panic: call panic handlers before kmsg_dump

kees · torvalds · commit 6723734cdff1 · 2013-09-11T15:59:30.000-07:00
Since the panic handlers may produce additional information (via printk)
for the kernel log, it should be reported as part of the panic output
saved by kmsg_dump().  Without this re-ordering, nothing that adds
information to a panic will show up in pstore's view when kmsg_dump runs,
and is therefore not visible to crash reporting tools that examine pstore
output.

Signed-off-by: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Anton Vorontsov &lt;anton@enomsg.org&gt;
Cc: Colin Cross &lt;ccross@android.com&gt;
Acked-by: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Stephen Boyd &lt;sboyd@codeaurora.org&gt;
Cc: Vikram Mulukutla &lt;markivx@codeaurora.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
diff --git a/kernel/panic.c b/kernel/panic.c
@@ -123,10 +123,14 @@ void panic(const char *fmt, ...)
 	 */
 	smp_send_stop();
 
-	kmsg_dump(KMSG_DUMP_PANIC);
-
+	/*
+	 * Run any panic handlers, including those that might need to
+	 * add information to the kmsg dump output.
+	 */
 	atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
 
+	kmsg_dump(KMSG_DUMP_PANIC);
+
 	bust_spinlocks(0);
 
 	if (!panic_blink)
