printk/NMI: handle continuous lines and missing newline

Commit 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing
continuation lines") added back KERN_CONT message header.  As a result
it might appear in the middle of the line when the parts are squashed
via the temporary NMI buffer.

A reasonable solution seems to be to split the text in the NNI temporary
not only by newlines but also by the message headers.

Another solution would be to filter out KERN_CONT when writing to the
temporary buffer.  But this would complicate the lockless handling.
Also it would not solve problems with a missing newline that was there
even before the KERN_CONT stuff.

This patch moves the temporary buffer handling into separate function.
I played with it and it seems that using the char pointers make the code
easier to read.

Also it prints the final newline as a continuous line.

Finally, it moves handling of the s->len overflow into the paranoid
check.  And allows to recover from the disaster.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Petr Mladek <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
Cc: Joe Perches <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Jason Wessel <[email protected]>
Cc: Jaroslav Kysela <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: Chris Mason <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: David Sterba <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions