xref: /freebsd/sys/kern/kern_ktr.c (revision a0a7328bb0e44e64393c1e1be6a9621945bb8edf)

/*
 * Copyright (c) 2000
 *	John Baldwin <jhb@FreeBSD.org>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JOHN BALDWIN AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL JOHN BALDWIN OR THE VOICES IN HIS HEAD
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $FreeBSD$
 */

/*
 * This module holds the global variables used by KTR and the ktr_tracepoint()
 * 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/kernel.h>
#include <sys/ktr.h>
#include <sys/libkern.h>
#include <sys/linker_set.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <machine/globals.h>
#include <machine/stdarg.h>

#include <ddb/ddb.h>

#ifndef KTR_MASK
#define	KTR_MASK	(KTR_GEN)
#endif

#ifndef KTR_CPUMASK
#define	KTR_CPUMASK	(~0)
#endif

#ifdef SMP
#define KTR_CPU		cpuid
#else
#define KTR_CPU		0
#endif

#ifdef KTR_EXTEND
#define KTR_EXTEND_DEFAULT	1
#else
#define KTR_EXTEND_DEFAULT	0
#endif

#ifdef KTR_VERBOSE
#define KTR_VERBOSE_DEFAULT	1
#else
#define KTR_VERBOSE_DEFAULT	0
#endif

SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");

/*
 * This variable is used only by gdb to work out what fields are in
 * ktr_entry.
 */
int     ktr_extend = KTR_EXTEND_DEFAULT;
SYSCTL_INT(_debug_ktr, OID_AUTO, extend, CTLFLAG_RD, &ktr_extend, 0, "");

int	ktr_cpumask;
TUNABLE_INT_DECL("debug.ktr.cpumask", KTR_CPUMASK, ktr_cpumask);
SYSCTL_INT(_debug_ktr, OID_AUTO, cpumask, CTLFLAG_RW, &ktr_cpumask, 0, "");

int	ktr_mask;
TUNABLE_INT_DECL("debug.ktr.mask", KTR_MASK, ktr_mask);
SYSCTL_INT(_debug_ktr, OID_AUTO, mask, CTLFLAG_RW, &ktr_mask, 0, "");

int	ktr_entries = KTR_ENTRIES;
SYSCTL_INT(_debug_ktr, OID_AUTO, entries, CTLFLAG_RD, &ktr_entries, 0, "");

volatile int	ktr_idx = 0;
struct	ktr_entry ktr_buf[KTR_ENTRIES];

int	ktr_verbose;
TUNABLE_INT_DECL("debug.ktr.verbose", KTR_VERBOSE_DEFAULT, ktr_verbose);
SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");

#ifdef KTR
#ifdef KTR_EXTEND
void
ktr_tracepoint(u_int mask, char *filename, u_int line, char *format, ...)
#else
void
ktr_tracepoint(u_int mask, char *format, u_long arg1, u_long arg2, u_long arg3,
	       u_long arg4, u_long arg5)
#endif
{
	struct ktr_entry *entry;
	int newindex, saveindex, saveintr;
#ifdef KTR_EXTEND
	va_list ap;
#endif

	if (panicstr)
		return;
	if ((ktr_mask & mask) == 0)
		return;
#ifdef KTR_EXTEND
	if (((1 << KTR_CPU) & ktr_cpumask) == 0)
		return;
#endif
	saveintr = save_intr();
	disable_intr();
	do {
		saveindex = ktr_idx;
		newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
	} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
	entry = &ktr_buf[saveindex];
	restore_intr(saveintr);
	if (ktr_mask & KTR_LOCK)
		/*
		 * We can't use nanotime with KTR_LOCK, it would cause
		 * endless recursion, at least under the Intel
		 * architecture.
		 */
		getnanotime(&entry->ktr_tv);
	else
		nanotime(&entry->ktr_tv);
#ifdef KTR_EXTEND
	strncpy(entry->ktr_filename, filename, KTRFILENAMESIZE - 1);
	entry->ktr_filename[KTRFILENAMESIZE - 1] = '\0';
	entry->ktr_line = line;
	entry->ktr_cpu = KTR_CPU;
	va_start(ap, format);
	vsnprintf(entry->ktr_desc, KTRDESCSIZE, format, ap);
	va_end(ap);
	if (ktr_verbose) {
#ifdef SMP
		printf("cpu%d ", entry->ktr_cpu);
#endif
		if (ktr_verbose > 1)
			printf("%s.%d\t", entry->ktr_filename, entry->ktr_line);
		va_start(ap, format);
		vprintf(format, ap);
		printf("\n");
		va_end(ap);
	}
#else
	entry->ktr_desc = format;
	entry->ktr_parm1 = arg1;
	entry->ktr_parm2 = arg2;
	entry->ktr_parm3 = arg3;
	entry->ktr_parm4 = arg4;
	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 */