libkern/os/log.c

   1 #include <stddef.h>
   2 #undef offset
   3
   4 #include <kern/cpu_data.h>
   5 #include <os/base.h>
   6 #include <os/object.h>
   7 #include <os/log.h>
   8 #include <stdbool.h>
   9 #include <stdint.h>
  10
  11 #include <vm/vm_kern.h>
  12 #include <mach/vm_statistics.h>
  13 #include <kern/debug.h>
  14 #include <libkern/libkern.h>
  15 #include <libkern/kernel_mach_header.h>
  16 #include <pexpert/pexpert.h>
  17 #include <uuid/uuid.h>
  18 #include <sys/msgbuf.h>
  19
  20 #include <mach/mach_time.h>
  21 #include <kern/thread.h>
  22 #include <kern/simple_lock.h>
  23 #include <kern/kalloc.h>
  24 #include <kern/clock.h>
  25 #include <kern/assert.h>
  26
  27 #include <firehose/tracepoint_private.h>
  28 #include <firehose/chunk_private.h>
  29 #include <os/firehose_buffer_private.h>
  30 #include <os/firehose.h>
  31
  32 #include <os/log_private.h>
  33 #include "trace_internal.h"
  34
  35 #include "log_encode.h"
  36
  37 struct os_log_s {
  38         int a;
  39 };
  40
  41 struct os_log_s _os_log_default;
  42 struct os_log_s _os_log_replay;
  43 extern vm_offset_t kernel_firehose_addr;
  44 extern firehose_chunk_t firehose_boot_chunk;
  45
  46 extern void bsd_log_lock(void);
  47 extern void bsd_log_unlock(void);
  48 extern void logwakeup(void);
  49
  50 decl_lck_spin_data(extern, oslog_stream_lock)
  51 extern void oslog_streamwakeup(void);
  52 void oslog_streamwrite_locked(firehose_tracepoint_id_u ftid,
  53                 uint64_t stamp, const void *pubdata, size_t publen);
  54 extern void oslog_streamwrite_metadata_locked(oslog_stream_buf_entry_t m_entry);
  55
  56 extern int oslog_stream_open;
  57
  58 extern void *OSKextKextForAddress(const void *);
  59
  60 /* Counters for persistence mode */
  61 uint32_t oslog_p_total_msgcount = 0;
  62 uint32_t oslog_p_metadata_saved_msgcount = 0;
  63 uint32_t oslog_p_metadata_dropped_msgcount = 0;
  64 uint32_t oslog_p_error_count = 0;
  65 uint32_t oslog_p_saved_msgcount = 0;
  66 uint32_t oslog_p_dropped_msgcount = 0;
  67 uint32_t oslog_p_boot_dropped_msgcount = 0;
  68
  69 /* Counters for streaming mode */
  70 uint32_t oslog_s_total_msgcount = 0;
  71 uint32_t oslog_s_error_count = 0;
  72 uint32_t oslog_s_metadata_msgcount = 0;
  73
  74 static bool oslog_boot_done = false;
  75 extern boolean_t early_boot_complete;
  76
  77 #ifdef XNU_KERNEL_PRIVATE
  78 bool startup_serial_logging_active = true;
  79 uint64_t startup_serial_num_procs = 300;
  80 #endif /* XNU_KERNEL_PRIVATE */
  81
  82 // XXX
  83 firehose_tracepoint_id_t
  84 firehose_debug_trace(firehose_stream_t stream, firehose_tracepoint_id_t trace_id,
  85                 uint64_t timestamp, const char *format, const void *pubdata, size_t publen);
  86
  87 static inline firehose_tracepoint_id_t
  88 _firehose_trace(firehose_stream_t stream, firehose_tracepoint_id_u ftid,
  89                 uint64_t stamp, const void *pubdata, size_t publen);
  90
  91 static oslog_stream_buf_entry_t
  92 oslog_stream_create_buf_entry(oslog_stream_link_type_t type, firehose_tracepoint_id_u ftid,
  93                                 uint64_t stamp, const void* pubdata, size_t publen);
  94
  95 static void
  96 _os_log_with_args_internal(os_log_t oslog __unused, os_log_type_t type __unused,
  97                 const char *format, va_list args, void *addr, void *dso);
  98
  99 static void
 100 _os_log_to_msgbuf_internal(const char *format, va_list args, bool safe, bool logging);
 101
 102 static void
 103 _os_log_to_log_internal(os_log_t oslog, os_log_type_t type,
 104                 const char *format, va_list args, void *addr, void *dso);
