Add in MI implementations of the KTR trace buffer ddb commands. The

commands have also been slightly updated as follows:
- Use ktr_idx to find the newest entry rather than walking the buffer
  comparing timespecs.  Timespecs are not always unique after the change
  to use getnanotime(9).
- Add a new verbose setting.  When the verbose setting is on, then the
  timestamp is printed with each message.  If KTR_EXTEND is on, then the
  filename and line number are output as well.  By default this option is
  off.  It can be turned on with the 'v' modifier passed to the 'tbuf'
  and 'tall' commands.  For the 'tnext' command, the 'v' modifier toggles
  the verbose mode.
- Only display the cpu number for each message on SMP systems.
- Don't display anything for an empty entry that hasn't been used yet.

1 files changed, 97 insertions, 0 deletions

diff --git a/sys/kern/kern_ktr.c b/sys/kern/kern_ktr.c
index 63f80ef..01467d1 100644
--- a/sys/kern/kern_ktr.c
+++ b/sys/kern/kern_ktr.c
@@ -34,9 +34,12 @@
  * function that does the actual tracing.
  */
 
+#include "opt_ddb.h"
 #include "opt_ktr.h"
 
+#include <sys/param.h>
 #include <sys/types.h>
+#include <sys/cons.h>
 #include <sys/time.h>
 #include <sys/ktr.h>
 #include <sys/libkern.h>
@@ -46,6 +49,8 @@
 #include <machine/globals.h>
 #include <machine/stdarg.h>
 
+#include <ddb/ddb.h>
+
 #ifndef KTR_MASK
 #define	KTR_MASK	(KTR_GEN)
 #endif
@@ -152,4 +157,96 @@ ktr_tracepoint(u_int mask, char *format, u_long arg1, u_long arg2, u_long arg3,
 	entry->ktr_parm5 = arg5;
 #endif
 }
+
+#ifdef DDB
+
+struct tstate {
+	int	cur;
+	int	first;
+};
+static	struct tstate tstate;
+static	int db_ktr_verbose;
+static	int db_mach_vtrace(void);
+
+DB_COMMAND(tbuf, db_mach_tbuf)
+{
+
+	tstate.cur = (ktr_idx - 1) & (KTR_ENTRIES - 1);
+	tstate.first = -1;
+	if (strcmp(modif, "v") == 0)
+		db_ktr_verbose = 1;
+	else
+		db_ktr_verbose = 0;
+	db_mach_vtrace();
+
+	return;
+}
+
+DB_COMMAND(tall, db_mach_tall)
+{
+	int	c;
+
+	db_mach_tbuf(addr, have_addr, count, modif);
+	while (db_mach_vtrace()) {
+		c = cncheckc();
+		if (c != -1)
+			break;
+	}
+
+	return;
+}
+
+DB_COMMAND(tnext, db_mach_tnext)
+{
+
+	if (strcmp(modif, "v") == 0)
+		db_ktr_verbose ^= 1;
+	db_mach_vtrace();
+}
+
+static int
+db_mach_vtrace(void)
+{
+	struct ktr_entry	*kp;
+
+	if (tstate.cur == tstate.first) {
+		db_printf("--- End of trace buffer ---\n");
+		return (0);
+	}
+	kp = &ktr_buf[tstate.cur];
+
+	/* Skip over unused entries. */
+#ifdef KTR_EXTEND
+	if (kp->ktr_desc[0] != '\0') {
+#else
+	if (kp->ktr_desc != NULL) {
+#endif
+		db_printf("%d: ", tstate.cur);
+		if (db_ktr_verbose)
+			db_printf("%4ld.%06ld ", kp->ktr_tv.tv_sec,
+			    kp->ktr_tv.tv_nsec / 1000);
+#ifdef KTR_EXTEND
+#ifdef SMP
+		db_printf("cpu%d ", kp->ktr_cpu);
+#endif
+		if (db_ktr_verbose)
+			db_printf("%s.%d\t", kp->ktr_filename, kp->ktr_line);
+		db_printf("%s", kp->ktr_desc);
+#else
+		db_printf(kp->ktr_desc, kp->ktr_parm1, kp->ktr_parm2,
+		    kp->ktr_parm3, kp->ktr_parm4, kp->ktr_parm5);
+#endif
+		db_printf("\n");
+	}
+
+	if (tstate.first == -1)
+		tstate.first = tstate.cur;
+
+	if (--tstate.cur < 0)
+		tstate.cur = KTR_ENTRIES - 1;
+
+	return (1);
+}
+
+#endif	/* DDB */
 #endif	/* KTR */