kern: Import kern_ktr.c

Update #4475

1 files changed, 476 insertions, 0 deletions

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@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 */