gen/stack_logging.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25
  26 /*      Bertrand from vmutils -> CF -> System */
  27
  28 #import "stack_logging.h"
  29
  30 #import <libc.h>
  31 #import <pthread.h>
  32 #import <mach/mach.h>
  33 #include <mach/vm_statistics.h>
  34 #import <malloc/malloc.h>
  35 #import <stdlib.h>
  36
  37 extern void spin_lock(int *);
  38
  39 static inline void *allocate_pages(unsigned bytes) {
  40     void *address;
  41     if (vm_allocate(mach_task_self(), (vm_address_t *)&address, bytes,
  42                     VM_MAKE_TAG(VM_MEMORY_ANALYSIS_TOOL)| TRUE)) {
  43         malloc_printf("malloc[%d]: Out of memory while stack logging\n", getpid());
  44         abort();
  45     }
  46     return (void *)address;
  47 }
  48
  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 *source, void *dest, unsigned bytes) {
  54     if (vm_copy(mach_task_self(), (vm_address_t)source, bytes, (vm_address_t)dest)) memmove(dest, source, bytes);
  55 }
  56
  57 /***************        Recording stack         ***********/
  58
  59 static void *first_frame_address(void) {
  60 #if 0
  61     return __builtin_frame_address(1);
  62 #elif defined(__ppc__)
  63     void *addr;
  64 #warning __builtin_frame_address IS BROKEN IN BEAKER: RADAR #2340421
  65     __asm__ volatile("mr %0, r1" : "=r" (addr));
  66     return addr;
  67 #else
  68 #warning first_frame_address WILL NOT BE FUNCTIONAL ON THIS ARCHITECTURE
  69     return NULL;
  70 #endif
  71 }
  72
  73 static void *next_frame_address(void *addr) {
  74     void *ret;
  75 #if defined(__MACH__) && defined(__i386__)
  76     __asm__ volatile("movl (%1),%0" : "=r" (ret) : "r" (addr));
  77 #elif defined(__MACH__) && defined(__ppc__)
  78     __asm__ volatile("lwz %0,0x0(%1)" : "=r" (ret) : "b" (addr));
  79 #elif defined(__hpux__)
  80     __asm__ volatile("ldw 0x0(%1),%0" : "=r" (ret) : "r" (addr));
  81 #elif defined(__svr4__)
  82     __asm__ volatile("ta 0x3");
  83     __asm__ volatile("ld [%1 + 56],%0" : "=r" (ret) : "r" (addr));
  84 #else
  85 #error Unknown architecture
  86 #endif
  87     return ret;
  88 }
  89
  90 #if defined(__i386__) || defined (__m68k__)
  91 #define FP_LINK_OFFSET 1
  92 #elif defined(__ppc__)
  93 #define FP_LINK_OFFSET 2
  94 #elif defined(__hppa__)
  95 #define FP_LINK_OFFSET -5
  96 #elif defined(__sparc__)
  97 #define FP_LINK_OFFSET 14
  98 #else
  99 #error  ********** Unimplemented architecture
 100 #endif
 101
 102 void thread_stack_pcs(vm_address_t *buffer, unsigned max, unsigned *nb) {
 103     void *addr;
 104     addr = first_frame_address();
 105     *nb = 0;
 106     while ((addr >= (void *)0x800) && (max--)) {
 107         vm_address_t    fp_link = (vm_address_t)(((unsigned *)addr)+FP_LINK_OFFSET);
 108         void    *addr2;
 109         buffer[*nb] = *((vm_address_t *)fp_link);
 110         (*nb)++;
 111         addr2 = next_frame_address(addr);
 112 #if defined(__ppc__)
 113         if ((unsigned)addr2 <= (unsigned)addr) break; // catch bozo frames
 114 #endif
 115         addr = addr2;
 116     }
 117 }
 118
 119 /***************        Uniquing stack          ***********/
 120
 121 #define MAX_COLLIDE     8
 122
 123 #define MAX_NUM_PC      512
 124
 125 static int enter_pair_in_table(unsigned *table, unsigned numPages, unsigned *uniquedParent, unsigned thisPC) {
 126     // uniquedParent is in-out; return 1 is collisions max not exceeded
 127     unsigned    base = numPages * vm_page_size / (sizeof(int)*2*2);
 128     unsigned    hash = base + (((*uniquedParent) << 4) ^ (thisPC >> 2)) % (base - 1); // modulo odd number for hashing
 129     unsigned    collisions = MAX_COLLIDE;
 130     while (collisions--) {
 131         unsigned        *head = table + hash*2;
 132         if (! head[0] && !head[1]) {
 133             /* end of chain; store this entry! */
 134             /* Note that we need to test for both head[0] and head[1] as (0, -1) is a valid entry */
 135             head[0] = thisPC;
 136             head[1] = *uniquedParent;
 137             *uniquedParent = hash;
 138             return 1;
 139         }
 140         if ((head[0] == thisPC) && (head[1] == *uniquedParent)) {
 141             /* we found the proper entry, the value for the pair is the entry offset */
 142             *uniquedParent = hash;
 143             return 1;
 144         }
 145         hash++;
 146         if (hash == base*2) hash = base;
 147     }
 148     return 0;
 149 }
 150
 151 unsigned stack_logging_get_unique_stack(unsigned **table, unsigned *table_num_pages, unsigned *stack_entries, unsigned count, unsigned num_hot_to_skip) {
 152     unsigned    uniquedParent = (unsigned)-1;
 153     // we skip the warmest entries that are an artefact of the code
 154     while (num_hot_to_skip--) {
 155         if (count > 0) { stack_entries++; count--; }
 156     }
 157     while (count--) {
 158         unsigned        thisPC = stack_entries[count];
 159         while (!enter_pair_in_table(*table, *table_num_pages, &uniquedParent, thisPC)) {
 160             unsigned    *newTable;
 161             unsigned    oldBytes = (*table_num_pages) * vm_page_size;
 162             newTable = allocate_pages(oldBytes*2);
 163             copy_pages(*table, newTable, oldBytes);
 164             deallocate_pages(*table, oldBytes);
 165             *table_num_pages *= 2;
 166             *table = newTable;
 167         }
 168     }
 169     return uniquedParent;
 170 }
 171
 172 /***************        Logging stack and arguments             ***********/
 173
 174 stack_logging_record_list_t *stack_logging_the_record_list = NULL;
 175
 176 int stack_logging_enable_logging = 0;
 177
 178 int stack_logging_dontcompact = 0;
 179
 180 static stack_logging_record_list_t *GrowLogRecords(stack_logging_record_list_t *records, unsigned desiredNumRecords) {
 181     stack_logging_record_list_t *new_records;
 182     unsigned    old_size = records->overall_num_bytes;
 183     if (desiredNumRecords*sizeof(stack_logging_record_t)+sizeof(stack_logging_record_list_t) < records->overall_num_bytes) return records;
 184     records->overall_num_bytes += records->overall_num_bytes + vm_page_size; // in order to always get an even number of pages
 185     new_records = allocate_pages(records->overall_num_bytes);
 186     copy_pages(records, new_records, old_size);
 187     deallocate_pages(records, old_size);
 188     return new_records;
 189 }
 190
 191 static void prepare_to_log_stack(void) {
 192     if (!stack_logging_the_record_list) {
 193         unsigned        totalSize = 4 * vm_page_size;
 194         stack_logging_the_record_list = allocate_pages(totalSize);
 195         memset(stack_logging_the_record_list, 0, sizeof(stack_logging_record_list_t));
 196         stack_logging_the_record_list->overall_num_bytes = totalSize;
 197         stack_logging_the_record_list->uniquing_table_num_pages = 128;
 198         stack_logging_the_record_list->uniquing_table = allocate_pages(stack_logging_the_record_list->uniquing_table_num_pages * vm_page_size);
 199     }
 200 }
 201
 202 void stack_logging_log_stack(unsigned type, unsigned arg1, unsigned arg2, unsigned arg3, unsigned result, unsigned num_hot_to_skip) {
 203     stack_logging_record_t      *rec;
 204     if (!stack_logging_enable_logging) return;
 205     // printf("stack_logging_log_stack 0x%x 0x%x 0x%x 0x%x -> 0x%x\n", type, arg1, arg2, arg3, result);
 206     if (type & stack_logging_flag_zone) {
 207         // just process it now and be done with it!
 208         arg1 = arg2; arg2 = arg3; arg3 = 0; type &= ~stack_logging_flag_zone;
 209     }
 210     if (type & stack_logging_flag_calloc) {
 211         // just process it now and be done with it!
 212         arg1 *= arg2; arg2 = arg3; arg3 = 0; type &= ~stack_logging_flag_calloc;
 213     }
 214     if (type & stack_logging_flag_object) {
 215         unsigned        *class = (unsigned *)arg1;
 216         arg1 = arg2 + class[5]; // corresponds to the instance_size field
 217         arg2 = 0; arg3 = 0; type = stack_logging_type_alloc;
 218     }
 219     if (type & stack_logging_flag_cleared) {
 220         type &= ~stack_logging_flag_cleared;
 221     }
 222     if (type & stack_logging_flag_handle) {
 223         if (stack_logging_type_alloc) {
 224             if (!result) return;
 225             stack_logging_log_stack(stack_logging_type_alloc, 0, 0, 0, result, num_hot_to_skip+1);
 226             stack_logging_log_stack(stack_logging_type_alloc, arg1, 0, 0, *((int *)result), num_hot_to_skip+1);
 227             return;
 228         }
 229         if (stack_logging_type_dealloc) {
 230             if (!arg1) return;
 231             stack_logging_log_stack(stack_logging_type_dealloc, *((int *)arg1), 0, 0, 0, num_hot_to_skip+1);
 232             stack_logging_log_stack(stack_logging_type_dealloc, arg1, 0, 0, 0, num_hot_to_skip+1);
 233             return;
 234         }
 235         printf("*** Unknown logging type: 0x%x\n", type);
 236     }
 237     if (type == stack_logging_flag_set_handle_size) {
 238         if (!arg1) return;
 239         // Thanks to a horrible hack, arg3 contains the prvious handle value
 240         if (arg3 == *((int *)arg1)) return;
 241         stack_logging_log_stack(stack_logging_type_dealloc, arg3, 0, 0, 0, num_hot_to_skip+1);
 242         stack_logging_log_stack(stack_logging_type_alloc, arg2, 0, 0, *((int *)arg1), num_hot_to_skip+1);
 243         return;
 244     }
 245     if (type == (stack_logging_type_dealloc|stack_logging_type_alloc)) {
 246         if (arg1 == result) return; // realloc had no effect, skipping
 247         if (!arg1) {
 248             // realloc(NULL, size) same as malloc(size)
 249             type = stack_logging_type_alloc; arg1 = arg2; arg2 = arg3; arg3 = 0;
 250         } else {
 251             // realloc(arg1, arg2) -> result is same as free(arg1); malloc(arg2) -> result
 252             stack_logging_log_stack(stack_logging_type_dealloc, arg1, 0, 0, 0, num_hot_to_skip+1);
 253             stack_logging_log_stack(stack_logging_type_alloc, arg2, 0, 0, result, num_hot_to_skip+1);
 254             return;
 255         }
 256     }
 257     if (type == stack_logging_type_dealloc) {
 258         // simple free
 259         if (!arg1) return; // free(nil)
 260     }
 261     prepare_to_log_stack();
 262     spin_lock(&stack_logging_the_record_list->lock);
 263     stack_logging_enable_logging = 0;
 264     stack_logging_the_record_list = GrowLogRecords(stack_logging_the_record_list, stack_logging_the_record_list->num_records + 1);
 265     rec = stack_logging_the_record_list->records + stack_logging_the_record_list->num_records;
 266     // We take care of the common case of alloc-dealloc
 267     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))) {
 268         stack_logging_the_record_list->num_records--;
 269         // printf("Erased previous record in alloc-dealloc sequence\n");
 270     } else {
 271         unsigned        stack_entries[MAX_NUM_PC];
 272         unsigned        count = 0;
 273         rec->type = type;
 274         if (type == stack_logging_type_dealloc) {
 275             rec->argument = 0;
 276             rec->address = STACK_LOGGING_DISGUISE(arg1); // we disguise the address
 277         } else if (type == stack_logging_type_alloc) {
 278             rec->argument = arg1;
 279             rec->address = STACK_LOGGING_DISGUISE(result); // we disguise the address
 280         } else {
 281             rec->argument = arg2;
 282             rec->address = STACK_LOGGING_DISGUISE(arg1); // we disguise the address
 283         }
 284         // printf("Before getting samples  0x%x 0x%x 0x%x 0x%x -> 0x%x\n", type, arg1, arg2, arg3, result);
 285         thread_stack_pcs(stack_entries, MAX_NUM_PC - 1, &count);
 286         // We put at the bottom of the stack a marker that denotes the thread (+1 for good measure...)
