smatch_db.c

   1 /*
   2  * smatch/smatch_db.c
   3  *
   4  * Copyright (C) 2010 Dan Carpenter.
   5  *
   6  * Licensed under the Open Software License version 1.1
   7  *
   8  */
   9
  10 #include <string.h>
  11 #include <errno.h>
  12 #include <sqlite3.h>
  13 #include "smatch.h"
  14 #include "smatch_slist.h"
  15 #include "smatch_extra.h"
  16
  17 static sqlite3 *db;
  18
  19 struct def_callback {
  20         int hook_type;
  21         void (*callback)(const char *name, struct symbol *sym, char *key, char *value);
  22 };
  23 ALLOCATOR(def_callback, "definition db hook callbacks");
  24 DECLARE_PTR_LIST(callback_list, struct def_callback);
  25 static struct callback_list *callbacks;
  26
  27 struct member_info_callback {
  28         int owner;
  29         void (*callback)(char *fn, int param, char *printed_name, struct smatch_state *state);
  30 };
  31 ALLOCATOR(member_info_callback, "caller_info callbacks");
  32 DECLARE_PTR_LIST(member_info_cb_list, struct member_info_callback);
  33 static struct member_info_cb_list *member_callbacks;
  34
  35 struct call_implies_callback {
  36         int type;
  37         void (*callback)(struct expression *arg, char *value);
  38 };
  39 ALLOCATOR(call_implies_callback, "call_implies callbacks");
  40 DECLARE_PTR_LIST(call_implies_cb_list, struct call_implies_callback);
  41 static struct call_implies_cb_list *call_implies_cb_list;
  42
  43 void sql_exec(int (*callback)(void*, int, char**, char**), const char *sql)
  44 {
  45         char *err = NULL;
  46         int rc;
  47
  48         if (option_no_db || !db)
  49                 return;
  50
  51         rc = sqlite3_exec(db, sql, callback, 0, &err);
  52         if (rc != SQLITE_OK)
  53                 fprintf(stderr, "SQL error #2: %s\n", err);
  54 }
  55
  56 void add_definition_db_callback(void (*callback)(const char *name, struct symbol *sym, char *key, char *value), int type)
  57 {
  58         struct def_callback *def_callback = __alloc_def_callback(0);
  59
  60         def_callback->hook_type = type;
  61         def_callback->callback = callback;
  62         add_ptr_list(&callbacks, def_callback);
  63 }
  64
  65 void add_member_info_callback(int owner, void (*callback)(char *fn, int param, char *printed_name, struct smatch_state *state))
  66 {
  67         struct member_info_callback *member_callback = __alloc_member_info_callback(0);
  68
  69         member_callback->owner = owner;
  70         member_callback->callback = callback;
  71         add_ptr_list(&member_callbacks, member_callback);
  72 }
  73
  74 void add_db_fn_call_callback(int type, void (*callback)(struct expression *arg, char *value))
  75 {
  76         struct call_implies_callback *cb = __alloc_call_implies_callback(0);
  77
  78         cb->type = type;
  79         cb->callback = callback;
  80         add_ptr_list(&call_implies_cb_list, cb);
  81 }
  82
  83 static struct range_list *return_range_list;
  84 static int db_return_callback(void *unused, int argc, char **argv, char **azColName)
  85 {
  86         struct range_list *rl = NULL;
  87
  88         if (argc != 1)
  89                 return 0;
  90
  91         get_value_ranges(argv[0], &rl);
  92         return_range_list = range_list_union(return_range_list, rl);
  93
  94         return 0;
  95 }
  96
  97 struct range_list *db_return_vals(struct expression *expr)
  98 {
  99         struct symbol *sym;
 100         static char sql_filter[1024];
 101
 102         if (expr->type != EXPR_CALL)
 103                 return NULL;
 104         if (expr->fn->type != EXPR_SYMBOL)
 105                 return NULL;
 106         sym = expr->fn->symbol;
 107         if (!sym)
 108                 return NULL;
 109
 110         if (sym->ctype.modifiers & MOD_STATIC) {
 111                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s' and type = %d;",
 112                          get_filename(), sym->ident->name, RETURN_VALUE);
 113         } else {
 114                 snprintf(sql_filter, 1024, "function = '%s' and type = %d;",
 115                                 sym->ident->name, RETURN_VALUE);
 116         }
 117
 118         return_range_list = NULL;
 119         run_sql(db_return_callback, "select value from return_info where %s",
 120                  sql_filter);
 121         return return_range_list;
 122 }
 123
 124 static void match_call_hack(struct expression *expr)
 125 {
 126         char *name;
 127
 128         /*
 129          * we just want to record something in the database so that if we have
 130          * two calls like:  frob(4); frob(some_unkown); then on the recieving
 131          * side we know that sometimes frob is called with unknown parameters.
