]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/kdebug.c
xnu-7195.101.1.tar.gz
[apple/xnu.git] / bsd / kern / kdebug.c
index f901211e07789f798821d8e6fa2d36a46a616279..2d3de0289e39c5799288f094211dc29d9ab1c273 100644 (file)
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000-2016 Apple Inc. All rights reserved.
+ * Copyright (c) 2000-2019 Apple Inc. All rights reserved.
  *
  * @Apple_LICENSE_HEADER_START@
  *
@@ -37,6 +37,7 @@
 #include <mach/mach_types.h>
 #include <mach/mach_time.h>
 #include <mach/mach_vm.h>
+#include <machine/atomic.h>
 #include <machine/machine_routines.h>
 
 #include <mach/machine.h>
@@ -55,6 +56,7 @@
 #include <kern/task.h>
 #include <kern/debug.h>
 #include <kern/kalloc.h>
+#include <kern/cpu_number.h>
 #include <kern/cpu_data.h>
 #include <kern/assert.h>
 #include <kern/telemetry.h>
 #include <machine/pal_routines.h>
 #include <machine/atomic.h>
 
+extern unsigned int wake_nkdbufs;
+extern unsigned int trace_wrap;
+
 /*
  * IOP(s)
  *
- * https://coreoswiki.apple.com/wiki/pages/U6z3i0q9/Consistent_Logging_Implementers_Guide.html
- *
  * IOP(s) are auxiliary cores that want to participate in kdebug event logging.
  * They are registered dynamically. Each is assigned a cpu_id at registration.
  *
@@ -242,7 +245,6 @@ static void kdbg_disable_typefilter(void);
  */
 
 void task_act_iterate_wth_args(task_t, void (*)(thread_t, void *), void *);
-int cpu_number(void);   /* XXX <machine/...> include path broken */
 void commpage_update_kdebug_state(void); /* XXX sign */
 
 extern int log_leaks;
@@ -265,13 +267,6 @@ kdbg_timestamp(void)
 
 static int kdbg_debug = 0;
 
-#if KDEBUG_MOJO_TRACE
-#include <sys/kdebugevents.h>
-static void kdebug_serial_print( /* forward */
-       uint32_t, uint32_t, uint64_t,
-       uintptr_t, uintptr_t, uintptr_t, uintptr_t, uintptr_t);
-#endif
-
 int kdbg_control(int *, u_int, user_addr_t, size_t *);
 
 static int kdbg_read(user_addr_t, size_t *, vnode_t, vfs_context_t, uint32_t);
@@ -282,26 +277,25 @@ static int kdbg_setreg(kd_regtype *);
 static int kdbg_setpidex(kd_regtype *);
 static int kdbg_setpid(kd_regtype *);
 static void kdbg_thrmap_init(void);
-static int kdbg_reinit(boolean_t);
-static int kdbg_bootstrap(boolean_t);
+static int kdbg_reinit(bool);
+static int kdbg_bootstrap(bool);
 static int kdbg_test(size_t flavor);
 
-static int kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx);
+static int kdbg_write_v1_header(bool write_thread_map, vnode_t vp, vfs_context_t ctx);
 static int kdbg_write_thread_map(vnode_t vp, vfs_context_t ctx);
 static int kdbg_copyout_thread_map(user_addr_t buffer, size_t *buffer_size);
 static void kdbg_clear_thread_map(void);
 
-static boolean_t kdbg_wait(uint64_t timeout_ms, boolean_t locked_wait);
+static bool kdbg_wait(uint64_t timeout_ms, bool locked_wait);
 static void kdbg_wakeup(void);
 
 int kdbg_cpumap_init_internal(kd_iop_t* iops, uint32_t cpu_count,
     uint8_t** cpumap, uint32_t* cpumap_size);
 
-static kd_threadmap *kdbg_thrmap_init_internal(unsigned int count,
-    unsigned int *mapsize,
-    unsigned int *mapcount);
+static kd_threadmap *kdbg_thrmap_init_internal(size_t max_count,
+    vm_size_t *map_size, vm_size_t *map_count);
 
-static boolean_t kdebug_current_proc_enabled(uint32_t debugid);
+static bool kdebug_current_proc_enabled(uint32_t debugid);
 static errno_t kdebug_check_trace_string(uint32_t debugid, uint64_t str_id);
 
 int kdbg_write_v3_header(user_addr_t, size_t *, int);
@@ -315,7 +309,7 @@ user_addr_t kdbg_write_v3_event_chunk_header(user_addr_t buffer, uint32_t tag,
 
 // Helper functions
 
-static int create_buffers(boolean_t);
+static int create_buffers(bool);
 static void delete_buffers(void);
 
 extern int tasks_count;
@@ -329,16 +323,16 @@ unsigned int kdebug_enable = 0;
 
 #define KD_EARLY_BUFFER_SIZE (16 * 1024)
 #define KD_EARLY_BUFFER_NBUFS (KD_EARLY_BUFFER_SIZE / sizeof(kd_buf))
-#if CONFIG_EMBEDDED
+#if defined(__x86_64__)
+__attribute__((aligned(KD_EARLY_BUFFER_SIZE)))
+static kd_buf kd_early_buffer[KD_EARLY_BUFFER_NBUFS];
+#else /* defined(__x86_64__) */
 /*
- * On embedded, the space for this is carved out by osfmk/arm/data.s -- clang
+ * On ARM, the space for this is carved out by osfmk/arm/data.s -- clang
  * has problems aligning to greater than 4K.
  */
 extern kd_buf kd_early_buffer[KD_EARLY_BUFFER_NBUFS];
-#else /* CONFIG_EMBEDDED */
-__attribute__((aligned(KD_EARLY_BUFFER_SIZE)))
-static kd_buf kd_early_buffer[KD_EARLY_BUFFER_NBUFS];
-#endif /* !CONFIG_EMBEDDED */
+#endif /* !defined(__x86_64__) */
 
 static unsigned int kd_early_index = 0;
 static bool kd_early_overflow = false;
@@ -365,7 +359,7 @@ struct kd_storage {
        uint32_t kds_bufindx;
        uint32_t kds_bufcnt;
        uint32_t kds_readlast;
-       boolean_t kds_lostevents;
+       bool kds_lostevents;
        uint64_t  kds_timestamp;
 
        kd_buf  kds_records[EVENTS_PER_STORAGE_UNIT];
@@ -392,7 +386,7 @@ int kds_waiter = 0;
 struct kd_bufinfo {
        union  kds_ptr kd_list_head;
        union  kds_ptr kd_list_tail;
-       boolean_t kd_lostevents;
+       bool kd_lostevents;
        uint32_t _pad;
        uint64_t kd_prev_timebase;
        uint32_t num_bufs;
@@ -446,12 +440,13 @@ unsigned int kdlog_value2 = 0;
 unsigned int kdlog_value3 = 0;
 unsigned int kdlog_value4 = 0;
 
-static lck_spin_t * kdw_spin_lock;
-static lck_spin_t * kds_spin_lock;
+static LCK_GRP_DECLARE(kdebug_lck_grp, "kdebug");
+static LCK_SPIN_DECLARE(kdw_spin_lock, &kdebug_lck_grp);
+static LCK_SPIN_DECLARE(kds_spin_lock, &kdebug_lck_grp);
 
 kd_threadmap *kd_mapptr = 0;
-unsigned int kd_mapsize = 0;
-unsigned int kd_mapcount = 0;
+vm_size_t kd_mapsize = 0;
+vm_size_t kd_mapcount = 0;
 
 off_t   RAW_file_offset = 0;
 int     RAW_file_written = 0;
@@ -480,45 +475,165 @@ static uint64_t g_str_id_signature = (0x70acULL << STR_ID_SIG_OFFSET);
 #define BSC_SysCall     0x040c0000
 #define MACH_SysCall    0x010c0000
 
-/* task to string structure */
-struct tts {
-       task_t    task;      /* from procs task */
-       pid_t     pid;       /* from procs p_pid  */
-       char      task_comm[20];/* from procs p_comm */
+struct kd_task_name {
+       task_t ktn_task;
+       pid_t ktn_pid;
+       char ktn_name[20];
 };
 
-typedef struct tts tts_t;
-
-struct krt {
-       kd_threadmap *map;    /* pointer to the map buffer */
-       int count;
-       int maxcount;
-       struct tts *atts;
+struct kd_resolver {
+       kd_threadmap *krs_map;
+       vm_size_t krs_count;
+       vm_size_t krs_maxcount;
+       struct kd_task_name *krs_task;
 };
 
+/*
+ * TRACE file formats...
+ *
+ * RAW_VERSION0
+ *
+ * uint32_t #threadmaps
+ * kd_threadmap[]
+ * kd_buf[]
+ *
+ * RAW_VERSION1
+ *
+ * RAW_header, with version_no set to RAW_VERSION1
+ * kd_threadmap[]
+ * Empty space to pad alignment to the nearest page boundary.
+ * kd_buf[]
+ *
+ * RAW_VERSION1+
+ *
+ * RAW_header, with version_no set to RAW_VERSION1
+ * kd_threadmap[]
+ * kd_cpumap_header, with version_no set to RAW_VERSION1
+ * kd_cpumap[]
+ * Empty space to pad alignment to the nearest page boundary.
+ * kd_buf[]
+ *
+ * V1+ implementation details...
+ *
+ * It would have been nice to add the cpumap data "correctly", but there were
+ * several obstacles. Existing code attempts to parse both V1 and V0 files.
+ * Due to the fact that V0 has no versioning or header, the test looks like
+ * this:
+ *
+ * // Read header
+ * if (header.version_no != RAW_VERSION1) { // Assume V0 }
+ *
+ * If we add a VERSION2 file format, all existing code is going to treat that
+ * as a VERSION0 file when reading it, and crash terribly when trying to read
+ * RAW_VERSION2 threadmap entries.
+ *
+ * To differentiate between a V1 and V1+ file, read as V1 until you reach
+ * the padding bytes. Then:
+ *
+ * boolean_t is_v1plus = FALSE;
+ * if (padding_bytes >= sizeof(kd_cpumap_header)) {
+ *     kd_cpumap_header header = // read header;
+ *     if (header.version_no == RAW_VERSION1) {
+ *         is_v1plus = TRUE;
+ *     }
+ * }
+ *
+ */
+
+#define RAW_VERSION3    0x00001000
+
+// Version 3 header
+// The header chunk has the tag 0x00001000 which also serves as a magic word
+// that identifies the file as a version 3 trace file. The header payload is
+// a set of fixed fields followed by a variable number of sub-chunks:
+/*
+ *  ____________________________________________________________________________
+ | Offset | Size | Field                                                    |
+ |  ----------------------------------------------------------------------------
+ |    0   |  4   | Tag (0x00001000)                                         |
+ |    4   |  4   | Sub-tag. Represents the version of the header.           |
+ |    8   |  8   | Length of header payload (40+8x)                         |
+ |   16   |  8   | Time base info. Two 32-bit numbers, numer/denom,         |
+ |        |      | for converting timestamps to nanoseconds.                |
+ |   24   |  8   | Timestamp of trace start.                                |
+ |   32   |  8   | Wall time seconds since Unix epoch.                      |
+ |        |      | As returned by gettimeofday().                           |
+ |   40   |  4   | Wall time microseconds. As returned by gettimeofday().   |
+ |   44   |  4   | Local time zone offset in minutes. ( " )                 |
+ |   48   |  4   | Type of daylight savings time correction to apply. ( " ) |
+ |   52   |  4   | Flags. 1 = 64-bit. Remaining bits should be written      |
+ |        |      | as 0 and ignored when reading.                           |
+ |   56   |  8x  | Variable number of sub-chunks. None are required.        |
+ |        |      | Ignore unknown chunks.                                   |
+ |  ----------------------------------------------------------------------------
+ */
+// NOTE: The header sub-chunks are considered part of the header chunk,
+// so they must be included in the header chunk’s length field.
+// The CPU map is an optional sub-chunk of the header chunk. It provides
+// information about the CPUs that are referenced from the trace events.
+typedef struct {
+       uint32_t tag;
+       uint32_t sub_tag;
+       uint64_t length;
+       uint32_t timebase_numer;
+       uint32_t timebase_denom;
+       uint64_t timestamp;
+       uint64_t walltime_secs;
+       uint32_t walltime_usecs;
+       uint32_t timezone_minuteswest;
+       uint32_t timezone_dst;
+       uint32_t flags;
+} __attribute__((packed)) kd_header_v3;
+
+typedef struct {
+       uint32_t tag;
+       uint32_t sub_tag;
+       uint64_t length;
+} __attribute__((packed)) kd_chunk_header_v3;
+
+#define V3_CONFIG       0x00001b00
+#define V3_CPU_MAP      0x00001c00
+#define V3_THREAD_MAP   0x00001d00
+#define V3_RAW_EVENTS   0x00001e00
+#define V3_NULL_CHUNK   0x00002000
+
+// The current version of all kernel managed chunks is 1. The
+// V3_CURRENT_CHUNK_VERSION is added to ease the simple case
+// when most/all the kernel managed chunks have the same version.
+
+#define V3_CURRENT_CHUNK_VERSION 1
+#define V3_HEADER_VERSION     V3_CURRENT_CHUNK_VERSION
+#define V3_CPUMAP_VERSION     V3_CURRENT_CHUNK_VERSION
+#define V3_THRMAP_VERSION     V3_CURRENT_CHUNK_VERSION
+#define V3_EVENT_DATA_VERSION V3_CURRENT_CHUNK_VERSION
+
 typedef struct krt krt_t;
 
 static uint32_t
-kdbg_cpu_count(boolean_t early_trace)
+kdbg_cpu_count(bool early_trace)
 {
        if (early_trace) {
-#if CONFIG_EMBEDDED
-               return ml_get_cpu_count();
-#else
+#if defined(__x86_64__)
                return max_ncpus;
-#endif
+#else /* defined(__x86_64__) */
+               return ml_get_cpu_count();
+#endif /* !defined(__x86_64__) */
        }
 
+#if defined(__x86_64__)
        host_basic_info_data_t hinfo;
        mach_msg_type_number_t count = HOST_BASIC_INFO_COUNT;
        host_info((host_t)1 /* BSD_HOST */, HOST_BASIC_INFO, (host_info_t)&hinfo, &count);
        assert(hinfo.logical_cpu_max > 0);
        return hinfo.logical_cpu_max;
+#else /* defined(__x86_64__) */
+       return ml_get_topology_info()->max_cpu_id + 1;
+#endif /* !defined(__x86_64__) */
 }
 
 #if MACH_ASSERT
-#if CONFIG_EMBEDDED
-static boolean_t
+
+static bool
 kdbg_iop_list_is_valid(kd_iop_t* iop)
 {
        if (iop) {
@@ -526,7 +641,7 @@ kdbg_iop_list_is_valid(kd_iop_t* iop)
                kd_iop_t* temp = iop;
                do {
                        assert(!temp->next || temp->next->cpu_id == temp->cpu_id - 1);
-                       assert(temp->next || (temp->cpu_id == kdbg_cpu_count(FALSE) || temp->cpu_id == kdbg_cpu_count(TRUE)));
+                       assert(temp->next || (temp->cpu_id == kdbg_cpu_count(false) || temp->cpu_id == kdbg_cpu_count(true)));
                } while ((temp = temp->next));
 
                /* Does each entry have a function and a name? */
@@ -537,22 +652,9 @@ kdbg_iop_list_is_valid(kd_iop_t* iop)
                } while ((temp = temp->next));
        }
 
-       return TRUE;
+       return true;
 }
 
-static boolean_t
-kdbg_iop_list_contains_cpu_id(kd_iop_t* list, uint32_t cpu_id)
-{
-       while (list) {
-               if (list->cpu_id == cpu_id) {
-                       return TRUE;
-               }
-               list = list->next;
-       }
-
-       return FALSE;
-}
-#endif /* CONFIG_EMBEDDED */
 #endif /* MACH_ASSERT */
 
 static void
@@ -564,16 +666,23 @@ kdbg_iop_list_callback(kd_iop_t* iop, kd_callback_type type, void* arg)
        }
 }
 
-static lck_grp_t      *kdebug_lck_grp      = NULL;
-
 static void
-kdbg_set_tracing_enabled(boolean_t enabled, uint32_t trace_type)
+kdbg_set_tracing_enabled(bool enabled, uint32_t trace_type)
 {
-       int s = ml_set_interrupts_enabled(FALSE);
-       lck_spin_lock_grp(kds_spin_lock, kdebug_lck_grp);
+       /*
+        * Drain any events from IOPs before making the state change.  On
+        * enabling, this removes any stale events from before tracing.  On
+        * disabling, this saves any events up to the point tracing is disabled.
+        */
+       kdbg_iop_list_callback(kd_ctrl_page.kdebug_iops, KD_CALLBACK_SYNC_FLUSH,
+           NULL);
+
+       int s = ml_set_interrupts_enabled(false);
+       lck_spin_lock_grp(&kds_spin_lock, &kdebug_lck_grp);
+
        if (enabled) {
                /*
-                * The oldest valid time is now; reject old events from IOPs.
+                * The oldest valid time is now; reject past events from IOPs.
                 */
                kd_ctrl_page.oldest_time = kdbg_timestamp();
                kdebug_enable |= trace_type;
@@ -586,27 +695,23 @@ kdbg_set_tracing_enabled(boolean_t enabled, uint32_t trace_type)
                kd_ctrl_page.enabled = 0;
                commpage_update_kdebug_state();
        }
-       lck_spin_unlock(kds_spin_lock);
+       lck_spin_unlock(&kds_spin_lock);
        ml_set_interrupts_enabled(s);
 
        if (enabled) {
-               kdbg_iop_list_callback(kd_ctrl_page.kdebug_iops, KD_CALLBACK_KDEBUG_ENABLED, NULL);
+               kdbg_iop_list_callback(kd_ctrl_page.kdebug_iops,
+                   KD_CALLBACK_KDEBUG_ENABLED, NULL);
        } else {
-               /*
-                * If you do not flush the IOP trace buffers, they can linger
-                * for a considerable period; consider code which disables and
-                * deallocates without a final sync flush.
-                */
-               kdbg_iop_list_callback(kd_ctrl_page.kdebug_iops, KD_CALLBACK_KDEBUG_DISABLED, NULL);
-               kdbg_iop_list_callback(kd_ctrl_page.kdebug_iops, KD_CALLBACK_SYNC_FLUSH, NULL);
+               kdbg_iop_list_callback(kd_ctrl_page.kdebug_iops,
+                   KD_CALLBACK_KDEBUG_DISABLED, NULL);
        }
 }
 
 static void
-kdbg_set_flags(int slowflag, int enableflag, boolean_t enabled)
+kdbg_set_flags(int slowflag, int enableflag, bool enabled)
 {
-       int s = ml_set_interrupts_enabled(FALSE);
-       lck_spin_lock_grp(kds_spin_lock, kdebug_lck_grp);
+       int s = ml_set_interrupts_enabled(false);
+       lck_spin_lock_grp(&kds_spin_lock, &kdebug_lck_grp);
 
        if (enabled) {
                kd_ctrl_page.kdebug_slowcheck |= slowflag;
@@ -616,19 +721,19 @@ kdbg_set_flags(int slowflag, int enableflag, boolean_t enabled)
                kdebug_enable &= ~enableflag;
        }
 
-       lck_spin_unlock(kds_spin_lock);
+       lck_spin_unlock(&kds_spin_lock);
        ml_set_interrupts_enabled(s);
 }
 
 /*
  * Disable wrapping and return true if trace wrapped, false otherwise.
  */
-static boolean_t
+static bool
 disable_wrap(uint32_t *old_slowcheck, uint32_t *old_flags)
 {
-       boolean_t wrapped;
-       int s = ml_set_interrupts_enabled(FALSE);
-       lck_spin_lock_grp(kds_spin_lock, kdebug_lck_grp);
+       bool wrapped;
+       int s = ml_set_interrupts_enabled(false);
+       lck_spin_lock_grp(&kds_spin_lock, &kdebug_lck_grp);
 
        *old_slowcheck = kd_ctrl_page.kdebug_slowcheck;
        *old_flags = kd_ctrl_page.kdebug_flags;
@@ -637,7 +742,7 @@ disable_wrap(uint32_t *old_slowcheck, uint32_t *old_flags)
        kd_ctrl_page.kdebug_flags &= ~KDBG_WRAPPED;
        kd_ctrl_page.kdebug_flags |= KDBG_NOWRAP;
 
-       lck_spin_unlock(kds_spin_lock);
+       lck_spin_unlock(&kds_spin_lock);
        ml_set_interrupts_enabled(s);
 
        return wrapped;
@@ -646,8 +751,8 @@ disable_wrap(uint32_t *old_slowcheck, uint32_t *old_flags)
 static void
 enable_wrap(uint32_t old_slowcheck)
 {
-       int s = ml_set_interrupts_enabled(FALSE);
-       lck_spin_lock_grp(kds_spin_lock, kdebug_lck_grp);
+       int s = ml_set_interrupts_enabled(false);
+       lck_spin_lock_grp(&kds_spin_lock, &kdebug_lck_grp);
 
        kd_ctrl_page.kdebug_flags &= ~KDBG_NOWRAP;
 
@@ -655,12 +760,12 @@ enable_wrap(uint32_t old_slowcheck)
                kd_ctrl_page.kdebug_slowcheck &= ~SLOW_NOLOG;
        }
 
-       lck_spin_unlock(kds_spin_lock);
+       lck_spin_unlock(&kds_spin_lock);
        ml_set_interrupts_enabled(s);
 }
 
 static int
-create_buffers(boolean_t early_trace)
+create_buffers(bool early_trace)
 {
        unsigned int i;
        unsigned int p_buffer_size;
@@ -677,9 +782,7 @@ create_buffers(boolean_t early_trace)
         */
        kd_ctrl_page.kdebug_iops = kd_iops;
 
-#if CONFIG_EMBEDDED
        assert(kdbg_iop_list_is_valid(kd_ctrl_page.kdebug_iops));
-#endif
 
        /*
         * If the list is valid, it is sorted, newest -> oldest. Each iop entry
@@ -748,13 +851,15 @@ create_buffers(boolean_t early_trace)
 
        for (i = 0; i < n_storage_buffers; i++) {
                struct kd_storage *kds;
-               int     n_elements;
-               int     n;
+               uint16_t n_elements;
+               static_assert(N_STORAGE_UNITS_PER_BUFFER <= UINT16_MAX);
+               assert(kd_bufs[i].kdsb_size <= N_STORAGE_UNITS_PER_BUFFER *
+                   sizeof(struct kd_storage));
 
                n_elements = kd_bufs[i].kdsb_size / sizeof(struct kd_storage);
                kds = kd_bufs[i].kdsb_addr;
 
-               for (n = 0; n < n_elements; n++) {
+               for (uint16_t n = 0; n < n_elements; n++) {
                        kds[n].kds_next.buffer_index = kd_ctrl_page.kds_free_list.buffer_index;
                        kds[n].kds_next.offset = kd_ctrl_page.kds_free_list.offset;
 
@@ -769,7 +874,7 @@ create_buffers(boolean_t early_trace)
        for (i = 0; i < kd_ctrl_page.kdebug_cpus; i++) {
                kdbip[i].kd_list_head.raw = KDS_PTR_NULL;
                kdbip[i].kd_list_tail.raw = KDS_PTR_NULL;
-               kdbip[i].kd_lostevents = FALSE;
+               kdbip[i].kd_lostevents = false;
                kdbip[i].num_bufs = 0;
        }
 
@@ -828,8 +933,8 @@ release_storage_unit(int cpu, uint32_t kdsp_raw)
 
        kdsp.raw = kdsp_raw;
 
-       s = ml_set_interrupts_enabled(FALSE);
-       lck_spin_lock_grp(kds_spin_lock, kdebug_lck_grp);
+       s = ml_set_interrupts_enabled(false);
+       lck_spin_lock_grp(&kds_spin_lock, &kdebug_lck_grp);
 
        kdbp = &kdbip[cpu];
 
@@ -852,23 +957,22 @@ release_storage_unit(int cpu, uint32_t kdsp_raw)
 
                kd_ctrl_page.kds_inuse_count--;
        }
-       lck_spin_unlock(kds_spin_lock);
+       lck_spin_unlock(&kds_spin_lock);
        ml_set_interrupts_enabled(s);
 }
 
-
-boolean_t
+bool
 allocate_storage_unit(int cpu)
 {
        union kds_ptr kdsp;
        struct kd_storage *kdsp_actual, *kdsp_next_actual;
        struct kd_bufinfo *kdbp, *kdbp_vict, *kdbp_try;
        uint64_t oldest_ts, ts;
-       boolean_t retval = TRUE;
+       bool retval = true;
        int s = 0;
 
