From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Thu, 16 Aug 2012 16:11:07 +0000 (-0700)
Subject: kernel - Stop KTR logging during panic
X-Git-Tag: v3.0.3~7
X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/1ecd457f72707d1dd6302a104d25bd9f6c74344b

kernel - Stop KTR logging during panic

* Stop all KTR logging when a panic occurs so the KTR buffer doesn't
  get wiped out by events during the panic & core dump.  This gives
  us a KTR buf snapshot as of the panic entry.
---

diff --git a/sys/kern/kern_ktr.c b/sys/kern/kern_ktr.c
index e4c819c..2963c79 100644
--- a/sys/kern/kern_ktr.c
+++ b/sys/kern/kern_ktr.c
@@ -419,7 +419,9 @@ ktr_begin_write_entry(struct ktr_info *info, const char *file, int line)
 
 	cpu = mycpu->gd_cpuid;
 	kcpu = &ktr_cpu[cpu].core;
-	if (kcpu->ktr_buf == NULL)
+	if (panicstr)			/* stop logging during panic */
+		return NULL;
+	if (kcpu->ktr_buf == NULL)	/* too early in boot */
 		return NULL;
 
 	crit_enter();