This is xnu-12377.1.9. See this file in:
/*
* Copyright (c) 2000-2021 Apple Inc. All rights reserved.
*
* @Apple_LICENSE_HEADER_START@
*
* The contents of this file constitute Original Code as defined in and
* are subject to the Apple Public Source License Version 1.1 (the
* "License"). You may not use this file except in compliance with the
* License. Please obtain a copy of the License at
* http://www.apple.com/publicsource and read it before using this file.
*
* This Original Code and all software distributed under the License are
* distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the
* License for the specific language governing rights and limitations
* under the License.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
#include <sys/errno.h>
#include <sys/kdebug_private.h>
#include <sys/proc_internal.h>
#include <sys/vm.h>
#include <sys/sysctl.h>
#include <sys/kdebug_common.h>
#include <sys/kdebug.h>
#include <sys/kdebug_triage.h>
#include <sys/kauth.h>
#include <sys/ktrace.h>
#include <sys/sysproto.h>
#include <sys/bsdtask_info.h>
#include <sys/random.h>
#include <mach/mach_vm.h>
#include <machine/atomic.h>
#include <mach/machine.h>
#include <mach/vm_map.h>
#include <kern/clock.h>
#include <kern/task.h>
#include <kern/debug.h>
#include <kern/kalloc.h>
#include <kern/telemetry.h>
#include <kern/sched_prim.h>
#include <sys/lock.h>
#include <pexpert/device_tree.h>
#include <os/atomic.h>
#include <sys/malloc.h>
#include <sys/vnode.h>
#include <sys/vnode_internal.h>
#include <sys/fcntl.h>
#include <sys/file_internal.h>
#include <sys/ubc.h>
#include <sys/param.h> /* for isset() */
#include <vm/vm_kern_xnu.h>
#include <vm/vm_map_xnu.h>
#include <libkern/OSAtomic.h>
#include <machine/pal_routines.h>
#include <machine/atomic.h>
extern unsigned int wake_nkdbufs;
extern unsigned int trace_wrap;
// Coprocessors (or "IOP"s)
//
// Coprocessors are auxiliary cores that want to participate in kdebug event
// logging. They are registered dynamically, as devices match hardware, and are
// each assigned an ID at registration.
//
// Once registered, a coprocessor is permanent; it cannot be unregistered.
// The current implementation depends on this for thread safety.
//
// The `kd_coprocs` list may be safely walked at any time, without holding
// locks.
//
// When starting a trace session, the current `kd_coprocs` head is captured. Any
// operations that depend on the buffer state (such as flushing IOP traces on
// reads, etc.) should use the captured list head. This will allow registrations
// to take place while trace is in use, though their events will be rejected
// until the next time a trace session is started.
struct kd_coproc {
char full_name[32];
kdebug_coproc_flags_t flags;
kd_callback_t callback;
uint32_t cpu_id;
struct kd_coproc *next;
struct mpsc_queue_chain chain;
};
static struct kd_coproc *kd_coprocs = NULL;
// Use an MPSC queue to notify coprocessors of the current trace state during
// registration, if space is available for them in the current trace session.
static struct mpsc_daemon_queue _coproc_notify_queue;
// Typefilter(s)
//
// A typefilter is a 8KB bitmap that is used to selectively filter events
// being recorded. It is able to individually address every class & subclass.
//
// There is a shared typefilter in the kernel which is lazily allocated. Once
// allocated, the shared typefilter is never deallocated. The shared typefilter
// is also mapped on demand into userspace processes that invoke kdebug_trace
// API from Libsyscall. When mapped into a userspace process, the memory is
// read only, and does not have a fixed address.
//
// It is a requirement that the kernel's shared typefilter always pass DBG_TRACE
// events. This is enforced automatically, by having the needed bits set any
// time the shared typefilter is mutated.
typedef uint8_t *typefilter_t;
static typefilter_t kdbg_typefilter;
static mach_port_t kdbg_typefilter_memory_entry;
/*
* There are 3 combinations of page sizes:
*
* 4KB / 4KB
* 4KB / 16KB
* 16KB / 16KB
*
* The typefilter is exactly 8KB. In the first two scenarios, we would like
* to use 2 pages exactly; in the third scenario we must make certain that
* a full page is allocated so we do not inadvertantly share 8KB of random
* data to userspace. The round_page_32 macro rounds to kernel page size.
*/
#define TYPEFILTER_ALLOC_SIZE MAX(round_page_32(KDBG_TYPEFILTER_BITMAP_SIZE), KDBG_TYPEFILTER_BITMAP_SIZE)
static typefilter_t
typefilter_create(void)
{
typefilter_t tf;
if (KERN_SUCCESS == kmem_alloc(kernel_map, (vm_offset_t*)&tf,
TYPEFILTER_ALLOC_SIZE, KMA_DATA_SHARED | KMA_ZERO, VM_KERN_MEMORY_DIAG)) {
return tf;
}
return NULL;
}
static void
typefilter_deallocate(typefilter_t tf)
{
assert(tf != NULL);
assert(tf != kdbg_typefilter);
kmem_free(kernel_map, (vm_offset_t)tf, TYPEFILTER_ALLOC_SIZE);
}
static void
typefilter_copy(typefilter_t dst, typefilter_t src)
{
assert(src != NULL);
assert(dst != NULL);
memcpy(dst, src, KDBG_TYPEFILTER_BITMAP_SIZE);
}
static void
typefilter_reject_all(typefilter_t tf)
{
assert(tf != NULL);
memset(tf, 0, KDBG_TYPEFILTER_BITMAP_SIZE);
}
static void
typefilter_allow_all(typefilter_t tf)
{
assert(tf != NULL);
memset(tf, ~0, KDBG_TYPEFILTER_BITMAP_SIZE);
}
static void
typefilter_allow_class(typefilter_t tf, uint8_t class)
{
assert(tf != NULL);
const uint32_t BYTES_PER_CLASS = 256 / 8; // 256 subclasses, 1 bit each
memset(&tf[class * BYTES_PER_CLASS], 0xFF, BYTES_PER_CLASS);
}
static void
typefilter_allow_csc(typefilter_t tf, uint16_t csc)
{
assert(tf != NULL);
setbit(tf, csc);
}
static bool
typefilter_is_debugid_allowed(typefilter_t tf, uint32_t id)
{
assert(tf != NULL);
return isset(tf, KDBG_EXTRACT_CSC(id));
}
static mach_port_t
typefilter_create_memory_entry(typefilter_t tf)
{
assert(tf != NULL);
mach_port_t memory_entry = MACH_PORT_NULL;
memory_object_size_t size = TYPEFILTER_ALLOC_SIZE;
kern_return_t kr = mach_make_memory_entry_64(kernel_map,
&size,
(memory_object_offset_t)tf,
VM_PROT_READ,
&memory_entry,
MACH_PORT_NULL);
if (kr != KERN_SUCCESS) {
return MACH_PORT_NULL;
}
return memory_entry;
}
static int kdbg_copyin_typefilter(user_addr_t addr, size_t size);
static void kdbg_enable_typefilter(void);
static void kdbg_disable_typefilter(void);
// External prototypes
void commpage_update_kdebug_state(void);
static int kdbg_readcurthrmap(user_addr_t, size_t *);
static int kdbg_setpidex(kd_regtype *);
static int kdbg_setpid(kd_regtype *);
static int kdbg_reinit(unsigned int extra_cpus);
#if DEVELOPMENT || DEBUG
static int kdbg_test(size_t flavor);
#endif /* DEVELOPMENT || DEBUG */
static int kdbg_copyout_thread_map(user_addr_t buffer, size_t *buffer_size);
static void _clear_thread_map(void);
static bool kdbg_wait(uint64_t timeout_ms);
static void _try_wakeup_waiter(void);
static void _wakeup_waiter(void);
static int _copy_cpu_map(int version, void **dst, size_t *size);
static kd_threadmap *_thread_map_create_live(size_t max_count,
vm_size_t *map_size, vm_size_t *map_count);
static bool kdebug_current_proc_enabled(uint32_t debugid);
static errno_t kdebug_check_trace_string(uint32_t debugid, uint64_t str_id);
#define RAW_FLUSH_SIZE (2 * 1024 * 1024)
__enum_closed_decl(kd_dest_kind_t, uint32_t, {
KD_DEST_COPYOUT = 0x1,
KD_DEST_VFS = 0x2,
});
struct kd_dest {
kd_dest_kind_t kdd_kind;
bool kdd_chunk_format;
off_t kdd_cur_offset;
union {
struct {
user_addr_t kdd_user_buffer;
size_t kdd_user_size;
};
struct {
struct vfs_context kdd_vfs_ctx;
vnode_t kdd_vnode;
off_t kdd_file_written_since_flush;
};
};
};
static inline struct kd_dest
kd_dest_copyout(user_addr_t buf, size_t size)
{
return (struct kd_dest){
.kdd_kind = KD_DEST_COPYOUT,
.kdd_user_buffer = buf,
.kdd_user_size = size,
};
}
static inline int
kd_dest_init_write(struct kd_dest *dest, int fd, struct fileproc **fp_out)
{
dest->kdd_kind = KD_DEST_VFS;
proc_t p = current_proc();
struct fileproc *fp = NULL;
if (fp_get_ftype(p, fd, DTYPE_VNODE, EBADF, &fp)) {
return EBADF;
}
dest->kdd_vnode = fp_get_data(fp);
int error = vnode_getwithref(dest->kdd_vnode);
if (error != 0) {
fp_drop(p, fd, fp, 0);
return error;
}
dest->kdd_vfs_ctx.vc_thread = current_thread();
dest->kdd_vfs_ctx.vc_ucred = fp->fp_glob->fg_cred;
dest->kdd_cur_offset = fp->fp_glob->fg_offset;
*fp_out = fp;
return 0;
}
static inline void
kd_dest_finish_write(struct kd_dest *dest, struct fileproc *fp, int fd)
{
fp->fp_glob->fg_offset = dest->kdd_cur_offset;
vnode_put(dest->kdd_vnode);
fp_drop(current_proc(), fd, fp, 0);
}
static int _send_events(struct kd_dest *dest, const void *src,
size_t event_count);
static int kdbg_write_thread_map(struct kd_dest *dest);
static int _write_legacy_header(bool write_thread_map, struct kd_dest *dest);
extern void IOSleep(int);
unsigned int kdebug_enable = 0;
// A static buffer to record events prior to the start of regular logging.
#define KD_EARLY_BUFFER_SIZE (16 * 1024)
#define KD_EARLY_EVENT_COUNT (KD_EARLY_BUFFER_SIZE / sizeof(kd_buf))
#if defined(__x86_64__)
__attribute__((aligned(KD_EARLY_BUFFER_SIZE)))
static kd_buf kd_early_buffer[KD_EARLY_EVENT_COUNT];
#else /* defined(__x86_64__) */
// 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_EVENT_COUNT];
#endif /* !defined(__x86_64__) */
static __security_const_late unsigned int kd_early_index = 0;
static __security_const_late bool kd_early_overflow = false;
static __security_const_late bool kd_early_done = false;
static bool kd_waiter = false;
static LCK_SPIN_DECLARE(kd_wait_lock, &kdebug_lck_grp);
// Synchronize access to coprocessor list for kdebug trace.
static LCK_SPIN_DECLARE(kd_coproc_spinlock, &kdebug_lck_grp);
#define TRACE_KDCOPYBUF_COUNT 8192
#define TRACE_KDCOPYBUF_SIZE (TRACE_KDCOPYBUF_COUNT * sizeof(kd_buf))
struct kd_control kd_control_trace = {
.kds_free_list = {.raw = KDS_PTR_NULL},
.enabled = 0,
.mode = KDEBUG_MODE_TRACE,
.kdebug_events_per_storage_unit = TRACE_EVENTS_PER_STORAGE_UNIT,
.kdebug_min_storage_units_per_cpu = TRACE_MIN_STORAGE_UNITS_PER_CPU,
.kdebug_kdcopybuf_count = TRACE_KDCOPYBUF_COUNT,
.kdebug_kdcopybuf_size = TRACE_KDCOPYBUF_SIZE,
.kdc_flags = 0,
.kdc_emit = KDEMIT_DISABLE,
.kdc_oldest_time = 0
};
struct kd_buffer kd_buffer_trace = {
.kdb_event_count = 0,
.kdb_storage_count = 0,
.kdb_storage_threshold = 0,
.kdb_region_count = 0,
.kdb_info = NULL,
.kd_bufs = NULL,
.kdcopybuf = NULL
};
unsigned int kdlog_beg = 0;
unsigned int kdlog_end = 0;
unsigned int kdlog_value1 = 0;
unsigned int kdlog_value2 = 0;
unsigned int kdlog_value3 = 0;
unsigned int kdlog_value4 = 0;
kd_threadmap *kd_mapptr = 0;
vm_size_t kd_mapsize = 0;
vm_size_t kd_mapcount = 0;
/*
* A globally increasing counter for identifying strings in trace. Starts at
* 1 because 0 is a reserved return value.
*/
__attribute__((aligned(MAX_CPU_CACHE_LINE_SIZE)))
static uint64_t g_curr_str_id = 1;
#define STR_ID_SIG_OFFSET (48)
#define STR_ID_MASK ((1ULL << STR_ID_SIG_OFFSET) - 1)
#define STR_ID_SIG_MASK (~STR_ID_MASK)
/*
* A bit pattern for identifying string IDs generated by
* kdebug_trace_string(2).