 287         stack_entries[count++] = (int)pthread_self() + 1;
 288         /* now let's unique the sample */
 289         // printf("Uniquing 0x%x 0x%x 0x%x 0x%x -> 0x%x\n", type, arg1, arg2, arg3, result);
 290         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
 291         stack_logging_the_record_list->num_records++;
 292     }
 293     stack_logging_enable_logging = 1;
 294     stack_logging_the_record_list->lock = 0;
 295 }
 296
 297 static kern_return_t default_reader(task_t task, vm_address_t address, vm_size_t size, void **ptr) {
 298     *ptr = (void *)address;
 299     return 0;
 300 }
 301
 302 static kern_return_t get_remote_records(task_t task, memory_reader_t reader, stack_logging_record_list_t **records) {
 303     // sets records
 304     vm_address_t        *remote_records_address_ref;
 305     kern_return_t       err;
 306     *records = NULL;
 307     err = reader(task, (vm_address_t)&stack_logging_the_record_list, sizeof(vm_address_t), (void **)&remote_records_address_ref);
 308     if (err) return err;
 309     if (!*remote_records_address_ref) {
 310         // printf("stack_logging: no stack record\n");
 311         return 0;
 312     }
 313     // printf("stack_logging: stack records at %p\n", (void *)(*remote_records_address_ref));
 314     // printf("stack_logging: reading %d bytes\n", sizeof(stack_logging_record_list_t));
 315     err = reader(task, *remote_records_address_ref, sizeof(stack_logging_record_list_t), (void **)records); // get the list head
 316     if (err) return err;
 317     // printf("stack_logging: overall num bytes = %d\n", records->overall_num_bytes);
 318     return reader(task, *remote_records_address_ref, (*records)->overall_num_bytes, (void **)records);
 319 }
 320
 321 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) {
 322     stack_logging_record_list_t *records;
 323     kern_return_t       err;
 324     unsigned            index;
 325     unsigned            disguised = STACK_LOGGING_DISGUISE(address);
 326     if (!reader) reader = default_reader;
 327     *num_frames = 0;
 328     err = get_remote_records(task, reader, &records);
 329     if (err || !records) return err;
 330     // printf("stack_logging: %d records\n", records->num_records);
 331     index = 0;
 332     while (index < records->num_records) {
 333         stack_logging_record_t  *record = records->records + index;
 334         if (record->address == disguised) {
 335             return stack_logging_frames_for_uniqued_stack(task, reader, record->uniqued_stack, stack_frames_buffer, max_stack_frames, num_frames);
 336         }
 337         index++;
 338     }
 339     fprintf(stderr, "*** stack_logging: no record found for 0x%x\n", address);
 340     return 0;
 341 }
 342
 343 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) {
 344     stack_logging_record_list_t *records;
 345     kern_return_t       err;
 346     unsigned            index;
 347     unsigned            disguised = STACK_LOGGING_DISGUISE(address);
 348     if (!reader) reader = default_reader;
 349     err = get_remote_records(task, reader, &records);
 350     if (err || !records) return err;
 351     // printf("stack_logging: %d records\n", records->num_records);
 352     index = 0;
 353     while (index < records->num_records) {
 354         stack_logging_record_t  *record = records->records + index;
 355         if (!address || (record->address == disguised)) enumerator(*record, context);
 356         index++;
 357     }
 358     return 0;
 359 }
 360
 361 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) {
 362     stack_logging_record_list_t *records;
 363     unsigned            *uniquing_table;
 364     kern_return_t       err;
 365     if (!reader) reader = default_reader;
 366     *num_frames = 0;
 367     err = get_remote_records(task, reader, &records);
 368     if (err || !records) return err;
 369     err = reader(task, (vm_address_t)records->uniquing_table, records->uniquing_table_num_pages * vm_page_size, (void **)&uniquing_table);
 370     if (err) return err;
 371     while (max_stack_frames && (uniqued_stack != -1)) {
 372         unsigned        thisPC;
 373         if ((uniqued_stack * 2 + 1) * sizeof(unsigned) >= records->uniquing_table_num_pages * vm_page_size) {
 374             fprintf(stderr, "*** stack_logging: Invalid uniqued stack 0x%x", uniqued_stack);
 375             break;
 376         }
 377         thisPC = uniquing_table[uniqued_stack * 2];
 378         uniqued_stack = uniquing_table[uniqued_stack * 2 + 1];
 379         if (!thisPC && !uniqued_stack) {
 380             // Invalid entry
 381             fprintf(stderr, "*** stack_logging: Invalid entry 0x%x", thisPC);
 382             break;
 383         }
 384         stack_frames_buffer[0] = thisPC;
 385         stack_frames_buffer++;
 386         (*num_frames)++;
 387         max_stack_frames--;
 388     }
 389     return 0;
 390 }