gen/stack_logging.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 /*      Bertrand from vmutils -> CF -> System */
  25
  26 #import "stack_logging.h"
  27
  28 #import <libc.h>
  29 #import <pthread.h>
  30 #import <mach/mach.h>
  31 #include <mach/vm_statistics.h>
  32 #import <malloc/malloc.h>
  33 #import <stdlib.h>
  34
  35 extern void spin_lock(int *);
  36
  37 static inline void *allocate_pages(unsigned) __attribute__((always_inline));
  38 static inline void *allocate_pages(unsigned bytes) {
  39     void *address;
  40     if (vm_allocate(mach_task_self(), (vm_address_t *)&address, bytes,
  41                     VM_MAKE_TAG(VM_MEMORY_ANALYSIS_TOOL)| TRUE)) {
  42         malloc_printf("*** out of memory while stack logging\n");
  43         abort();
  44     }
  45     return (void *)address;
  46 }
  47
  48 static inline void deallocate_pages(void *, unsigned) __attribute__((always_inline));
  49 static inline void deallocate_pages(void *ptr, unsigned bytes) {
  50     vm_deallocate(mach_task_self(), (vm_address_t)ptr, bytes);
  51 }
  52
  53 static inline void copy_pages(const void *, void *, unsigned) __attribute__((always_inline));
  54 static inline void copy_pages(const void *source, void *dest, unsigned bytes) {
  55     if (vm_copy(mach_task_self(), (vm_address_t)source, bytes, (vm_address_t)dest)) memmove(dest, source, bytes);
  56 }
  57
  58 /***************        Recording stack         ***********/
  59
  60 static void *first_frame_address(void) {
  61 #if defined(__i386__)
  62     return __builtin_frame_address(1);
  63 #elif defined(__ppc__) || defined(__ppc64__)
  64     void *addr;
  65 #warning __builtin_frame_address IS BROKEN IN BEAKER: RADAR #2340421
  66     __asm__ volatile("mr %0, r1" : "=r" (addr));
  67     return addr;
  68 #else
  69 #warning first_frame_address WILL NOT BE FUNCTIONAL ON THIS ARCHITECTURE
  70     return NULL;
  71 #endif
  72 }
  73
  74 static void *next_frame_address(void *addr) {
  75     void *ret;
  76 #if defined(__MACH__) && defined(__i386__)
  77     __asm__ volatile("movl (%1),%0" : "=r" (ret) : "r" (addr));
  78 #elif defined(__MACH__) && (defined(__ppc__) || defined(__ppc64__))
  79     __asm__ volatile("lwz %0,0x0(%1)" : "=r" (ret) : "b" (addr));
  80 #elif defined(__hpux__)
  81     __asm__ volatile("ldw 0x0(%1),%0" : "=r" (ret) : "r" (addr));
  82 #elif defined(__svr4__)
  83     __asm__ volatile("ta 0x3");
  84     __asm__ volatile("ld [%1 + 56],%0" : "=r" (ret) : "r" (addr));
  85 #else
  86 #error Unknown architecture
  87 #endif
  88     return ret;
  89 }
  90
  91 #if defined(__i386__) || defined (__m68k__)
  92 #define FP_LINK_OFFSET 1
  93 #elif defined(__ppc__) || defined(__ppc64__)
  94 #define FP_LINK_OFFSET 2
  95 #elif defined(__hppa__)
  96 #define FP_LINK_OFFSET -5
  97 #elif defined(__sparc__)
  98 #define FP_LINK_OFFSET 14
  99 #else
 100 #error  ********** Unimplemented architecture
 101 #endif
 102
 103 void thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb) {
 104     void *addr;
 105     addr = first_frame_address();
 106     *nb = 0;
 107     while ((addr >= (void *)0x800) && (max--)) {
 108         vm_address_t    fp_link = (vm_address_t)(((unsigned *)addr)+FP_LINK_OFFSET);
 109         void    *addr2;
 110         buffer[*nb] = *((vm_address_t *)fp_link);
 111         (*nb)++;
 112         addr2 = next_frame_address(addr);
 113 #if defined(__ppc__) || defined(__ppc64__)
 114         if ((unsigned)addr2 <= (unsigned)addr) break; // catch bozo frames
 115 #endif
 116         addr = addr2;
 117     }
 118 }
 119
 120 /***************        Uniquing stack          ***********/
 121
 122 #define MAX_COLLIDE     8
 123
 124 #define MAX_NUM_PC      512
 125
 126 static int enter_pair_in_table(unsigned *table, unsigned numPages, unsigned *uniquedParent, unsigned thisPC) {
 127     // uniquedParent is in-out; return 1 is collisions max not exceeded
 128     unsigned    base = numPages * vm_page_size / (sizeof(int)*2*2);
 129     unsigned    hash = base + (((*uniquedParent) << 4) ^ (thisPC >> 2)) % (base - 1); // modulo odd number for hashing
 130     unsigned    collisions = MAX_COLLIDE;
 131     while (collisions--) {
 132         unsigned        *head = table + hash*2;
 133         if (! head[0] && !head[1]) {
 134             /* end of chain; store this entry! */
 135             /* Note that we need to test for both head[0] and head[1] as (0, -1) is a valid entry */
 136             head[0] = thisPC;
 137             head[1] = *uniquedParent;
 138             *uniquedParent = hash;
 139             return 1;
 140         }
 141         if ((head[0] == thisPC) && (head[1] == *uniquedParent)) {
 142             /* we found the proper entry, the value for the pair is the entry offset */
 143             *uniquedParent = hash;
 144             return 1;
 145         }
 146         hash++;
 147         if (hash == base*2) hash = base;
 148     }
 149     return 0;
 150 }
 151
 152 unsigned stack_logging_get_unique_stack(unsigned **table, unsigned *table_num_pages, unsigned *stack_entries, unsigned count, unsigned num_hot_to_skip) {
 153     unsigned    uniquedParent = (unsigned)-1;
 154     // we skip the warmest entries that are an artefact of the code
 155     while (num_hot_to_skip--) {
 156         if (count > 0) { stack_entries++; count--; }
 157     }
 158     while (count--) {
 159         unsigned        thisPC = stack_entries[count];
 160         while (!enter_pair_in_table(*table, *table_num_pages, &uniquedParent, thisPC)) {
 161             unsigned    *newTable;
 162             unsigned    oldBytes = (*table_num_pages) * vm_page_size;
 163             newTable = allocate_pages(oldBytes*2);
 164             copy_pages(*table, newTable, oldBytes);
 165             deallocate_pages(*table, oldBytes);
 166             *table_num_pages *= 2;
 167             *table = newTable;
 168         }
 169     }
 170     return uniquedParent;
 171 }
 172
 173 /***************        Logging stack and arguments             ***********/
 174
 175 stack_logging_record_list_t *stack_logging_the_record_list = NULL;
 176
 177 int stack_logging_enable_logging = 0;
 178
 179 int stack_logging_dontcompact = 0;
 180
 181 static stack_logging_record_list_t *GrowLogRecords(stack_logging_record_list_t *records, unsigned desiredNumRecords) {
 182     stack_logging_record_list_t *new_records;
 183     unsigned    old_size = records->overall_num_bytes;
 184     if (desiredNumRecords*sizeof(stack_logging_record_t)+sizeof(stack_logging_record_list_t) < records->overall_num_bytes) return records;
 185     records->overall_num_bytes += records->overall_num_bytes + vm_page_size; // in order to always get an even number of pages
 186     new_records = allocate_pages(records->overall_num_bytes);
 187     copy_pages(records, new_records, old_size);
 188     deallocate_pages(records, old_size);
 189     return new_records;
 190 }
 191
 192 static void prepare_to_log_stack(void) {
 193     if (!stack_logging_the_record_list) {
 194         unsigned        totalSize = 4 * vm_page_size;
 195         stack_logging_the_record_list = allocate_pages(totalSize);
 196         memset(stack_logging_the_record_list, 0, sizeof(stack_logging_record_list_t));
 197         stack_logging_the_record_list->overall_num_bytes = totalSize;
 198         stack_logging_the_record_list->uniquing_table_num_pages = 128;
 199         stack_logging_the_record_list->uniquing_table = allocate_pages(stack_logging_the_record_list->uniquing_table_num_pages * vm_page_size);
 200     }
 201 }
 202
 203 void stack_logging_log_stack(unsigned type, unsigned arg1, unsigned arg2, unsigned arg3, unsigned result, unsigned num_hot_to_skip) {
 204     stack_logging_record_t      *rec;
 205     if (!stack_logging_enable_logging) return;
 206     // printf("stack_logging_log_stack 0x%x 0x%x 0x%x 0x%x -> 0x%x\n", type, arg1, arg2, arg3, result);
 207     if (type & stack_logging_flag_zone) {
 208         // just process it now and be done with it!
 209         arg1 = arg2; arg2 = arg3; arg3 = 0; type &= ~stack_logging_flag_zone;
 210     }
 211     if (type & stack_logging_flag_calloc) {
 212         // just process it now and be done with it!
 213         arg1 *= arg2; arg2 = arg3; arg3 = 0; type &= ~stack_logging_flag_calloc;
 214     }
 215     if (type & stack_logging_flag_object) {
 216         unsigned        *class = (unsigned *)arg1;
 217         arg1 = arg2 + class[5]; // corresponds to the instance_size field
 218         arg2 = 0; arg3 = 0; type = stack_logging_type_alloc;
 219     }
 220     if (type & stack_logging_flag_cleared) {
 221         type &= ~stack_logging_flag_cleared;
 222     }
 223     if (type & stack_logging_flag_handle) {
 224         if (stack_logging_type_alloc) {
 225             if (!result) return;
 226             stack_logging_log_stack(stack_logging_type_alloc, 0, 0, 0, result, num_hot_to_skip+1);
 227             stack_logging_log_stack(stack_logging_type_alloc, arg1, 0, 0, *((int *)result), num_hot_to_skip+1);
 228             return;
 229         }
 230         if (stack_logging_type_dealloc) {
 231             if (!arg1) return;
 232             stack_logging_log_stack(stack_logging_type_dealloc, *((int *)arg1), 0, 0, 0, num_hot_to_skip+1);
 233             stack_logging_log_stack(stack_logging_type_dealloc, arg1, 0, 0, 0, num_hot_to_skip+1);
 234             return;
 235         }
 236         printf("*** Unknown logging type: 0x%x\n", type);
 237     }
 238     if (type == stack_logging_flag_set_handle_size) {
 239         if (!arg1) return;
 240         // Thanks to a horrible hack, arg3 contains the prvious handle value
 241         if (arg3 == *((int *)arg1)) return;
 242         stack_logging_log_stack(stack_logging_type_dealloc, arg3, 0, 0, 0, num_hot_to_skip+1);
 243         stack_logging_log_stack(stack_logging_type_alloc, arg2, 0, 0, *((int *)arg1), num_hot_to_skip+1);
 244         return;
 245     }
 246     if (type == (stack_logging_type_dealloc|stack_logging_type_alloc)) {
 247         if (arg1 == result) return; // realloc had no effect, skipping
 248         if (!arg1) {
 249             // realloc(NULL, size) same as malloc(size)
 250             type = stack_logging_type_alloc; arg1 = arg2; arg2 = arg3; arg3 = 0;
 251         } else {
 252             // realloc(arg1, arg2) -> result is same as free(arg1); malloc(arg2) -> result
 253             stack_logging_log_stack(stack_logging_type_dealloc, arg1, 0, 0, 0, num_hot_to_skip+1);
 254             stack_logging_log_stack(stack_logging_type_alloc, arg2, 0, 0, result, num_hot_to_skip+1);
 255             return;
 256         }
 257     }
 258     if (type == stack_logging_type_dealloc) {
 259         // simple free
 260         if (!arg1) return; // free(nil)
 261     }
 262     prepare_to_log_stack();
 263     spin_lock(&stack_logging_the_record_list->lock);
 264     stack_logging_enable_logging = 0;
 265     stack_logging_the_record_list = GrowLogRecords(stack_logging_the_record_list, stack_logging_the_record_list->num_records + 1);
 266     rec = stack_logging_the_record_list->records + stack_logging_the_record_list->num_records;
 267     // We take care of the common case of alloc-dealloc
 268     if (!stack_logging_dontcompact && stack_logging_the_record_list->num_records && (type == stack_logging_type_dealloc) && arg1 && ((rec-1)->type == stack_logging_type_alloc) && (arg1 == STACK_LOGGING_DISGUISE((rec-1)->address))) {
