[PATCH rtems-libbsd 6/7] kern: Import kern_ktr.c
chrisj at rtems.org
chrisj at rtems.org
Tue Jul 27 08:58:50 UTC 2021
From: Chris Johns <chrisj at rtems.org>
Update #4475
---
freebsd/sys/kern/kern_ktr.c | 476 ++++++++++++++++++++++++++++++++++++
1 file changed, 476 insertions(+)
create mode 100644 freebsd/sys/kern/kern_ktr.c
diff --git a/freebsd/sys/kern/kern_ktr.c b/freebsd/sys/kern/kern_ktr.c
new file mode 100644
index 00000000..bf925d47
--- /dev/null
+++ b/freebsd/sys/kern/kern_ktr.c
@@ -0,0 +1,476 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2000 John Baldwin <jhb at 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_IS_IDLETHREAD(td)) == 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 timestamp 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 */
--
2.24.1
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