 105
 106
 107 static void
 108 _os_log_actual(os_log_t oslog, os_log_type_t type, const char *format, void
 109                 *dso, void *addr, os_log_buffer_context_t context);
 110
 111 bool
 112 os_log_info_enabled(os_log_t log __unused)
 113 {
 114         return true;
 115 }
 116
 117 bool
 118 os_log_debug_enabled(os_log_t log __unused)
 119 {
 120         return true;
 121 }
 122
 123 os_log_t
 124 os_log_create(const char *subsystem __unused, const char *category __unused)
 125 {
 126         return &_os_log_default;
 127 }
 128
 129 bool
 130 _os_log_string_is_public(const char *str __unused)
 131 {
 132         return true;
 133 }
 134
 135 __attribute__((noinline,not_tail_called)) void
 136 _os_log_internal(void *dso, os_log_t log, uint8_t type, const char *message, ...)
 137 {
 138     va_list args;
 139     void *addr = __builtin_return_address(0);
 140
 141     va_start(args, message);
 142
 143     _os_log_with_args_internal(log, type, message, args, addr, dso);
 144
 145     va_end(args);
 146
 147     return;
 148 }
 149
 150 #pragma mark - shim functions
 151
 152 __attribute__((noinline,not_tail_called)) void
 153 os_log_with_args(os_log_t oslog, os_log_type_t type, const char *format, va_list args, void *addr)
 154 {
 155     // if no address passed, look it up
 156     if (addr == NULL) {
 157         addr = __builtin_return_address(0);
 158     }
 159
 160     _os_log_with_args_internal(oslog, type, format, args, addr, NULL);
 161 }
 162
 163 static void
 164 _os_log_with_args_internal(os_log_t oslog, os_log_type_t type,
 165                 const char *format, va_list args, void *addr, void *dso)
 166 {
 167     uint32_t  logging_config = atm_get_diagnostic_config();
 168     boolean_t safe;
 169     boolean_t logging;
 170
 171     if (format[0] == '\0') {
 172         return;
 173     }
 174
 175     /* early boot can log to dmesg for later replay (27307943) */
 176     safe = (!early_boot_complete || oslog_is_safe());
 177
 178         if (logging_config & ATM_TRACE_DISABLE || logging_config & ATM_TRACE_OFF) {
 179                 logging = false;
 180         } else {
 181                 logging = true;
 182         }
 183
 184     if (oslog != &_os_log_replay) {
 185         _os_log_to_msgbuf_internal(format, args, safe, logging);
 186     }
 187
 188     if (safe && logging) {
 189         _os_log_to_log_internal(oslog, type, format, args, addr, dso);
 190     }
 191 }
 192
 193 static void
 194 _os_log_to_msgbuf_internal(const char *format, va_list args, bool safe, bool logging)
 195 {
 196     static int msgbufreplay = -1;
 197     va_list args_copy;
 198
 199     bsd_log_lock();
 200
 201     if (!safe) {
 202         if (-1 == msgbufreplay) msgbufreplay = msgbufp->msg_bufx;
 203     } else if (logging && (-1 != msgbufreplay)) {
 204         uint32_t i;
 205         uint32_t localbuff_size;
 206         int newl, position;
 207         char *localbuff, *p, *s, *next, ch;
 208
 209         position = msgbufreplay;
 210         msgbufreplay = -1;
 211         localbuff_size = (msgbufp->msg_size + 2); /* + '\n' + '\0' */
 212         /* Size for non-blocking */
 213         if (localbuff_size > 4096) localbuff_size = 4096;
 214         bsd_log_unlock();
 215         /* Allocate a temporary non-circular buffer */
 216         if ((localbuff = (char *)kalloc_noblock(localbuff_size))) {
 217             /* in between here, the log could become bigger, but that's fine */
 218             bsd_log_lock();
 219             /*
 220              * The message buffer is circular; start at the replay pointer, and
 221              * make one loop up to write pointer - 1.