 269         stack_logging_the_record_list->num_records--;
 270         // printf("Erased previous record in alloc-dealloc sequence\n");
 271     } else {
 272         unsigned        stack_entries[MAX_NUM_PC];
 273         unsigned        count = 0;
 274         rec->type = type;
 275         if (type == stack_logging_type_dealloc) {
 276             rec->argument = 0;
 277             rec->address = STACK_LOGGING_DISGUISE(arg1); // we disguise the address
 278         } else if (type == stack_logging_type_alloc) {
 279             rec->argument = arg1;
 280             rec->address = STACK_LOGGING_DISGUISE(result); // we disguise the address
 281         } else {
 282             rec->argument = arg2;
 283             rec->address = STACK_LOGGING_DISGUISE(arg1); // we disguise the address
 284         }
 285         // printf("Before getting samples  0x%x 0x%x 0x%x 0x%x -> 0x%x\n", type, arg1, arg2, arg3, result);
 286         thread_stack_pcs(stack_entries, MAX_NUM_PC - 1, &count);
 287         // We put at the bottom of the stack a marker that denotes the thread (+1 for good measure...)
 288         stack_entries[count++] = (int)pthread_self() + 1;
 289         /* now let's unique the sample */
 290         // printf("Uniquing 0x%x 0x%x 0x%x 0x%x -> 0x%x\n", type, arg1, arg2, arg3, result);
 291         rec->uniqued_stack = stack_logging_get_unique_stack(&stack_logging_the_record_list->uniquing_table, &stack_logging_the_record_list->uniquing_table_num_pages, stack_entries, count, num_hot_to_skip+2); // we additionally skip the warmest 2 entries that are an artefact of the code
 292         stack_logging_the_record_list->num_records++;
 293     }
 294     stack_logging_enable_logging = 1;
 295     stack_logging_the_record_list->lock = 0;
 296 }
 297
 298 static kern_return_t default_reader(task_t task, vm_address_t address, vm_size_t size, void **ptr) {
 299     *ptr = (void *)address;
 300     return 0;
 301 }
 302
 303 static kern_return_t get_remote_records(task_t task, memory_reader_t reader, stack_logging_record_list_t **records) {
 304     // sets records
 305     vm_address_t        *remote_records_address_ref;
 306     kern_return_t       err;
 307     *records = NULL;
 308     err = reader(task, (vm_address_t)&stack_logging_the_record_list, sizeof(vm_address_t), (void **)&remote_records_address_ref);
 309     if (err) return err;
 310     if (!*remote_records_address_ref) {
 311         // printf("stack_logging: no stack record\n");
 312         return 0;
 313     }
 314     // printf("stack_logging: stack records at %p\n", (void *)(*remote_records_address_ref));
 315     // printf("stack_logging: reading %d bytes\n", sizeof(stack_logging_record_list_t));
 316     err = reader(task, *remote_records_address_ref, sizeof(stack_logging_record_list_t), (void **)records); // get the list head
 317     if (err) return err;
 318     // printf("stack_logging: overall num bytes = %d\n", records->overall_num_bytes);
 319     return reader(task, *remote_records_address_ref, (*records)->overall_num_bytes, (void **)records);
 320 }
 321
 322 kern_return_t stack_logging_get_frames(task_t task, memory_reader_t reader, vm_address_t address, vm_address_t *stack_frames_buffer, unsigned max_stack_frames, unsigned *num_frames) {