*/
static uint64_t g_str_id_signature = (0x70acULL << STR_ID_SIG_OFFSET);
#define RAW_VERSION3 0x00001000
#define V3_RAW_EVENTS 0x00001e00
static void
_coproc_lock(void)
{
lck_spin_lock_grp(&kd_coproc_spinlock, &kdebug_lck_grp);
}
static void
_coproc_unlock(void)
{
lck_spin_unlock(&kd_coproc_spinlock);
}
static void
_coproc_list_check(void)
{
#if MACH_ASSERT
_coproc_lock();
struct kd_coproc *coproc = kd_control_trace.kdc_coprocs;
if (coproc) {
/* Is list sorted by cpu_id? */
struct kd_coproc* temp = coproc;
do {
assert(!temp->next || temp->next->cpu_id == temp->cpu_id - 1);
assert(temp->next || (temp->cpu_id == kdbg_cpu_count()));
} while ((temp = temp->next));
/* Does each entry have a function and a name? */
temp = coproc;
do {
assert(temp->callback.func);
assert(strlen(temp->callback.iop_name) < sizeof(temp->callback.iop_name));
} while ((temp = temp->next));
}
_coproc_unlock();
#endif // MACH_ASSERT
}
static void
_coproc_list_callback(kd_callback_type type, void *arg)
{
if (kd_control_trace.kdc_flags & KDBG_DISABLE_COPROCS) {
return;
}
_coproc_lock();
// Coprocessor list is only ever prepended to.
struct kd_coproc *head = kd_control_trace.kdc_coprocs;
_coproc_unlock();
while (head) {
head->callback.func(head->callback.context, type, arg);
head = head->next;
}
}
// Leave some extra space for coprocessors to register while tracing is active.
#define EXTRA_COPROC_COUNT (16)
// There are more coprocessors registering during boot tracing.
#define EXTRA_COPROC_COUNT_BOOT (32)
static kdebug_emit_filter_t
_trace_emit_filter(void)
{
if (!kdebug_enable) {
return KDEMIT_DISABLE;
} else if (kd_control_trace.kdc_flags & KDBG_TYPEFILTER_CHECK) {
return KDEMIT_TYPEFILTER;
} else if (kd_control_trace.kdc_flags & KDBG_RANGECHECK) {
return KDEMIT_RANGE;
} else if (kd_control_trace.kdc_flags & KDBG_VALCHECK) {
return KDEMIT_EXACT;
} else {
return KDEMIT_ALL;
}
}
static void
kdbg_set_tracing_enabled(bool enabled, uint32_t trace_type)
{
// Drain any events from coprocessors 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.
_coproc_list_callback(KD_CALLBACK_SYNC_FLUSH, NULL);
if (!enabled) {
// Give coprocessors a chance to log any events before tracing is
// disabled, outside the lock.
_coproc_list_callback(KD_CALLBACK_KDEBUG_DISABLED, NULL);
}
int intrs_en = kdebug_storage_lock(&kd_control_trace);
if (enabled) {
// Latch the status of the user-controlled flags for wrapping.
kd_control_trace.kdc_live_flags = kd_control_trace.kdc_flags & KDBG_NOWRAP;
// The oldest valid time is now; reject past events from coprocessors.
kd_control_trace.kdc_oldest_time = kdebug_timestamp();
kdebug_enable |= trace_type;
kd_control_trace.kdc_emit = _trace_emit_filter();
kd_control_trace.enabled = 1;
commpage_update_kdebug_state();
} else {
kdebug_enable = 0;
kd_control_trace.kdc_emit = KDEMIT_DISABLE;
kd_control_trace.enabled = 0;
commpage_update_kdebug_state();
}
kdebug_storage_unlock(&kd_control_trace, intrs_en);
if (enabled) {
_coproc_list_callback(KD_CALLBACK_KDEBUG_ENABLED, NULL);
}
}
static int
create_buffers_trace(unsigned int extra_cpus)
{
int events_per_storage_unit = kd_control_trace.kdebug_events_per_storage_unit;
int min_storage_units_per_cpu = kd_control_trace.kdebug_min_storage_units_per_cpu;
// For the duration of this allocation, trace code will only reference
// kdc_coprocs.
kd_control_trace.kdc_coprocs = kd_coprocs;
_coproc_list_check();
// If the list is valid, it is sorted from newest to oldest. Each entry is
// prepended, so the CPU IDs are sorted in descending order.
kd_control_trace.kdebug_cpus = kd_control_trace.kdc_coprocs ?
kd_control_trace.kdc_coprocs->cpu_id + 1 : kdbg_cpu_count();
kd_control_trace.alloc_cpus = kd_control_trace.kdebug_cpus + extra_cpus;
size_t min_event_count = kd_control_trace.alloc_cpus *
events_per_storage_unit * min_storage_units_per_cpu;
if (kd_buffer_trace.kdb_event_count < min_event_count) {
kd_buffer_trace.kdb_storage_count = kd_control_trace.alloc_cpus * min_storage_units_per_cpu;
} else {
kd_buffer_trace.kdb_storage_count = kd_buffer_trace.kdb_event_count / events_per_storage_unit;
}
kd_buffer_trace.kdb_event_count = kd_buffer_trace.kdb_storage_count * events_per_storage_unit;
kd_buffer_trace.kd_bufs = NULL;
int error = create_buffers(&kd_control_trace, &kd_buffer_trace,
VM_KERN_MEMORY_DIAG);
if (!error) {
struct kd_bufinfo *info = kd_buffer_trace.kdb_info;
struct kd_coproc *cur_iop = kd_control_trace.kdc_coprocs;
while (cur_iop != NULL) {
info[cur_iop->cpu_id].continuous_timestamps = ISSET(cur_iop->flags,
KDCP_CONTINUOUS_TIME);
cur_iop = cur_iop->next;
}
kd_buffer_trace.kdb_storage_threshold = kd_buffer_trace.kdb_storage_count / 2;
}
return error;
}
static void
delete_buffers_trace(void)
{
delete_buffers(&kd_control_trace, &kd_buffer_trace);
}
static int
_register_coproc_internal(const char *name, kdebug_coproc_flags_t flags,
kd_callback_fn callback, void *context)
{
struct kd_coproc *coproc = NULL;
coproc = zalloc_permanent_type(struct kd_coproc);
coproc->callback.func = callback;
coproc->callback.context = context;
coproc->flags = flags;
strlcpy(coproc->full_name, name, sizeof(coproc->full_name));
_coproc_lock();
coproc->next = kd_coprocs;
coproc->cpu_id = kd_coprocs == NULL ? kdbg_cpu_count() : kd_coprocs->cpu_id + 1;
kd_coprocs = coproc;
if (coproc->cpu_id < kd_control_trace.alloc_cpus) {
kd_control_trace.kdc_coprocs = kd_coprocs;
kd_control_trace.kdebug_cpus += 1;
if (kdebug_enable) {
mpsc_daemon_enqueue(&_coproc_notify_queue, &coproc->chain,
MPSC_QUEUE_NONE);
}
}
_coproc_unlock();
return coproc->cpu_id;
}
int
kernel_debug_register_callback(kd_callback_t callback)
{
// Be paranoid about using the provided name, but it's too late to reject
// it.
bool is_valid_name = false;
for (uint32_t length = 0; length < sizeof(callback.iop_name); ++length) {
if (callback.iop_name[length] > 0x20 && callback.iop_name[length] < 0x7F) {
continue;
}
if (callback.iop_name[length] == 0) {
if (length) {
is_valid_name = true;
}
break;
}
}
kd_callback_t sane_cb = callback;
if (!is_valid_name) {
strlcpy(sane_cb.iop_name, "IOP-???", sizeof(sane_cb.iop_name));
}
return _register_coproc_internal(sane_cb.iop_name, 0, sane_cb.func,
sane_cb.context);
}
int
kdebug_register_coproc(const char *name, kdebug_coproc_flags_t flags,
kd_callback_fn callback, void *context)
{
size_t name_len = strlen(name);
if (!name || name_len == 0) {
panic("kdebug: invalid name for coprocessor: %p", name);
}
for (size_t i = 0; i < name_len; i++) {
if (name[i] <= 0x20 || name[i] >= 0x7F) {
panic("kdebug: invalid name for coprocessor: %s", name);
}
}
if (!callback) {
panic("kdebug: no callback for coprocessor `%s'", name);
}
return _register_coproc_internal(name, flags, callback, context);
}
static inline bool
_should_emit_debugid(kdebug_emit_filter_t emit, uint32_t debugid)
{
switch (emit) {
case KDEMIT_DISABLE:
return false;
case KDEMIT_TYPEFILTER:
return typefilter_is_debugid_allowed(kdbg_typefilter, debugid);
case KDEMIT_RANGE:
return debugid >= kdlog_beg && debugid <= kdlog_end;
case KDEMIT_EXACT:;
uint32_t eventid = debugid & KDBG_EVENTID_MASK;
return eventid == kdlog_value1 || eventid == kdlog_value2 ||
eventid == kdlog_value3 || eventid == kdlog_value4;
case KDEMIT_ALL:
return true;
}
}
static void
_try_wakeup_above_threshold(uint32_t debugid)
{
bool over_threshold = kd_control_trace.kdc_storage_used >=
kd_buffer_trace.kdb_storage_threshold;
if (kd_waiter && over_threshold) {
// Wakeup any waiters if called from a safe context.
const uint32_t INTERRUPT_EVENT = 0x01050000;
const uint32_t VMFAULT_EVENT = 0x01300008;
const uint32_t BSD_SYSCALL_CSC = 0x040c0000;
const uint32_t MACH_SYSCALL_CSC = 0x010c0000;
uint32_t eventid = debugid & KDBG_EVENTID_MASK;
uint32_t csc = debugid & KDBG_CSC_MASK;
if (eventid == INTERRUPT_EVENT || eventid == VMFAULT_EVENT ||
csc == BSD_SYSCALL_CSC || csc == MACH_SYSCALL_CSC) {
_try_wakeup_waiter();
}
}
}
__attribute__((always_inline))
static struct kd_storage *
_next_storage_unit(struct kd_bufinfo *info, unsigned int cpu)
{
struct kd_storage *store = NULL;
do {
bool needs_new_store = true;
union kds_ptr kds_raw = info->kd_list_tail;
if (kds_raw.raw != KDS_PTR_NULL) {
store = POINTER_FROM_KDS_PTR(kd_buffer_trace.kd_bufs, kds_raw);
if (store->kds_bufindx < kd_control_trace.kdebug_events_per_storage_unit) {
needs_new_store = false;
}
}
if (!needs_new_store) {
return store;
}
bool allocated = kdebug_storage_alloc(&kd_control_trace, &kd_buffer_trace, cpu);
if (!allocated) {
// Failed to allocate while wrapping is disabled.
return NULL;
}
} while (true);
}
__attribute__((always_inline))
static kd_buf *
_next_timestamped_coproc_record(unsigned int cpu, uint64_t timestamp)
{
struct kd_bufinfo *info = &kd_buffer_trace.kdb_info[cpu];
bool timestamp_is_continuous = info->continuous_timestamps;
if (kdebug_using_continuous_time()) {
if (!timestamp_is_continuous) {
timestamp = absolutetime_to_continuoustime(timestamp);
}
} else {
if (timestamp_is_continuous) {
timestamp = continuoustime_to_absolutetime(timestamp);
}
}
if (timestamp < kd_control_trace.kdc_oldest_time) {
if (info->latest_past_event_timestamp < timestamp) {
info->latest_past_event_timestamp = timestamp;
}
return NULL;
}
struct kd_storage *store = NULL;
uint32_t store_index = 0;
do {
store = _next_storage_unit(info, cpu);
if (!store) {
return NULL;
}
store_index = store->kds_bufindx;
// Prevent an interrupt from stealing this slot in the storage unit,
// retrying if necessary. No barriers are needed because this only
// concerns visibility on this same CPU.
if (os_atomic_cmpxchg(&store->kds_bufindx, store_index, store_index + 1, relaxed)) {
break;
}
} while (true);
// Make sure kds_timestamp is less than any event in this buffer. This can
// only happen for coprocessors because this field is initialized to the
// current time when a storage unit is allocated by a CPU.
if (timestamp < store->kds_timestamp) {
store->kds_timestamp = timestamp;
}
os_atomic_inc(&store->kds_bufcnt, relaxed);
kd_buf *kd = &store->kds_records[store_index];
kd->timestamp = timestamp;
return kd;
}
__attribute__((always_inline))
static void
_write_trace_record_coproc_nopreempt(
uint64_t timestamp,
uint32_t debugid,
uintptr_t arg1,
uintptr_t arg2,
uintptr_t arg3,
uintptr_t arg4,
uintptr_t arg5,
unsigned int cpu)
{
if (kd_control_trace.enabled == 0) {
return;
}
kd_buf *kd = _next_timestamped_coproc_record(cpu, timestamp);
if (kd) {
kd->debugid = debugid;
kd->arg1 = arg1;
kd->arg2 = arg2;
kd->arg3 = arg3;
kd->arg4 = arg4;
kd->arg5 = arg5;
kd->cpuid = cpu;
}
}
__attribute__((always_inline))
static kd_buf *
_next_timestamped_record(unsigned int cpu)
{
struct kd_bufinfo *info = &kd_buffer_trace.kdb_info[cpu];
struct kd_storage *store = NULL;
uint64_t now = 0;
uint32_t store_index = 0;
do {
store = _next_storage_unit(info, cpu);
if (!store) {
return NULL;
}
store_index = store->kds_bufindx;
// Re-capture the timestamp to ensure time is monotonically-increasing
// within storage units.