 222              */
 223             p = msgbufp->msg_bufc + position;
 224             for (i = newl = 0; p != msgbufp->msg_bufc + msgbufp->msg_bufx - 1; ++p) {
 225                 if (p >= msgbufp->msg_bufc + msgbufp->msg_size)
 226                     p = msgbufp->msg_bufc;
 227                 ch = *p;
 228                 if (ch == '\0') continue;
 229                 newl = (ch == '\n');
 230                 localbuff[i++] = ch;
 231                 if (i >= (localbuff_size - 2)) break;
 232             }
 233             bsd_log_unlock();
 234
 235             if (!newl) localbuff[i++] = '\n';
 236             localbuff[i++] = 0;
 237
 238             s = localbuff;
 239             while ((next = strchr(s, '\n'))) {
 240                 next++;
 241                 ch = next[0];
 242                 next[0] = 0;
 243                 os_log(&_os_log_replay, "%s", s);
 244                 next[0] = ch;
 245                 s = next;
 246             }
 247             kfree(localbuff, localbuff_size);
 248         }
 249         bsd_log_lock();
 250     }
 251
 252     va_copy(args_copy, args);
 253     vprintf_log_locked(format, args_copy);
 254     va_end(args_copy);
 255
 256     bsd_log_unlock();
 257
 258     if (safe) logwakeup();
 259 }
 260
 261 static void
 262 _os_log_to_log_internal(os_log_t oslog, os_log_type_t type,
 263                 const char *format, va_list args, void *addr, void *dso)
 264 {
 265     struct os_log_buffer_context_s context;
 266     unsigned char buffer_data[OS_LOG_BUFFER_MAX_SIZE] __attribute__((aligned(8)));
 267     os_log_buffer_t buffer = (os_log_buffer_t)buffer_data;
 268     uint8_t pubdata[OS_LOG_BUFFER_MAX_SIZE];
 269     va_list args_copy;
 270
 271     if (dso == NULL) {
 272         dso = (void *) OSKextKextForAddress(format);
 273         if (dso == NULL) {
 274             return;
 275         }
 276     }
 277
 278     if (!_os_trace_addr_in_text_segment(dso, format)) {
 279         return;
 280     }
 281
 282     if (addr == NULL) {
 283         return;
 284     }
 285
 286     void *dso_addr = (void *) OSKextKextForAddress(addr);
 287     if (dso != dso_addr) {
 288         return;
 289     }
 290
 291     memset(&context, 0, sizeof(context));
 292     memset(buffer, 0, OS_LOG_BUFFER_MAX_SIZE);
 293
 294     context.shimmed = true;
 295     context.buffer = buffer;
 296     context.content_sz = OS_LOG_BUFFER_MAX_SIZE - sizeof(*buffer);
 297     context.pubdata = pubdata;
 298     context.pubdata_sz = sizeof(pubdata);
 299
 300     va_copy(args_copy, args);
 301
 302     (void)hw_atomic_add(&oslog_p_total_msgcount, 1);
 303     if (_os_log_encode(format, args_copy, 0, &context)) {
 304         _os_log_actual(oslog, type, format, dso, addr, &context);
 305     }
 306     else {
 307         (void)hw_atomic_add(&oslog_p_error_count, 1);
 308     }
 309
 310     va_end(args_copy);
 311 }
 312
 313 static inline size_t
 314 _os_trace_write_location_for_address(uint8_t buf[static sizeof(uint64_t)],
 315                 void *dso, const void *address, firehose_tracepoint_flags_t *flags)
 316 {
 317         kernel_mach_header_t *mh = dso;
 318
 319         if (mh->filetype == MH_EXECUTE) {
 320                 *flags = _firehose_tracepoint_flags_pc_style_main_exe;
 321                 memcpy(buf, (uint32_t[]){ (uintptr_t)address - (uintptr_t)dso },
 322                                 sizeof(uint32_t));
 323                 return sizeof(uint32_t);
 324         } else {
 325                 *flags = _firehose_tracepoint_flags_pc_style_absolute;
 326                 memcpy(buf, (uintptr_t[]){ VM_KERNEL_UNSLIDE(address) }, sizeof(uintptr_t));
 327 #if __LP64__
 328                 return 6; // 48 bits are enough
 329 #else
 330                 return sizeof(uintptr_t);
 331 #endif
 332         }
 333 }
 334
 335
 336 OS_ALWAYS_INLINE
 337 static inline size_t
 338 _os_log_buffer_pack(uint8_t *buffdata, size_t buffdata_sz,
 339                 os_log_buffer_context_t ctx)
 340 {
 341         os_log_buffer_t buffer = ctx->buffer;