 132          */
 133
 134         name = get_fnptr_name(expr->fn);
 135         if (!name)
 136                 return;
 137         if (ptr_list_empty(expr->args))
 138                 return;
 139         sm_msg("info: passes param_value '%s' -1 '$$' min-max", name);
 140         free_string(name);
 141 }
 142
 143 static void print_struct_members(char *fn, struct expression *expr, int param, struct state_list *slist,
 144         void (*callback)(char *fn, int param, char *printed_name, struct smatch_state *state))
 145 {
 146         struct sm_state *sm;
 147         char *name;
 148         struct symbol *sym;
 149         int len;
 150         char printed_name[256];
 151         int is_address = 0;
 152
 153         expr = strip_expr(expr);
 154         if (expr->type == EXPR_PREOP && expr->op == '&') {
 155                 expr = strip_expr(expr->unop);
 156                 is_address = 1;
 157         }
 158
 159         name = get_variable_from_expr(expr, &sym);
 160         if (!name || !sym)
 161                 goto free;
 162
 163         len = strlen(name);
 164         FOR_EACH_PTR(slist, sm) {
 165                 if (sm->sym != sym)
 166                         continue;
 167                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 168                         continue;
 169                 if (is_address)
 170                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 171                 else
 172                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 173                 callback(fn, param, printed_name, sm->state);
 174         } END_FOR_EACH_PTR(sm);
 175 free:
 176         free_string(name);
 177 }
 178
 179 static void match_call_info(struct expression *expr)
 180 {
 181         struct member_info_callback *cb;
 182         struct expression *arg;
 183         struct state_list *slist;
 184         char *name;
 185         int i;
 186
 187         name = get_fnptr_name(expr->fn);
 188         if (!name)
 189                 return;
 190
 191         FOR_EACH_PTR(member_callbacks, cb) {
 192                 slist = get_all_states(cb->owner);
 193                 i = 0;
 194                 FOR_EACH_PTR(expr->args, arg) {
 195                         print_struct_members(name, arg, i, slist, cb->callback);
 196                         i++;
 197                 } END_FOR_EACH_PTR(arg);
 198         } END_FOR_EACH_PTR(cb);
 199
 200         free_string(name);
 201         free_slist(&slist);
 202 }
 203
 204 static int get_param(int param, char **name, struct symbol **sym)
 205 {
 206         struct symbol *arg;
 207         int i;
 208
 209         i = 0;
 210         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 211                 /*
 212                  * this is a temporary hack to work around a bug (I think in sparse?)
 213                  * 2.6.37-rc1:fs/reiserfs/journal.o
 214                  * If there is a function definition without parameter name found
 215                  * after a function implementation then it causes a crash.