now = kdebug_timestamp();
if (os_atomic_cmpxchg(&store->kds_bufindx, store_index, store_index + 1, relaxed)) {
break;
}
} while (true);
os_atomic_inc(&store->kds_bufcnt, relaxed);
kd_buf *kd = &store->kds_records[store_index];
kd->timestamp = now;
return kd;
}
static bool kdebug_debugid_procfilt_allowed(uint32_t debugid);
static void
_write_trace_record(
uint32_t debugid,
uintptr_t arg1,
uintptr_t arg2,
uintptr_t arg3,
uintptr_t arg4,
uintptr_t arg5,
kdebug_emit_flags_t flags)
{
kdebug_emit_filter_t emit = kd_control_trace.kdc_emit;
if (!emit || !kdebug_enable) {
return;
}
bool only_filter = flags & KDBG_FILTER_ONLY;
bool observe_procfilt = !(flags & KDBG_NON_PROCESS);
if (!_should_emit_debugid(emit, debugid)) {
return;
}
if (emit == KDEMIT_ALL && only_filter) {
return;
}
if (!ml_at_interrupt_context() && observe_procfilt &&
!kdebug_debugid_procfilt_allowed(debugid)) {
return;
}
disable_preemption();
if (kd_control_trace.enabled == 0) {
enable_preemption();
return;
}
unsigned int cpu = cpu_number();
kd_buf *kd = _next_timestamped_record(cpu);
if (kd) {
kd->debugid = debugid;
kd->arg1 = arg1;
kd->arg2 = arg2;
kd->arg3 = arg3;
kd->arg4 = arg4;
kd->arg5 = arg5;
kd->cpuid = cpu;
}
enable_preemption();
#if KPERF
kperf_kdebug_callback(debugid, __builtin_frame_address(0));
#endif // KPERF
}
static void
kernel_debug_internal(
uint32_t debugid,
uintptr_t arg1,
uintptr_t arg2,
uintptr_t arg3,
uintptr_t arg4,
uintptr_t arg5,
kdebug_emit_flags_t flags)
{
_write_trace_record(debugid, arg1, arg2, arg3, arg4, arg5, flags);
_try_wakeup_above_threshold(debugid);
}
__attribute__((noinline))
void
kernel_debug(uint32_t debugid, uintptr_t arg1, uintptr_t arg2, uintptr_t arg3,
uintptr_t arg4, __unused uintptr_t arg5)
{
uintptr_t tid = (uintptr_t)thread_tid(current_thread());
kernel_debug_internal(debugid, arg1, arg2, arg3, arg4, tid, 0);
}
__attribute__((noinline))
void
kernel_debug1(uint32_t debugid, uintptr_t arg1, uintptr_t arg2, uintptr_t arg3,
uintptr_t arg4, uintptr_t arg5)
{
kernel_debug_internal(debugid, arg1, arg2, arg3, arg4, arg5, 0);
}
__attribute__((noinline))
void
kernel_debug_flags(
uint32_t debugid,
uintptr_t arg1,
uintptr_t arg2,
uintptr_t arg3,
uintptr_t arg4,
kdebug_emit_flags_t flags)
{
uintptr_t tid = (uintptr_t)thread_tid(current_thread());
kernel_debug_internal(debugid, arg1, arg2, arg3, arg4, tid, flags);
}
__attribute__((noinline))
void
kernel_debug_filtered(
uint32_t debugid,
uintptr_t arg1,
uintptr_t arg2,
uintptr_t arg3,
uintptr_t arg4)
{
kernel_debug_flags(debugid, arg1, arg2, arg3, arg4, KDBG_FILTER_ONLY);
}
void
kernel_debug_string_early(const char *message)
{
uintptr_t a[4] = { 0 };
strncpy((char *)a, message, sizeof(a));
KERNEL_DEBUG_EARLY(TRACE_INFO_STRING, a[0], a[1], a[2], a[3]);
}
// Emit events from coprocessors.
void
kernel_debug_enter(
uint32_t coreid,
uint32_t debugid,
uint64_t timestamp,
uintptr_t arg1,
uintptr_t arg2,
uintptr_t arg3,
uintptr_t arg4,
uintptr_t threadid
)
{
if (kd_control_trace.kdc_flags & KDBG_DISABLE_COPROCS) {
return;
}
if (coreid >= kd_control_trace.kdebug_cpus) {
return;
}
kdebug_emit_filter_t emit = kd_control_trace.kdc_emit;
if (!emit || !kdebug_enable) {
return;
}
if (!_should_emit_debugid(emit, debugid)) {
return;
}
disable_preemption();
_write_trace_record_coproc_nopreempt(timestamp, debugid, arg1, arg2, arg3, arg4, threadid, coreid);
enable_preemption();
}
__pure2
static inline proc_t
kdebug_current_proc_unsafe(void)
{
return get_thread_ro_unchecked(current_thread())->tro_proc;
}
// Return true iff the debug ID should be traced by the current process.
__attribute__((always_inline))
static bool
kdebug_debugid_procfilt_allowed(uint32_t debugid)
{
uint32_t procfilt_flags = kd_control_trace.kdc_flags &
(KDBG_PIDCHECK | KDBG_PIDEXCLUDE);
if (!procfilt_flags) {
return true;
}
// DBG_TRACE and MACH_SCHED tracepoints ignore the process filter.
if ((debugid & KDBG_CSC_MASK) == MACHDBG_CODE(DBG_MACH_SCHED, 0) ||
(KDBG_EXTRACT_CLASS(debugid) == DBG_TRACE)) {
return true;
}
struct proc *curproc = kdebug_current_proc_unsafe();
// If the process is missing (early in boot), allow it.
if (!curproc) {
return true;
}
switch (procfilt_flags) {
case KDBG_PIDCHECK:
return curproc->p_kdebug;
case KDBG_PIDEXCLUDE:
return !curproc->p_kdebug;
default:
panic("kdebug: invalid procfilt flags %x", kd_control_trace.kdc_flags);
}
}
#define SIMPLE_STR_LEN (64)
static_assert(SIMPLE_STR_LEN % sizeof(uintptr_t) == 0);
void
kernel_debug_string_simple(uint32_t eventid, const char *str)
{
if (!kdebug_enable) {
return;
}
/* array of uintptr_ts simplifies emitting the string as arguments */
uintptr_t str_buf[(SIMPLE_STR_LEN / sizeof(uintptr_t)) + 1] = { 0 };
size_t len = strlcpy((char *)str_buf, str, SIMPLE_STR_LEN + 1);
len = MIN(len, SIMPLE_STR_LEN);
uintptr_t thread_id = (uintptr_t)thread_tid(current_thread());
uint32_t debugid = eventid | DBG_FUNC_START;
/* string can fit in a single tracepoint */
if (len <= (4 * sizeof(uintptr_t))) {
debugid |= DBG_FUNC_END;
}
kernel_debug_internal(debugid, str_buf[0], str_buf[1], str_buf[2],
str_buf[3], thread_id, 0);
debugid &= KDBG_EVENTID_MASK;
int i = 4;
size_t written = 4 * sizeof(uintptr_t);
for (; written < len; i += 4, written += 4 * sizeof(uintptr_t)) {
/* if this is the last tracepoint to be emitted */
if ((written + (4 * sizeof(uintptr_t))) >= len) {
debugid |= DBG_FUNC_END;
}
kernel_debug_internal(debugid, str_buf[i], str_buf[i + 1],
str_buf[i + 2], str_buf[i + 3], thread_id, 0);
}
}
extern int master_cpu; /* MACH_KERNEL_PRIVATE */
/*
* Used prior to start_kern_tracing() being called.
* Log temporarily into a static buffer.
*/
void
kernel_debug_early(
uint32_t debugid,
uintptr_t arg1,
uintptr_t arg2,
uintptr_t arg3,
uintptr_t arg4)
{
#if defined(__x86_64__)
extern int early_boot;
/*
* Note that "early" isn't early enough in some cases where
* we're invoked before gsbase is set on x86, hence the
* check of "early_boot".
*/
if (early_boot) {
return;
}
#endif
/* If early tracing is over, use the normal path. */
if (kd_early_done) {
KDBG_RELEASE(debugid, arg1, arg2, arg3, arg4);
return;
}
/* Do nothing if the buffer is full or we're not on the boot cpu. */
kd_early_overflow = kd_early_index >= KD_EARLY_EVENT_COUNT;
if (kd_early_overflow || cpu_number() != master_cpu) {
return;
}
kd_early_buffer[kd_early_index].debugid = debugid;
kd_early_buffer[kd_early_index].timestamp = mach_absolute_time();
kd_early_buffer[kd_early_index].arg1 = arg1;
kd_early_buffer[kd_early_index].arg2 = arg2;
kd_early_buffer[kd_early_index].arg3 = arg3;
kd_early_buffer[kd_early_index].arg4 = arg4;
kd_early_buffer[kd_early_index].arg5 = 0;
kd_early_index++;
}
/*
* Transfer the contents of the temporary buffer into the trace buffers.
* Precede that by logging the rebase time (offset) - the TSC-based time (in ns)
* when mach_absolute_time is set to 0.
*/
static void
kernel_debug_early_end(void)
{
if (cpu_number() != master_cpu) {
panic("kernel_debug_early_end() not call on boot processor");
}
/* reset the current oldest time to allow early events */
kd_control_trace.kdc_oldest_time = 0;
#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 /* defined(__x86_64__) */
for (unsigned int i = 0; i < kd_early_index; i++) {
kernel_debug_enter(0,
kd_early_buffer[i].debugid,
kd_early_buffer[i].timestamp,
kd_early_buffer[i].arg1,
kd_early_buffer[i].arg2,
kd_early_buffer[i].arg3,
kd_early_buffer[i].arg4,
0);
}
/* Cut events-lost event on overflow */
if (kd_early_overflow) {
KDBG_RELEASE(TRACE_LOST_EVENTS, 1);
}
kd_early_done = true;
/* This trace marks the start of kernel tracing */
kernel_debug_string_early("early trace done");
}
void
kernel_debug_disable(void)
{
kdbg_set_tracing_enabled(false, 0);
_wakeup_waiter();
}
// Returns true if debugid should only be traced from the kernel.
static int
_kernel_only_event(uint32_t debugid)
{
return KDBG_EXTRACT_CLASS(debugid) == DBG_TRACE;
}
/*
* Support syscall SYS_kdebug_typefilter.
*/
int
kdebug_typefilter(__unused struct proc* p, struct kdebug_typefilter_args* uap,
__unused int *retval)
{
if (uap->addr == USER_ADDR_NULL || uap->size == USER_ADDR_NULL) {
return EINVAL;
}
mach_vm_offset_t user_addr = 0;
vm_map_t user_map = current_map();
const bool copy = false;
kern_return_t kr = mach_vm_map_kernel(user_map, &user_addr,
TYPEFILTER_ALLOC_SIZE, 0, VM_MAP_KERNEL_FLAGS_ANYWHERE(),
kdbg_typefilter_memory_entry, 0, copy,
VM_PROT_READ, VM_PROT_READ, VM_INHERIT_SHARE);
if (kr != KERN_SUCCESS) {
return mach_to_bsd_errno(kr);
}
vm_size_t user_ptr_size = vm_map_is_64bit(user_map) ? 8 : 4;
int error = copyout((void *)&user_addr, uap->addr, user_ptr_size);
if (error != 0) {
mach_vm_deallocate(user_map, user_addr, TYPEFILTER_ALLOC_SIZE);
}
return error;
}
// Support SYS_kdebug_trace.
int
kdebug_trace(struct proc *p, struct kdebug_trace_args *uap, int32_t *retval)
{
struct kdebug_trace64_args uap64 = {
.code = uap->code,
.arg1 = uap->arg1,
.arg2 = uap->arg2,
.arg3 = uap->arg3,
.arg4 = uap->arg4,
};
return kdebug_trace64(p, &uap64, retval);
}
// Support kdebug_trace(2). 64-bit arguments on K32 will get truncated
// to fit in the 32-bit record format.
//
// It is intentional that error conditions are not checked until kdebug is
// enabled. This is to match the userspace wrapper behavior, which is optimizing
// for non-error case performance.
int
kdebug_trace64(__unused struct proc *p, struct kdebug_trace64_args *uap,
__unused int32_t *retval)
{
if (__probable(kdebug_enable == 0)) {
return 0;
}
if (_kernel_only_event(uap->code)) {
return EPERM;
}
kernel_debug_internal(uap->code, (uintptr_t)uap->arg1, (uintptr_t)uap->arg2,
(uintptr_t)uap->arg3, (uintptr_t)uap->arg4,
(uintptr_t)thread_tid(current_thread()), 0);
return 0;
}
/*
* Adding enough padding to contain a full tracepoint for the last
* portion of the string greatly simplifies the logic of splitting the
* string between tracepoints. Full tracepoints can be generated using
* the buffer itself, without having to manually add zeros to pad the
* arguments.
*/
/* 2 string args in first tracepoint and 9 string data tracepoints */
#define STR_BUF_ARGS (2 + (32 * 4))
/* times the size of each arg on K64 */
#define MAX_STR_LEN (STR_BUF_ARGS * sizeof(uint64_t))
/* on K32, ending straddles a tracepoint, so reserve blanks */
#define STR_BUF_SIZE (MAX_STR_LEN + (2 * sizeof(uint32_t)))
/*
* This function does no error checking and assumes that it is called with
* the correct arguments, including that the buffer pointed to by str is at
* least STR_BUF_SIZE bytes. However, str must be aligned to word-size and
* be NUL-terminated. In cases where a string can fit evenly into a final
* tracepoint without its NUL-terminator, this function will not end those
* strings with a NUL in trace. It's up to clients to look at the function
* qualifier for DBG_FUNC_END in this case, to end the string.
*/
static uint64_t
kernel_debug_string_internal(uint32_t debugid, uint64_t str_id, void *vstr,
size_t str_len)
{
/* str must be word-aligned */
uintptr_t *str = vstr;
size_t written = 0;
uintptr_t thread_id;
int i;
uint32_t trace_debugid = TRACEDBG_CODE(DBG_TRACE_STRING,
TRACE_STRING_GLOBAL);
thread_id = (uintptr_t)thread_tid(current_thread());
/* if the ID is being invalidated, just emit that */
if (str_id != 0 && str_len == 0) {
kernel_debug_internal(trace_debugid | DBG_FUNC_START | DBG_FUNC_END,
(uintptr_t)debugid, (uintptr_t)str_id, 0, 0, thread_id, 0);
return str_id;
}
/* generate an ID, if necessary */
if (str_id == 0) {
str_id = OSIncrementAtomic64((SInt64 *)&g_curr_str_id);
str_id = (str_id & STR_ID_MASK) | g_str_id_signature;
}
trace_debugid |= DBG_FUNC_START;
/* string can fit in a single tracepoint */
if (str_len <= (2 * sizeof(uintptr_t))) {
trace_debugid |= DBG_FUNC_END;
}
kernel_debug_internal(trace_debugid, (uintptr_t)debugid, (uintptr_t)str_id,
str[0], str[1], thread_id, 0);
trace_debugid &= KDBG_EVENTID_MASK;
i = 2;
written += 2 * sizeof(uintptr_t);
for (; written < str_len; i += 4, written += 4 * sizeof(uintptr_t)) {
if ((written + (4 * sizeof(uintptr_t))) >= str_len) {
trace_debugid |= DBG_FUNC_END;
}
kernel_debug_internal(trace_debugid, str[i], str[i + 1], str[i + 2],
str[i + 3], thread_id, 0);
}
return str_id;
}
/*
* Returns true if the current process can emit events, and false otherwise.
