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