-       s = ml_set_interrupts_enabled(FALSE);
-       lck_spin_lock_grp(kds_spin_lock, kdebug_lck_grp);
+       s = ml_set_interrupts_enabled(false);
+       lck_spin_lock_grp(&kds_spin_lock, &kdebug_lck_grp);
 
        kdbp = &kdbip[cpu];
 
@@ -896,8 +1000,8 @@ allocate_storage_unit(int cpu)
                 */
                if (kd_ctrl_page.kdebug_flags & KDBG_NOWRAP) {
                        kd_ctrl_page.kdebug_slowcheck |= SLOW_NOLOG;
-                       kdbp->kd_lostevents = TRUE;
-                       retval = FALSE;
+                       kdbp->kd_lostevents = true;
+                       retval = false;
                        goto out;
                }
                kdbp_vict = NULL;
@@ -941,7 +1045,7 @@ allocate_storage_unit(int cpu)
                        kdebug_enable = 0;
                        kd_ctrl_page.enabled = 0;
                        commpage_update_kdebug_state();
-                       retval = FALSE;
+                       retval = false;
                        goto out;
                }
                kdsp = kdbp_vict->kd_list_head;
@@ -950,9 +1054,9 @@ allocate_storage_unit(int cpu)
 
                if (kdbp_vict->kd_list_head.raw != KDS_PTR_NULL) {
                        kdsp_next_actual = POINTER_FROM_KDS_PTR(kdbp_vict->kd_list_head);
-                       kdsp_next_actual->kds_lostevents = TRUE;
+                       kdsp_next_actual->kds_lostevents = true;
                } else {
-                       kdbp_vict->kd_lostevents = TRUE;
+                       kdbp_vict->kd_lostevents = true;
                }
 
                if (kd_ctrl_page.oldest_time < oldest_ts) {
@@ -966,7 +1070,7 @@ allocate_storage_unit(int cpu)
        kdsp_actual->kds_readlast = 0;
 
        kdsp_actual->kds_lostevents = kdbp->kd_lostevents;
-       kdbp->kd_lostevents = FALSE;
+       kdbp->kd_lostevents = false;
        kdsp_actual->kds_bufindx = 0;
 
        if (kdbp->kd_list_head.raw == KDS_PTR_NULL) {
@@ -976,7 +1080,7 @@ allocate_storage_unit(int cpu)
        }
        kdbp->kd_list_tail = kdsp;
 out:
-       lck_spin_unlock(kds_spin_lock);
+       lck_spin_unlock(&kds_spin_lock);
        ml_set_interrupts_enabled(s);
 
        return retval;
@@ -995,7 +1099,7 @@ kernel_debug_register_callback(kd_callback_t callback)
                 * Remove when fixed.
                 */
                {
-                       boolean_t is_valid_name = FALSE;
+                       bool is_valid_name = false;
                        for (uint32_t length = 0; length < sizeof(callback.iop_name); ++length) {
                                /* This is roughly isprintable(c) */
                                if (callback.iop_name[length] > 0x20 && callback.iop_name[length] < 0x7F) {
@@ -1003,7 +1107,7 @@ kernel_debug_register_callback(kd_callback_t callback)
                                }
                                if (callback.iop_name[length] == 0) {
                                        if (length) {
-                                               is_valid_name = TRUE;
+                                               is_valid_name = true;
                                        }
                                        break;
                                }
@@ -1026,7 +1130,7 @@ kernel_debug_register_callback(kd_callback_t callback)
                         * TLDR; Must not read kd_iops more than once per loop.
                         */
                        iop->next = kd_iops;
-                       iop->cpu_id = iop->next ? (iop->next->cpu_id + 1) : kdbg_cpu_count(FALSE);
+                       iop->cpu_id = iop->next ? (iop->next->cpu_id + 1) : kdbg_cpu_count(false);
 
                        /*
                         * Header says OSCompareAndSwapPtr has a memory barrier
@@ -1087,19 +1191,6 @@ record_event:
                goto out1;
        }
 
-#if CONFIG_EMBEDDED
-       /*
-        * When start_kern_tracing is called by the kernel to trace very
-        * early kernel events, it saves data to a secondary buffer until
-        * it is possible to initialize ktrace, and then dumps the events
-        * into the ktrace buffer using this method. In this case, iops will
-        * be NULL, and the coreid will be zero. It is not possible to have
-        * a valid IOP coreid of zero, so pass if both iops is NULL and coreid
-        * is zero.
-        */
-       assert(kdbg_iop_list_contains_cpu_id(kd_ctrl_page.kdebug_iops, coreid) || (kd_ctrl_page.kdebug_iops == NULL && coreid == 0));
-#endif
-
        disable_preemption();
 
        if (kd_ctrl_page.enabled == 0) {
@@ -1109,13 +1200,6 @@ record_event:
        kdbp = &kdbip[coreid];
        timestamp &= KDBG_TIMESTAMP_MASK;
 
-#if KDEBUG_MOJO_TRACE
-       if (kdebug_enable & KDEBUG_ENABLE_SERIAL) {
-               kdebug_serial_print(coreid, debugid, timestamp,
-                   arg1, arg2, arg3, arg4, threadid);
-       }
-#endif
-
 retry_q:
        kds_raw = kdbp->kd_list_tail;
 
@@ -1128,7 +1212,7 @@ retry_q:
        }
 
        if (kdsp_actual == NULL || bindx >= EVENTS_PER_STORAGE_UNIT) {
-               if (allocate_storage_unit(coreid) == FALSE) {
+               if (allocate_storage_unit(coreid) == false) {
                        /*
                         * this can only happen if wrapping
                         * has been disabled
@@ -1288,14 +1372,6 @@ record_event:
        cpu = cpu_number();
        kdbp = &kdbip[cpu];
 
-#if KDEBUG_MOJO_TRACE
-       if (kdebug_enable & KDEBUG_ENABLE_SERIAL) {
-               kdebug_serial_print(cpu, debugid,
-                   kdbg_timestamp() & KDBG_TIMESTAMP_MASK,
-                   arg1, arg2, arg3, arg4, arg5);
-       }
-#endif
-
 retry_q:
        kds_raw = kdbp->kd_list_tail;
 
@@ -1308,7 +1384,7 @@ retry_q:
        }
 
        if (kdsp_actual == NULL || bindx >= EVENTS_PER_STORAGE_UNIT) {
-               if (allocate_storage_unit(cpu) == FALSE) {
+               if (allocate_storage_unit(cpu) == false) {
                        /*
                         * this can only happen if wrapping
                         * has been disabled
@@ -1357,6 +1433,7 @@ out1:
        }
 }
 
+__attribute__((noinline))
 void
 kernel_debug(
        uint32_t        debugid,
@@ -1370,6 +1447,7 @@ kernel_debug(
            (uintptr_t)thread_tid(current_thread()), 0);
 }
 
+__attribute__((noinline))
 void
 kernel_debug1(
        uint32_t        debugid,
@@ -1382,6 +1460,7 @@ kernel_debug1(
        kernel_debug_internal(debugid, arg1, arg2, arg3, arg4, arg5, 0);
 }
 
+__attribute__((noinline))
 void
 kernel_debug_flags(
        uint32_t debugid,
@@ -1395,6 +1474,7 @@ kernel_debug_flags(
            (uintptr_t)thread_tid(current_thread()), flags);
 }
 
+__attribute__((noinline))
 void
 kernel_debug_filtered(
        uint32_t debugid,
@@ -1488,7 +1568,7 @@ kernel_debug_early(
 
        /* If early tracing is over, use the normal path. */
        if (kd_early_done) {
-               KERNEL_DEBUG_CONSTANT(debugid, arg1, arg2, arg3, arg4, 0);
+               KDBG_RELEASE(debugid, arg1, arg2, arg3, arg4);
                return;
        }
 
@@ -1523,17 +1603,12 @@ kernel_debug_early_end(void)
        /* reset the current oldest time to allow early events */
        kd_ctrl_page.oldest_time = 0;
 
-#if !CONFIG_EMBEDDED
+#if defined(__x86_64__)
        /* Fake sentinel marking the start of kernel time relative to TSC */
-       kernel_debug_enter(0,
-           TRACE_TIMESTAMPS,
-           0,
-           (uint32_t)(tsc_rebase_abs_time >> 32),
-           (uint32_t)tsc_rebase_abs_time,
-           tsc_at_boot,
-           0,
-           0);
-#endif
+       kernel_debug_enter(0, TRACE_TIMESTAMPS, 0,
+           (uint32_t)(tsc_rebase_abs_time >> 32), (uint32_t)tsc_rebase_abs_time,
+           tsc_at_boot, 0, 0);
+#endif /* defined(__x86_64__) */
        for (unsigned int i = 0; i < kd_early_index; i++) {
                kernel_debug_enter(0,
                    kd_early_buffer[i].debugid,
@@ -1560,7 +1635,7 @@ void
 kernel_debug_disable(void)
 {
        if (kdebug_enable) {
-               kdbg_set_tracing_enabled(FALSE, 0);
+               kdbg_set_tracing_enabled(false, 0);
        }
 }
 
@@ -1624,7 +1699,7 @@ kdebug_typefilter(__unused struct proc* p,
         * the first atomic load test of Global Typefilter Ptr, this function
         * can then safely use the remaining global state without atomic checks.
         */
-       if (!__c11_atomic_load((_Atomic typefilter_t *)&kdbg_typefilter, memory_order_acquire)) {
+       if (!os_atomic_load(&kdbg_typefilter, acquire)) {
                return EINVAL;
        }
 
@@ -1643,7 +1718,7 @@ kdebug_typefilter(__unused struct proc* p,
                VM_KERN_MEMORY_NONE,
                kdbg_typefilter_memory_entry,                           // port (memory entry!)
                0,                                                      // offset (in memory entry)
-               FALSE,                                                  // should copy
+               false,                                                  // should copy
                VM_PROT_READ,                                           // cur_prot
                VM_PROT_READ,                                           // max_prot
                VM_INHERIT_SHARE));                                     // inherit behavior on fork
@@ -1787,18 +1862,18 @@ kernel_debug_string_internal(uint32_t debugid, uint64_t str_id, void *vstr,
  * Trace system and scheduling events circumvent this check, as do events
  * emitted in interrupt context.
  */
-static boolean_t
+static bool
 kdebug_current_proc_enabled(uint32_t debugid)
 {
        /* can't determine current process in interrupt context */
        if (ml_at_interrupt_context()) {
-               return TRUE;
+               return true;
        }
 
        /* always emit trace system and scheduling events */
        if ((KDBG_EXTRACT_CLASS(debugid) == DBG_TRACE ||
            (debugid & KDBG_CSC_MASK) == MACHDBG_CODE(DBG_MACH_SCHED, 0))) {
-               return TRUE;
+               return true;
        }
 
        if (kd_ctrl_page.kdebug_flags & KDBG_PIDCHECK) {
@@ -1806,52 +1881,58 @@ kdebug_current_proc_enabled(uint32_t debugid)
 
                /* only the process with the kdebug bit set is allowed */
                if (cur_proc && !(cur_proc->p_kdebug)) {
-                       return FALSE;
+                       return false;
                }
        } else if (kd_ctrl_page.kdebug_flags & KDBG_PIDEXCLUDE) {
                proc_t cur_proc = current_proc();
 
                /* every process except the one with the kdebug bit set is allowed */
                if (cur_proc && cur_proc->p_kdebug) {
-                       return FALSE;
+                       return false;
                }
        }
 
-       return TRUE;
+       return true;
 }
 
-boolean_t
+bool
 kdebug_debugid_enabled(uint32_t debugid)
 {
        /* if no filtering is enabled */
        if (!kd_ctrl_page.kdebug_slowcheck) {
-               return TRUE;
+               return true;
        }
 
        return kdebug_debugid_explicitly_enabled(debugid);
 }
 
-boolean_t
+bool
 kdebug_debugid_explicitly_enabled(uint32_t debugid)
 {
        if (kd_ctrl_page.kdebug_flags & KDBG_TYPEFILTER_CHECK) {
                return typefilter_is_debugid_allowed(kdbg_typefilter, debugid);
        } else if (KDBG_EXTRACT_CLASS(debugid) == DBG_TRACE) {
-               return TRUE;
+               return true;
        } else if (kd_ctrl_page.kdebug_flags & KDBG_RANGECHECK) {
                if (debugid < kdlog_beg || debugid > kdlog_end) {
-                       return FALSE;
+                       return false;
                }
        } else if (kd_ctrl_page.kdebug_flags & KDBG_VALCHECK) {
                if ((debugid & KDBG_EVENTID_MASK) != kdlog_value1 &&
                    (debugid & KDBG_EVENTID_MASK) != kdlog_value2 &&
                    (debugid & KDBG_EVENTID_MASK) != kdlog_value3 &&
                    (debugid & KDBG_EVENTID_MASK) != kdlog_value4) {
-                       return FALSE;
+                       return false;
                }
        }
 
