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 oslog_early_boot_complete;
  76
  77 // XXX
  78 firehose_tracepoint_id_t
  79 firehose_debug_trace(firehose_stream_t stream, firehose_tracepoint_id_t trace_id,
  80                 uint64_t timestamp, const char *format, const void *pubdata, size_t publen);
  81
  82 static inline firehose_tracepoint_id_t
  83 _firehose_trace(firehose_stream_t stream, firehose_tracepoint_id_u ftid,
  84                 uint64_t stamp, const void *pubdata, size_t publen);
  85
  86 static oslog_stream_buf_entry_t
  87 oslog_stream_create_buf_entry(oslog_stream_link_type_t type, firehose_tracepoint_id_u ftid,
  88                                 uint64_t stamp, const void* pubdata, size_t publen);
  89
  90 static void
  91 _os_log_with_args_internal(os_log_t oslog __unused, os_log_type_t type __unused,
  92                 const char *format, va_list args, void *addr, void *dso);
  93
  94 static void
  95 _os_log_to_msgbuf_internal(const char *format, va_list args, bool safe, bool logging);
  96
  97 static void
  98 _os_log_to_log_internal(os_log_t oslog, os_log_type_t type,
  99                 const char *format, va_list args, void *addr, void *dso);
 100
 101
 102 static void
 103 _os_log_actual(os_log_t oslog, os_log_type_t type, const char *format, void
 104                 *dso, void *addr, os_log_buffer_context_t context);
 105
 106 bool
 107 os_log_info_enabled(os_log_t log __unused)
 108 {
 109         return true;
 110 }
 111
 112 bool
 113 os_log_debug_enabled(os_log_t log __unused)
 114 {
 115         return true;
 116 }
 117
 118 os_log_t
 119 os_log_create(const char *subsystem __unused, const char *category __unused)
 120 {
 121         return &_os_log_default;
 122 }
 123
 124 bool
 125 _os_log_string_is_public(const char *str __unused)
 126 {
 127         return true;
 128 }
 129
 130 __attribute__((noinline,not_tail_called)) void
 131 _os_log_internal(void *dso, os_log_t log, uint8_t type, const char *message, ...)
 132 {
 133     va_list args;
 134     void *addr = __builtin_return_address(0);
 135
 136     va_start(args, message);
 137
 138     _os_log_with_args_internal(log, type, message, args, addr, dso);
 139
 140     va_end(args);
 141
 142     return;
 143 }
 144
 145 #pragma mark - shim functions
 146
 147 __attribute__((noinline,not_tail_called)) void
 148 os_log_with_args(os_log_t oslog, os_log_type_t type, const char *format, va_list args, void *addr)
 149 {
 150     // if no address passed, look it up
 151     if (addr == NULL) {
 152         addr = __builtin_return_address(0);
 153     }
 154
 155     _os_log_with_args_internal(oslog, type, format, args, addr, NULL);
 156 }
 157
 158 static void
 159 _os_log_with_args_internal(os_log_t oslog, os_log_type_t type,
 160                 const char *format, va_list args, void *addr, void *dso)
 161 {
 162     uint32_t  logging_config = atm_get_diagnostic_config();
 163     boolean_t safe;
 164     boolean_t logging;
 165
 166     if (format[0] == '\0') {
 167         return;
 168     }
 169     /* cf. r24974766 & r25201228*/
 170     safe    = (!oslog_early_boot_complete || oslog_is_safe());
 171     logging = (!(logging_config & ATM_TRACE_DISABLE) || !(logging_config & ATM_TRACE_OFF));
 172
 173     if (oslog != &_os_log_replay) {
 174         _os_log_to_msgbuf_internal(format, args, safe, logging);
 175     }
 176
 177     if (safe && logging) {
 178         _os_log_to_log_internal(oslog, type, format, args, addr, dso);
 179     }
 180 }
 181
 182 static void
 183 _os_log_to_msgbuf_internal(const char *format, va_list args, bool safe, bool logging)
 184 {
 185     static int msgbufreplay = -1;
 186     va_list args_copy;
 187
 188     bsd_log_lock();
 189
 190     if (!safe) {
 191         if (-1 == msgbufreplay) msgbufreplay = msgbufp->msg_bufx;
 192     } else if (logging && (-1 != msgbufreplay)) {
 193         uint32_t i;
 194         uint32_t localbuff_size;
 195         int newl, position;
 196         char *localbuff, *p, *s, *next, ch;
 197
 198         position = msgbufreplay;
 199         msgbufreplay = -1;
 200         localbuff_size = (msgbufp->msg_size + 2); /* + '\n' + '\0' */
 201         /* Size for non-blocking */
 202         if (localbuff_size > 4096) localbuff_size = 4096;
 203         bsd_log_unlock();
 204         /* Allocate a temporary non-circular buffer */
 205         if ((localbuff = (char *)kalloc_noblock(localbuff_size))) {
 206             /* in between here, the log could become bigger, but that's fine */
 207             bsd_log_lock();
 208             /*
 209              * The message buffer is circular; start at the replay pointer, and
 210              * make one loop up to write pointer - 1.