 342         size_t buffer_sz = sizeof(*ctx->buffer) + ctx->content_sz;
 343         size_t total_sz  = buffer_sz + ctx->pubdata_sz;
 344
 345         if (total_sz > buffdata_sz) {
 346                 return 0;
 347         }
 348
 349         memcpy(buffdata, buffer, buffer_sz);
 350         memcpy(&buffdata[buffer_sz], ctx->pubdata, ctx->pubdata_sz);
 351         return total_sz;
 352 }
 353
 354 static void
 355 _os_log_actual(os_log_t oslog __unused, os_log_type_t type, const char *format,
 356                 void *dso, void *addr, os_log_buffer_context_t context)
 357 {
 358         firehose_stream_t stream;
 359         firehose_tracepoint_flags_t flags = 0;
 360         firehose_tracepoint_id_u trace_id;
 361         uint8_t buffdata[OS_LOG_BUFFER_MAX_SIZE];
 362         size_t addr_len = 0, buffdata_sz;
 363         uint64_t timestamp;
 364         uint64_t thread_id;
 365
 366         // dso == the start of the binary that was loaded
 367         addr_len = _os_trace_write_location_for_address(buffdata, dso, addr, &flags);
 368         buffdata_sz = _os_log_buffer_pack(buffdata + addr_len,
 369                         sizeof(buffdata) - addr_len, context);
 370         if (buffdata_sz == 0) {
 371                 return;
 372         }
 373         buffdata_sz += addr_len;
 374
 375         timestamp = firehose_tracepoint_time(firehose_activity_flags_default);
 376         thread_id = thread_tid(current_thread());
 377
 378         // create trace_id after we've set additional flags
 379         trace_id.ftid_value = FIREHOSE_TRACE_ID_MAKE(firehose_tracepoint_namespace_log,
 380                         type, flags, _os_trace_offset(dso, format, flags));
 381
 382         if (FALSE) {
 383                 firehose_debug_trace(stream, trace_id.ftid_value, timestamp,
 384                                         format, buffdata, buffdata_sz);
 385         }
 386         if (type == OS_LOG_TYPE_INFO || type == OS_LOG_TYPE_DEBUG) {
 387                 stream = firehose_stream_memory;
 388         }
 389         else {
 390                 stream = firehose_stream_persist;
 391         }
 392         _firehose_trace(stream, trace_id, timestamp, buffdata, buffdata_sz);
 393 }
 394
 395 static inline firehose_tracepoint_id_t
 396 _firehose_trace(firehose_stream_t stream, firehose_tracepoint_id_u ftid,
 397                 uint64_t stamp, const void *pubdata, size_t publen)
 398 {
 399         const uint16_t ft_size = offsetof(struct firehose_tracepoint_s, ft_data);
 400         const size_t _firehose_chunk_payload_size =
 401                         sizeof(((struct firehose_chunk_s *)0)->fc_data);
 402
 403         firehose_tracepoint_t ft;
 404
 405         if (slowpath(ft_size + publen > _firehose_chunk_payload_size)) {
 406                 // We'll need to have some handling here. For now - return 0
 407                 (void)hw_atomic_add(&oslog_p_error_count, 1);
 408                 return 0;
 409         }
 410
 411         if (oslog_stream_open && (stream != firehose_stream_metadata)) {
 412
 413                 lck_spin_lock(&oslog_stream_lock);
 414                 if (!oslog_stream_open) {
 415                         lck_spin_unlock(&oslog_stream_lock);
 416                         goto out;
 417                 }
 418
 419                 oslog_s_total_msgcount++;
 420                 oslog_streamwrite_locked(ftid, stamp, pubdata, publen);
 421                 lck_spin_unlock(&oslog_stream_lock);
 422                 oslog_streamwakeup();
 423         }
 424
 425 out:
 426         ft = __firehose_buffer_tracepoint_reserve(stamp, stream, (uint16_t)publen, 0, NULL);
 427         if (!fastpath(ft)) {
 428                 if (oslog_boot_done) {
 429                         if (stream == firehose_stream_metadata) {
 430                                 (void)hw_atomic_add(&oslog_p_metadata_dropped_msgcount, 1);
 431                         }
 432                         else {
 433                                 // If we run out of space in the persistence buffer we're
 434                                 // dropping the message.