* Trace system and scheduling events circumvent this check, as do events
* emitted in interrupt context.
*/
static bool
kdebug_current_proc_enabled(uint32_t debugid)
{
/* can't determine current process in interrupt context */
if (ml_at_interrupt_context()) {
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;
}
if (kd_control_trace.kdc_flags & KDBG_PIDCHECK) {
proc_t cur_proc = kdebug_current_proc_unsafe();
/* only the process with the kdebug bit set is allowed */
if (cur_proc && !(cur_proc->p_kdebug)) {
return false;
}
} else if (kd_control_trace.kdc_flags & KDBG_PIDEXCLUDE) {
proc_t cur_proc = kdebug_current_proc_unsafe();
/* every process except the one with the kdebug bit set is allowed */
if (cur_proc && cur_proc->p_kdebug) {
return false;
}
}
return true;
}
bool
kdebug_debugid_enabled(uint32_t debugid)
{
return _should_emit_debugid(kd_control_trace.kdc_emit, debugid);
}
bool
kdebug_debugid_explicitly_enabled(uint32_t debugid)
{
if (kd_control_trace.kdc_flags & KDBG_TYPEFILTER_CHECK) {
return typefilter_is_debugid_allowed(kdbg_typefilter, debugid);
} else if (KDBG_EXTRACT_CLASS(debugid) == DBG_TRACE) {
return true;
} else if (kd_control_trace.kdc_flags & KDBG_RANGECHECK) {
if (debugid < kdlog_beg || debugid > kdlog_end) {
return false;
}
} else if (kd_control_trace.kdc_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 true;
}
/*
* Returns 0 if a string can be traced with these arguments. Returns errno
* value if error occurred.
*/
static errno_t
kdebug_check_trace_string(uint32_t debugid, uint64_t str_id)
{
if (debugid & (DBG_FUNC_START | DBG_FUNC_END)) {
return EINVAL;
}
if (_kernel_only_event(debugid)) {
return EPERM;
}
if (str_id != 0 && (str_id & STR_ID_SIG_MASK) != g_str_id_signature) {
return EINVAL;
}
return 0;
}
/*
* Implementation of KPI kernel_debug_string.
*/
int
kernel_debug_string(uint32_t debugid, uint64_t *str_id, const char *str)
{
/* arguments to tracepoints must be word-aligned */
__attribute__((aligned(sizeof(uintptr_t)))) char str_buf[STR_BUF_SIZE];
static_assert(sizeof(str_buf) > MAX_STR_LEN);
vm_size_t len_copied;
int err;
assert(str_id);
if (__probable(kdebug_enable == 0)) {
return 0;
}
if (!kdebug_current_proc_enabled(debugid)) {
return 0;
}
if (!kdebug_debugid_enabled(debugid)) {
return 0;
}
if ((err = kdebug_check_trace_string(debugid, *str_id)) != 0) {
return err;
}
if (str == NULL) {
if (str_id == 0) {
return EINVAL;
}
*str_id = kernel_debug_string_internal(debugid, *str_id, NULL, 0);
return 0;
}
memset(str_buf, 0, sizeof(str_buf));
len_copied = strlcpy(str_buf, str, MAX_STR_LEN + 1);
*str_id = kernel_debug_string_internal(debugid, *str_id, str_buf,
len_copied);
return 0;
}
// Support kdebug_trace_string(2).
int
kdebug_trace_string(__unused struct proc *p,
struct kdebug_trace_string_args *uap,
uint64_t *retval)
{
__attribute__((aligned(sizeof(uintptr_t)))) char str_buf[STR_BUF_SIZE];
static_assert(sizeof(str_buf) > MAX_STR_LEN);
size_t len_copied;
int err;
if (__probable(kdebug_enable == 0)) {
return 0;
}
if (!kdebug_current_proc_enabled(uap->debugid)) {
return 0;
}
if (!kdebug_debugid_enabled(uap->debugid)) {
return 0;
}
if ((err = kdebug_check_trace_string(uap->debugid, uap->str_id)) != 0) {
return err;
}
if (uap->str == USER_ADDR_NULL) {
if (uap->str_id == 0) {
return EINVAL;
}
*retval = kernel_debug_string_internal(uap->debugid, uap->str_id,
NULL, 0);
return 0;
}
memset(str_buf, 0, sizeof(str_buf));
err = copyinstr(uap->str, str_buf, MAX_STR_LEN + 1, &len_copied);
/* it's alright to truncate the string, so allow ENAMETOOLONG */
if (err == ENAMETOOLONG) {
str_buf[MAX_STR_LEN] = '\0';
} else if (err) {
return err;
}
if (len_copied <= 1) {
return EINVAL;
}
/* convert back to a length */
len_copied--;
*retval = kernel_debug_string_internal(uap->debugid, uap->str_id, str_buf,
len_copied);
return 0;
}
int
kdbg_reinit(unsigned int extra_cpus)
{
kernel_debug_disable();
// Wait for any event writers to see the disable status.
IOSleep(100);
delete_buffers_trace();
_clear_thread_map();
kd_control_trace.kdc_live_flags &= ~KDBG_WRAPPED;
return create_buffers_trace(extra_cpus);
}
void
kdbg_trace_data(struct proc *proc, long *arg_pid, long *arg_uniqueid)
{
if (proc) {
*arg_pid = proc_getpid(proc);
*arg_uniqueid = (long)proc_uniqueid(proc);
if ((uint64_t)*arg_uniqueid != proc_uniqueid(proc)) {
*arg_uniqueid = 0;
}
} else {
*arg_pid = 0;
*arg_uniqueid = 0;
}
}
void kdebug_proc_name_args(struct proc *proc, long args[static 4]);
void
kdebug_proc_name_args(struct proc *proc, long args[static 4])
{
if (proc) {
strncpy((char *)args, proc_best_name(proc), 4 * sizeof(args[0]));
}
}
static void
_copy_ap_name(unsigned int cpuid, void *dst, size_t size)
{
const char *name = "AP";
#if defined(__arm64__)
const ml_topology_info_t *topology = ml_get_topology_info();
switch (topology->cpus[cpuid].cluster_type) {
case CLUSTER_TYPE_E:
name = "AP-E";
break;
case CLUSTER_TYPE_P:
name = "AP-P";
break;
default:
break;
}
#else /* defined(__arm64__) */
#pragma unused(cpuid)
#endif /* !defined(__arm64__) */
strlcpy(dst, name, size);
}
// Write the specified `map_version` of CPU map to the `dst` buffer, using at
// most `size` bytes. Returns 0 on success and sets `size` to the number of
// bytes written, and either ENOMEM or EINVAL on failure.
//
// If the value pointed to by `dst` is NULL, memory is allocated, and `size` is
// adjusted to the allocated buffer's size.
//
// NB: `coprocs` is used to determine whether the stashed CPU map captured at
// the start of tracing should be used.
static errno_t
_copy_cpu_map(int map_version, void **dst, size_t *size)
{
_coproc_lock();
struct kd_coproc *coprocs = kd_control_trace.kdc_coprocs;
unsigned int cpu_count = kd_control_trace.kdebug_cpus;
_coproc_unlock();
assert(cpu_count != 0);
assert(coprocs == NULL || coprocs[0].cpu_id + 1 == cpu_count);
bool ext = map_version != RAW_VERSION1;
size_t stride = ext ? sizeof(kd_cpumap_ext) : sizeof(kd_cpumap);
size_t size_needed = sizeof(kd_cpumap_header) + cpu_count * stride;
size_t size_avail = *size;
*size = size_needed;
if (*dst == NULL) {
kern_return_t alloc_ret = kmem_alloc(kernel_map, (vm_offset_t *)dst,
(vm_size_t)size_needed, KMA_DATA_SHARED | KMA_ZERO, VM_KERN_MEMORY_DIAG);
if (alloc_ret != KERN_SUCCESS) {
return ENOMEM;
}
} else if (size_avail < size_needed) {
return EINVAL;
}
kd_cpumap_header *header = *dst;
header->version_no = map_version;
header->cpu_count = cpu_count;
void *cpus = &header[1];
size_t name_size = ext ? sizeof(((kd_cpumap_ext *)NULL)->name) :
sizeof(((kd_cpumap *)NULL)->name);
int i = cpu_count - 1;
for (struct kd_coproc *cur_coproc = coprocs; cur_coproc != NULL;
cur_coproc = cur_coproc->next, i--) {
kd_cpumap_ext *cpu = (kd_cpumap_ext *)((uintptr_t)cpus + stride * i);
cpu->cpu_id = cur_coproc->cpu_id;
cpu->flags = KDBG_CPUMAP_IS_IOP;
strlcpy((void *)&cpu->name, cur_coproc->full_name, name_size);
}
for (; i >= 0; i--) {
kd_cpumap *cpu = (kd_cpumap *)((uintptr_t)cpus + stride * i);
cpu->cpu_id = i;
cpu->flags = 0;
_copy_ap_name(i, &cpu->name, name_size);
}
return 0;
}
static void
_threadmap_init(void)
{
ktrace_assert_lock_held();
if (kd_control_trace.kdc_flags & KDBG_MAPINIT) {
return;
}
kd_mapptr = _thread_map_create_live(0, &kd_mapsize, &kd_mapcount);
if (kd_mapptr) {
kd_control_trace.kdc_flags |= KDBG_MAPINIT;
}
}
struct kd_resolver {
kd_threadmap *krs_map;
vm_size_t krs_count;
vm_size_t krs_maxcount;
};
static int
_resolve_iterator(proc_t proc, void *opaque)
{
if (proc == kernproc) {
/* Handled specially as it lacks uthreads. */
return PROC_RETURNED;
}
struct kd_resolver *resolver = opaque;
struct uthread *uth = NULL;
const char *proc_name = proc_best_name(proc);
pid_t pid = proc_getpid(proc);
proc_lock(proc);
TAILQ_FOREACH(uth, &proc->p_uthlist, uu_list) {
if (resolver->krs_count >= resolver->krs_maxcount) {
break;
}
kd_threadmap *map = &resolver->krs_map[resolver->krs_count];
map->thread = (uintptr_t)uthread_tid(uth);
(void)strlcpy(map->command, proc_name, sizeof(map->command));
map->valid = pid;
resolver->krs_count++;
}
proc_unlock(proc);
bool done = resolver->krs_count >= resolver->krs_maxcount;
return done ? PROC_RETURNED_DONE : PROC_RETURNED;
}
static void
_resolve_kernel_task(thread_t thread, void *opaque)
{
struct kd_resolver *resolver = opaque;
if (resolver->krs_count >= resolver->krs_maxcount) {
return;
}
kd_threadmap *map = &resolver->krs_map[resolver->krs_count];
map->thread = (uintptr_t)thread_tid(thread);
(void)strlcpy(map->command, "kernel_task", sizeof(map->command));
map->valid = 1;
resolver->krs_count++;
}
static vm_size_t
_resolve_threads(kd_threadmap *map, vm_size_t nthreads)
{
struct kd_resolver resolver = {
.krs_map = map, .krs_count = 0, .krs_maxcount = nthreads,
};
// Handle kernel_task specially, as it lacks uthreads.
extern void task_act_iterate_wth_args(task_t, void (*)(thread_t, void *),
void *);
task_act_iterate_wth_args(kernel_task, _resolve_kernel_task, &resolver);
proc_iterate(PROC_ALLPROCLIST | PROC_NOWAITTRANS, _resolve_iterator,
&resolver, NULL, NULL);
return resolver.krs_count;
}
static kd_threadmap *
_thread_map_create_live(size_t maxthreads, vm_size_t *mapsize,
vm_size_t *mapcount)
{
kd_threadmap *thread_map = NULL;
assert(mapsize != NULL);
assert(mapcount != NULL);
extern int threads_count;
vm_size_t nthreads = threads_count;
// Allow 25% more threads to be started while iterating processes.
if (os_add_overflow(nthreads, nthreads / 4, &nthreads)) {
return NULL;
}
*mapcount = nthreads;
if (os_mul_overflow(nthreads, sizeof(kd_threadmap), mapsize)) {
return NULL;
}
// 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;
}
// This allocation can be too large for `Z_NOFAIL`.
thread_map = kalloc_data_tag(*mapsize, Z_WAITOK | Z_ZERO,
VM_KERN_MEMORY_DIAG);
if (thread_map != NULL) {
*mapcount = _resolve_threads(thread_map, nthreads);
}
return thread_map;
}
static void
kdbg_clear(void)
{
kernel_debug_disable();
kdbg_disable_typefilter();
// Wait for any event writers to see the disable status.