 211              */
 212             p = msgbufp->msg_bufc + position;
 213             for (i = newl = 0; p != msgbufp->msg_bufc + msgbufp->msg_bufx - 1; ++p) {
 214                 if (p >= msgbufp->msg_bufc + msgbufp->msg_size)
 215                     p = msgbufp->msg_bufc;
 216                 ch = *p;
 217                 if (ch == '\0') continue;
 218                 newl = (ch == '\n');
 219                 localbuff[i++] = ch;
 220                 if (i >= (localbuff_size - 2)) break;
 221             }
 222             bsd_log_unlock();
 223
 224             if (!newl) localbuff[i++] = '\n';
 225             localbuff[i++] = 0;
 226
 227             s = localbuff;
 228             while ((next = strchr(s, '\n'))) {
 229                 next++;
 230                 ch = next[0];
 231                 next[0] = 0;
 232                 os_log(&_os_log_replay, "%s", s);
 233                 next[0] = ch;
 234                 s = next;
 235             }
 236             kfree(localbuff, localbuff_size);
 237         }
 238         bsd_log_lock();
 239     }
 240
 241     va_copy(args_copy, args);
 242     vprintf_log_locked(format, args_copy);
 243     va_end(args_copy);
 244
 245     bsd_log_unlock();
 246
 247     if (safe) logwakeup();
 248 }
 249
 250 static void
 251 _os_log_to_log_internal(os_log_t oslog, os_log_type_t type,
 252                 const char *format, va_list args, void *addr, void *dso)
 253 {
 254     struct os_log_buffer_context_s context;
 255     unsigned char buffer_data[OS_LOG_BUFFER_MAX_SIZE] __attribute__((aligned(8)));
 256     os_log_buffer_t buffer = (os_log_buffer_t)buffer_data;
 257     uint8_t pubdata[OS_LOG_BUFFER_MAX_SIZE];
 258     va_list args_copy;
 259
 260     if (dso == NULL) {
 261         dso = (void *) OSKextKextForAddress(format);
 262         if (dso == NULL) {
 263             return;
 264         }
 265     }
 266
 267     if (!_os_trace_addr_in_text_segment(dso, format)) {
 268         return;
 269     }
 270
 271     if (addr == NULL) {
 272         return;
 273     }
 274
 275     void *dso_addr = (void *) OSKextKextForAddress(addr);
 276     if (dso != dso_addr) {
 277         return;
 278     }
 279
 280     memset(&context, 0, sizeof(context));
 281     memset(buffer, 0, OS_LOG_BUFFER_MAX_SIZE);
 282
 283     context.shimmed = true;
 284     context.buffer = buffer;
 285     context.content_sz = OS_LOG_BUFFER_MAX_SIZE - sizeof(*buffer);
 286     context.pubdata = pubdata;
 287     context.pubdata_sz = sizeof(pubdata);
 288
 289     va_copy(args_copy, args);
 290
 291     (void)hw_atomic_add(&oslog_p_total_msgcount, 1);
 292     if (_os_log_encode(format, args_copy, 0, &context)) {
 293         _os_log_actual(oslog, type, format, dso, addr, &context);
 294     }
 295     else {
 296         (void)hw_atomic_add(&oslog_p_error_count, 1);
 297     }
 298
 299     va_end(args_copy);
 300 }
 301
 302 static inline size_t
 303 _os_trace_write_location_for_address(uint8_t buf[static sizeof(uint64_t)],
 304                 void *dso, const void *address, firehose_tracepoint_flags_t *flags)
 305 {
 306         kernel_mach_header_t *mh = dso;
 307
 308         if (mh->filetype == MH_EXECUTE) {
 309                 *flags = _firehose_tracepoint_flags_pc_style_main_exe;
 310                 memcpy(buf, (uint32_t[]){ (uintptr_t)address - (uintptr_t)dso },
 311                                 sizeof(uint32_t));
 312                 return sizeof(uint32_t);
 313         } else {
 314                 *flags = _firehose_tracepoint_flags_pc_style_absolute;
 315                 memcpy(buf, (uintptr_t[]){ VM_KERNEL_UNSLIDE(address) }, sizeof(uintptr_t));
 316 #if __LP64__
 317                 return 6; // 48 bits are enough
 318 #else
 319                 return sizeof(uintptr_t);
 320 #endif
 321         }
 322 }
 323
 324
 325 OS_ALWAYS_INLINE
 326 static inline size_t
 327 _os_log_buffer_pack(uint8_t *buffdata, size_t buffdata_sz,
 328                 os_log_buffer_context_t ctx)
 329 {
 330         os_log_buffer_t buffer = ctx->buffer;
