Revision - 19feeff - printk/nmi: avoid direct printk()-s from __printk_nmi_flush() - origin: https://github.com/torvalds/linux

visit type:

https://github.com/torvalds/linux

27 March 2024, 02:37:15 UTC

Revision 19feeff18bbfde659baa58c2346f15a24d7c405e authored by Sergey Senozhatsky on 01 September 2016, 23:15:04 UTC, committed by Linus Torvalds on 02 September 2016, 00:52:01 UTC

printk/nmi: avoid direct printk()-s from __printk_nmi_flush()

__printk_nmi_flush() can be called from nmi_panic(), therefore it has to
test whether it's executed in NMI context and thus must route the
messages through deferred printk() or via direct printk().

This is to avoid potential deadlocks, as described in commit
cf9b1106c81c ("printk/nmi: flush NMI messages on the system panic").

However there remain two places where __printk_nmi_flush() does
unconditional direct printk() calls:

 - pr_err("printk_nmi_flush: internal error ...")
 - pr_cont("\n")

Factor out print_nmi_seq_line() parts into a new printk_nmi_flush_line()
function, which takes care of in_nmi(), and use it in
__printk_nmi_flush() for printing and error-reporting.

Link: http://lkml.kernel.org/r/20160830161354.581-1-sergey.senozhatsky@gmail.com
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 parent 7e93215

Files
Changes

Tip revision: 19feeff18bbfde659baa58c2346f15a24d7c405e authored by Sergey Senozhatsky on 01 September 2016, 23:15:04 UTC
printk/nmi: avoid direct printk()-s from __printk_nmi_flush()

Tip revision: 19feeff

File	Mode	Size
Documentation
arch
block
certs
crypto
drivers
firmware
fs
include
init
ipc
kernel
lib
mm
net
samples
scripts
security
sound
tools
usr
virt
.cocciconfig	-rw-r--r--	59 bytes
.get_maintainer.ignore	-rw-r--r--	31 bytes
.gitignore	-rw-r--r--	1.3 KB
.mailmap	-rw-r--r--	7.1 KB
COPYING	-rw-r--r--	18.3 KB
CREDITS	-rw-r--r--	95.5 KB
Kbuild	-rw-r--r--	2.8 KB
Kconfig	-rw-r--r--	252 bytes
MAINTAINERS	-rw-r--r--	363.1 KB
Makefile	-rw-r--r--	56.8 KB
README	-rw-r--r--	18.1 KB
REPORTING-BUGS	-rw-r--r--	7.3 KB

Showing with 0 additions and 0 deletions (0 / 0 diffs computed)

Computing file changes ...

https://github.com/torvalds/linux

printk/nmi: avoid direct printk()-s from __printk_nmi_flush()

README