
++		7,160,424069,-;pci_root PNP0A03:00: host bridge window [io  0x0000-0x0cf7] (ignored)
+ 		 SUBSYSTEM=acpi
+ 		 DEVICE=+acpi:PNP0A03:00
+-		6,339,5140900;NET: Registered protocol family 10
+-		30,340,5690716;udevd[80]: starting version 181
++		6,339,5140900,-;NET: Registered protocol family 10
++		30,340,5690716,-;udevd[80]: starting version 181
+ 
+ 		The DEVICE= key uniquely identifies devices the following way:
+ 		  b12:8        - block dev_t
+@@ -87,4 +89,13 @@ Description:	The /dev/kmsg character dev
+ 		  n8           - netdev ifindex
+ 		  +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
++		neccessarily 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.
++
+ Users:		dmesg(1), userspace kernel log consumers
 --- a/kernel/printk.c
 +++ b/kernel/printk.c
 @@ -360,6 +360,7 @@ static void log_store(int facility, int