 331         size_t buffer_sz = sizeof(*ctx->buffer) + ctx->content_sz;
 332         size_t total_sz  = buffer_sz + ctx->pubdata_sz;
 333
 334         if (total_sz > buffdata_sz) {
 335                 return 0;
 336         }
 337
 338         memcpy(buffdata, buffer, buffer_sz);
 339         memcpy(&buffdata[buffer_sz], ctx->pubdata, ctx->pubdata_sz);
 340         return total_sz;
 341 }
 342
 343 static void
 344 _os_log_actual(os_log_t oslog __unused, os_log_type_t type, const char *format,
 345                 void *dso, void *addr, os_log_buffer_context_t context)
 346 {
 347         firehose_stream_t stream;
 348         firehose_tracepoint_flags_t flags = 0;
 349         firehose_tracepoint_id_u trace_id;
 350         uint8_t buffdata[OS_LOG_BUFFER_MAX_SIZE];
 351         size_t addr_len = 0, buffdata_sz;
 352         uint64_t timestamp;
 353         uint64_t thread_id;
 354
 355         // dso == the start of the binary that was loaded
 356         addr_len = _os_trace_write_location_for_address(buffdata, dso, addr, &flags);
 357         buffdata_sz = _os_log_buffer_pack(buffdata + addr_len,
 358                         sizeof(buffdata) - addr_len, context);
 359         if (buffdata_sz == 0) {
 360                 return;
 361         }
 362         buffdata_sz += addr_len;
 363
 364         timestamp = firehose_tracepoint_time(firehose_activity_flags_default);
 365         thread_id = thread_tid(current_thread());
 366
 367         // create trace_id after we've set additional flags
 368         trace_id.ftid_value = FIREHOSE_TRACE_ID_MAKE(firehose_tracepoint_namespace_log,
 369                         type, flags, _os_trace_offset(dso, format, flags));
 370
 371         if (FALSE) {
 372                 firehose_debug_trace(stream, trace_id.ftid_value, timestamp,
 373                                         format, buffdata, buffdata_sz);
 374         }
 375         if (type == OS_LOG_TYPE_INFO || type == OS_LOG_TYPE_DEBUG) {
 376                 stream = firehose_stream_memory;
 377         }
 378         else {
 379                 stream = firehose_stream_persist;
 380         }
 381         _firehose_trace(stream, trace_id, timestamp, buffdata, buffdata_sz);
 382 }
 383
 384 static inline firehose_tracepoint_id_t
 385 _firehose_trace(firehose_stream_t stream, firehose_tracepoint_id_u ftid,
 386                 uint64_t stamp, const void *pubdata, size_t publen)
 387 {
 388         const uint16_t ft_size = offsetof(struct firehose_tracepoint_s, ft_data);
 389         const size_t _firehose_chunk_payload_size =
 390                         sizeof(((struct firehose_chunk_s *)0)->fc_data);
 391
 392         firehose_tracepoint_t ft;
 393
 394         if (slowpath(ft_size + publen > _firehose_chunk_payload_size)) {
 395                 // We'll need to have some handling here. For now - return 0
 396                 (void)hw_atomic_add(&oslog_p_error_count, 1);
 397                 return 0;
 398         }
 399
 400         if (oslog_stream_open && (stream != firehose_stream_metadata)) {
 401
 402                 lck_spin_lock(&oslog_stream_lock);
 403                 if (!oslog_stream_open) {
 404                         lck_spin_unlock(&oslog_stream_lock);
 405                         goto out;
 406                 }
 407
 408                 oslog_s_total_msgcount++;
 409                 oslog_streamwrite_locked(ftid, stamp, pubdata, publen);
 410                 lck_spin_unlock(&oslog_stream_lock);
 411                 oslog_streamwakeup();
 412         }
 413
 414 out:
 415         ft = __firehose_buffer_tracepoint_reserve(stamp, stream, (uint16_t)publen, 0, NULL);
 416         if (!fastpath(ft)) {
 417                 if (oslog_boot_done) {
 418                         if (stream == firehose_stream_metadata) {
 419                                 (void)hw_atomic_add(&oslog_p_metadata_dropped_msgcount, 1);
 420                         }
 421                         else {
 422                                 // If we run out of space in the persistence buffer we're
 423                                 // dropping the message.
