core: Add kernel message dumper to call on oopses and panics

The core functionality is implemented as per Linus suggestion from

  http://lists.infradead.org/pipermail/linux-mtd/2009-October/027620.html

(with the kmsg_dump implementation by Linus). A struct kmsg_dumper has
been added which contains a callback to dump the kernel log buffers on
crashes. The kmsg_dump function gets called from oops_exit() and panic()
and invokes this callbacks with the crash reason.

[dwmw2: Fix log_end handling]
Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
Reviewed-by: Anders Grafstrom <anders.grafstrom@netinsight.net>
Reviewed-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index bcdef26e3332..8c43226a544d 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -10,6 +10,7 @@
  */
 #include <linux/debug_locks.h>
 #include <linux/interrupt.h>
+#include <linux/kmsg_dump.h>
 #include <linux/kallsyms.h>
 #include <linux/notifier.h>
 #include <linux/module.h>
@@ -74,6 +75,7 @@ NORET_TYPE void panic(const char * fmt, ...)
         dump_stack();
 #endif
 
+        kmsg_dump(KMSG_DUMP_PANIC);
         /*
          * If we have crashed and we have a crash kernel loaded let it handle
          * everything else.
@@ -338,6 +340,7 @@ void oops_exit(void)
 {
         do_oops_enter_exit();
         print_oops_end_marker();
+        kmsg_dump(KMSG_DUMP_OOPS);
 }
 
 #ifdef WANT_WARN_ON_SLOWPATH