-       return TRUE;
+       return true;
+}
+
+bool
+kdebug_using_continuous_time(void)
+{
+       return kdebug_enable & KDEBUG_ENABLE_CONT_TIME;
 }
 
 /*
@@ -1984,29 +2065,8 @@ kdebug_trace_string(__unused struct proc *p,
        return 0;
 }
 
-static void
-kdbg_lock_init(void)
-{
-       static lck_grp_attr_t *kdebug_lck_grp_attr = NULL;
-       static lck_attr_t     *kdebug_lck_attr     = NULL;
-
-       if (kd_ctrl_page.kdebug_flags & KDBG_LOCKINIT) {
-               return;
-       }
-
-       assert(kdebug_lck_grp_attr == NULL);
-       kdebug_lck_grp_attr = lck_grp_attr_alloc_init();
-       kdebug_lck_grp = lck_grp_alloc_init("kdebug", kdebug_lck_grp_attr);
-       kdebug_lck_attr = lck_attr_alloc_init();
-
-       kds_spin_lock = lck_spin_alloc_init(kdebug_lck_grp, kdebug_lck_attr);
-       kdw_spin_lock = lck_spin_alloc_init(kdebug_lck_grp, kdebug_lck_attr);
-
-       kd_ctrl_page.kdebug_flags |= KDBG_LOCKINIT;
-}
-
 int
-kdbg_bootstrap(boolean_t early_trace)
+kdbg_bootstrap(bool early_trace)
 {
        kd_ctrl_page.kdebug_flags &= ~KDBG_WRAPPED;
 
@@ -2014,7 +2074,7 @@ kdbg_bootstrap(boolean_t early_trace)
 }
 
 int
-kdbg_reinit(boolean_t early_trace)
+kdbg_reinit(bool early_trace)
 {
        int ret = 0;
 
@@ -2051,7 +2111,8 @@ kdbg_trace_data(struct proc *proc, long *arg_pid, long *arg_uniqueid)
                *arg_uniqueid = 0;
        } else {
                *arg_pid = proc->p_pid;
-               *arg_uniqueid = proc->p_uniqueid;
+               /* Fit in a trace point */
+               *arg_uniqueid = (long)proc->p_uniqueid;
                if ((uint64_t) *arg_uniqueid != proc->p_uniqueid) {
                        *arg_uniqueid = 0;
                }
@@ -2060,12 +2121,9 @@ kdbg_trace_data(struct proc *proc, long *arg_pid, long *arg_uniqueid)
 
 
 void
-kdbg_trace_string(struct proc *proc, long *arg1, long *arg2, long *arg3, long *arg4)
+kdbg_trace_string(struct proc *proc, long *arg1, long *arg2, long *arg3,
+    long *arg4)
 {
-       char *dbg_nameptr;
-       int dbg_namelen;
-       long dbg_parms[4];
-
        if (!proc) {
                *arg1 = 0;
                *arg2 = 0;
@@ -2073,52 +2131,22 @@ kdbg_trace_string(struct proc *proc, long *arg1, long *arg2, long *arg3, long *a
                *arg4 = 0;
                return;
        }
-       /*
-        * Collect the pathname for tracing
-        */
-       dbg_nameptr = proc->p_comm;
-       dbg_namelen = (int)strlen(proc->p_comm);
-       dbg_parms[0] = 0L;
-       dbg_parms[1] = 0L;
-       dbg_parms[2] = 0L;
-       dbg_parms[3] = 0L;
 
-       if (dbg_namelen > (int)sizeof(dbg_parms)) {
-               dbg_namelen = (int)sizeof(dbg_parms);
-       }
-
-       strncpy((char *)dbg_parms, dbg_nameptr, dbg_namelen);
+       const char *procname = proc_best_name(proc);
+       size_t namelen = strlen(procname);
 
-       *arg1 = dbg_parms[0];
-       *arg2 = dbg_parms[1];
-       *arg3 = dbg_parms[2];
-       *arg4 = dbg_parms[3];
-}
+       long args[4] = { 0 };
 
-static void
-kdbg_resolve_map(thread_t th_act, void *opaque)
-{
-       kd_threadmap *mapptr;
-       krt_t *t = (krt_t *)opaque;
+       if (namelen > sizeof(args)) {
+               namelen = sizeof(args);
+       }
 
-       if (t->count < t->maxcount) {
-               mapptr = &t->map[t->count];
-               mapptr->thread  = (uintptr_t)thread_tid(th_act);
+       strncpy((char *)args, procname, namelen);
 
-               (void) strlcpy(mapptr->command, t->atts->task_comm,
-                   sizeof(t->atts->task_comm));
-               /*
-                * Some kernel threads have no associated pid.
-                * We still need to mark the entry as valid.
-                */
-               if (t->atts->pid) {
-                       mapptr->valid = t->atts->pid;
-               } else {
-                       mapptr->valid = 1;
-               }
-
-               t->count++;
-       }
+       *arg1 = args[0];
+       *arg2 = args[1];
+       *arg3 = args[2];
+       *arg4 = args[3];
 }
 
 /*
@@ -2211,99 +2239,119 @@ kdbg_thrmap_init(void)
        }
 }
 
-static kd_threadmap *
-kdbg_thrmap_init_internal(unsigned int count, unsigned int *mapsize, unsigned int *mapcount)
+static void
+kd_resolve_map(thread_t thread, void *opaque)
 {
-       kd_threadmap *mapptr;
-       proc_t p;
-       struct krt akrt;
-       int tts_count = 0;    /* number of task-to-string structures */
-       struct tts *tts_mapptr;
-       unsigned int tts_mapsize = 0;
-       vm_offset_t kaddr;
-
-       assert(mapsize != NULL);
-       assert(mapcount != NULL);
-
-       *mapcount = threads_count;
-       tts_count = tasks_count;
-
-       /*
-        * The proc count could change during buffer allocation,
-        * so introduce a small fudge factor to bump up the
-        * buffer sizes. This gives new tasks some chance of
-        * making into the tables.  Bump up by 25%.
-        */
-       *mapcount += *mapcount / 4;
-       tts_count += tts_count / 4;
-
-       *mapsize = *mapcount * sizeof(kd_threadmap);
+       struct kd_resolver *resolve = opaque;
 
-       if (count && count < *mapcount) {
-               return 0;
-       }
+       if (resolve->krs_count < resolve->krs_maxcount) {
+               kd_threadmap *map = &resolve->krs_map[resolve->krs_count];
+               struct kd_task_name *task_name = resolve->krs_task;
+               map->thread = (uintptr_t)thread_tid(thread);
 
-       if ((kmem_alloc(kernel_map, &kaddr, (vm_size_t)*mapsize, VM_KERN_MEMORY_DIAG) == KERN_SUCCESS)) {
-               bzero((void *)kaddr, *mapsize);
-               mapptr = (kd_threadmap *)kaddr;
-       } else {
-               return 0;
+               (void)strlcpy(map->command, task_name->ktn_name, sizeof(map->command));
+               /*
+                * Kernel threads should still be marked with non-zero valid bit.
+                */
+               pid_t pid = resolve->krs_task->ktn_pid;
+               map->valid = pid == 0 ? 1 : pid;
+               resolve->krs_count++;
        }
+}
 
-       tts_mapsize = tts_count * sizeof(struct tts);
-
-       if ((kmem_alloc(kernel_map, &kaddr, (vm_size_t)tts_mapsize, VM_KERN_MEMORY_DIAG) == KERN_SUCCESS)) {
-               bzero((void *)kaddr, tts_mapsize);
-               tts_mapptr = (struct tts *)kaddr;
-       } else {
-               kmem_free(kernel_map, (vm_offset_t)mapptr, *mapsize);
-
-               return 0;
-       }
+static vm_size_t
+kd_resolve_tasks(struct kd_task_name *task_names, vm_size_t ntasks)
+{
+       vm_size_t i = 0;
+       proc_t p = PROC_NULL;
 
-       /*
-        * Save the proc's name and take a reference for each task associated
-        * with a valid process.
-        */
        proc_list_lock();
-
-       int i = 0;
        ALLPROC_FOREACH(p) {
-               if (i >= tts_count) {
+               if (i >= ntasks) {
                        break;
                }
-               if (p->p_lflag & P_LEXIT) {
-                       continue;
-               }
-               if (p->task) {
+               /*
+                * Only record processes that can be referenced and are not exiting.
+                */
+               if (p->task && (p->p_lflag & P_LEXIT) == 0) {
                        task_reference(p->task);
-                       tts_mapptr[i].task = p->task;
-                       tts_mapptr[i].pid = p->p_pid;
-                       (void)strlcpy(tts_mapptr[i].task_comm, proc_best_name(p), sizeof(tts_mapptr[i].task_comm));
+                       task_names[i].ktn_task = p->task;
+                       task_names[i].ktn_pid = p->p_pid;
+                       (void)strlcpy(task_names[i].ktn_name, proc_best_name(p),
+                           sizeof(task_names[i].ktn_name));
                        i++;
                }
        }
-       tts_count = i;
-
        proc_list_unlock();
 
+       return i;
+}
+
+static vm_size_t
+kd_resolve_threads(kd_threadmap *map, struct kd_task_name *task_names,
+    vm_size_t ntasks, vm_size_t nthreads)
+{
+       struct kd_resolver resolver = {
+               .krs_map = map, .krs_count = 0, .krs_maxcount = nthreads,
+       };
+
+       for (int i = 0; i < ntasks; i++) {
+               struct kd_task_name *cur_task = &task_names[i];
+               resolver.krs_task = cur_task;
+               task_act_iterate_wth_args(cur_task->ktn_task, kd_resolve_map,
+                   &resolver);
+               task_deallocate(cur_task->ktn_task);
+       }
+
+       return resolver.krs_count;
+}
+
+static kd_threadmap *
+kdbg_thrmap_init_internal(size_t maxthreads, vm_size_t *mapsize,
+    vm_size_t *mapcount)
+{
+       kd_threadmap *thread_map = NULL;
+       struct kd_task_name *task_names;
+       vm_size_t names_size = 0;
+
+       assert(mapsize != NULL);
+       assert(mapcount != NULL);
+
+       vm_size_t nthreads = threads_count;
+       vm_size_t ntasks = tasks_count;
+
        /*
-        * Initialize thread map data
+        * Allow 25% more threads and tasks to be created between now and taking the
+        * proc_list_lock.
         */
-       akrt.map = mapptr;
-       akrt.count = 0;
-       akrt.maxcount = *mapcount;
+       if (os_add_overflow(nthreads, nthreads / 4, &nthreads) ||
+           os_add_overflow(ntasks, ntasks / 4, &ntasks)) {
+               return NULL;
+       }
 
-       for (i = 0; i < tts_count; i++) {
-               akrt.atts = &tts_mapptr[i];
-               task_act_iterate_wth_args(tts_mapptr[i].task, kdbg_resolve_map, &akrt);
-               task_deallocate((task_t)tts_mapptr[i].task);
+       *mapcount = nthreads;
+       if (os_mul_overflow(nthreads, sizeof(kd_threadmap), mapsize)) {
+               return NULL;
+       }
+       if (os_mul_overflow(ntasks, sizeof(task_names[0]), &names_size)) {
+               return NULL;
        }
-       kmem_free(kernel_map, (vm_offset_t)tts_mapptr, tts_mapsize);
 
-       *mapcount = akrt.count;
+       /*
+        * Wait until the out-parameters have been filled with the needed size to
+        * do the bounds checking on the provided maximum.
+        */
+       if (maxthreads != 0 && maxthreads < nthreads) {
+               return NULL;
+       }
 