IOSleep(100);
// Reset kdebug status for each process.
if (kd_control_trace.kdc_flags & (KDBG_PIDCHECK | KDBG_PIDEXCLUDE)) {
proc_list_lock();
proc_t p;
ALLPROC_FOREACH(p) {
p->p_kdebug = 0;
}
proc_list_unlock();
}
kd_control_trace.kdc_flags &= (unsigned int)~KDBG_CKTYPES;
kd_control_trace.kdc_flags &= ~(KDBG_RANGECHECK | KDBG_VALCHECK);
kd_control_trace.kdc_flags &= ~(KDBG_PIDCHECK | KDBG_PIDEXCLUDE);
kd_control_trace.kdc_flags &= ~KDBG_CONTINUOUS_TIME;
kd_control_trace.kdc_flags &= ~KDBG_DISABLE_COPROCS;
kd_control_trace.kdc_flags &= ~KDBG_MATCH_DISABLE;
kd_control_trace.kdc_flags &= ~(KDBG_NOWRAP | KDBG_WRAPPED);
kd_control_trace.kdc_live_flags &= ~(KDBG_NOWRAP | KDBG_WRAPPED);
kd_control_trace.kdc_oldest_time = 0;
delete_buffers_trace();
kd_buffer_trace.kdb_event_count = 0;
_clear_thread_map();
}
void
kdebug_reset(void)
{
ktrace_assert_lock_held();
kdbg_clear();
typefilter_reject_all(kdbg_typefilter);
typefilter_allow_class(kdbg_typefilter, DBG_TRACE);
}
void
kdebug_free_early_buf(void)
{
#if defined(__x86_64__)
ml_static_mfree((vm_offset_t)&kd_early_buffer, sizeof(kd_early_buffer));
#endif /* defined(__x86_64__) */
// ARM handles this as part of the BOOTDATA segment.
}
int
kdbg_setpid(kd_regtype *kdr)
{
pid_t pid;
int flag, ret = 0;
struct proc *p;
pid = (pid_t)kdr->value1;
flag = (int)kdr->value2;
if (pid >= 0) {
if ((p = proc_find(pid)) == NULL) {
ret = ESRCH;
} else {
if (flag == 1) {
/*
* turn on pid check for this and all pids
*/
kd_control_trace.kdc_flags |= KDBG_PIDCHECK;
kd_control_trace.kdc_flags &= ~KDBG_PIDEXCLUDE;
p->p_kdebug = 1;
} else {
/*
* turn off pid check for this pid value
* Don't turn off all pid checking though
*
* kd_control_trace.kdc_flags &= ~KDBG_PIDCHECK;
*/
p->p_kdebug = 0;
}
proc_rele(p);
}
} else {
ret = EINVAL;
}
return ret;
}
/* This is for pid exclusion in the trace buffer */
int
kdbg_setpidex(kd_regtype *kdr)
{
pid_t pid;
int flag, ret = 0;
struct proc *p;
pid = (pid_t)kdr->value1;
flag = (int)kdr->value2;
if (pid >= 0) {
if ((p = proc_find(pid)) == NULL) {
ret = ESRCH;
} else {
if (flag == 1) {
/*
* turn on pid exclusion
*/
kd_control_trace.kdc_flags |= KDBG_PIDEXCLUDE;
kd_control_trace.kdc_flags &= ~KDBG_PIDCHECK;
p->p_kdebug = 1;
} else {
/*
* turn off pid exclusion for this pid value
* Don't turn off all pid exclusion though
*
* kd_control_trace.kdc_flags &= ~KDBG_PIDEXCLUDE;
*/
p->p_kdebug = 0;
}
proc_rele(p);
}
} else {
ret = EINVAL;
}
return ret;
}
/*
* The following functions all operate on the typefilter singleton.
*/
static int
kdbg_copyin_typefilter(user_addr_t addr, size_t size)
{
int ret = ENOMEM;
typefilter_t tf;
ktrace_assert_lock_held();
if (size != KDBG_TYPEFILTER_BITMAP_SIZE) {
return EINVAL;
}
if ((tf = typefilter_create())) {
if ((ret = copyin(addr, tf, KDBG_TYPEFILTER_BITMAP_SIZE)) == 0) {
/* The kernel typefilter must always allow DBG_TRACE */
typefilter_allow_class(tf, DBG_TRACE);
typefilter_copy(kdbg_typefilter, tf);
kdbg_enable_typefilter();
_coproc_list_callback(KD_CALLBACK_TYPEFILTER_CHANGED, kdbg_typefilter);
}
if (tf) {
typefilter_deallocate(tf);
}
}
return ret;
}
/*
* Enable the flags in the control page for the typefilter. Assumes that
* kdbg_typefilter has already been allocated, so events being written
* don't see a bad typefilter.
*/
static void
kdbg_enable_typefilter(void)
{
kd_control_trace.kdc_flags &= ~(KDBG_RANGECHECK | KDBG_VALCHECK);
kd_control_trace.kdc_flags |= KDBG_TYPEFILTER_CHECK;
if (kdebug_enable) {
kd_control_trace.kdc_emit = _trace_emit_filter();
}
commpage_update_kdebug_state();
}
// Disable the flags in the control page for the typefilter. The typefilter
// may be safely deallocated shortly after this function returns.
static void
kdbg_disable_typefilter(void)
{
bool notify_coprocs = kd_control_trace.kdc_flags & KDBG_TYPEFILTER_CHECK;
kd_control_trace.kdc_flags &= ~KDBG_TYPEFILTER_CHECK;
commpage_update_kdebug_state();
if (notify_coprocs) {
// Notify coprocessors that the typefilter will now allow everything.
// Otherwise, they won't know a typefilter is no longer in effect.
typefilter_allow_all(kdbg_typefilter);
_coproc_list_callback(KD_CALLBACK_TYPEFILTER_CHANGED, kdbg_typefilter);
}
}
uint32_t
kdebug_commpage_state(void)
{
uint32_t state = 0;
if (kdebug_enable) {
state |= KDEBUG_COMMPAGE_ENABLE_TRACE;
if (kd_control_trace.kdc_flags & KDBG_TYPEFILTER_CHECK) {
state |= KDEBUG_COMMPAGE_ENABLE_TYPEFILTER;
}
if (kd_control_trace.kdc_flags & KDBG_CONTINUOUS_TIME) {
state |= KDEBUG_COMMPAGE_CONTINUOUS;
}
}
return state;
}
static int
kdbg_setreg(kd_regtype * kdr)
{
switch (kdr->type) {
case KDBG_CLASSTYPE:
kdlog_beg = KDBG_EVENTID(kdr->value1 & 0xff, 0, 0);
kdlog_end = KDBG_EVENTID(kdr->value2 & 0xff, 0, 0);
kd_control_trace.kdc_flags &= ~KDBG_VALCHECK;
kd_control_trace.kdc_flags |= KDBG_RANGECHECK;
break;
case KDBG_SUBCLSTYPE:;
unsigned int cls = kdr->value1 & 0xff;
unsigned int subcls = kdr->value2 & 0xff;
unsigned int subcls_end = subcls + 1;
kdlog_beg = KDBG_EVENTID(cls, subcls, 0);
kdlog_end = KDBG_EVENTID(cls, subcls_end, 0);
kd_control_trace.kdc_flags &= ~KDBG_VALCHECK;
kd_control_trace.kdc_flags |= KDBG_RANGECHECK;
break;
case KDBG_RANGETYPE:
kdlog_beg = kdr->value1;
kdlog_end = kdr->value2;
kd_control_trace.kdc_flags &= ~KDBG_VALCHECK;
kd_control_trace.kdc_flags |= KDBG_RANGECHECK;
break;
case KDBG_VALCHECK:
kdlog_value1 = kdr->value1;
kdlog_value2 = kdr->value2;
kdlog_value3 = kdr->value3;
kdlog_value4 = kdr->value4;
kd_control_trace.kdc_flags &= ~KDBG_RANGECHECK;
kd_control_trace.kdc_flags |= KDBG_VALCHECK;
break;
case KDBG_TYPENONE:
kd_control_trace.kdc_flags &= ~(KDBG_RANGECHECK | KDBG_VALCHECK);
kdlog_beg = 0;
kdlog_end = 0;
break;
default:
return EINVAL;
}
if (kdebug_enable) {
kd_control_trace.kdc_emit = _trace_emit_filter();
}
return 0;
}
static int
_copyin_event_disable_mask(user_addr_t uaddr, size_t usize)
{
if (usize < 2 * sizeof(kd_event_matcher)) {
return ERANGE;
}
int ret = copyin(uaddr, &kd_control_trace.disable_event_match,
sizeof(kd_event_matcher));
if (ret != 0) {
return ret;
}
ret = copyin(uaddr + sizeof(kd_event_matcher),
&kd_control_trace.disable_event_mask, sizeof(kd_event_matcher));
if (ret != 0) {
memset(&kd_control_trace.disable_event_match, 0,
sizeof(kd_event_matcher));
return ret;
}
return 0;
}
static int
_copyout_event_disable_mask(user_addr_t uaddr, size_t usize)
{
if (usize < 2 * sizeof(kd_event_matcher)) {
return ERANGE;
}
int ret = copyout(&kd_control_trace.disable_event_match, uaddr,
sizeof(kd_event_matcher));
if (ret != 0) {
return ret;
}
ret = copyout(&kd_control_trace.disable_event_mask,
uaddr + sizeof(kd_event_matcher), sizeof(kd_event_matcher));
if (ret != 0) {
return ret;
}
return 0;
}
static errno_t
_copyout_cpu_map(int map_version, user_addr_t udst, size_t *usize)
{
if ((kd_control_trace.kdc_flags & KDBG_BUFINIT) == 0) {
return EINVAL;
}
void *cpu_map = NULL;
size_t size = 0;
int error = _copy_cpu_map(map_version, &cpu_map, &size);
if (0 == error) {
if (udst) {
size_t copy_size = MIN(*usize, size);
error = copyout(cpu_map, udst, copy_size);
}
*usize = size;
kmem_free(kernel_map, (vm_offset_t)cpu_map, size);
}
if (EINVAL == error && 0 == udst) {
*usize = size;
// User space only needs the size if it passes NULL;
error = 0;
}
return error;
}
int
kdbg_readcurthrmap(user_addr_t buffer, size_t *bufsize)
{
kd_threadmap *mapptr;
vm_size_t mapsize;
vm_size_t mapcount;
int ret = 0;
size_t count = *bufsize / sizeof(kd_threadmap);
*bufsize = 0;
if ((mapptr = _thread_map_create_live(count, &mapsize, &mapcount))) {
if (copyout(mapptr, buffer, mapcount * sizeof(kd_threadmap))) {
ret = EFAULT;
} else {
*bufsize = (mapcount * sizeof(kd_threadmap));
}
kfree_data(mapptr, mapsize);
} else {
ret = EINVAL;
}
return ret;
}
static void
_clear_thread_map(void)
{
ktrace_assert_lock_held();
if (kd_control_trace.kdc_flags & KDBG_MAPINIT) {
assert(kd_mapptr != NULL);
kfree_data(kd_mapptr, kd_mapsize);
kd_mapptr = NULL;
kd_mapsize = 0;
kd_mapcount = 0;
kd_control_trace.kdc_flags &= ~KDBG_MAPINIT;
}
}
/*
* Write out a version 1 header and the thread map, if it is initialized, to a
* vnode. Used by KDWRITEMAP and kdbg_dump_trace_to_file.
*
* Returns write errors from vn_rdwr if a write fails. Returns ENODATA if the
* thread map has not been initialized, but the header will still be written.
* Returns ENOMEM if padding could not be allocated. Returns 0 otherwise.
*/
static int
kdbg_write_thread_map(struct kd_dest *dest)
{
ktrace_assert_lock_held();
if (dest->kdd_kind != KD_DEST_VFS) {
panic("kdebug: must write thread map to VFS");
}
bool map_initialized = (kd_control_trace.kdc_flags & KDBG_MAPINIT);
int ret = _write_legacy_header(map_initialized, dest);
if (ret == 0) {
if (map_initialized) {
_clear_thread_map();
} else {
ret = ENODATA;
}
}
return ret;
}
/*
* Copy out the thread map to a user space buffer. Used by KDTHRMAP.
*
* Returns copyout errors if the copyout fails. Returns ENODATA if the thread
* map has not been initialized. Returns EINVAL if the buffer provided is not
* large enough for the entire thread map. Returns 0 otherwise.
*/
static int
kdbg_copyout_thread_map(user_addr_t buffer, size_t *buffer_size)
{
bool map_initialized;
size_t map_size;
int ret = 0;
ktrace_assert_lock_held();
assert(buffer_size != NULL);
map_initialized = (kd_control_trace.kdc_flags & KDBG_MAPINIT);
if (!map_initialized) {
return ENODATA;
}
map_size = kd_mapcount * sizeof(kd_threadmap);
if (*buffer_size < map_size) {
return EINVAL;
}
ret = copyout(kd_mapptr, buffer, map_size);
if (ret == 0) {
_clear_thread_map();
}
return ret;
}
static void
kdbg_set_nkdbufs_trace(unsigned int req_nkdbufs_trace)
{
/*
* Only allow allocations of up to half the kernel's data range or "sane
* size", whichever is smaller.
*/
kmem_range_id_t range_id = kmem_needs_data_share_range() ?
KMEM_RANGE_ID_DATA_SHARED : KMEM_RANGE_ID_DATA;
const uint64_t max_nkdbufs_trace_64 =
MIN(kmem_range_id_size(range_id), sane_size) / 2 /
sizeof(kd_buf);
/*
* Can't allocate more than 2^38 (2^32 * 64) bytes of events without
* switching to a 64-bit event count; should be fine.
*/
const unsigned int max_nkdbufs_trace =
(unsigned int)MIN(max_nkdbufs_trace_64, UINT_MAX);
kd_buffer_trace.kdb_event_count = MIN(req_nkdbufs_trace, max_nkdbufs_trace);
}
/*
* Block until there are `kd_buffer_trace.kdb_storage_threshold` storage units filled with
* events or `timeout_ms` milliseconds have passed. If `locked_wait` is true,
* `ktrace_lock` is held while waiting. This is necessary while waiting to
* write events out of the buffers.
*
* Returns true if the threshold was reached and false otherwise.
*
* Called with `ktrace_lock` locked and interrupts enabled.
