freebsd-skq/sys/kern/kern_ktr.c
John Baldwin 69e9495750 Use a per-thread variable for keeping state when a thread is processing
a KTR log entry.  Any KTR requests made while working on an entry are
ignored/discarded to prevent recursion.  This is a better fix for the
hack to futz with the CPU mask and call getnanotime() if KTR_LOCK or
KTR_WITNESS was on.  It also covers the actual formatting of the log entry
including dumping it to the display which the earlier hacks did not.
2001-12-13 10:33:20 +00:00

269 lines
6.4 KiB
C

/*
* 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/cons.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/libkern.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <machine/stdarg.h>
#include <ddb/ddb.h>
#ifndef KTR_ENTRIES
#define KTR_ENTRIES 1024
#endif
#ifndef KTR_MASK
#define KTR_MASK (KTR_GEN)
#endif
#ifndef KTR_CPUMASK
#define KTR_CPUMASK (~0)
#endif
#ifdef SMP
#define KTR_CPU PCPU_GET(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 = KTR_CPUMASK;
TUNABLE_INT("debug.ktr.cpumask", &ktr_cpumask);
SYSCTL_INT(_debug_ktr, OID_AUTO, cpumask, CTLFLAG_RW, &ktr_cpumask, 0, "");
int ktr_mask = KTR_MASK;
TUNABLE_INT("debug.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 = KTR_VERBOSE_DEFAULT;
TUNABLE_INT("debug.ktr.verbose", &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, const char *filename, u_int line,
const char *format, ...)
#else
void
ktr_tracepoint(u_int mask, const char *format, u_long arg1, u_long arg2,
u_long arg3, u_long arg4, u_long arg5, u_long arg6)
#endif
{
struct ktr_entry *entry;
int newindex, saveindex;
critical_t savecrit;
struct thread *td;
#ifdef KTR_EXTEND
va_list ap;
#endif
if (panicstr)
return;
if ((ktr_mask & mask) == 0)
return;
td = curthread;
if (td->td_inktr)
return;
savecrit = critical_enter();
if (((1 << KTR_CPU) & ktr_cpumask) == 0) {
critical_exit(savecrit);
return;
}
td->td_inktr++;
do {
saveindex = ktr_idx;
newindex = (saveindex + 1) & (KTR_ENTRIES - 1);
} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
entry = &ktr_buf[saveindex];
entry->ktr_cpu = KTR_CPU;
critical_exit(savecrit);
nanotime(&entry->ktr_tv);
#ifdef KTR_EXTEND
entry->ktr_filename = filename;
entry->ktr_line = line;
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;
entry->ktr_parm6 = arg6;
#endif
td->td_inktr--;
}
#ifdef DDB
struct tstate {
int cur;
int first;
};
static struct tstate tstate;
static int db_ktr_verbose;
static int db_mach_vtrace(void);
#define NUM_LINES_PER_PAGE 18
DB_SHOW_COMMAND(ktr, db_ktr_all)
{
int c, lines;
lines = NUM_LINES_PER_PAGE;
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;
while (db_mach_vtrace())
if (--lines == 0) {
db_printf("--More--");
c = cngetc();
db_printf("\r");
switch (c) {
case '\n': /* one more line */
lines = 1;
break;
case ' ': /* one more page */
lines = NUM_LINES_PER_PAGE;
break;
default:
db_printf("\n");
return;
}
}
}
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("--- End of trace buffer ---\n");
return (0);
}
db_printf("%d: ", tstate.cur);
if (db_ktr_verbose)
db_printf("%4ld.%06ld ", (long)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 */