-       return mapptr;
+       thread_map = kalloc_tag(*mapsize, VM_KERN_MEMORY_DIAG);
+       bzero(thread_map, *mapsize);
+       task_names = kheap_alloc(KHEAP_TEMP, names_size, Z_WAITOK | Z_ZERO);
+       ntasks = kd_resolve_tasks(task_names, ntasks);
+       *mapcount = kd_resolve_threads(thread_map, task_names, ntasks, nthreads);
+       kheap_free(KHEAP_TEMP, task_names, names_size);
+       return thread_map;
 }
 
 static void
@@ -2355,8 +2403,6 @@ kdebug_reset(void)
 {
        ktrace_assert_lock_held();
 
-       kdbg_lock_init();
-
        kdbg_clear();
        if (kdbg_typefilter) {
                typefilter_reject_all(kdbg_typefilter);
@@ -2367,11 +2413,13 @@ kdebug_reset(void)
 void
 kdebug_free_early_buf(void)
 {
-#if !CONFIG_EMBEDDED
-       /* Must be done with the buffer, so release it back to the VM.
-        * On embedded targets this buffer is freed when the BOOTDATA segment is freed. */
+#if defined(__x86_64__)
+       /*
+        * Make Intel aware that the early buffer is no longer being used.  ARM
+        * handles this as part of the BOOTDATA segment.
+        */
        ml_static_mfree((vm_offset_t)&kd_early_buffer, sizeof(kd_early_buffer));
-#endif
+#endif /* defined(__x86_64__) */
 }
 
 int
@@ -2394,7 +2442,7 @@ kdbg_setpid(kd_regtype *kdr)
                                 */
                                kd_ctrl_page.kdebug_flags |= KDBG_PIDCHECK;
                                kd_ctrl_page.kdebug_flags &= ~KDBG_PIDEXCLUDE;
-                               kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+                               kdbg_set_flags(SLOW_CHECKS, 0, true);
 
                                p->p_kdebug = 1;
                        } else {
@@ -2436,7 +2484,7 @@ kdbg_setpidex(kd_regtype *kdr)
                                 */
                                kd_ctrl_page.kdebug_flags |= KDBG_PIDEXCLUDE;
                                kd_ctrl_page.kdebug_flags &= ~KDBG_PIDCHECK;
-                               kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+                               kdbg_set_flags(SLOW_CHECKS, 0, true);
 
                                p->p_kdebug = 1;
                        } else {
@@ -2490,7 +2538,7 @@ kdbg_initialize_typefilter(typefilter_t tf)
         * that any non-null kdbg_typefilter means a
         * valid memory_entry is available.
         */
-       __c11_atomic_store(((_Atomic typefilter_t*)&kdbg_typefilter), tf, memory_order_release);
+       os_atomic_store(&kdbg_typefilter, tf, release);
 
        return KERN_SUCCESS;
 }
@@ -2552,7 +2600,7 @@ kdbg_enable_typefilter(void)
        assert(kdbg_typefilter);
        kd_ctrl_page.kdebug_flags &= ~(KDBG_RANGECHECK | KDBG_VALCHECK);
        kd_ctrl_page.kdebug_flags |= KDBG_TYPEFILTER_CHECK;
-       kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+       kdbg_set_flags(SLOW_CHECKS, 0, true);
        commpage_update_kdebug_state();
 }
 
@@ -2567,9 +2615,9 @@ kdbg_disable_typefilter(void)
        kd_ctrl_page.kdebug_flags &= ~KDBG_TYPEFILTER_CHECK;
 
        if ((kd_ctrl_page.kdebug_flags & (KDBG_PIDCHECK | KDBG_PIDEXCLUDE))) {
-               kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+               kdbg_set_flags(SLOW_CHECKS, 0, true);
        } else {
-               kdbg_set_flags(SLOW_CHECKS, 0, FALSE);
+               kdbg_set_flags(SLOW_CHECKS, 0, false);
        }
        commpage_update_kdebug_state();
 
@@ -2613,7 +2661,7 @@ kdbg_setreg(kd_regtype * kdr)
                kd_ctrl_page.kdebug_flags &= (unsigned int)~KDBG_CKTYPES;
                kd_ctrl_page.kdebug_flags &= ~KDBG_VALCHECK;       /* Turn off specific value check  */
                kd_ctrl_page.kdebug_flags |= (KDBG_RANGECHECK | KDBG_CLASSTYPE);
-               kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+               kdbg_set_flags(SLOW_CHECKS, 0, true);
                break;
        case KDBG_SUBCLSTYPE:
                val_1 = (kdr->value1 & 0xff);
@@ -2624,7 +2672,7 @@ kdbg_setreg(kd_regtype * kdr)
                kd_ctrl_page.kdebug_flags &= (unsigned int)~KDBG_CKTYPES;
                kd_ctrl_page.kdebug_flags &= ~KDBG_VALCHECK;       /* Turn off specific value check  */
                kd_ctrl_page.kdebug_flags |= (KDBG_RANGECHECK | KDBG_SUBCLSTYPE);
-               kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+               kdbg_set_flags(SLOW_CHECKS, 0, true);
                break;
        case KDBG_RANGETYPE:
                kdlog_beg = (kdr->value1);
@@ -2632,7 +2680,7 @@ kdbg_setreg(kd_regtype * kdr)
                kd_ctrl_page.kdebug_flags &= (unsigned int)~KDBG_CKTYPES;
                kd_ctrl_page.kdebug_flags &= ~KDBG_VALCHECK;       /* Turn off specific value check  */
                kd_ctrl_page.kdebug_flags |= (KDBG_RANGECHECK | KDBG_RANGETYPE);
-               kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+               kdbg_set_flags(SLOW_CHECKS, 0, true);
                break;
        case KDBG_VALCHECK:
                kdlog_value1 = (kdr->value1);
@@ -2642,7 +2690,7 @@ kdbg_setreg(kd_regtype * kdr)
                kd_ctrl_page.kdebug_flags &= (unsigned int)~KDBG_CKTYPES;
                kd_ctrl_page.kdebug_flags &= ~KDBG_RANGECHECK;    /* Turn off range check */
                kd_ctrl_page.kdebug_flags |= KDBG_VALCHECK;       /* Turn on specific value check  */
-               kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+               kdbg_set_flags(SLOW_CHECKS, 0, true);
                break;
        case KDBG_TYPENONE:
                kd_ctrl_page.kdebug_flags &= (unsigned int)~KDBG_CKTYPES;
@@ -2650,9 +2698,9 @@ kdbg_setreg(kd_regtype * kdr)
                if ((kd_ctrl_page.kdebug_flags & (KDBG_RANGECHECK | KDBG_VALCHECK   |
                    KDBG_PIDCHECK   | KDBG_PIDEXCLUDE |
                    KDBG_TYPEFILTER_CHECK))) {
-                       kdbg_set_flags(SLOW_CHECKS, 0, TRUE);
+                       kdbg_set_flags(SLOW_CHECKS, 0, true);
                } else {
-                       kdbg_set_flags(SLOW_CHECKS, 0, FALSE);
+                       kdbg_set_flags(SLOW_CHECKS, 0, false);
                }
 
                kdlog_beg = 0;
@@ -2668,7 +2716,8 @@ kdbg_setreg(kd_regtype * kdr)
 static int
 kdbg_write_to_vnode(caddr_t buffer, size_t size, vnode_t vp, vfs_context_t ctx, off_t file_offset)
 {
-       return vn_rdwr(UIO_WRITE, vp, buffer, size, file_offset, UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT,
+       assert(size < INT_MAX);
+       return vn_rdwr(UIO_WRITE, vp, buffer, (int)size, file_offset, UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT,
                   vfs_context_ucred(ctx), (int *) 0, vfs_context_proc(ctx));
 }
 
@@ -2705,25 +2754,7 @@ write_error:
        return ret;
 }
 
-int
-kdbg_write_v3_chunk_header_to_buffer(void * buffer, uint32_t tag, uint32_t sub_tag, uint64_t length)
-{
-       kd_chunk_header_v3 header = {
-               .tag = tag,
-               .sub_tag = sub_tag,
-               .length = length,
-       };
-
-       if (!buffer) {
-               return 0;
-       }
-
-       memcpy(buffer, &header, sizeof(kd_chunk_header_v3));
-
-       return sizeof(kd_chunk_header_v3);
-}
-
-int
+static int
 kdbg_write_v3_chunk_to_fd(uint32_t tag, uint32_t sub_tag, uint64_t length, void *payload, uint64_t payload_size, int fd)
 {
        proc_t p;
@@ -2732,25 +2763,16 @@ kdbg_write_v3_chunk_to_fd(uint32_t tag, uint32_t sub_tag, uint64_t length, void
        vnode_t vp;
        p = current_proc();
 
-       proc_fdlock(p);
-       if ((fp_lookup(p, fd, &fp, 1))) {
-               proc_fdunlock(p);
-               return EFAULT;
+       if (fp_get_ftype(p, fd, DTYPE_VNODE, EBADF, &fp)) {
+               return EBADF;
        }
 
+       vp = fp->fp_glob->fg_data;
        context.vc_thread = current_thread();
-       context.vc_ucred = fp->f_fglob->fg_cred;
-
-       if (FILEGLOB_DTYPE(fp->f_fglob) != DTYPE_VNODE) {
-               fp_drop(p, fd, fp, 1);
-               proc_fdunlock(p);
-               return EBADF;
-       }
-       vp = (struct vnode *) fp->f_fglob->fg_data;
-       proc_fdunlock(p);
+       context.vc_ucred = fp->fp_glob->fg_cred;
 
        if ((vnode_getwithref(vp)) == 0) {
-               RAW_file_offset = fp->f_fglob->fg_offset;
+               RAW_file_offset = fp->fp_glob->fg_offset;
 
                kd_chunk_header_v3 chunk_header = {
                        .tag = tag,
@@ -2768,7 +2790,7 @@ kdbg_write_v3_chunk_to_fd(uint32_t tag, uint32_t sub_tag, uint64_t length, void
                        RAW_file_offset  += payload_size;
                }
 
-               fp->f_fglob->fg_offset = RAW_file_offset;
+               fp->fp_glob->fg_offset = RAW_file_offset;
                vnode_put(vp);
        }
 
@@ -2846,7 +2868,10 @@ kdbg_write_v3_header(user_addr_t user_header, size_t *user_header_size, int fd)
                ret = EINVAL;
                goto bail;
        }
-       thrmap_size = kd_mapcount * sizeof(kd_threadmap);
+       if (os_mul_overflow(kd_mapcount, sizeof(kd_threadmap), &thrmap_size)) {
+               ret = ERANGE;
+               goto bail;
+       }
 
        mach_timebase_info_data_t timebase = {0, 0};
        clock_timebase_info(&timebase);
@@ -2873,7 +2898,7 @@ kdbg_write_v3_header(user_addr_t user_header, size_t *user_header_size, int fd)
 
        // If its a buffer, check if we have enough space to copy the header and the maps.
        if (user_header) {
-               bytes_needed = header.length + thrmap_size + (2 * sizeof(kd_chunk_header_v3));
+               bytes_needed = (size_t)header.length + thrmap_size + (2 * sizeof(kd_chunk_header_v3));
                if (*user_header_size < bytes_needed) {
                        ret = EINVAL;
                        goto bail;
@@ -2982,12 +3007,11 @@ int
 kdbg_readcurthrmap(user_addr_t buffer, size_t *bufsize)
 {
        kd_threadmap *mapptr;
-       unsigned int mapsize;
-       unsigned int mapcount;
-       unsigned int count = 0;
+       vm_size_t mapsize;
+       vm_size_t mapcount;
        int ret = 0;
+       size_t count = *bufsize / sizeof(kd_threadmap);
 
-       count = *bufsize / sizeof(kd_threadmap);
        *bufsize = 0;
 
        if ((mapptr = kdbg_thrmap_init_internal(count, &mapsize, &mapcount))) {
@@ -2997,7 +3021,7 @@ kdbg_readcurthrmap(user_addr_t buffer, size_t *bufsize)
                        *bufsize = (mapcount * sizeof(kd_threadmap));
                }
 
-               kmem_free(kernel_map, (vm_offset_t)mapptr, mapsize);
+               kfree(mapptr, mapsize);
        } else {
                ret = EINVAL;
        }
@@ -3006,7 +3030,7 @@ kdbg_readcurthrmap(user_addr_t buffer, size_t *bufsize)
 }
 
 static int
-kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx)
+kdbg_write_v1_header(bool write_thread_map, vnode_t vp, vfs_context_t ctx)
 {
        int ret = 0;
        RAW_header header;
@@ -3017,12 +3041,20 @@ kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx)
        uint32_t extra_thread_count = 0;
        uint32_t cpumap_size;
        size_t map_size = 0;
-       size_t map_count = 0;
+       uint32_t map_count = 0;
 
        if (write_thread_map) {
                assert(kd_ctrl_page.kdebug_flags & KDBG_MAPINIT);
-               map_count = kd_mapcount;
-               map_size = map_count * sizeof(kd_threadmap);
+               if (kd_mapcount > UINT32_MAX) {
+                       return ERANGE;
+               }
+               map_count = (uint32_t)kd_mapcount;
+               if (os_mul_overflow(map_count, sizeof(kd_threadmap), &map_size)) {
+                       return ERANGE;
+               }
+               if (map_size >= INT_MAX) {
+                       return ERANGE;
+               }
        }
 