*/
static bool
kdbg_wait(uint64_t timeout_ms)
{
int wait_result = THREAD_AWAKENED;
uint64_t deadline_mach = 0;
ktrace_assert_lock_held();
if (timeout_ms != 0) {
uint64_t ns = timeout_ms * NSEC_PER_MSEC;
nanoseconds_to_absolutetime(ns, &deadline_mach);
clock_absolutetime_interval_to_deadline(deadline_mach, &deadline_mach);
}
bool s = ml_set_interrupts_enabled(false);
if (!s) {
panic("kdbg_wait() called with interrupts disabled");
}
lck_spin_lock_grp(&kd_wait_lock, &kdebug_lck_grp);
/* drop the mutex to allow others to access trace */
ktrace_unlock();
while (wait_result == THREAD_AWAKENED &&
kd_control_trace.kdc_storage_used < kd_buffer_trace.kdb_storage_threshold) {
kd_waiter = true;
if (deadline_mach) {
wait_result = lck_spin_sleep_deadline(&kd_wait_lock, 0, &kd_waiter,
THREAD_ABORTSAFE, deadline_mach);
} else {
wait_result = lck_spin_sleep(&kd_wait_lock, 0, &kd_waiter,
THREAD_ABORTSAFE);
}
}
bool threshold_exceeded = (kd_control_trace.kdc_storage_used >= kd_buffer_trace.kdb_storage_threshold);
lck_spin_unlock(&kd_wait_lock);
ml_set_interrupts_enabled(s);
ktrace_lock();
return threshold_exceeded;
}
/*
* Wakeup a thread waiting using `kdbg_wait` if there are at least
* `kd_buffer_trace.kdb_storage_threshold` storage units in use.
*/
static void
_try_wakeup_waiter(void)
{
bool need_kds_wakeup = false;
/*
* Try to take the lock here to synchronize with the waiter entering
* the blocked state. Use the try mode to prevent deadlocks caused by
* re-entering this routine due to various trace points triggered in the
* lck_spin_sleep_xxxx routines used to actually enter one of our 2 wait
* conditions. No problem if we fail, there will be lots of additional
* events coming in that will eventually succeed in grabbing this lock.
*/
bool s = ml_set_interrupts_enabled(false);
if (lck_spin_try_lock(&kd_wait_lock)) {
if (kd_waiter &&
(kd_control_trace.kdc_storage_used >= kd_buffer_trace.kdb_storage_threshold)) {
kd_waiter = 0;
need_kds_wakeup = true;
}
lck_spin_unlock(&kd_wait_lock);
}
ml_set_interrupts_enabled(s);
if (need_kds_wakeup == true) {
wakeup(&kd_waiter);
}
}
static void
_wakeup_waiter(void)
{
bool was_waiting = false;
bool s = ml_set_interrupts_enabled(false);
lck_spin_lock(&kd_wait_lock);
if (kd_waiter) {
was_waiting = true;
kd_waiter = 0;
}
lck_spin_unlock(&kd_wait_lock);
ml_set_interrupts_enabled(s);
if (was_waiting) {
wakeup(&kd_waiter);
}
}
static void
_storage_free(struct kd_control *kd_ctrl_page, struct kd_buffer *kd_data_page, int cpu, uint32_t kdsp_raw)
{
struct kd_storage *kdsp_actual;
struct kd_bufinfo *kdbp;
union kds_ptr kdsp;
kdbp = &kd_data_page->kdb_info[cpu];
kdsp.raw = kdsp_raw;
int intrs_en = kdebug_storage_lock(kd_ctrl_page);
if (kdsp.raw == kdbp->kd_list_head.raw) {
/*
* it's possible for the storage unit pointed to
* by kdsp to have already been stolen... so
* check to see if it's still the head of the list
* now that we're behind the lock that protects
* adding and removing from the queue...
* since we only ever release and steal units from
* that position, if it's no longer the head
* we having nothing to do in this context
*/
kdsp_actual = POINTER_FROM_KDS_PTR(kd_data_page->kd_bufs, kdsp);
kdbp->kd_list_head = kdsp_actual->kds_next;
kdsp_actual->kds_next = kd_ctrl_page->kds_free_list;
kd_ctrl_page->kds_free_list = kdsp;
kd_ctrl_page->kdc_storage_used--;
}
kdebug_storage_unlock(kd_ctrl_page, intrs_en);
}
static bool
_reading_set_flags(
struct kd_control *ctl,
kdebug_emit_filter_t *old_emit,
kdebug_live_flags_t *old_live)
{
int intrs_en = kdebug_storage_lock(ctl);
*old_emit = ctl->kdc_emit;
*old_live = ctl->kdc_live_flags;
bool wrapped = ctl->kdc_live_flags & KDBG_WRAPPED;
ctl->kdc_live_flags |= KDBG_NOWRAP;
kdebug_storage_unlock(ctl, intrs_en);
return wrapped;
}
static bool
_reading_restore_flags(
struct kd_control *ctl,
kdebug_emit_filter_t old_emit,
kdebug_live_flags_t old_live)
{
int intrs_en = kdebug_storage_lock(ctl);
bool disabled_during_read = !ctl->enabled;
// The wrapped bit was handled already, by adding a lost-events event, don't
// replace it.
ctl->kdc_live_flags = old_live & ~KDBG_WRAPPED;
bool was_wrapping = (old_live & KDBG_NOWRAP) == 0;
// Only re-enable trace if the reader causes lost events if wrapping was
// previously enabled.
if (was_wrapping && old_emit) {
ctl->kdc_emit = old_emit;
}
kdebug_storage_unlock(ctl, intrs_en);
return disabled_during_read;
}
static inline void
_clear_oldest_lostevents(void)
{
for (unsigned int cpu = 0; cpu < kd_control_trace.kdebug_cpus; cpu++) {
struct kd_bufinfo *info = &kd_buffer_trace.kdb_info[cpu];
union kds_ptr oldest_ptr = info->kd_list_head;
if (oldest_ptr.raw != KDS_PTR_NULL) {
struct kd_storage *store = POINTER_FROM_KDS_PTR(kd_buffer_trace.kd_bufs, oldest_ptr);
store->kds_lostevents = false;
}
}
}
static inline bool
_event_should_disable(kd_buf *event)
{
if ((kd_control_trace.kdc_flags & KDBG_MATCH_DISABLE) == 0) {
return false;
}
kd_event_matcher *match = &kd_control_trace.disable_event_match;
kd_event_matcher *mask = &kd_control_trace.disable_event_mask;
return (event->debugid & mask->kem_debugid) == match->kem_debugid &&
(event->arg1 & mask->kem_args[0]) == match->kem_args[0] &&
(event->arg2 & mask->kem_args[1]) == match->kem_args[1] &&
(event->arg3 & mask->kem_args[2]) == match->kem_args[2] &&
(event->arg4 & mask->kem_args[3]) == match->kem_args[3];
}
static inline struct kd_storage *
_store_read_inc(struct kd_storage *store, struct kd_bufinfo *info,
unsigned int cpu, union kds_ptr *store_ptr)
{
store->kds_readlast++;
if (store->kds_readlast < kd_control_trace.kdebug_events_per_storage_unit) {
return store;
}
_storage_free(&kd_control_trace, &kd_buffer_trace, cpu, store_ptr->raw);
union kds_ptr oldest_ptr = info->kd_list_head;
if (oldest_ptr.raw == KDS_PTR_NULL) {
return NULL;
}
*store_ptr = oldest_ptr;
return POINTER_FROM_KDS_PTR(kd_buffer_trace.kd_bufs, oldest_ptr);
}
static inline uint64_t
_store_earliest_timestamp(
struct kd_storage *store,
uint64_t min,
uint64_t max,
struct kd_bufinfo *info,
unsigned int cpu,
union kds_ptr store_ptr)
{
while (true) {
uint32_t rcursor = store->kds_readlast;
if (rcursor == store->kds_bufindx) {
// Out of events to read on this store.
return UINT64_MAX;
}
uint64_t t = store->kds_records[rcursor].timestamp;
if (t > max) {
return UINT64_MAX;
} else if (__improbable(t < store->kds_timestamp)) {
// This can only happen for coprocessors that haven't
// finished emitting this event, it will be processed the
// next time through.
return UINT64_MAX;
} else if (t >= min) {
return t;
}
// Skip to the next event.
store = _store_read_inc(store, info, cpu, &store_ptr);
if (!store) {
return UINT64_MAX;
}
}
}
static int
_read_trace_events_internal(struct kd_dest *dest, size_t event_count,
uint64_t barrier_max, bool wrapped, bool *should_disable,
size_t *events_written)
{
bool traced_retrograde = false;
bool out_of_events = false;
bool const wrapping_enabled = !(kd_control_trace.kdc_flags & KDBG_NOWRAP);
struct kd_bufinfo *kdbip = kd_buffer_trace.kdb_info;
struct kd_region *kd_bufs = kd_buffer_trace.kd_bufs;
event_count = MIN(event_count, kd_buffer_trace.kdb_event_count);
if (wrapped) {
// If buffers have wrapped, do not emit additional lost events for the
// oldest storage units.
_clear_oldest_lostevents();
}
uint64_t barrier_min = kd_control_trace.kdc_oldest_time;
while (event_count && !out_of_events) {
kd_buf *tempbuf = kd_buffer_trace.kdcopybuf;
uint32_t used_count = 0;
size_t avail_count = MIN(event_count, kd_control_trace.kdebug_kdcopybuf_count);
while (used_count < avail_count) {
bool lostevents = false;
int lostcpu = -1;
uint64_t earliest_time = UINT64_MAX;
int min_cpu = -1;
// Find the earliest event from all the oldest storage units.
for (unsigned int cpu = 0; cpu < kd_control_trace.kdebug_cpus; cpu++) {
struct kd_bufinfo *info = &kdbip[cpu];
union kds_ptr oldest_ptr = info->kd_list_head;
if (oldest_ptr.raw == KDS_PTR_NULL) {
continue;
}
struct kd_storage *store = POINTER_FROM_KDS_PTR(kd_bufs, oldest_ptr);
// If the storage unit was stolen, make sure to emit a lost
// events event with the earliest time to expect an event stream
// with no gaps.
if (__improbable(store->kds_lostevents)) {
store->kds_lostevents = false;
lostevents = true;
uint64_t lost_time = store->kds_records[0].timestamp;
if (kd_control_trace.kdc_oldest_time < lost_time) {
// This time is now the oldest that can be read to
// ensure an event stream with no gaps from this point
// forward.
kd_control_trace.kdc_oldest_time = barrier_min = lost_time;
lostcpu = cpu;
}
continue;
} else if (__improbable(lostevents)) {
// On lost events, just find the latest timestamp of the
// gaps.
continue;
}
uint64_t t = _store_earliest_timestamp(store, barrier_min,
barrier_max, info, cpu, oldest_ptr);
if (t < earliest_time) {
earliest_time = t;
min_cpu = cpu;
}
}
if (lostevents) {
wrapped = false;
// Only emit a lost events event if the user allowed wrapping.
if (wrapping_enabled) {
tempbuf[used_count++] = (kd_buf){
.debugid = TRACE_LOST_EVENTS,
.timestamp = barrier_min,
.cpuid = lostcpu,
.arg1 = 1,
};
}
continue;
}
if (min_cpu == -1) {
out_of_events = true;
break;
}
if (wrapped) {
// Emit a single lost events event in the case of expected
// wrapping.
wrapped = false;
if (wrapping_enabled) {
tempbuf[used_count++] = (kd_buf){
.debugid = TRACE_LOST_EVENTS,
.timestamp = barrier_min,
};
}
}
struct kd_bufinfo *min_info = &kdbip[min_cpu];
union kds_ptr oldest_ptr = min_info->kd_list_head;
struct kd_storage *min_store = POINTER_FROM_KDS_PTR(kd_bufs, oldest_ptr);
kd_buf *earliest_event = &min_store->kds_records[min_store->kds_readlast];
if (__improbable(min_info->latest_past_event_timestamp != 0)) {
if (__improbable(kdbg_debug)) {
printf("kdebug: PAST EVENT: debugid %#8x: "
"time %lld from CPU %u "
"(barrier at time %lld)\n",
earliest_event->debugid,
min_info->latest_past_event_timestamp, min_cpu,
barrier_min);
}
tempbuf[used_count++] = (kd_buf){
.timestamp = earliest_time,
.cpuid = min_cpu,
.arg1 = (kd_buf_argtype)min_info->latest_past_event_timestamp,
.arg2 = 0,
.arg3 = 0,
.arg4 = 0,
.debugid = TRACE_PAST_EVENTS,
};
min_info->latest_past_event_timestamp = 0;
continue;
}
if (__improbable(_event_should_disable(earliest_event))) {
*should_disable = true;
}
tempbuf[used_count] = *earliest_event;
(void)_store_read_inc(min_store, min_info, min_cpu, &oldest_ptr);
if (__improbable(earliest_time < min_info->kd_prev_timebase)) {
if (traced_retrograde) {
continue;
}
traced_retrograde = true;
if (__improbable(kdbg_debug)) {
printf("kdebug: RETRO EVENT: debugid %#8x: "
"time %lld from CPU %u "
"(previous earliest at time %lld)\n",
tempbuf[used_count].debugid,
earliest_time, min_cpu, min_info->kd_prev_timebase);
}
tempbuf[used_count] = (kd_buf){
.timestamp = min_info->kd_prev_timebase,
.cpuid = tempbuf[used_count].cpuid,
.arg1 = tempbuf->debugid,
.arg2 = (kd_buf_argtype)earliest_time,
.arg3 = 0,
.arg4 = 0,
.debugid = TRACE_RETROGRADE_EVENTS,
};
} else {
min_info->kd_prev_timebase = earliest_time;
}
used_count++;
}
if (used_count > 0) {
/*
* Remember the latest timestamp of events that we've merged so we
* don't think we've lost events later.
*/
uint64_t latest_time = tempbuf[used_count - 1].timestamp;
if (kd_control_trace.kdc_oldest_time < latest_time) {
kd_control_trace.kdc_oldest_time = latest_time;
}
int error = _send_events(dest, kd_buffer_trace.kdcopybuf, used_count);
if (error != 0) {
// XXX Why zero this when some events may have been written?
*events_written = 0;
return error;
}
event_count -= used_count;
*events_written += used_count;
}
}
return 0;
}
// Read events from kdebug storage units into a user space buffer or file.