 435                                 (void)hw_atomic_add(&oslog_p_dropped_msgcount, 1);
 436                         }
 437                         return 0;
 438                 }
 439                 firehose_chunk_t fbc = firehose_boot_chunk;
 440                 long offset;
 441
 442                 //only stream available during boot is persist
 443                 offset = firehose_chunk_tracepoint_try_reserve(fbc, stamp,
 444                                 firehose_stream_persist, 0, publen, 0, NULL);
 445                 if (offset <= 0) {
 446                         (void)hw_atomic_add(&oslog_p_boot_dropped_msgcount, 1);
 447                         return 0;
 448                 }
 449
 450                 ft = firehose_chunk_tracepoint_begin(fbc, stamp, publen,
 451                                 thread_tid(current_thread()), offset);
 452                 memcpy(ft->ft_data, pubdata, publen);
 453                 firehose_chunk_tracepoint_end(fbc, ft, ftid);
 454                 (void)hw_atomic_add(&oslog_p_saved_msgcount, 1);
 455                 return ftid.ftid_value;
 456         }
 457         if (!oslog_boot_done) {
 458                 oslog_boot_done = true;
 459         }
 460         memcpy(ft->ft_data, pubdata, publen);
 461
 462         __firehose_buffer_tracepoint_flush(ft, ftid);
 463         if (stream == firehose_stream_metadata) {
 464                 (void)hw_atomic_add(&oslog_p_metadata_saved_msgcount, 1);
 465         }
 466         else {
 467                 (void)hw_atomic_add(&oslog_p_saved_msgcount, 1);
 468         }
 469         return ftid.ftid_value;
 470 }
 471
 472 static oslog_stream_buf_entry_t
 473 oslog_stream_create_buf_entry(oslog_stream_link_type_t type, firehose_tracepoint_id_u ftid,
 474                                 uint64_t stamp, const void* pubdata, size_t publen)
 475 {
 476         oslog_stream_buf_entry_t m_entry = NULL;
 477         firehose_tracepoint_t ft = NULL;
 478         size_t m_entry_len = 0;
 479
 480         if (!pubdata) {
 481                 return NULL;
 482         }
 483
 484         m_entry_len = sizeof(struct oslog_stream_buf_entry_s) +
 485                         sizeof(struct firehose_tracepoint_s) + publen;
 486         m_entry = (oslog_stream_buf_entry_t) kalloc(m_entry_len);
 487         if (!m_entry) {
 488                 return NULL;
 489         }
 490
 491         m_entry->type = type;
 492         m_entry->timestamp = stamp;
 493         m_entry->size = sizeof(struct firehose_tracepoint_s) + publen;
 494
 495         ft = m_entry->metadata;
 496         ft->ft_thread = thread_tid(current_thread());
 497         ft->ft_id.ftid_value = ftid.ftid_value;
 498         ft->ft_length = publen;
 499         memcpy(ft->ft_data, pubdata, publen);
 500
 501         return m_entry;
 502 }
 503
 504 #ifdef KERNEL
 505 void
 506 firehose_trace_metadata(firehose_stream_t stream, firehose_tracepoint_id_u ftid,
 507                 uint64_t stamp, const void *pubdata, size_t publen)
 508 {
 509         oslog_stream_buf_entry_t m_entry = NULL;
 510
 511         // If streaming mode is not on, only log  the metadata
 512         // in the persistence buffer
 513
 514         lck_spin_lock(&oslog_stream_lock);
 515         if (!oslog_stream_open) {
 516                 lck_spin_unlock(&oslog_stream_lock);
 517                 goto finish;
 518         }
 519         lck_spin_unlock(&oslog_stream_lock);
 520
 521         // Setup and write the stream metadata entry