        /*
@@ -3043,7 +3075,7 @@ kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx)
        assert(vp);
        assert(ctx);
 
-       pad_size = PAGE_16KB - ((sizeof(RAW_header) + map_size) & PAGE_MASK_64);
+       pad_size = PAGE_16KB - ((sizeof(RAW_header) + map_size) & PAGE_MASK);
        cpumap_size = sizeof(kd_cpumap_header) + kd_ctrl_page.kdebug_cpus * sizeof(kd_cpumap);
 
        if (cpumap_size > pad_size) {
@@ -3075,7 +3107,7 @@ kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx)
        header.TOD_secs = secs;
        header.TOD_usecs = usecs;
 
-       ret = vn_rdwr(UIO_WRITE, vp, (caddr_t)&header, sizeof(RAW_header), RAW_file_offset,
+       ret = vn_rdwr(UIO_WRITE, vp, (caddr_t)&header, (int)sizeof(RAW_header), RAW_file_offset,
            UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT, vfs_context_ucred(ctx), (int *) 0, vfs_context_proc(ctx));
        if (ret) {
                goto write_error;
@@ -3084,7 +3116,8 @@ kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx)
        RAW_file_written += sizeof(RAW_header);
 
        if (write_thread_map) {
-               ret = vn_rdwr(UIO_WRITE, vp, (caddr_t)kd_mapptr, map_size, RAW_file_offset,
+               assert(map_size < INT_MAX);
+               ret = vn_rdwr(UIO_WRITE, vp, (caddr_t)kd_mapptr, (int)map_size, RAW_file_offset,
                    UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT, vfs_context_ucred(ctx), (int *) 0, vfs_context_proc(ctx));
                if (ret) {
                        goto write_error;
@@ -3096,16 +3129,16 @@ kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx)
 
        if (extra_thread_count) {
                pad_size = extra_thread_count * sizeof(kd_threadmap);
-               pad_buf = kalloc(pad_size);
+               pad_buf = kheap_alloc(KHEAP_TEMP, pad_size, Z_WAITOK | Z_ZERO);
                if (!pad_buf) {
                        ret = ENOMEM;
                        goto write_error;
                }
-               memset(pad_buf, 0, pad_size);
 
-               ret = vn_rdwr(UIO_WRITE, vp, (caddr_t)pad_buf, pad_size, RAW_file_offset,
+               assert(pad_size < INT_MAX);
+               ret = vn_rdwr(UIO_WRITE, vp, (caddr_t)pad_buf, (int)pad_size, RAW_file_offset,
                    UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT, vfs_context_ucred(ctx), (int *) 0, vfs_context_proc(ctx));
-               kfree(pad_buf, pad_size);
+               kheap_free(KHEAP_TEMP, pad_buf, pad_size);
                if (ret) {
                        goto write_error;
                }
@@ -3114,14 +3147,13 @@ kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx)
                RAW_file_written += pad_size;
        }
 
-       pad_size = PAGE_SIZE - (RAW_file_offset & PAGE_MASK_64);
+       pad_size = PAGE_SIZE - (RAW_file_offset & PAGE_MASK);
        if (pad_size) {
-               pad_buf = (char *)kalloc(pad_size);
+               pad_buf = (char *)kheap_alloc(KHEAP_TEMP, pad_size, Z_WAITOK | Z_ZERO);
                if (!pad_buf) {
                        ret = ENOMEM;
                        goto write_error;
                }
-               memset(pad_buf, 0, pad_size);
 
                /*
                 * embed a cpumap in the padding bytes.
@@ -3133,9 +3165,10 @@ kdbg_write_v1_header(boolean_t write_thread_map, vnode_t vp, vfs_context_t ctx)
                        memset(pad_buf, 0, pad_size);
                }
 
-               ret = vn_rdwr(UIO_WRITE, vp, (caddr_t)pad_buf, pad_size, RAW_file_offset,
+               assert(pad_size < INT_MAX);
+               ret = vn_rdwr(UIO_WRITE, vp, (caddr_t)pad_buf, (int)pad_size, RAW_file_offset,
                    UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT, vfs_context_ucred(ctx), (int *) 0, vfs_context_proc(ctx));
-               kfree(pad_buf, pad_size);
+               kheap_free(KHEAP_TEMP, pad_buf, pad_size);
                if (ret) {
                        goto write_error;
                }
@@ -3155,7 +3188,7 @@ kdbg_clear_thread_map(void)
 
        if (kd_ctrl_page.kdebug_flags & KDBG_MAPINIT) {
                assert(kd_mapptr != NULL);
-               kmem_free(kernel_map, (vm_offset_t)kd_mapptr, kd_mapsize);
+               kfree(kd_mapptr, kd_mapsize);
                kd_mapptr = NULL;
                kd_mapsize = 0;
                kd_mapcount = 0;
@@ -3175,7 +3208,7 @@ static int
 kdbg_write_thread_map(vnode_t vp, vfs_context_t ctx)
 {
        int ret = 0;
-       boolean_t map_initialized;
+       bool map_initialized;
 
        ktrace_assert_lock_held();
        assert(ctx != NULL);
@@ -3204,7 +3237,7 @@ kdbg_write_thread_map(vnode_t vp, vfs_context_t ctx)
 static int
 kdbg_copyout_thread_map(user_addr_t buffer, size_t *buffer_size)
 {
-       boolean_t map_initialized;
+       bool map_initialized;
        size_t map_size;
        int ret = 0;
 
@@ -3233,7 +3266,7 @@ int
 kdbg_readthrmap_v3(user_addr_t buffer, size_t buffer_size, int fd)
 {
        int ret = 0;
-       boolean_t map_initialized;
+       bool map_initialized;
        size_t map_size;
 
        ktrace_assert_lock_held();
@@ -3265,7 +3298,8 @@ kdbg_set_nkdbufs(unsigned int req_nkdbufs)
         * Only allow allocation up to half the available memory (sane_size).
         */
        uint64_t max_nkdbufs = (sane_size / 2) / sizeof(kd_buf);
-       nkdbufs = (req_nkdbufs > max_nkdbufs) ? max_nkdbufs : req_nkdbufs;
+       nkdbufs = (req_nkdbufs > max_nkdbufs) ? (unsigned int)max_nkdbufs :
+           req_nkdbufs;
 }
 
 /*
@@ -3278,8 +3312,8 @@ kdbg_set_nkdbufs(unsigned int req_nkdbufs)
  *
  * Called with `ktrace_lock` locked and interrupts enabled.
  */
-static boolean_t
-kdbg_wait(uint64_t timeout_ms, boolean_t locked_wait)
+static bool
+kdbg_wait(uint64_t timeout_ms, bool locked_wait)
 {
        int wait_result = THREAD_AWAKENED;
        uint64_t abstime = 0;
@@ -3292,11 +3326,11 @@ kdbg_wait(uint64_t timeout_ms, boolean_t locked_wait)
                clock_absolutetime_interval_to_deadline(abstime, &abstime);
        }
 
-       boolean_t s = ml_set_interrupts_enabled(FALSE);
+       bool s = ml_set_interrupts_enabled(false);
        if (!s) {
                panic("kdbg_wait() called with interrupts disabled");
        }
-       lck_spin_lock_grp(kdw_spin_lock, kdebug_lck_grp);
+       lck_spin_lock_grp(&kdw_spin_lock, &kdebug_lck_grp);
 
        if (!locked_wait) {
                /* drop the mutex to allow others to access trace */
@@ -3308,18 +3342,18 @@ kdbg_wait(uint64_t timeout_ms, boolean_t locked_wait)
                kds_waiter = 1;
 
                if (abstime) {
-                       wait_result = lck_spin_sleep_deadline(kdw_spin_lock, 0, &kds_waiter, THREAD_ABORTSAFE, abstime);
+                       wait_result = lck_spin_sleep_deadline(&kdw_spin_lock, 0, &kds_waiter, THREAD_ABORTSAFE, abstime);
                } else {
-                       wait_result = lck_spin_sleep(kdw_spin_lock, 0, &kds_waiter, THREAD_ABORTSAFE);
+                       wait_result = lck_spin_sleep(&kdw_spin_lock, 0, &kds_waiter, THREAD_ABORTSAFE);
                }
 
                kds_waiter = 0;
        }
 
        /* check the count under the spinlock */
-       boolean_t threshold_exceeded = (kd_ctrl_page.kds_inuse_count >= n_storage_threshold);
+       bool threshold_exceeded = (kd_ctrl_page.kds_inuse_count >= n_storage_threshold);
 
-       lck_spin_unlock(kdw_spin_lock);
+       lck_spin_unlock(&kdw_spin_lock);
        ml_set_interrupts_enabled(s);
 
        if (!locked_wait) {
@@ -3338,7 +3372,7 @@ kdbg_wait(uint64_t timeout_ms, boolean_t locked_wait)
 static void
 kdbg_wakeup(void)
 {
-       boolean_t need_kds_wakeup = FALSE;
+       bool need_kds_wakeup = false;
 
        /*
         * Try to take the lock here to synchronize with the waiter entering
@@ -3348,20 +3382,20 @@ kdbg_wakeup(void)
         * conditions.  No problem if we fail, there will be lots of additional
         * events coming in that will eventually succeed in grabbing this lock.
         */
-       boolean_t s = ml_set_interrupts_enabled(FALSE);
+       bool s = ml_set_interrupts_enabled(false);
 
-       if (lck_spin_try_lock(kdw_spin_lock)) {
+       if (lck_spin_try_lock(&kdw_spin_lock)) {
                if (kds_waiter &&
                    (kd_ctrl_page.kds_inuse_count >= n_storage_threshold)) {
                        kds_waiter = 0;
-                       need_kds_wakeup = TRUE;
+                       need_kds_wakeup = true;
                }
-               lck_spin_unlock(kdw_spin_lock);
+               lck_spin_unlock(&kdw_spin_lock);
        }
 
        ml_set_interrupts_enabled(s);
 
-       if (need_kds_wakeup == TRUE) {
+       if (need_kds_wakeup == true) {
                wakeup(&kds_waiter);
        }
 }
@@ -3390,9 +3424,6 @@ kdbg_control(int *name, u_int namelen, user_addr_t where, size_t *sizep)
                value = name[1];
        }
 
-       kdbg_lock_init();
-       assert(kd_ctrl_page.kdebug_flags & KDBG_LOCKINIT);
-
        ktrace_lock();
 
        /*
@@ -3426,8 +3457,8 @@ kdbg_control(int *name, u_int namelen, user_addr_t where, size_t *sizep)
                memset(&kd_bufinfo, 0, sizeof(kd_bufinfo));
 
                kd_bufinfo.nkdbufs = nkdbufs;
-               kd_bufinfo.nkdthreads = kd_mapcount;
-
+               kd_bufinfo.nkdthreads = kd_mapcount < INT_MAX ? (int)kd_mapcount :
+                   INT_MAX;
                if ((kd_ctrl_page.kdebug_slowcheck & SLOW_NOLOG)) {
                        kd_bufinfo.nolog = 1;
                } else {
@@ -3493,7 +3524,7 @@ kdbg_control(int *name, u_int namelen, user_addr_t where, size_t *sizep)
                        }
                        kdbg_thrmap_init();
 
-                       kdbg_set_tracing_enabled(TRUE, value);
+                       kdbg_set_tracing_enabled(true, value);
                } else {
                        if (!kdebug_enable) {
                                break;
@@ -3508,7 +3539,7 @@ kdbg_control(int *name, u_int namelen, user_addr_t where, size_t *sizep)
                break;
 
        case KERN_KDSETUP:
-               ret = kdbg_reinit(FALSE);
+               ret = kdbg_reinit(false);
                break;
 
        case KERN_KDREMOVE:
@@ -3548,31 +3579,23 @@ kdbg_control(int *name, u_int namelen, user_addr_t where, size_t *sizep)
                int     fd;
 
                if (name[0] == KERN_KDWRITETR || name[0] == KERN_KDWRITETR_V3) {
-                       (void)kdbg_wait(size, TRUE);
+                       (void)kdbg_wait(size, true);
                }
                p = current_proc();
                fd = value;
 