//
// This code runs while events are emitted -- storage unit allocation and
// deallocation will synchronize with the emitters under the storage lock.
// Otherwise, mutual exclusion for this function must be provided by the caller,
// typically using the ktrace lock.
static int
_read_trace_events(struct kd_dest *dest, size_t event_count, size_t *events_written)
{
bool should_disable = false;
int const prev_kdebug_enable = kdebug_enable;
*events_written = 0;
if (!(kd_control_trace.kdc_flags & KDBG_BUFINIT) || kd_buffer_trace.kdcopybuf == NULL) {
return EINVAL;
}
thread_set_eager_preempt(current_thread());
/*
* 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.
*/
uint64_t barrier_max = kdebug_timestamp() & KDBG_TIMESTAMP_MASK;
// Disable wrap so storage units cannot be stolen while inspecting events.
//
// With ktrace_lock held, no other control threads can be modifying
// kdc_flags. The code that emits new events could be running, but
// acquiring new storage units requires holding the storage lock, and it
// looks at the flags there. The only issue is if events are being written
// to the same chunk being read from.
kdebug_emit_filter_t old_emit;
kdebug_live_flags_t old_live_flags;
bool wrapped = _reading_set_flags(&kd_control_trace, &old_emit, &old_live_flags);
bool const no_wrapping = old_live_flags & KDBG_NOWRAP;
int error = _read_trace_events_internal(dest, event_count, barrier_max,
wrapped, &should_disable, events_written);
bool disabled_during_read = _reading_restore_flags(&kd_control_trace, old_emit,
old_live_flags);
should_disable = should_disable || (disabled_during_read && no_wrapping);
thread_clear_eager_preempt(current_thread());
if (should_disable) {
kernel_debug_disable();
} else if (disabled_during_read && !no_wrapping && old_emit) {
kd_control_trace.kdc_emit = old_emit;
kdebug_enable = prev_kdebug_enable;
kd_control_trace.enabled = 1;
commpage_update_kdebug_state();
}
return error;
}
static int
_read_merged_trace_events(struct kd_dest *dest, size_t event_count, size_t *events_written)
{
ktrace_assert_lock_held();
if (event_count == 0 || !(kd_control_trace.kdc_flags & KDBG_BUFINIT) ||
kd_buffer_trace.kdcopybuf == 0) {
*events_written = 0;
return EINVAL;
}
// Before merging, make sure coprocessors have provided up-to-date events.
_coproc_list_callback(KD_CALLBACK_SYNC_FLUSH, NULL);
return _read_trace_events(dest, event_count, events_written);
}
struct event_chunk_header {
uint32_t tag;
uint32_t sub_tag;
uint64_t length;
uint64_t future_events_timestamp;
};
static int
_send_data_vfs(struct kd_dest *dest, const void *src, size_t size)
{
assert(size < INT_MAX);
assert(dest->kdd_kind == KD_DEST_VFS);
return vn_rdwr(UIO_WRITE, dest->kdd_vnode, (caddr_t)(uintptr_t)src,
(int)size, dest->kdd_cur_offset, UIO_SYSSPACE, IO_NODELOCKED | IO_UNIT,
vfs_context_ucred(&dest->kdd_vfs_ctx), (int *) 0,
vfs_context_proc(&dest->kdd_vfs_ctx));
}
static int
_send_data(struct kd_dest *dest, const void *src, size_t size)
{
int error = 0;
switch (dest->kdd_kind) {
case KD_DEST_COPYOUT:
if (size > dest->kdd_user_size - dest->kdd_cur_offset) {
return ERANGE;
}
error = copyout(src, dest->kdd_user_buffer + dest->kdd_cur_offset, size);
break;
case KD_DEST_VFS:
error = _send_data_vfs(dest, src, size);
// XXX Previous code flushed with `VNOP_FSYNC` every 2MB, still needed?
break;
default:
panic("kdebug: unrecognized destination %d", dest->kdd_kind);
}
if (error == 0) {
dest->kdd_cur_offset += size;
}
return error;
}
static int
_send_event_chunk_header(struct kd_dest *dest, size_t event_count)
{
struct event_chunk_header header = {
.tag = V3_RAW_EVENTS,
.sub_tag = 1,
.length = event_count * sizeof(kd_buf),
};
return _send_data(dest, &header, sizeof(header));
}
int
_send_events(struct kd_dest *dest, const void *src, size_t event_count)
{
if (dest->kdd_chunk_format) {
int error = _send_event_chunk_header(dest, event_count);
if (error != 0) {
return error;
}
}
return _send_data(dest, src, event_count * sizeof(kd_buf));
}
static int
_write_legacy_header(bool write_thread_map, struct kd_dest *dest)
{
uint32_t pad_size;
uint32_t extra_thread_count = 0;
uint32_t cpumap_size;
size_t map_size = 0;
uint32_t map_count = 0;
if (write_thread_map) {
assert(kd_control_trace.kdc_flags & KDBG_MAPINIT);
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;
}
}
/*
* Without the buffers initialized, we cannot construct a CPU map or a
* thread map, and cannot write a header.
*/
if (!(kd_control_trace.kdc_flags & KDBG_BUFINIT)) {
return EINVAL;
}
/*
* To write a RAW_VERSION1+ file, we must embed a cpumap in the
* "padding" used to page align the events following the threadmap. If
* the threadmap happens to not require enough padding, we artificially
* increase its footprint until it needs enough padding.
*/
pad_size = 16384 - ((sizeof(RAW_header) + map_size) & PAGE_MASK);
cpumap_size = sizeof(kd_cpumap_header) + kd_control_trace.kdebug_cpus * sizeof(kd_cpumap);
if (cpumap_size > pad_size) {
/* If the cpu map doesn't fit in the current available pad_size,
* we increase the pad_size by 16K. We do this so that the event
* data is always available on a page aligned boundary for both
* 4k and 16k systems. We enforce this alignment for the event
* data so that we can take advantage of optimized file/disk writes.
*/
pad_size += 16384;
}
/* The way we are silently embedding a cpumap in the "padding" is by artificially
* increasing the number of thread entries. However, we'll also need to ensure that
* the cpumap is embedded in the last 4K page before when the event data is expected.
* This way the tools can read the data starting the next page boundary on both
* 4K and 16K systems preserving compatibility with older versions of the tools
*/
if (pad_size > 4096) {
pad_size -= 4096;
extra_thread_count = (pad_size / sizeof(kd_threadmap)) + 1;
}
int error = 0;
do {
clock_sec_t secs;
clock_usec_t usecs;
clock_get_calendar_microtime(&secs, &usecs);
RAW_header header = {
.version_no = RAW_VERSION1,
.thread_count = map_count + extra_thread_count,
.TOD_secs = secs,
.TOD_usecs = usecs,
};
error = _send_data(dest, &header, sizeof(header));
if (error != 0) {
break;
}
if (write_thread_map) {
error = _send_data(dest, kd_mapptr, map_size);
if (error != 0) {
break;
}
}
if (extra_thread_count) {
pad_size = extra_thread_count * sizeof(kd_threadmap);
void *pad_buf = kalloc_data(pad_size, Z_WAITOK | Z_ZERO);
if (!pad_buf) {
error = ENOMEM;
break;
}
error = _send_data(dest, pad_buf, pad_size);
if (error != 0) {
break;
}
}
pad_size = PAGE_SIZE - (dest->kdd_cur_offset & PAGE_MASK);
if (pad_size) {
void *pad_buf = kalloc_data(pad_size, Z_WAITOK | Z_ZERO);
if (!pad_buf) {
error = ENOMEM;
break;
}
/*
* Embed the CPU map in the padding bytes -- old code will skip it,
* while newer code knows it's there.
*/
size_t temp = pad_size;
(void)_copy_cpu_map(RAW_VERSION1, &pad_buf, &temp);
error = _send_data(dest, pad_buf, pad_size);
kfree_data(pad_buf, pad_size);
if (error != 0) {
break;
}
}
} while (false);
return error;
}
#pragma mark - User space interface
static int
_kd_sysctl_internal(int op, int value, user_addr_t where, size_t *sizep)
{
size_t size = *sizep;
kd_regtype kd_Reg;
bool read_only = (op == KERN_KDGETBUF || op == KERN_KDREADCURTHRMAP);
int perm_error = read_only ? ktrace_read_check() :
ktrace_configure(KTRACE_KDEBUG);
if (perm_error != 0) {
return perm_error;
}
switch (op) {
case KERN_KDGETBUF:;
pid_t owning_pid = ktrace_get_owning_pid();
const kbufinfo_t info = {
.nkdbufs = kd_buffer_trace.kdb_event_count,
.nkdthreads = (int)MIN(kd_mapcount, INT_MAX),
.nolog = kd_control_trace.kdc_emit == KDEMIT_DISABLE,
.flags = kd_control_trace.kdc_flags | kd_control_trace.kdc_live_flags | KDBG_LP64,
.bufid = owning_pid ?: -1,
};
size = MIN(size, sizeof(info));
return copyout(&info, where, size);
case KERN_KDREADCURTHRMAP:
return kdbg_readcurthrmap(where, sizep);
case KERN_KDEFLAGS:
value &= KDBG_USERFLAGS;
kd_control_trace.kdc_flags |= value;
return 0;
case KERN_KDDFLAGS:
value &= KDBG_USERFLAGS;
kd_control_trace.kdc_flags &= ~value;
return 0;
case KERN_KDENABLE:
if (value) {
if (!(kd_control_trace.kdc_flags & KDBG_BUFINIT) ||
!(value == KDEBUG_ENABLE_TRACE || value == KDEBUG_ENABLE_PPT)) {
return EINVAL;
}
_threadmap_init();
kdbg_set_tracing_enabled(true, value);
} else {
if (!kdebug_enable) {
return 0;
}
kernel_debug_disable();
}
return 0;
case KERN_KDSETBUF:
kdbg_set_nkdbufs_trace(value);
return 0;
case KERN_KDSETUP:
return kdbg_reinit(EXTRA_COPROC_COUNT);
case KERN_KDREMOVE:
ktrace_reset(KTRACE_KDEBUG);
return 0;
case KERN_KDSETREG:
if (size < sizeof(kd_regtype)) {
return EINVAL;
}
if (copyin(where, &kd_Reg, sizeof(kd_regtype))) {
return EINVAL;
}
return kdbg_setreg(&kd_Reg);
case KERN_KDGETREG:
return EINVAL;
case KERN_KDREADTR: {
struct kd_dest copy_dest = kd_dest_copyout(where, *sizep);
size_t event_count = *sizep / sizeof(kd_buf);
size_t events_written = 0;
int error = _read_merged_trace_events(©_dest, event_count, &events_written);
*sizep = events_written;
return error;
}
case KERN_KDWRITETR:
case KERN_KDWRITETR_V3:
case KERN_KDWRITEMAP: {
struct kd_dest write_dest = {};
int fd = value;
if (op == KERN_KDWRITETR || op == KERN_KDWRITETR_V3) {
(void)kdbg_wait(size);
// Re-check whether this process can configure ktrace, since waiting
// will drop the ktrace lock.
int no_longer_owner_error = ktrace_configure(KTRACE_KDEBUG);
if (no_longer_owner_error != 0) {
return no_longer_owner_error;
}
}
struct fileproc *fp;
int error = kd_dest_init_write(&write_dest, fd, &fp);
if (error != 0) {
return error;
}
if (op == KERN_KDWRITETR || op == KERN_KDWRITETR_V3) {
size_t event_count = kd_buffer_trace.kdb_event_count;
size_t events_written = 0;
if (op == KERN_KDWRITETR_V3) {
write_dest.kdd_chunk_format = true;
}
KDBG_RELEASE(TRACE_WRITING_EVENTS | DBG_FUNC_START);
error = _read_merged_trace_events(&write_dest, event_count,
&events_written);
KDBG_RELEASE(TRACE_WRITING_EVENTS | DBG_FUNC_END, events_written);
*sizep = events_written;
} else {
error = kdbg_write_thread_map(&write_dest);
if (error == 0) {
*sizep = kd_mapcount * sizeof(kd_threadmap);
}
}
kd_dest_finish_write(&write_dest, fp, fd);
return error;
}
case KERN_KDBUFWAIT:
*sizep = kdbg_wait(size);
return 0;
case KERN_KDPIDTR:
if (size < sizeof(kd_regtype)) {
return EINVAL;
}
if (copyin(where, &kd_Reg, sizeof(kd_regtype))) {
return EINVAL;
}
return kdbg_setpid(&kd_Reg);
case KERN_KDPIDEX:
if (size < sizeof(kd_regtype)) {
return EINVAL;
}
if (copyin(where, &kd_Reg, sizeof(kd_regtype))) {
return EINVAL;
}
return kdbg_setpidex(&kd_Reg);
case KERN_KDCPUMAP:
return _copyout_cpu_map(RAW_VERSION1, where, sizep);
case KERN_KDCPUMAP_EXT:
return _copyout_cpu_map(1, where, sizep);
case KERN_KDTHRMAP:
return kdbg_copyout_thread_map(where, sizep);
case KERN_KDSET_TYPEFILTER:
return kdbg_copyin_typefilter(where, size);
case KERN_KDSET_EDM:
return _copyin_event_disable_mask(where, size);
case KERN_KDGET_EDM:
return _copyout_event_disable_mask(where, size);
#if DEVELOPMENT || DEBUG
case KERN_KDTEST:
return kdbg_test(size);
#endif // DEVELOPMENT || DEBUG
default:
return ENOTSUP;
}
}
static int
kdebug_sysctl SYSCTL_HANDLER_ARGS
{
int *names = arg1;
int name_count = arg2;
user_addr_t udst = req->oldptr;
size_t *usize = &req->oldlen;
int value = 0;
if (name_count == 0) {
return ENOTSUP;
}
int op = names[0];
// Some operations have an argument stuffed into the next OID argument.
switch (op) {
case KERN_KDWRITETR:
case KERN_KDWRITETR_V3:
case KERN_KDWRITEMAP:
case KERN_KDEFLAGS:
case KERN_KDDFLAGS:
case KERN_KDENABLE:
case KERN_KDSETBUF:
if (name_count < 2) {
return EINVAL;
}
value = names[1];
break;
default:
break;
}
ktrace_lock();
int ret = _kd_sysctl_internal(op, value, udst, usize);
ktrace_unlock();
if (0 == ret) {
req->oldidx += req->oldlen;
}
return ret;
}
SYSCTL_PROC(_kern, KERN_KDEBUG, kdebug,
CTLTYPE_NODE | CTLFLAG_RD | CTLFLAG_LOCKED, 0, 0, kdebug_sysctl, NULL, "");
#pragma mark - Tests
#if DEVELOPMENT || DEBUG
static int test_coproc = 0;
static int sync_flush_coproc = 0;
#define KDEBUG_TEST_CODE(code) BSDDBG_CODE(DBG_BSD_KDEBUG_TEST, (code))
/*
* A test IOP for the SYNC_FLUSH callback.
