freebsd-dev/sys/kern/kern_ktr.c
John Baldwin 21119d0641 Expand ktr_mask to be a 64-bit unsigned integer.
The mask does not really need to be updated with atomic operations and
the downside of losing races during transitions is not great (it is
not marked volatile, so those races are pretty wide open as it is).

Differential Revision:	https://reviews.freebsd.org/D2595
Reviewed by:	emaste, neel, rpaulo
MFC after:	2 weeks
2015-05-22 11:09:41 +00:00

478 lines
12 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.
*
* 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 __sparc64__
#include <machine/ktr.h>
#endif
#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 */