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f-stack/freebsd/kern/kern_ktr.c

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/*-
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 THE AUTHOR OR CONTRIBUTORS 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.
*/
/*
* This module holds the global variables used by KTR and the ktr_tracepoint()
* function that does the actual tracing.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_ktr.h"
#include "opt_alq.h"
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/alq.h>
#include <sys/cons.h>
#include <sys/cpuset.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/ktr.h>
#include <sys/libkern.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/smp.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <machine/cpu.h>
#ifdef DDB
#include <ddb/ddb.h>
#include <ddb/db_output.h>
#endif
#ifndef KTR_BOOT_ENTRIES
#define KTR_BOOT_ENTRIES 1024
#endif
#ifndef KTR_ENTRIES
#define KTR_ENTRIES 1024
#endif
/* Limit the allocations to something manageable. */
#define KTR_ENTRIES_MAX (8 * 1024 * 1024)
#ifndef KTR_MASK
#define KTR_MASK (0)
#endif
#ifndef KTR_CPUMASK
#define KTR_CPUMASK CPUSET_FSET
#endif
#ifndef KTR_TIME
#define KTR_TIME get_cyclecount()
#endif
#ifndef KTR_CPU
#define KTR_CPU PCPU_GET(cpuid)
#endif
static MALLOC_DEFINE(M_KTR, "KTR", "KTR");
FEATURE(ktr, "Kernel support for KTR kernel tracing facility");
volatile int ktr_idx = 0;
uint64_t ktr_mask = KTR_MASK;
uint64_t ktr_compile = KTR_COMPILE;
int ktr_entries = KTR_BOOT_ENTRIES;
int ktr_version = KTR_VERSION;
struct ktr_entry ktr_buf_init[KTR_BOOT_ENTRIES];
struct ktr_entry *ktr_buf = ktr_buf_init;
cpuset_t ktr_cpumask = CPUSET_T_INITIALIZER(KTR_CPUMASK);
static SYSCTL_NODE(_debug, OID_AUTO, ktr, CTLFLAG_RD, 0, "KTR options");
SYSCTL_INT(_debug_ktr, OID_AUTO, version, CTLFLAG_RD,
&ktr_version, 0, "Version of the KTR interface");
SYSCTL_UQUAD(_debug_ktr, OID_AUTO, compile, CTLFLAG_RD,
&ktr_compile, 0, "Bitmask of KTR event classes compiled into the kernel");
static int
sysctl_debug_ktr_cpumask(SYSCTL_HANDLER_ARGS)
{
char lktr_cpumask_str[CPUSETBUFSIZ];
cpuset_t imask;
int error;
cpusetobj_strprint(lktr_cpumask_str, &ktr_cpumask);
error = sysctl_handle_string(oidp, lktr_cpumask_str,
sizeof(lktr_cpumask_str), req);
if (error != 0 || req->newptr == NULL)
return (error);
if (cpusetobj_strscan(&imask, lktr_cpumask_str) == -1)
return (EINVAL);
CPU_COPY(&imask, &ktr_cpumask);
return (error);
}
SYSCTL_PROC(_debug_ktr, OID_AUTO, cpumask,
CTLFLAG_RWTUN | CTLFLAG_MPSAFE | CTLTYPE_STRING, NULL, 0,
sysctl_debug_ktr_cpumask, "S",
"Bitmask of CPUs on which KTR logging is enabled");
static int
sysctl_debug_ktr_clear(SYSCTL_HANDLER_ARGS)
{
int clear, error;
clear = 0;
error = sysctl_handle_int(oidp, &clear, 0, req);
if (error || !req->newptr)
return (error);
if (clear) {
bzero(ktr_buf, sizeof(*ktr_buf) * ktr_entries);
ktr_idx = 0;
}
return (error);
}
SYSCTL_PROC(_debug_ktr, OID_AUTO, clear, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
sysctl_debug_ktr_clear, "I", "Clear KTR Buffer");
/*
* This is a sysctl proc so that it is serialized as !MPSAFE along with
* the other ktr sysctl procs.
*/
static int
sysctl_debug_ktr_mask(SYSCTL_HANDLER_ARGS)
{
uint64_t mask;
int error;
mask = ktr_mask;
error = sysctl_handle_64(oidp, &mask, 0, req);
if (error || !req->newptr)
return (error);
ktr_mask = mask;
return (error);
}
SYSCTL_PROC(_debug_ktr, OID_AUTO, mask, CTLTYPE_U64 | CTLFLAG_RWTUN, 0, 0,
sysctl_debug_ktr_mask, "QU",
"Bitmask of KTR event classes for which logging is enabled");
#if KTR_ENTRIES > KTR_BOOT_ENTRIES
/*
* A simplified version of sysctl_debug_ktr_entries.
* No need to care about SMP, scheduling, etc.