 522         m_entry = oslog_stream_create_buf_entry(oslog_stream_link_type_metadata, ftid,
 523                                                         stamp, pubdata, publen);
 524         if (!m_entry) {
 525                 (void)hw_atomic_add(&oslog_s_error_count, 1);
 526                 goto finish;
 527         }
 528
 529         lck_spin_lock(&oslog_stream_lock);
 530         if (!oslog_stream_open) {
 531                 lck_spin_unlock(&oslog_stream_lock);
 532                 kfree(m_entry, sizeof(struct oslog_stream_buf_entry_s) +
 533                         sizeof(struct firehose_tracepoint_s) + publen);
 534                 goto finish;
 535         }
 536         oslog_s_metadata_msgcount++;
 537         oslog_streamwrite_metadata_locked(m_entry);
 538         lck_spin_unlock(&oslog_stream_lock);
 539
 540 finish:
 541         _firehose_trace(stream, ftid, stamp, pubdata, publen);
 542 }
 543 #endif
 544
 545 firehose_tracepoint_id_t
 546 firehose_debug_trace(firehose_stream_t stream, firehose_tracepoint_id_t trace_id,
 547                 uint64_t timestamp, const char *format, const void *pubdata, size_t publen)
 548 {
 549         kprintf("[os_log stream 0x%x trace_id 0x%llx timestamp %llu format '%s' data %p len %lu]\n",
 550                         (unsigned int)stream, (unsigned long long)trace_id, timestamp,
 551                         format, pubdata, publen);
 552         size_t i;
 553         const unsigned char *cdata = (const unsigned char *)pubdata;
 554         for (i=0; i < publen; i += 8) {
 555                 kprintf(">oslog 0x%08x: 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
 556                                 (unsigned int)i,
 557                                 (i+0) < publen ? cdata[i+0] : 0,
 558                                 (i+1) < publen ? cdata[i+1] : 0,
 559                                 (i+2) < publen ? cdata[i+2] : 0,
 560                                 (i+3) < publen ? cdata[i+3] : 0,
 561                                 (i+4) < publen ? cdata[i+4] : 0,
 562                                 (i+5) < publen ? cdata[i+5] : 0,
 563                                 (i+6) < publen ? cdata[i+6] : 0,
 564                                 (i+7) < publen ? cdata[i+7] : 0
 565                         );
 566         }
 567         return trace_id;
 568 }
 569
 570 void
 571 __firehose_buffer_push_to_logd(firehose_buffer_t fb __unused, bool for_io __unused) {
 572         oslogwakeup();
 573         return;
 574 }
 575
 576 void
 577 __firehose_allocate(vm_offset_t *addr, vm_size_t size __unused)
 578 {
 579         firehose_chunk_t kernel_buffer = (firehose_chunk_t)kernel_firehose_addr;
 580
 581         if (kernel_firehose_addr) {
 582                 *addr = kernel_firehose_addr;
 583         }
 584         else {
 585                 *addr = 0;
 586                 return;
 587         }
 588         // Now that we are done adding logs to this chunk, set the number of writers to 0
 589         // Without this, logd won't flush when the page is full
 590         firehose_boot_chunk->fc_pos.fcp_refcnt = 0;
 591         memcpy(&kernel_buffer[FIREHOSE_BUFFER_KERNEL_CHUNK_COUNT - 1], (const void *)firehose_boot_chunk, FIREHOSE_CHUNK_SIZE);
 592         return;
 593 }
 594 // There isnt a lock held in this case.
 595 void
 596 __firehose_critical_region_enter(void) {
 597         disable_preemption();
 598         return;
 599 }
 600
 601 void
 602 __firehose_critical_region_leave(void) {
 603         enable_preemption();
 604         return;
 605 }
 606