linux/kernel/printk
Petr Mladek 22c2c7b2ef printk/NMI: handle continuous lines and missing newline
Commit 4bcc595ccd ("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/1478695291-12169-2-git-send-email-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Joe Perches <joe@perches.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12 18:55:09 -08:00
..
braille.c printk: fix parsing of "brl=" option 2016-08-26 17:39:35 -07:00
braille.h printk: move braille console support into separate braille.[ch] files 2013-07-31 14:41:03 -07:00
console_cmdline.h console: Fix console name size mismatch 2015-03-07 03:39:55 +01:00
internal.h Revert "printk: create pr_<level> functions" 2016-08-09 10:48:18 -07:00
Makefile printk/nmi: generic solution for safe printk in NMI 2016-05-20 17:58:30 -07:00
nmi.c printk/NMI: handle continuous lines and missing newline 2016-12-12 18:55:09 -08:00
printk.c Revert "printk: make reading the kernel log flush pending lines" 2016-11-14 09:31:52 -08:00