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authorFeng Tang <feng.tang@intel.com>2019-05-17 14:31:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-18 15:52:26 -0700
commitde6da1e8bcf0dd2058b950b127491821207679dc (patch)
tree2d54c823763d46cd070e5a721040bc1514df52ed /Documentation
parent5d59aa8f9ce972b472201aed86e904bb75879ff0 (diff)
downloadlwn-de6da1e8bcf0dd2058b950b127491821207679dc.tar.gz
lwn-de6da1e8bcf0dd2058b950b127491821207679dc.zip
panic: add an option to replay all the printk message in buffer
Currently on panic, kernel will lower the loglevel and print out pending printk msg only with console_flush_on_panic(). Add an option for users to configure the "panic_print" to replay all dmesg in buffer, some of which they may have never seen due to the loglevel setting, which will help panic debugging . [feng.tang@intel.com: keep the original console_flush_on_panic() inside panic()] Link: http://lkml.kernel.org/r/1556199137-14163-1-git-send-email-feng.tang@intel.com [feng.tang@intel.com: use logbuf lock to protect the console log index] Link: http://lkml.kernel.org/r/1556269868-22654-1-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1556095872-36838-1-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Aaro Koskinen <aaro.koskinen@nokia.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt1
1 files changed, 1 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 52e6fbb042cc..138f6664b2e2 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3212,6 +3212,7 @@
bit 2: print timer info
bit 3: print locks info if CONFIG_LOCKDEP is on
bit 4: print ftrace buffer
+ bit 5: print all printk messages in buffer
panic_on_warn panic() instead of WARN(). Useful to cause kdump
on a WARN().