printk: guard the amount written per line by devkmsg_read()
authorTejun Heo <tj@kernel.org>
Thu, 25 Jun 2015 22:01:24 +0000 (15:01 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 26 Jun 2015 00:00:38 +0000 (17:00 -0700)
commitd43ff430f434d862db59582c0f1f02382a678036
tree1ade66d9cce26fc358a3d814bec1ad7bb06ec8cc
parent4ae555a5313a302d36e34b3273545e4088c37cce
printk: guard the amount written per line by devkmsg_read()

This patchset updates netconsole so that it can emit messages with the
same header as used in /dev/kmsg which gives neconsole receiver full log
information which enables things like structured logging and detection
of lost messages.

This patch (of 7):

devkmsg_read() uses 8k buffer and assumes that the formatted output
message won't overrun which seems safe given LOG_LINE_MAX, the current use
of dict and the escaping method being used; however, we're planning to use
devkmsg formatting wider and accounting for the buffer size properly isn't
that complicated.

This patch defines CONSOLE_EXT_LOG_MAX as 8192 and updates devkmsg_read()
so that it limits output accordingly.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/printk.h
kernel/printk/printk.c