update kmsg-docs.patch

2 files changed, 87 insertions, 8 deletions

diff --git a/kern-cont-mm.patch b/kern-cont-mm.patch
index a78dfa3..1e5717b 100644
--- a/kern-cont-mm.patch
+++ b/kern-cont-mm.patch
@@ -1,6 +1,7 @@
 From: Kay Sievers <kay@vrfy.org>
 Subject: mm: use KERN_CONT in printk() continuation lines
 
+Cc: Andrew Morton <akpm@linux-foundation.org>
 Signed-off-by: Kay Sievers <kay@vrfy.org>
 ---
  mm/page_alloc.c |    6 +++---
diff --git a/kmsg-docs.patch b/kmsg-docs.patch
index 507d3fc..667a429 100644
--- a/kmsg-docs.patch
+++ b/kmsg-docs.patch
@@ -3,13 +3,13 @@ Subject: kmsg - add Documentation/ABI/testing/dev-kmsg
 
 Signed-off-by: Kay Sievers <kay@vrfy.org>
 ---
- Documentation/ABI/testing/dev-kmsg |   12 ++++++++++++
- Documentation/devices.txt          |    3 ++-
- 2 files changed, 14 insertions(+), 1 deletion(-)
+ Documentation/ABI/testing/dev-kmsg |   90 +++++++++++++++++++++++++++++++++++++
+ Documentation/devices.txt          |    3 -
+ 2 files changed, 92 insertions(+), 1 deletion(-)
 
 --- /dev/null
 +++ b/Documentation/ABI/testing/dev-kmsg
-@@ -0,0 +1,12 @@
+@@ -0,0 +1,90 @@
 +What:		/dev/kmsg
 +Date:		Mai 2012
 +KernelVersion:	3.4
@@ -17,11 +17,89 @@ Signed-off-by: Kay Sievers <kay@vrfy.org>
 +Description:	The /dev/kmsg character device node provides userspace access
 +		to the kernel's printk buffer.
 +
-+		Userspace can inject messages into the kernel printk buffer by
-+		opening the device node and writing a plain text line into it.
-+		The line can optionally start with a syslog prefix.
++		Injecting messages:
++		Every write() to the opened device node places a log entry in
++		the kernel's printk buffer.
 +
-+Users:		dmesg(1), userspace kernel log consumers, systemd-journald
++		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.
++
++		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
++		is not possible to inject messages from userspace with the
++		facility number LOG_KERN (0), to make sure that the origin of
++		the messages can always be reliably determined.
++
++		Accessing the buffer:
++		Every read() from the opened device node receives one record
++		of the kernel's printk buffer.
++
++		The first read() directly following an open() always returns
++		first message in the buffer; there is no kernel-internal
++		persistent state; many readers can concurrently open the device
++		and read from it, without affecting other readers.
++
++		Every read() will receive the next available record. If no more
++		records are available read() will block, or if O_NONBLOCK is
++		used -EAGAIN returned.
++
++		Messages in the record ring buffer get overwritten as whole,
++		there are never partial messages received by read().
++
++		In case messages get overwritten in the circular buffer while
++		the device is kept open, the next read() will return -EPIPE,
++		and the seek position be updated to the next available record.
++		Subsequent reads() will return available records again.
++
++		Unlike the classic syslog() interface, the 64 bit record
++		sequence numbers allow to calculate the amount of lost
++		messages, in case the buffer gets overwritten. And they allow
++		to reconnect to the buffer and reconstruct the read position
++		if needed, without limiting the interface to a single reader.
++
++		The device supports seek with the following parameters:
++		SEEK_SET, 0
++		  seek to the first entry in the buffer
++		SEEK_END, 0
++		  seek after the last entry in the buffer
++		SEEK_DATA, 0
++		  seek after the last record available at the time
++		  the last SYSLOG_ACTION_CLEAR was issued.
++
++		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.
++
++		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.
++
++		A line starting with ' ', is a continuation line, adding
++		key/value pairs to the log message, which provide the machine
++		readable context of the message, for reliable processing in
++		userspace.
++
++		Example:
++		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
++
++		The DEVICE= key uniquely identifies devices the following way:
++		  b12:8        - block dev_t
++		  c127:3       - char dev_t
++		  n8           - netdev ifindex
++		  + sound:card0 - subsystem:devname
++
++Users:		dmesg(1), userspace kernel log consumers
 --- a/Documentation/devices.txt
 +++ b/Documentation/devices.txt
 @@ -98,7 +98,8 @@ Your cooperation is appreciated.