*/
static void
sync_flush_callback(void * __unused context, kd_callback_type reason,
void * __unused arg)
{
assert(sync_flush_coproc > 0);
if (reason == KD_CALLBACK_SYNC_FLUSH) {
kernel_debug_enter(sync_flush_coproc, KDEBUG_TEST_CODE(0xff),
kdebug_timestamp(), 0, 0, 0, 0, 0);
}
}
static struct kd_callback sync_flush_kdcb = {
.func = sync_flush_callback,
.iop_name = "test_sf",
};
#define TEST_COPROC_CTX 0xabadcafe
static void
test_coproc_cb(__assert_only void *context, kd_callback_type __unused reason,
void * __unused arg)
{
assert((uintptr_t)context == TEST_COPROC_CTX);
}
static int
kdbg_test(size_t flavor)
{
int code = 0;
int dummy_iop = 0;
switch (flavor) {
case KDTEST_KERNEL_MACROS:
/* try each macro */
KDBG(KDEBUG_TEST_CODE(code)); code++;
KDBG(KDEBUG_TEST_CODE(code), 1); code++;
KDBG(KDEBUG_TEST_CODE(code), 1, 2); code++;
KDBG(KDEBUG_TEST_CODE(code), 1, 2, 3); code++;
KDBG(KDEBUG_TEST_CODE(code), 1, 2, 3, 4); code++;
KDBG_RELEASE(KDEBUG_TEST_CODE(code)); code++;
KDBG_RELEASE(KDEBUG_TEST_CODE(code), 1); code++;
KDBG_RELEASE(KDEBUG_TEST_CODE(code), 1, 2); code++;
KDBG_RELEASE(KDEBUG_TEST_CODE(code), 1, 2, 3); code++;
KDBG_RELEASE(KDEBUG_TEST_CODE(code), 1, 2, 3, 4); code++;
KDBG_FILTERED(KDEBUG_TEST_CODE(code)); code++;
KDBG_FILTERED(KDEBUG_TEST_CODE(code), 1); code++;
KDBG_FILTERED(KDEBUG_TEST_CODE(code), 1, 2); code++;
KDBG_FILTERED(KDEBUG_TEST_CODE(code), 1, 2, 3); code++;
KDBG_FILTERED(KDEBUG_TEST_CODE(code), 1, 2, 3, 4); code++;
KDBG_RELEASE_NOPROCFILT(KDEBUG_TEST_CODE(code)); code++;
KDBG_RELEASE_NOPROCFILT(KDEBUG_TEST_CODE(code), 1); code++;
KDBG_RELEASE_NOPROCFILT(KDEBUG_TEST_CODE(code), 1, 2); code++;
KDBG_RELEASE_NOPROCFILT(KDEBUG_TEST_CODE(code), 1, 2, 3); code++;
KDBG_RELEASE_NOPROCFILT(KDEBUG_TEST_CODE(code), 1, 2, 3, 4); code++;
KDBG_DEBUG(KDEBUG_TEST_CODE(code)); code++;
KDBG_DEBUG(KDEBUG_TEST_CODE(code), 1); code++;
KDBG_DEBUG(KDEBUG_TEST_CODE(code), 1, 2); code++;
KDBG_DEBUG(KDEBUG_TEST_CODE(code), 1, 2, 3); code++;
KDBG_DEBUG(KDEBUG_TEST_CODE(code), 1, 2, 3, 4); code++;
break;
case KDTEST_OLD_TIMESTAMP:
if (kd_control_trace.kdc_coprocs) {
/* avoid the assertion in kernel_debug_enter for a valid IOP */
dummy_iop = kd_control_trace.kdc_coprocs[0].cpu_id;
}
/* 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, 0);
code++;
kernel_debug_enter(dummy_iop, KDEBUG_TEST_CODE(code),
kdebug_timestamp(), 0, 0, 0, 0, 0);
code++;
break;
case KDTEST_FUTURE_TIMESTAMP:
if (kd_control_trace.kdc_coprocs) {
dummy_iop = kd_control_trace.kdc_coprocs[0].cpu_id;
}
kernel_debug_enter(dummy_iop, KDEBUG_TEST_CODE(code),
kdebug_timestamp() * 2 /* !!! */, 0, 0, 0, 0, 0);
break;
case KDTEST_SETUP_IOP:
if (!sync_flush_coproc) {
ktrace_unlock();
int new_sync_flush_coproc = kernel_debug_register_callback(
sync_flush_kdcb);
assert(new_sync_flush_coproc > 0);
ktrace_lock();
if (!sync_flush_coproc) {
sync_flush_coproc = new_sync_flush_coproc;
}
}
break;
case KDTEST_SETUP_COPROCESSOR:
if (!test_coproc) {
ktrace_unlock();
int new_test_coproc = kdebug_register_coproc("test_coproc",
KDCP_CONTINUOUS_TIME, test_coproc_cb, (void *)TEST_COPROC_CTX);
assert(new_test_coproc > 0);
ktrace_lock();
if (!test_coproc) {
test_coproc = new_test_coproc;
}
}
break;
case KDTEST_ABSOLUTE_TIMESTAMP:;
uint64_t atime = mach_absolute_time();
kernel_debug_enter(sync_flush_coproc, KDEBUG_TEST_CODE(0),
atime, (uintptr_t)atime, (uintptr_t)(atime >> 32), 0, 0, 0);
break;
case KDTEST_CONTINUOUS_TIMESTAMP:;
uint64_t ctime = mach_continuous_time();
kernel_debug_enter(test_coproc, KDEBUG_TEST_CODE(1),
ctime, (uintptr_t)ctime, (uintptr_t)(ctime >> 32), 0, 0, 0);
break;
case KDTEST_PAST_EVENT:;
uint64_t old_time = 1;
kernel_debug_enter(test_coproc, KDEBUG_TEST_CODE(1), old_time, 0, 0, 0,
0, 0);
kernel_debug_enter(test_coproc, KDEBUG_TEST_CODE(1), kdebug_timestamp(),
0, 0, 0, 0, 0);
break;
default:
return ENOTSUP;
}
return 0;
}
#undef KDEBUG_TEST_CODE
#endif /* DEVELOPMENT || DEBUG */
static void
_deferred_coproc_notify(mpsc_queue_chain_t e, mpsc_daemon_queue_t queue __unused)
{
struct kd_coproc *coproc = mpsc_queue_element(e, struct kd_coproc, chain);
if (kd_control_trace.kdc_emit == KDEMIT_TYPEFILTER) {
coproc->callback.func(coproc->callback.context,
KD_CALLBACK_TYPEFILTER_CHANGED, kdbg_typefilter);
}
if (kdebug_enable) {
coproc->callback.func(coproc->callback.context,
KD_CALLBACK_KDEBUG_ENABLED, kdbg_typefilter);
}
}
void
kdebug_init(unsigned int n_events, char *filter_desc, enum kdebug_opts opts)
{
assert(filter_desc != NULL);
kdbg_typefilter = typefilter_create();
assert(kdbg_typefilter != NULL);
kdbg_typefilter_memory_entry = typefilter_create_memory_entry(kdbg_typefilter);
assert(kdbg_typefilter_memory_entry != MACH_PORT_NULL);
(void)mpsc_daemon_queue_init_with_thread_call(&_coproc_notify_queue,
_deferred_coproc_notify, THREAD_CALL_PRIORITY_KERNEL,
MPSC_DAEMON_INIT_NONE);
kdebug_trace_start(n_events, filter_desc, opts);
}
static void
kdbg_set_typefilter_string(const char *filter_desc)
{
char *end = NULL;
ktrace_assert_lock_held();
assert(filter_desc != NULL);
typefilter_reject_all(kdbg_typefilter);
typefilter_allow_class(kdbg_typefilter, DBG_TRACE);
/* if the filter description starts with a number, assume it's a csc */
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, (uint16_t)csc);
}
return;
}
while (filter_desc[0] != '\0') {
unsigned long allow_value;
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) {
printf("kdebug: cannot parse `%s' as integer\n", filter_desc);
return;
}
switch (filter_type) {
case 'C':
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) {
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:
__builtin_unreachable();
}
/* advance to next filter entry */
filter_desc = end;
if (filter_desc[0] == ',') {
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 kdebug_wake.
*/
void
kdebug_trace_start(unsigned int n_events, const char *filter_desc,
enum kdebug_opts opts)
{
if (!n_events) {
kd_early_done = true;
return;
}
ktrace_start_single_threaded();
ktrace_kernel_configure(KTRACE_KDEBUG);
kdbg_set_nkdbufs_trace(n_events);
kernel_debug_string_early("start_kern_tracing");
int error = kdbg_reinit(EXTRA_COPROC_COUNT_BOOT);
if (error != 0) {
printf("kdebug: allocation failed, kernel tracing not started: %d\n",
error);
kd_early_done = true;
goto out;
}
/*
* Wrapping is disabled because boot and wake tracing is interested in
* the earliest events, at the expense of later ones.
*/
if ((opts & KDOPT_WRAPPING) == 0) {
kd_control_trace.kdc_flags |= KDBG_NOWRAP;
}
if (filter_desc && filter_desc[0] != '\0') {
kdbg_set_typefilter_string(filter_desc);
kdbg_enable_typefilter();
}
/*
* Hold off interrupts between getting a thread map and enabling trace
* and until the early traces are recorded.
*/
bool s = ml_set_interrupts_enabled(false);
if (!(opts & KDOPT_ATBOOT)) {
_threadmap_init();
}
kdbg_set_tracing_enabled(true, KDEBUG_ENABLE_TRACE);
if ((opts & KDOPT_ATBOOT)) {
/*
* Transfer all very early events from the static buffer into the real
* buffers.
*/
kernel_debug_early_end();
}
ml_set_interrupts_enabled(s);
printf("kernel tracing started with %u events, filter = %s\n", n_events,
filter_desc ?: "none");
out:
ktrace_end_single_threaded();
}
void
kdbg_dump_trace_to_file(const char *filename, bool reenable)
{
vfs_context_t ctx;
vnode_t vp;
int ret;
int reenable_trace = 0;
ktrace_lock();
if (!(kdebug_enable & KDEBUG_ENABLE_TRACE)) {
goto out;
}
if (ktrace_get_owning_pid() != 0) {
/*
* Another process owns ktrace and is still active, disable tracing to
* prevent wrapping.
*/
kdebug_enable = 0;
kd_control_trace.enabled = 0;
commpage_update_kdebug_state();
goto out;
}
KDBG_RELEASE(TRACE_WRITING_EVENTS | DBG_FUNC_START);
reenable_trace = reenable ? kdebug_enable : 0;
kdebug_enable = 0;
kd_control_trace.enabled = 0;
commpage_update_kdebug_state();
ctx = vfs_context_kernel();
if (vnode_open(filename, (O_CREAT | FWRITE | O_NOFOLLOW), 0600, 0, &vp, ctx)) {
goto out;
}
struct kd_dest file_dest = {
.kdd_kind = KD_DEST_VFS,
.kdd_vnode = vp,
.kdd_vfs_ctx = *ctx,
};
kdbg_write_thread_map(&file_dest);
size_t events_written = 0;
ret = _read_merged_trace_events(&file_dest, kd_buffer_trace.kdb_event_count,
&events_written);
if (ret) {
goto out_close;
}
/*
* Wait to synchronize the file to capture the I/O in the
* TRACE_WRITING_EVENTS interval.
*/
ret = VNOP_FSYNC(vp, MNT_WAIT, ctx);
if (ret == KERN_SUCCESS) {
ret = VNOP_IOCTL(vp, F_FULLFSYNC, (caddr_t)NULL, 0, ctx);
}
/*
* Balance the starting TRACE_WRITING_EVENTS tracepoint manually.
*/
kd_buf end_event = {
.debugid = TRACE_WRITING_EVENTS | DBG_FUNC_END,
.arg1 = events_written,
.arg2 = ret,
.arg5 = (kd_buf_argtype)thread_tid(current_thread()),
.timestamp = kdebug_timestamp(),
.cpuid = cpu_number(),
};
/* this is best effort -- ignore any errors */
(void)_send_data_vfs(&file_dest, &end_event, sizeof(kd_buf));
out_close:
vnode_close(vp, FWRITE, ctx);
sync(current_proc(), (void *)NULL, (int *)NULL);
out:
if (reenable_trace != 0) {
kdebug_enable = reenable_trace;
kd_control_trace.enabled = 1;
commpage_update_kdebug_state();
}
ktrace_unlock();
}
SYSCTL_NODE(_kern, OID_AUTO, kdbg, CTLFLAG_RD | CTLFLAG_LOCKED, 0,
"kdbg");
SYSCTL_INT(_kern_kdbg, OID_AUTO, debug,
CTLFLAG_RW | CTLFLAG_LOCKED,
&kdbg_debug, 0, "Set kdebug debug mode");
SYSCTL_QUAD(_kern_kdbg, OID_AUTO, oldest_time,
CTLTYPE_QUAD | CTLFLAG_RD | CTLFLAG_LOCKED,
&kd_control_trace.kdc_oldest_time,
"Find the oldest timestamp still in trace");