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authorLinus Torvalds <torvalds@linux-foundation.org>2020-08-04 22:22:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-04 22:22:25 -0700
commita754292348bf88ec6b55563eca4faba7dcfe2ae7 (patch)
treee83a65dae3699223687c47f9c9a4d4b2d12ef14c /Documentation
parent95ffa676583b23baed40861d30b65fe31397da00 (diff)
parent57e60db3bc4d2755aefe5abd1024662f478770ac (diff)
Merge tag 'printk-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek: - Herbert Xu made printk header file self-contained. - Andy Shevchenko and Sergey Senozhatsky cleaned up console->setup() error handling. - Andy Shevchenko did some cleanups (e.g. sparse warning) in vsprintf code. - Minor documentation updates. * tag 'printk-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: lib/vsprintf: Force type of flags value for gfp_t lib/vsprintf: Replace custom spec to print decimals with generic one lib/vsprintf: Replace hidden BUILD_BUG_ON() with static_assert() printk: Make linux/printk.h self-contained doc:kmsg: explicitly state the return value in case of SEEK_CUR Replace HTTP links with HTTPS ones: vsprintf hvc: unify console setup naming console: Fix trivia typo 'change' -> 'chance' console: Propagate error code from console ->setup() tty: hvc: Return proper error code from console ->setup() hook serial: sunzilog: Return proper error code from console ->setup() hook serial: sunsab: Return proper error code from console ->setup() hook mips: Return proper error code from console ->setup() hook
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/dev-kmsg11
-rw-r--r--Documentation/core-api/printk-formats.rst4
2 files changed, 13 insertions, 2 deletions
diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg
index f307506eb54c..3c0bb76e3417 100644
--- a/Documentation/ABI/testing/dev-kmsg
+++ b/Documentation/ABI/testing/dev-kmsg
@@ -56,6 +56,17 @@ Description: The /dev/kmsg character device node provides userspace access
seek after the last record available at the time
the last SYSLOG_ACTION_CLEAR was issued.
+ Other seek operations or offsets are not supported because of
+ the special behavior this device has. The device allows to read
+ or write only whole variable length messages (records) that are
+ stored in a ring buffer.
+
+ Because of the non-standard behavior also the error values are
+ non-standard. -ESPIPE is returned for non-zero offset. -EINVAL
+ is returned for other operations, e.g. SEEK_CUR. This behavior
+ and values are historical and could not be modified without the
+ risk of breaking userspace.
+
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,
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index 8c9aba262b1e..1beac4719e43 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -317,7 +317,7 @@ colon-separators. Leading zeros are always used.
The additional ``c`` specifier can be used with the ``I`` specifier to
print a compressed IPv6 address as described by
-http://tools.ietf.org/html/rfc5952
+https://tools.ietf.org/html/rfc5952
Passed by reference.
@@ -341,7 +341,7 @@ The additional ``p``, ``f``, and ``s`` specifiers are used to specify port
flowinfo a ``/`` and scope a ``%``, each followed by the actual value.
In case of an IPv6 address the compressed IPv6 address as described by
-http://tools.ietf.org/html/rfc5952 is being used if the additional
+https://tools.ietf.org/html/rfc5952 is being used if the additional
specifier ``c`` is given. The IPv6 address is surrounded by ``[``, ``]`` in
case of additional specifiers ``p``, ``f`` or ``s`` as suggested by
https://tools.ietf.org/html/draft-ietf-6man-text-addr-representation-07