 323     stack_logging_record_list_t *records;
 324     kern_return_t       err;
 325     unsigned            index;
 326     unsigned            disguised = STACK_LOGGING_DISGUISE(address);
 327     if (!reader) reader = default_reader;
 328     *num_frames = 0;
 329     err = get_remote_records(task, reader, &records);
 330     if (err || !records) return err;
 331     // printf("stack_logging: %d records\n", records->num_records);
 332     index = 0;
 333     while (index < records->num_records) {
 334         stack_logging_record_t  *record = records->records + index;
 335         if (record->address == disguised) {
 336             return stack_logging_frames_for_uniqued_stack(task, reader, record->uniqued_stack, stack_frames_buffer, max_stack_frames, num_frames);
 337         }
 338         index++;
 339     }
 340     fprintf(stderr, "*** stack_logging: no record found for 0x%x\n", address);
 341     return 0;
 342 }
 343
 344 kern_return_t stack_logging_enumerate_records(task_t task, memory_reader_t reader, vm_address_t address, void enumerator(stack_logging_record_t, void *), void *context) {
 345     stack_logging_record_list_t *records;
 346     kern_return_t       err;
 347     unsigned            index;
 348     unsigned            disguised = STACK_LOGGING_DISGUISE(address);
 349     if (!reader) reader = default_reader;
 350     err = get_remote_records(task, reader, &records);
 351     if (err || !records) return err;
 352     // printf("stack_logging: %d records\n", records->num_records);
 353     index = 0;
 354     while (index < records->num_records) {
 355         stack_logging_record_t  *record = records->records + index;
 356         if (!address || (record->address == disguised)) enumerator(*record, context);
 357         index++;
 358     }
 359     return 0;
 360 }
 361
 362 kern_return_t stack_logging_frames_for_uniqued_stack(task_t task, memory_reader_t reader, unsigned uniqued_stack, vm_address_t *stack_frames_buffer, unsigned max_stack_frames, unsigned *num_frames) {
 363     stack_logging_record_list_t *records;
 364     unsigned            *uniquing_table;
 365     kern_return_t       err;
 366     if (!reader) reader = default_reader;
 367     *num_frames = 0;
 368     err = get_remote_records(task, reader, &records);
 369     if (err || !records) return err;
 370     err = reader(task, (vm_address_t)records->uniquing_table, records->uniquing_table_num_pages * vm_page_size, (void **)&uniquing_table);
 371     if (err) return err;
 372     while (max_stack_frames && (uniqued_stack != -1)) {
 373         unsigned        thisPC;
 374         if ((uniqued_stack * 2 + 1) * sizeof(unsigned) >= records->uniquing_table_num_pages * vm_page_size) {
 375             fprintf(stderr, "*** stack_logging: Invalid uniqued stack 0x%x", uniqued_stack);
 376             break;
 377         }
 378         thisPC = uniquing_table[uniqued_stack * 2];
 379         uniqued_stack = uniquing_table[uniqued_stack * 2 + 1];
 380         if (!thisPC && !uniqued_stack) {
 381             // Invalid entry
 382             fprintf(stderr, "*** stack_logging: Invalid entry 0x%x", thisPC);
 383             break;
 384         }
 385         stack_frames_buffer[0] = thisPC;
 386         stack_frames_buffer++;
 387         (*num_frames)++;
 388         max_stack_frames--;
 389     }
 390     return 0;
 391 }