*/
static void
ktr_entries_initializer(void *dummy __unused)
{
uint64_t mask;
/* Temporarily disable ktr in case malloc() is being traced. */
mask = ktr_mask;
ktr_mask = 0;
ktr_buf = malloc(sizeof(*ktr_buf) * KTR_ENTRIES, M_KTR,
M_WAITOK | M_ZERO);
memcpy(ktr_buf, ktr_buf_init + ktr_idx,
(KTR_BOOT_ENTRIES - ktr_idx) * sizeof(*ktr_buf));
if (ktr_idx != 0) {
memcpy(ktr_buf + KTR_BOOT_ENTRIES - ktr_idx, ktr_buf_init,
ktr_idx * sizeof(*ktr_buf));
ktr_idx = KTR_BOOT_ENTRIES;
}
ktr_entries = KTR_ENTRIES;
ktr_mask = mask;
}
SYSINIT(ktr_entries_initializer, SI_SUB_KMEM, SI_ORDER_ANY,
ktr_entries_initializer, NULL);
#endif
static int
sysctl_debug_ktr_entries(SYSCTL_HANDLER_ARGS)
{
uint64_t mask;
int entries, error;
struct ktr_entry *buf, *oldbuf;
entries = ktr_entries;
error = sysctl_handle_int(oidp, &entries, 0, req);
if (error || !req->newptr)
return (error);
if (entries > KTR_ENTRIES_MAX)
return (ERANGE);
/* Disable ktr temporarily. */
mask = ktr_mask;
ktr_mask = 0;
/* Wait for threads to go idle. */
if ((error = quiesce_all_cpus("ktrent", PCATCH)) != 0) {
ktr_mask = mask;
return (error);
}
if (ktr_buf != ktr_buf_init)
oldbuf = ktr_buf;
else
oldbuf = NULL;
/* Allocate a new buffer. */
buf = malloc(sizeof(*buf) * entries, M_KTR, M_WAITOK | M_ZERO);
/* Install the new buffer and restart ktr. */
ktr_buf = buf;
ktr_entries = entries;
ktr_idx = 0;
ktr_mask = mask;
if (oldbuf != NULL)
free(oldbuf, M_KTR);
return (error);
}
SYSCTL_PROC(_debug_ktr, OID_AUTO, entries, CTLTYPE_INT|CTLFLAG_RW, 0, 0,
sysctl_debug_ktr_entries, "I", "Number of entries in the KTR buffer");
#ifdef KTR_VERBOSE
int ktr_verbose = KTR_VERBOSE;
TUNABLE_INT("debug.ktr.verbose", &ktr_verbose);
SYSCTL_INT(_debug_ktr, OID_AUTO, verbose, CTLFLAG_RW, &ktr_verbose, 0, "");
#endif
#ifdef KTR_ALQ
struct alq *ktr_alq;
char ktr_alq_file[MAXPATHLEN] = "/tmp/ktr.out";
int ktr_alq_cnt = 0;
int ktr_alq_depth = KTR_ENTRIES;
int ktr_alq_enabled = 0;
int ktr_alq_failed = 0;
int ktr_alq_max = 0;
SYSCTL_INT(_debug_ktr, OID_AUTO, alq_max, CTLFLAG_RW, &ktr_alq_max, 0,
"Maximum number of entries to write");
SYSCTL_INT(_debug_ktr, OID_AUTO, alq_cnt, CTLFLAG_RD, &ktr_alq_cnt, 0,
"Current number of written entries");
SYSCTL_INT(_debug_ktr, OID_AUTO, alq_failed, CTLFLAG_RD, &ktr_alq_failed, 0,
"Number of times we overran the buffer");
SYSCTL_INT(_debug_ktr, OID_AUTO, alq_depth, CTLFLAG_RW, &ktr_alq_depth, 0,
"Number of items in the write buffer");
SYSCTL_STRING(_debug_ktr, OID_AUTO, alq_file, CTLFLAG_RW, ktr_alq_file,
sizeof(ktr_alq_file), "KTR logging file");
static int
sysctl_debug_ktr_alq_enable(SYSCTL_HANDLER_ARGS)
{
int error;
int enable;
enable = ktr_alq_enabled;
error = sysctl_handle_int(oidp, &enable, 0, req);
if (error || !req->newptr)
return (error);
if (enable) {
if (ktr_alq_enabled)
return (0);
error = alq_open(&ktr_alq, (const char *)ktr_alq_file,
req->td->td_ucred, ALQ_DEFAULT_CMODE,
sizeof(struct ktr_entry), ktr_alq_depth);
if (error == 0) {
ktr_alq_cnt = 0;
ktr_alq_failed = 0;
ktr_alq_enabled = 1;
}
} else {
if (ktr_alq_enabled == 0)
return (0);
ktr_alq_enabled = 0;
alq_close(ktr_alq);
ktr_alq = NULL;
}
return (error);
}
SYSCTL_PROC(_debug_ktr, OID_AUTO, alq_enable,
CTLTYPE_INT|CTLFLAG_RW, 0, 0, sysctl_debug_ktr_alq_enable,
"I", "Enable KTR logging");
#endif
void
ktr_tracepoint(uint64_t mask, const char *file, int line, const char *format,