-               proc_fdlock(p);
-               if ((ret = fp_lookup(p, fd, &fp, 1))) {
-                       proc_fdunlock(p);
-                       break;
-               }
-               context.vc_thread = current_thread();
-               context.vc_ucred = fp->f_fglob->fg_cred;
-
-               if (FILEGLOB_DTYPE(fp->f_fglob) != DTYPE_VNODE) {
-                       fp_drop(p, fd, fp, 1);
-                       proc_fdunlock(p);
 
+               if (fp_get_ftype(p, fd, DTYPE_VNODE, EBADF, &fp)) {
                        ret = EBADF;
                        break;
                }
-               vp = (struct vnode *)fp->f_fglob->fg_data;
-               proc_fdunlock(p);
+
+               vp = fp->fp_glob->fg_data;
+               context.vc_thread = current_thread();
+               context.vc_ucred = fp->fp_glob->fg_cred;
 
                if ((ret = vnode_getwithref(vp)) == 0) {
-                       RAW_file_offset = fp->f_fglob->fg_offset;
+                       RAW_file_offset = fp->fp_glob->fg_offset;
                        if (name[0] == KERN_KDWRITETR || name[0] == KERN_KDWRITETR_V3) {
                                number = nkdbufs * sizeof(kd_buf);
 
@@ -3593,7 +3616,7 @@ kdbg_control(int *name, u_int namelen, user_addr_t where, size_t *sizep)
                                        ret = kdbg_write_thread_map(vp, &context);
                                }
                        }
-                       fp->f_fglob->fg_offset = RAW_file_offset;
+                       fp->fp_glob->fg_offset = RAW_file_offset;
                        vnode_put(vp);
                }
                fp_drop(p, fd, fp, 0);
@@ -3601,7 +3624,7 @@ kdbg_control(int *name, u_int namelen, user_addr_t where, size_t *sizep)
                break;
        }
        case KERN_KDBUFWAIT:
-               *sizep = kdbg_wait(size, FALSE);
+               *sizep = kdbg_wait(size, false);
                break;
 
        case KERN_KDPIDTR:
@@ -3667,7 +3690,7 @@ out:
 int
 kdbg_read(user_addr_t buffer, size_t *number, vnode_t vp, vfs_context_t ctx, uint32_t file_version)
 {
-       unsigned int count;
+       size_t count;
        unsigned int cpu, min_cpu;
        uint64_t barrier_min = 0, barrier_max = 0, t, earliest_time;
        int error = 0;
@@ -3679,14 +3702,14 @@ kdbg_read(user_addr_t buffer, size_t *number, vnode_t vp, vfs_context_t ctx, uin
        struct kd_storage *kdsp_actual;
        struct kd_bufinfo *kdbp;
        struct kd_bufinfo *min_kdbp;
-       uint32_t tempbuf_count;
+       size_t tempbuf_count;
        uint32_t tempbuf_number;
        uint32_t old_kdebug_flags;
        uint32_t old_kdebug_slowcheck;
-       boolean_t out_of_events = FALSE;
-       boolean_t wrapped = FALSE;
+       bool out_of_events = false;
+       bool wrapped = false;
 
-       assert(number);
+       assert(number != NULL);
        count = *number / sizeof(kd_buf);
        *number = 0;
 
@@ -3701,22 +3724,19 @@ kdbg_read(user_addr_t buffer, size_t *number, vnode_t vp, vfs_context_t ctx, uin
        memset(&lostevent, 0, sizeof(lostevent));
        lostevent.debugid = TRACE_LOST_EVENTS;
 
-       /*
-        * Capture the current time. Only sort events that have occured
-        * before now.  Since the IOPs are being flushed here, it is possible
-        * that events occur on the AP while running live tracing. If we are
-        * disabled, no new events should occur on the AP.
-        */
-       if (kd_ctrl_page.enabled) {
-               barrier_max = kdbg_timestamp() & KDBG_TIMESTAMP_MASK;
-       }
-
        /*
         * Request each IOP to provide us with up to date entries before merging
         * buffers together.
         */
        kdbg_iop_list_callback(kd_ctrl_page.kdebug_iops, KD_CALLBACK_SYNC_FLUSH, NULL);
 
+       /*
+        * Capture the current time.  Only sort events that have occured
+        * before now.  Since the IOPs are being flushed here, it is possible
+        * that events occur on the AP while running live tracing.
+        */
+       barrier_max = kdbg_timestamp() & KDBG_TIMESTAMP_MASK;
+
        /*
         * Disable wrap so storage units cannot be stolen out from underneath us
         * while merging events.
@@ -3749,7 +3769,7 @@ kdbg_read(user_addr_t buffer, size_t *number, vnode_t vp, vfs_context_t ctx, uin
                                continue;
                        }
                        kdsp_actual = POINTER_FROM_KDS_PTR(kdsp);
-                       kdsp_actual->kds_lostevents = FALSE;
+                       kdsp_actual->kds_lostevents = false;
                }
        }
        /*
@@ -3771,7 +3791,7 @@ kdbg_read(user_addr_t buffer, size_t *number, vnode_t vp, vfs_context_t ctx, uin
                         */
                        kdbg_set_timestamp_and_cpu(&lostevent, barrier_min, 0);
                        *tempbuf = lostevent;
-                       wrapped = FALSE;
+                       wrapped = false;
                        goto nextevent;
                }
 
@@ -3809,7 +3829,7 @@ next_event:
                                 */
                                if (kdsp_actual->kds_lostevents) {
                                        lostevents = true;
-                                       kdsp_actual->kds_lostevents = FALSE;
+                                       kdsp_actual->kds_lostevents = false;
 
                                        /*
                                         * The earliest event we can trust is the first one in this
@@ -3831,7 +3851,7 @@ next_event:
 
                                t = kdbg_get_timestamp(&kdsp_actual->kds_records[rcursor]);
 
-                               if ((t > barrier_max) && (barrier_max > 0)) {
+                               if (t > barrier_max) {
                                        if (kdbg_debug) {
                                                printf("kdebug: FUTURE EVENT: debugid %#8x: "
                                                    "time %lld from CPU %u "
@@ -3839,12 +3859,7 @@ next_event:
                                                    kdsp_actual->kds_records[rcursor].debugid,
                                                    t, cpu, barrier_max, *number + tempbuf_number);
                                        }
-                                       /*
-                                        * Need to flush IOPs again before we can sort any more
-                                        * data from the buffers.
-                                        */
-                                       out_of_events = TRUE;
-                                       break;
+                                       goto next_cpu;
                                }
                                if (t < kdsp_actual->kds_timestamp) {
                                        /*
@@ -3857,7 +3872,7 @@ next_event:
                                         * Bail out so we don't get out-of-order events by
                                         * continuing to read events from other CPUs' events.
                                         */
-                                       out_of_events = TRUE;
+                                       out_of_events = true;
                                        break;
                                }
 
@@ -3867,6 +3882,13 @@ next_event:
                                 */
                                if (t < barrier_min) {
                                        kdsp_actual->kds_readlast++;
+                                       if (kdbg_debug) {
+                                               printf("kdebug: PAST EVENT: debugid %#8x: "
+                                                   "time %lld from CPU %u "
+                                                   "(barrier at time %lld)\n",
+                                                   kdsp_actual->kds_records[rcursor].debugid,
+                                                   t, cpu, barrier_min);
+                                       }
 
                                        if (kdsp_actual->kds_readlast >= EVENTS_PER_STORAGE_UNIT) {
                                                release_storage_unit(cpu, kdsp.raw);
@@ -3906,7 +3928,7 @@ next_event:
                        }
                        if (min_kdbp == NULL) {
                                /* All buffers ran empty. */
-                               out_of_events = TRUE;
+                               out_of_events = true;
                        }
                        if (out_of_events) {
                                break;
@@ -3933,10 +3955,17 @@ next_event:
                                if (traced_retrograde) {
                                        continue;
                                }
+                               if (kdbg_debug) {
+                                       printf("kdebug: RETRO EVENT: debugid %#8x: "
+                                           "time %lld from CPU %u "
+                                           "(barrier at time %lld)\n",
+                                           kdsp_actual->kds_records[rcursor].debugid,
+                                           t, cpu, barrier_min);
+                               }
 
                                kdbg_set_timestamp_and_cpu(tempbuf, min_kdbp->kd_prev_timebase, kdbg_get_cpu(tempbuf));
                                tempbuf->arg1 = tempbuf->debugid;
-                               tempbuf->arg2 = earliest_time;
+                               tempbuf->arg2 = (kd_buf_argtype)earliest_time;
                                tempbuf->arg3 = 0;
                                tempbuf->arg4 = 0;
                                tempbuf->debugid = TRACE_RETROGRADE_EVENTS;
@@ -4000,7 +4029,7 @@ check_error:
                        count   -= tempbuf_number;
                        *number += tempbuf_number;
                }
-               if (out_of_events == TRUE) {
+               if (out_of_events == true) {
                        /*
                         * all trace buffers are empty
                         */
@@ -4018,13 +4047,37 @@ check_error:
        return error;
 }
 
+#define KDEBUG_TEST_CODE(code) BSDDBG_CODE(DBG_BSD_KDEBUG_TEST, (code))
+
+/*
+ * A test IOP for the SYNC_FLUSH callback.
+ */
+
+static int sync_flush_iop = 0;
+
+static void
+sync_flush_callback(void * __unused context, kd_callback_type reason,
+    void * __unused arg)
+{
+       assert(sync_flush_iop > 0);
+
+       if (reason == KD_CALLBACK_SYNC_FLUSH) {
+               kernel_debug_enter(sync_flush_iop, KDEBUG_TEST_CODE(0xff),
+                   kdbg_timestamp(), 0, 0, 0, 0, 0);
+       }
+}
+
+static struct kd_callback sync_flush_kdcb = {
+       .func = sync_flush_callback,
+       .iop_name = "test_sf",
+};
+
 static int
 kdbg_test(size_t flavor)
 {
        int code = 0;
        int dummy_iop = 0;
 
-#define KDEBUG_TEST_CODE(code) BSDDBG_CODE(DBG_BSD_KDEBUG_TEST, (code))
        switch (flavor) {
        case 1:
                /* try each macro */
@@ -4067,45 +4120,48 @@ kdbg_test(size_t flavor)
 
                /* ensure old timestamps are not emitted from kernel_debug_enter */
                kernel_debug_enter(dummy_iop, KDEBUG_TEST_CODE(code),
-                   100 /* very old timestamp */, 0, 0, 0,
-                   0, (uintptr_t)thread_tid(current_thread()));
+                   100 /* very old timestamp */, 0, 0, 0, 0, 0);
                code++;
                kernel_debug_enter(dummy_iop, KDEBUG_TEST_CODE(code),
-                   kdbg_timestamp(), 0, 0, 0, 0,
-                   (uintptr_t)thread_tid(current_thread()));
+                   kdbg_timestamp(), 0, 0, 0, 0, 0);
                code++;
                break;
 
+       case 3:
+               if (kd_ctrl_page.kdebug_iops) {
+                       dummy_iop = kd_ctrl_page.kdebug_iops[0].cpu_id;
+               }
+               kernel_debug_enter(dummy_iop, KDEBUG_TEST_CODE(code),
+                   kdbg_timestamp() * 2 /* !!! */, 0, 0, 0, 0, 0);
+               break;
+
+       case 4:
+               if (!sync_flush_iop) {
+                       sync_flush_iop = kernel_debug_register_callback(
+                               sync_flush_kdcb);
+                       assert(sync_flush_iop > 0);
+               }
+               break;
+
        default:
                return ENOTSUP;
        }
-#undef KDEBUG_TEST_CODE
 
        return 0;
 }
 
+#undef KDEBUG_TEST_CODE
+
 void
-kdebug_init(unsigned int n_events, char *filter_desc, boolean_t wrapping)
+kdebug_init(unsigned int n_events, char *filter_desc, enum kdebug_opts opts)
 {
        assert(filter_desc != NULL);
 