 424                                 (void)hw_atomic_add(&oslog_p_dropped_msgcount, 1);
 425                         }
 426                         return 0;
 427                 }
 428                 firehose_chunk_t fbc = firehose_boot_chunk;
 429                 long offset;
 430
 431                 //only stream available during boot is persist
 432                 offset = firehose_chunk_tracepoint_try_reserve(fbc, stamp,
 433                                 firehose_stream_persist, 0, publen, 0, NULL);
 434                 if (offset <= 0) {
 435                         (void)hw_atomic_add(&oslog_p_boot_dropped_msgcount, 1);
 436                         return 0;
 437                 }
 438
 439                 ft = firehose_chunk_tracepoint_begin(fbc, stamp, publen,
 440                                 thread_tid(current_thread()), offset);
 441                 memcpy(ft->ft_data, pubdata, publen);
 442                 firehose_chunk_tracepoint_end(fbc, ft, ftid);
 443                 (void)hw_atomic_add(&oslog_p_saved_msgcount, 1);
 444                 return ftid.ftid_value;
 445         }
 446         if (!oslog_boot_done) {
 447                 oslog_boot_done = true;
 448         }
 449         memcpy(ft->ft_data, pubdata, publen);
 450
 451         __firehose_buffer_tracepoint_flush(ft, ftid);
 452         if (stream == firehose_stream_metadata) {
 453                 (void)hw_atomic_add(&oslog_p_metadata_saved_msgcount, 1);
 454         }
 455         else {
 456                 (void)hw_atomic_add(&oslog_p_saved_msgcount, 1);
 457         }
 458         return ftid.ftid_value;
 459 }
 460
 461 static oslog_stream_buf_entry_t
 462 oslog_stream_create_buf_entry(oslog_stream_link_type_t type, firehose_tracepoint_id_u ftid,
 463                                 uint64_t stamp, const void* pubdata, size_t publen)
 464 {
 465         oslog_stream_buf_entry_t m_entry = NULL;
 466         firehose_tracepoint_t ft = NULL;
 467         size_t m_entry_len = 0;
 468
 469         if (!pubdata) {
 470                 return NULL;
 471         }
 472
 473         m_entry_len = sizeof(struct oslog_stream_buf_entry_s) +
 474                         sizeof(struct firehose_tracepoint_s) + publen;
 475         m_entry = (oslog_stream_buf_entry_t) kalloc(m_entry_len);
 476         if (!m_entry) {
 477                 return NULL;
 478         }
 479
 480         m_entry->type = type;
 481         m_entry->timestamp = stamp;
 482         m_entry->size = sizeof(struct firehose_tracepoint_s) + publen;
 483
 484         ft = m_entry->metadata;
 485         ft->ft_thread = thread_tid(current_thread());
 486         ft->ft_id.ftid_value = ftid.ftid_value;
 487         ft->ft_length = publen;
 488         memcpy(ft->ft_data, pubdata, publen);
 489
 490         return m_entry;
 491 }
 492
 493 #ifdef KERNEL
 494 void
 495 firehose_trace_metadata(firehose_stream_t stream, firehose_tracepoint_id_u ftid,
 496                 uint64_t stamp, const void *pubdata, size_t publen)
 497 {
 498         oslog_stream_buf_entry_t m_entry = NULL;
 499
 500         // If streaming mode is not on, only log  the metadata
 501         // in the persistence buffer
 502
 503         lck_spin_lock(&oslog_stream_lock);
 504         if (!oslog_stream_open) {
 505                 lck_spin_unlock(&oslog_stream_lock);
 506                 goto finish;
 507         }
 508         lck_spin_unlock(&oslog_stream_lock);
 509
 510         // Setup and write the stream metadata entry
