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authorLinus Torvalds <torvalds@linux-foundation.org>2020-06-01 22:13:30 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-01 22:13:30 +0300
commitca1f5df23f28228c46aa45d934abad38c6b6ff2e (patch)
tree2a104624002b3c78fee0f0efc5a29150d6292206 /Documentation
parent4d67829e11863072aec7cd1dd2939b1fd3eda17b (diff)
parent8b390ab725fddc443bb0082a6c67e82e25bfba7e (diff)
downloadlinux-ca1f5df23f28228c46aa45d934abad38c6b6ff2e.tar.xz
Merge tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux
Pull printk updates from Petr Mladek: - Benjamin Herrenschmidt solved a problem with non-matched console aliases by first checking consoles defined on the command line. It is a more conservative approach than the previous attempts. - Benjamin also made sure that the console accessible via /dev/console always has CON_CONSDEV flag. - Andy Shevchenko added the %ptT modifier for printing struct time64_t. It extends the existing %ptR handling for struct rtc_time. - Bruno Meneguele fixed /dev/kmsg error value returned by unsupported SEEK_CUR. - Tetsuo Handa removed unused pr_cont_once(). ... and a few small fixes. * tag 'printk-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: Remove pr_cont_once() printk: handle blank console arguments passed in. kernel/printk: add kmsg SEEK_CUR handling printk: Fix a typo in comment "interator"->"iterator" usb: pulse8-cec: Switch to use %ptT ARM: bcm2835: Switch to use %ptT lib/vsprintf: Print time64_t in human readable format lib/vsprintf: update comment about simple_strto<foo>() functions printk: Correctly set CON_CONSDEV even when preferred console was not registered printk: Fix preferred console selection with multiple matches printk: Move console matching logic into a separate function printk: Convert a use of sprintf to snprintf in console_unlock
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/dev-kmsg5
-rw-r--r--Documentation/core-api/printk-formats.rst22
2 files changed, 17 insertions, 10 deletions
diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg
index f307506eb54c..1e6c28b1942b 100644
--- a/Documentation/ABI/testing/dev-kmsg
+++ b/Documentation/ABI/testing/dev-kmsg
@@ -56,6 +56,11 @@ 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.
+ Due to the record nature of this interface with a "read all"
+ behavior and the specific positions each seek operation sets,
+ SEEK_CUR is not supported, returning -ESPIPE (invalid seek) to
+ errno whenever requested.
+
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 5dfcc4592b23..5d8f1e84dd90 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -482,21 +482,23 @@ Examples (OF)::
%pfwf /ocp@68000000/i2c@48072000/camera@10/port/endpoint - Full name
%pfwP endpoint - Node name
-Time and date (struct rtc_time)
--------------------------------
+Time and date
+-------------
::
- %ptR YYYY-mm-ddTHH:MM:SS
- %ptRd YYYY-mm-dd
- %ptRt HH:MM:SS
- %ptR[dt][r]
+ %pt[RT] YYYY-mm-ddTHH:MM:SS
+ %pt[RT]d YYYY-mm-dd
+ %pt[RT]t HH:MM:SS
+ %pt[RT][dt][r]
-For printing date and time as represented by struct rtc_time structure in
-human readable format.
+For printing date and time as represented by
+ R struct rtc_time structure
+ T time64_t type
+in human readable format.
-By default year will be incremented by 1900 and month by 1. Use %ptRr (raw)
-to suppress this behaviour.
+By default year will be incremented by 1900 and month by 1.
+Use %pt[RT]r (raw) to suppress this behaviour.
Passed by reference.