-#if defined(__x86_64__)
-       /* only trace MACH events when outputting kdebug to serial */
-       if (kdebug_serial) {
-               n_events = 1;
-               if (filter_desc[0] == '\0') {
-                       filter_desc[0] = 'C';
-                       filter_desc[1] = '1';
-                       filter_desc[2] = '\0';
-               }
-       }
-#endif /* defined(__x86_64__) */
-
        if (log_leaks && n_events == 0) {
                n_events = 200000;
        }
 
-       kdebug_trace_start(n_events, filter_desc, wrapping, FALSE);
+       kdebug_trace_start(n_events, filter_desc, opts);
 }
 
 static void
@@ -4124,7 +4180,7 @@ kdbg_set_typefilter_string(const char *filter_desc)
        if (filter_desc[0] >= '0' && filter_desc[0] <= '9') {
                unsigned long csc = strtoul(filter_desc, NULL, 0);
                if (filter_desc != end && csc <= KDBG_CSC_MAX) {
-                       typefilter_allow_csc(kdbg_typefilter, csc);
+                       typefilter_allow_csc(kdbg_typefilter, (uint16_t)csc);
                }
                return;
        }
@@ -4134,35 +4190,36 @@ kdbg_set_typefilter_string(const char *filter_desc)
 
                char filter_type = filter_desc[0];
                if (filter_type != 'C' && filter_type != 'S') {
+                       printf("kdebug: unexpected filter type `%c'\n", filter_type);
                        return;
                }
                filter_desc++;
 
                allow_value = strtoul(filter_desc, &end, 0);
                if (filter_desc == end) {
-                       /* cannot parse as integer */
+                       printf("kdebug: cannot parse `%s' as integer\n", filter_desc);
                        return;
                }
 
                switch (filter_type) {
                case 'C':
-                       if (allow_value <= KDBG_CLASS_MAX) {
-                               typefilter_allow_class(kdbg_typefilter, allow_value);
-                       } else {
-                               /* illegal class */
+                       if (allow_value > KDBG_CLASS_MAX) {
+                               printf("kdebug: class 0x%lx is invalid\n", allow_value);
                                return;
                        }
+                       printf("kdebug: C 0x%lx\n", allow_value);
+                       typefilter_allow_class(kdbg_typefilter, (uint8_t)allow_value);
                        break;
                case 'S':
-                       if (allow_value <= KDBG_CSC_MAX) {
-                               typefilter_allow_csc(kdbg_typefilter, allow_value);
-                       } else {
-                               /* illegal class subclass */
+                       if (allow_value > KDBG_CSC_MAX) {
+                               printf("kdebug: class-subclass 0x%lx is invalid\n", allow_value);
                                return;
                        }
+                       printf("kdebug: S 0x%lx\n", allow_value);
+                       typefilter_allow_csc(kdbg_typefilter, (uint16_t)allow_value);
                        break;
                default:
-                       return;
+                       __builtin_unreachable();
                }
 
                /* advance to next filter entry */
@@ -4173,13 +4230,23 @@ kdbg_set_typefilter_string(const char *filter_desc)
        }
 }
 
+uint64_t
+kdebug_wake(void)
+{
+       if (!wake_nkdbufs) {
+               return 0;
+       }
+       uint64_t start = mach_absolute_time();
+       kdebug_trace_start(wake_nkdbufs, NULL, trace_wrap ? KDOPT_WRAPPING : 0);
+       return mach_absolute_time() - start;
+}
+
 /*
- * This function is meant to be called from the bootstrap thread or coming out
- * of acpi_idle_kernel.
+ * This function is meant to be called from the bootstrap thread or kdebug_wake.
  */
 void
 kdebug_trace_start(unsigned int n_events, const char *filter_desc,
-    boolean_t wrapping, boolean_t at_wake)
+    enum kdebug_opts opts)
 {
        if (!n_events) {
                kd_early_done = true;
@@ -4188,15 +4255,13 @@ kdebug_trace_start(unsigned int n_events, const char *filter_desc,
 
        ktrace_start_single_threaded();
 
-       kdbg_lock_init();
-
        ktrace_kernel_configure(KTRACE_KDEBUG);
 
        kdbg_set_nkdbufs(n_events);
 
        kernel_debug_string_early("start_kern_tracing");
 
-       if (kdbg_reinit(TRUE)) {
+       if (kdbg_reinit((opts & KDOPT_ATBOOT))) {
                printf("error from kdbg_reinit, kernel tracing not started\n");
                goto out;
        }
@@ -4205,7 +4270,7 @@ kdebug_trace_start(unsigned int n_events, const char *filter_desc,
         * Wrapping is disabled because boot and wake tracing is interested in
         * the earliest events, at the expense of later ones.
         */
-       if (!wrapping) {
+       if (!(opts & KDOPT_WRAPPING)) {
                uint32_t old1, old2;
                (void)disable_wrap(&old1, &old2);
        }
@@ -4221,16 +4286,15 @@ kdebug_trace_start(unsigned int n_events, const char *filter_desc,
         * Hold off interrupts between getting a thread map and enabling trace
         * and until the early traces are recorded.
         */
-       boolean_t s = ml_set_interrupts_enabled(FALSE);
+       bool s = ml_set_interrupts_enabled(false);
 
-       if (at_wake) {
+       if (!(opts & KDOPT_ATBOOT)) {
                kdbg_thrmap_init();
        }
 
-       kdbg_set_tracing_enabled(TRUE, KDEBUG_ENABLE_TRACE | (kdebug_serial ?
-           KDEBUG_ENABLE_SERIAL : 0));
+       kdbg_set_tracing_enabled(true, KDEBUG_ENABLE_TRACE);
 
-       if (!at_wake) {
+       if ((opts & KDOPT_ATBOOT)) {
                /*
                 * Transfer all very early events from the static buffer into the real
                 * buffers.
@@ -4240,14 +4304,8 @@ kdebug_trace_start(unsigned int n_events, const char *filter_desc,
 
        ml_set_interrupts_enabled(s);
 
-       printf("kernel tracing started with %u events\n", n_events);
-
-#if KDEBUG_MOJO_TRACE
-       if (kdebug_serial) {
-               printf("serial output enabled with %lu named events\n",
-                   sizeof(kd_events) / sizeof(kd_event_t));
-       }
-#endif /* KDEBUG_MOJO_TRACE */
+       printf("kernel tracing started with %u events, filter = %s\n", n_events,
+           filter_desc ?: "none");
 
 out:
        ktrace_end_single_threaded();
@@ -4311,7 +4369,7 @@ kdbg_dump_trace_to_file(const char *filename)
                .debugid = TRACE_WRITING_EVENTS | DBG_FUNC_END,
                .arg1 = write_size,
                .arg2 = ret,
-               .arg5 = thread_tid(current_thread()),
+               .arg5 = (kd_buf_argtype)thread_tid(current_thread()),
        };
        kdbg_set_timestamp_and_cpu(&end_event, kdbg_timestamp(),
            cpu_number());
@@ -4359,150 +4417,3 @@ SYSCTL_QUAD(_kern_kdbg, OID_AUTO, oldest_time,
     CTLTYPE_QUAD | CTLFLAG_RD | CTLFLAG_LOCKED,
     &kd_ctrl_page.oldest_time,
     "Find the oldest timestamp still in trace");
-
-#if KDEBUG_MOJO_TRACE
-static kd_event_t *
-binary_search(uint32_t id)
-{
-       int low, high, mid;
-
-       low = 0;
-       high = (int)(sizeof(kd_events) / sizeof(kd_event_t)) - 1;
-
-       while (TRUE) {
-               mid = (low + high) / 2;
-
-               if (low > high) {
-                       return NULL; /* failed */
-               } else if (low + 1 >= high) {
-                       /* We have a match */
-                       if (kd_events[high].id == id) {
-                               return &kd_events[high];
-                       } else if (kd_events[low].id == id) {
-                               return &kd_events[low];
-                       } else {
-                               return NULL;  /* search failed */
-                       }
-               } else if (id < kd_events[mid].id) {
-                       high = mid;
-               } else {
-                       low = mid;
-               }
-       }
-}
-
-/*
- * Look up event id to get name string.
- * Using a per-cpu cache of a single entry
- * before resorting to a binary search of the full table.
- */
-#define NCACHE  1
-static kd_event_t       *last_hit[MAX_CPUS];
-static kd_event_t *
-event_lookup_cache(uint32_t cpu, uint32_t id)
-{
-       if (last_hit[cpu] == NULL || last_hit[cpu]->id != id) {
-               last_hit[cpu] = binary_search(id);
-       }
-       return last_hit[cpu];
-}
-
-static uint64_t kd_last_timstamp;
-
-static void
-kdebug_serial_print(
-       uint32_t        cpunum,
-       uint32_t        debugid,
-       uint64_t        timestamp,
-       uintptr_t       arg1,
-       uintptr_t       arg2,
-       uintptr_t       arg3,
-       uintptr_t       arg4,
-       uintptr_t       threadid
-       )
-{
-       char            kprintf_line[192];
-       char            event[40];
-       uint64_t        us = timestamp / NSEC_PER_USEC;
-       uint64_t        us_tenth = (timestamp % NSEC_PER_USEC) / 100;
-       uint64_t        delta = timestamp - kd_last_timstamp;
-       uint64_t        delta_us = delta / NSEC_PER_USEC;
-       uint64_t        delta_us_tenth = (delta % NSEC_PER_USEC) / 100;
-       uint32_t        event_id = debugid & KDBG_EVENTID_MASK;
-       const char      *command;
-       const char      *bra;
-       const char      *ket;
-       kd_event_t      *ep;
-
-       /* event time and delta from last */
-       snprintf(kprintf_line, sizeof(kprintf_line),
-           "%11llu.%1llu %8llu.%1llu ",
-           us, us_tenth, delta_us, delta_us_tenth);
-
-
-       /* event (id or name) - start prefixed by "[", end postfixed by "]" */
-       bra = (debugid & DBG_FUNC_START) ? "[" : " ";
-       ket = (debugid & DBG_FUNC_END)   ? "]" : " ";
-       ep = event_lookup_cache(cpunum, event_id);
-       if (ep) {
-               if (strlen(ep->name) < sizeof(event) - 3) {
-                       snprintf(event, sizeof(event), "%s%s%s",
-                           bra, ep->name, ket);
-               } else {
-                       snprintf(event, sizeof(event), "%s%x(name too long)%s",
-                           bra, event_id, ket);
-               }
-       } else {
-               snprintf(event, sizeof(event), "%s%x%s",
-                   bra, event_id, ket);
-       }
-       snprintf(kprintf_line + strlen(kprintf_line),
-           sizeof(kprintf_line) - strlen(kprintf_line),
-           "%-40s  ", event);
-
-       /* arg1 .. arg4 with special cases for strings */
-       switch (event_id) {
-       case VFS_LOOKUP:
-       case VFS_LOOKUP_DONE:
-               if (debugid & DBG_FUNC_START) {
-                       /* arg1 hex then arg2..arg4 chars */
-                       snprintf(kprintf_line + strlen(kprintf_line),
-                           sizeof(kprintf_line) - strlen(kprintf_line),
-                           "%-16lx %-8s%-8s%-8s                          ",
-                           arg1, (char*)&arg2, (char*)&arg3, (char*)&arg4);
-                       break;
-               }
-       /* else fall through for arg1..arg4 chars */
-       case TRACE_STRING_EXEC:
-       case TRACE_STRING_NEWTHREAD:
-       case TRACE_INFO_STRING:
-               snprintf(kprintf_line + strlen(kprintf_line),
-                   sizeof(kprintf_line) - strlen(kprintf_line),
-                   "%-8s%-8s%-8s%-8s                                   ",
-                   (char*)&arg1, (char*)&arg2, (char*)&arg3, (char*)&arg4);
-               break;
-       default:
-               snprintf(kprintf_line + strlen(kprintf_line),
-                   sizeof(kprintf_line) - strlen(kprintf_line),
-                   "%-16lx %-16lx %-16lx %-16lx",
-                   arg1, arg2, arg3, arg4);
-       }
-
-       /* threadid, cpu and command name */
-       if (threadid == (uintptr_t)thread_tid(current_thread()) &&
-           current_proc() &&
-           current_proc()->p_comm[0]) {
-               command = current_proc()->p_comm;
-       } else {
-               command = "-";
-       }
-       snprintf(kprintf_line + strlen(kprintf_line),
-           sizeof(kprintf_line) - strlen(kprintf_line),
-           "  %-16lx  %-2d %s\n",
-           threadid, cpunum, command);
-
-       kprintf("%s", kprintf_line);
-       kd_last_timstamp = timestamp;
-}
-
-#endif