kernel/printk: add kmsg SEEK_CUR handling

[thirdparty/linux.git] / Documentation / ABI / testing / dev-kmsg

diff --git a/Documentation/ABI/testing/dev-kmsg b/Documentation/ABI/testing/dev-kmsg
index f307506eb54ce9a44601ba37ba798314049da762..1e6c28b1942bd45de652339b807cff538140dd62 100644 (file)
--- 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,