 511         m_entry = oslog_stream_create_buf_entry(oslog_stream_link_type_metadata, ftid,
 512                                                         stamp, pubdata, publen);
 513         if (!m_entry) {
 514                 (void)hw_atomic_add(&oslog_s_error_count, 1);
 515                 goto finish;
 516         }
 517
 518         lck_spin_lock(&oslog_stream_lock);
 519         if (!oslog_stream_open) {
 520                 lck_spin_unlock(&oslog_stream_lock);
 521                 kfree(m_entry, sizeof(struct oslog_stream_buf_entry_s) +
 522                         sizeof(struct firehose_tracepoint_s) + publen);
 523                 goto finish;
 524         }
 525         oslog_s_metadata_msgcount++;
 526         oslog_streamwrite_metadata_locked(m_entry);
 527         lck_spin_unlock(&oslog_stream_lock);
 528
 529 finish:
 530         _firehose_trace(stream, ftid, stamp, pubdata, publen);
 531 }
 532 #endif
 533
 534 firehose_tracepoint_id_t
 535 firehose_debug_trace(firehose_stream_t stream, firehose_tracepoint_id_t trace_id,
 536                 uint64_t timestamp, const char *format, const void *pubdata, size_t publen)
 537 {
 538         kprintf("[os_log stream 0x%x trace_id 0x%llx timestamp %llu format '%s' data %p len %lu]\n",
 539                         (unsigned int)stream, (unsigned long long)trace_id, timestamp,
 540                         format, pubdata, publen);
 541         size_t i;
 542         const unsigned char *cdata = (const unsigned char *)pubdata;
 543         for (i=0; i < publen; i += 8) {
 544                 kprintf(">oslog 0x%08x: 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
 545                                 (unsigned int)i,
 546                                 (i+0) < publen ? cdata[i+0] : 0,
 547                                 (i+1) < publen ? cdata[i+1] : 0,
 548                                 (i+2) < publen ? cdata[i+2] : 0,
 549                                 (i+3) < publen ? cdata[i+3] : 0,
 550                                 (i+4) < publen ? cdata[i+4] : 0,
 551                                 (i+5) < publen ? cdata[i+5] : 0,
 552                                 (i+6) < publen ? cdata[i+6] : 0,
 553                                 (i+7) < publen ? cdata[i+7] : 0
 554                         );
 555         }
 556         return trace_id;
 557 }
 558
 559 void
 560 __firehose_buffer_push_to_logd(firehose_buffer_t fb __unused, bool for_io __unused) {
 561         oslogwakeup();
 562         return;
 563 }
 564
 565 void
 566 __firehose_allocate(vm_offset_t *addr, vm_size_t size __unused)
 567 {
 568         firehose_chunk_t kernel_buffer = (firehose_chunk_t)kernel_firehose_addr;
 569
 570         if (kernel_firehose_addr) {
 571                 *addr = kernel_firehose_addr;
 572         }
 573         else {
 574                 *addr = 0;
 575                 return;
 576         }
 577         // Now that we are done adding logs to this chunk, set the number of writers to 0
 578         // Without this, logd won't flush when the page is full
 579         firehose_boot_chunk->fc_pos.fcp_refcnt = 0;
 580         memcpy(&kernel_buffer[FIREHOSE_BUFFER_KERNEL_CHUNK_COUNT - 1], (const void *)firehose_boot_chunk, FIREHOSE_CHUNK_SIZE);
 581         return;
 582 }
 583 // There isnt a lock held in this case.
 584 void
 585 __firehose_critical_region_enter(void) {
 586         disable_preemption();
 587         return;
 588 }
 589
 590 void
 591 __firehose_critical_region_leave(void) {
 592         enable_preemption();
 593         return;
 594 }
 595