u_long arg1, u_long arg2, u_long arg3, u_long arg4, u_long arg5,
u_long arg6)
{
struct ktr_entry *entry;
#ifdef KTR_ALQ
struct ale *ale = NULL;
#endif
int newindex, saveindex;
#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
struct thread *td;
#endif
int cpu;
if (panicstr || kdb_active)
return;
if ((ktr_mask & mask) == 0 || ktr_buf == NULL)
return;
cpu = KTR_CPU;
if (!CPU_ISSET(cpu, &ktr_cpumask))
return;
#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
td = curthread;
if (td->td_pflags & TDP_INKTR)
return;
td->td_pflags |= TDP_INKTR;
#endif
#ifdef KTR_ALQ
if (ktr_alq_enabled) {
if (td->td_critnest == 0 &&
(td->td_flags & TDF_IDLETD) == 0 &&
td != ald_thread) {
if (ktr_alq_max && ktr_alq_cnt > ktr_alq_max)
goto done;
if ((ale = alq_get(ktr_alq, ALQ_NOWAIT)) == NULL) {
ktr_alq_failed++;
goto done;
}
ktr_alq_cnt++;
entry = (struct ktr_entry *)ale->ae_data;
} else {
goto done;
}
} else
#endif
{
do {
saveindex = ktr_idx;
newindex = (saveindex + 1) % ktr_entries;
} while (atomic_cmpset_rel_int(&ktr_idx, saveindex, newindex) == 0);
entry = &ktr_buf[saveindex];
}
entry->ktr_timestamp = KTR_TIME;
entry->ktr_cpu = cpu;
entry->ktr_thread = curthread;
if (file != NULL)
while (strncmp(file, "../", 3) == 0)
file += 3;
entry->ktr_file = file;
entry->ktr_line = line;
#ifdef KTR_VERBOSE
if (ktr_verbose) {
#ifdef SMP
printf("cpu%d ", cpu);
#endif
if (ktr_verbose > 1) {
printf("%s.%d\t", entry->ktr_file,
entry->ktr_line);
}
printf(format, arg1, arg2, arg3, arg4, arg5, arg6);
printf("\n");
}
#endif
entry->ktr_desc = format;
entry->ktr_parms[0] = arg1;
entry->ktr_parms[1] = arg2;
entry->ktr_parms[2] = arg3;
entry->ktr_parms[3] = arg4;
entry->ktr_parms[4] = arg5;
entry->ktr_parms[5] = arg6;
#ifdef KTR_ALQ
if (ktr_alq_enabled && ale)
alq_post(ktr_alq, ale);
done:
#endif
#if defined(KTR_VERBOSE) || defined(KTR_ALQ)
td->td_pflags &= ~TDP_INKTR;
#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_SHOW_COMMAND(ktr, db_ktr_all)
{
tstate.cur = (ktr_idx - 1) % ktr_entries;
tstate.first = -1;
db_ktr_verbose = 0;
db_ktr_verbose |= (strchr(modif, 'v') != NULL) ? 2 : 0;
db_ktr_verbose |= (strchr(modif, 'V') != NULL) ? 1 : 0; /* just timestap please */
if (strchr(modif, 'a') != NULL) {
db_disable_pager();
while (cncheckc() == -1)
if (db_mach_vtrace() == 0)
break;
} else {
while (!db_pager_quit)
if (db_mach_vtrace() == 0)
break;
}
}
static int
db_mach_vtrace(void)
{
struct ktr_entry *kp;
if (tstate.cur == tstate.first || ktr_buf == NULL) {
db_printf("--- End of trace buffer ---\n");
return (0);
}
kp = &ktr_buf[tstate.cur];
/* Skip over unused entries. */
if (kp->ktr_desc == NULL) {
db_printf("--- End of trace buffer ---\n");
return (0);
}
db_printf("%d (%p", tstate.cur, kp->ktr_thread);
#ifdef SMP
db_printf(":cpu%d", kp->ktr_cpu);
#endif
db_printf(")");
if (db_ktr_verbose >= 1) {
db_printf(" %10.10lld", (long long)kp->ktr_timestamp);
}
if (db_ktr_verbose >= 2) {
db_printf(" %s.%d", kp->ktr_file, kp->ktr_line);
}
db_printf(": ");
db_printf(kp->ktr_desc, kp->ktr_parms[0], kp->ktr_parms[1],
kp->ktr_parms[2], kp->ktr_parms[3], kp->ktr_parms[4],
kp->ktr_parms[5]);
db_printf("\n");
if (tstate.first == -1)
tstate.first = tstate.cur;
if (--tstate.cur < 0)
tstate.cur = ktr_entries - 1;
return (1);
}
#endif /* DDB */
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