 216                  * int foo() {}
 217                  * int bar(char *);
 218                  */
 219                 if (arg->ident->name < (char *)100)
 220                         continue;
 221                 if (i == param && arg->ident->name) {
 222                         *name = arg->ident->name;
 223                         *sym = arg;
 224                         return TRUE;
 225                 }
 226                 i++;
 227         } END_FOR_EACH_PTR(arg);
 228
 229         return FALSE;
 230 }
 231
 232 static struct state_list *final_states;
 233 static int prev_func_id = -1;
 234 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 235 {
 236         int func_id;
 237         long type;
 238         long param;
 239         char *name;
 240         struct symbol *sym;
 241         struct def_callback *def_callback;
 242
 243         if (argc != 5)
 244                 return 0;
 245
 246         func_id = atoi(argv[0]);
 247         errno = 0;
 248         type = strtol(argv[1], NULL, 10);
 249         param = strtol(argv[2], NULL, 10);
 250         if (errno)
 251                 return 0;
 252
 253         if (prev_func_id == -1)
 254                 prev_func_id = func_id;
 255         if (func_id != prev_func_id) {
 256                 merge_slist(&final_states, __pop_fake_cur_slist());
 257                 __push_fake_cur_slist();
 258                 __unnullify_path();
 259                 prev_func_id = func_id;
 260         }
 261
 262         if (param == -1 || !get_param(param, &name, &sym))
 263                 return 0;
 264
 265         FOR_EACH_PTR(callbacks, def_callback) {
 266                 if (def_callback->hook_type == type)
 267                         def_callback->callback(name, sym, argv[3], argv[4]);
 268         } END_FOR_EACH_PTR(def_callback);
 269
 270         return 0;
 271 }
 272
 273 static void get_direct_callers(struct symbol *sym)
 274 {
 275         char sql_filter[1024];
 276
 277         if (sym->ctype.modifiers & MOD_STATIC) {
 278                 snprintf(sql_filter, 1024,
 279                          "file = '%s' and function = '%s' order by function_id;",
 280                          get_filename(), sym->ident->name);
 281         } else {
 282                 snprintf(sql_filter, 1024,
 283                          "function = '%s' order by function_id;",
 284                          sym->ident->name);
 285         }
 286
 287         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 288                 " where %s", sql_filter);
 289 }
 290
 291 static char *ptr_name;
 292 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 293 {
 294         if (!ptr_name)
 295                 ptr_name = alloc_string(argv[0]);
 296         return 0;
 297 }
 298
 299 static void get_function_pointer_callers(struct symbol *sym)
 300 {
 301         ptr_name = NULL;
 302         run_sql(get_ptr_name, "select ptr from function_ptr where function = '%s'",
 303                 sym->ident->name);
 304         if (!ptr_name)
 305                 return;
 306
 307         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 308                 " where function = '%s' order by function_id", ptr_name);
 309 }
 310
 311 static void match_data_from_db(struct symbol *sym)
 312 {
 313         struct sm_state *sm;
 314
 315         if (!sym || !sym->ident || !sym->ident->name)
 316                 return;
 317
 318         __push_fake_cur_slist();
 319         __unnullify_path();
 320         prev_func_id = -1;
 321
 322         get_direct_callers(sym);
 323         get_function_pointer_callers(sym);
 324
 325         merge_slist(&final_states, __pop_fake_cur_slist());
 326
 327         FOR_EACH_PTR(final_states, sm) {
 328                 __set_sm(sm);
 329         } END_FOR_EACH_PTR(sm);
 330
 331         free_slist(&final_states);
 332 }
 333
 334 static void match_function_assign(struct expression *expr)
 335 {
 336         struct expression *right = expr->right;
 337         struct symbol *sym;
 338         char *fn_name;
 339         char *ptr_name;
 340
 341         if (right->type == EXPR_PREOP && right->op == '&')
 342                 right = right->unop;
 343         if (right->type != EXPR_SYMBOL)
 344                 return;
 345         sym = get_type(right);
 346         if (!sym || sym->type != SYM_FN)
 347                 return;
 348
 349         fn_name = get_variable_from_expr(right, NULL);
 350         ptr_name = get_fnptr_name(expr->left);
 351         if (!fn_name || !ptr_name)
 352                 goto free;
 353
 354         sm_msg("info: sets_fn_ptr '%s' '%s'", ptr_name, fn_name);
 355
 356 free:
 357         free_string(fn_name);
 358         free_string(ptr_name);
 359 }
 360
 361 static struct expression *call_implies_call_expr;
 362 static int call_implies_callbacks(void *unused, int argc, char **argv, char **azColName)
 363 {
 364         struct call_implies_callback *cb;
 365         struct expression *arg;
 366         int type;
 367         int param;
 368
 369         if (argc != 4)
 370                 return 0;
 371
 372         type = atoi(argv[1]);
 373         param = atoi(argv[2]);
 374
 375         FOR_EACH_PTR(call_implies_cb_list, cb) {
 376                 if (cb->type != type)
 377                         continue;
 378                 arg = get_argument_from_call_expr(call_implies_call_expr->args, param);
 379                 if (!arg)
 380                         continue;
 381                 cb->callback(arg, argv[3]);
 382         } END_FOR_EACH_PTR(cb);
 383
 384         return 0;
 385 }
 386
 387 static void match_call_implies(struct expression *expr)
 388 {
 389         struct symbol *sym;
 390         static char sql_filter[1024];
 391
 392         if (expr->fn->type != EXPR_SYMBOL)
 393                 return;
 394         sym = expr->fn->symbol;
 395         if (!sym)
 396                 return;
 397
 398         if (sym->ctype.modifiers & MOD_STATIC) {
 399                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 400                          get_filename(), sym->ident->name);
 401         } else {
 402                 snprintf(sql_filter, 1024, "function = '%s';",
 403                                 sym->ident->name);
 404         }
 405
 406         call_implies_call_expr = expr;
 407         run_sql(call_implies_callbacks,
 408                 "select function, type, parameter, value from call_implies where %s",
 409                 sql_filter);
 410         return;
 411 }
 412
 413 static void print_initializer_list(struct expression_list *expr_list,
 414                 struct symbol *struct_type)
 415 {
 416         struct expression *expr;
 417         struct symbol *base_type;
 418
 419         FOR_EACH_PTR(expr_list, expr) {
 420                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 421                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 422                         continue;
 423                 }
 424                 if (expr->type != EXPR_IDENTIFIER)
 425                         continue;
 426                 if (!expr->expr_ident)
 427                         continue;
 428                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 429                         continue;
 430                 base_type = get_type(expr->ident_expression);
 431                 if (!base_type || base_type->type != SYM_FN)
 432                         continue;
 433                 sm_msg("info: sets_fn_ptr '(struct %s)->%s' '%s'", struct_type->ident->name,
 434                        expr->expr_ident->name,
 435                        expr->ident_expression->symbol_name->name);
 436         } END_FOR_EACH_PTR(expr);
 437
 438 }
 439
 440 static void global_variable(struct symbol *sym)
 441 {
 442         struct symbol *struct_type;
 443
 444         if (!sym->ident)
 445                 return;
 446         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 447                 return;
 448         struct_type = get_base_type(sym);
 449         if (!struct_type)
 450                 return;
 451         if (struct_type->type == SYM_ARRAY) {
 452                 struct_type = get_base_type(struct_type);
 453                 if (!struct_type)
 454                         return;
 455         }
 456         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 457                 return;
 458         print_initializer_list(sym->initializer->expr_list, struct_type);
 459 }
 460
 461 void open_smatch_db(void)
 462 {
 463 #ifdef SQLITE_OPEN_READONLY
 464         int rc;
 465
 466         if (option_no_db)
 467                 return;
 468
 469         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 470         if (rc != SQLITE_OK) {
 471                 option_no_db = 1;
 472                 return;
 473         }
 474         return;
 475 #else
 476         option_no_db = 1;
 477         return;
 478 #endif
 479 }
 480
 481 void register_definition_db_callbacks(int id)
 482 {
 483         if (option_info) {
 484                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 485                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 486                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 487                 add_hook(&global_variable, BASE_HOOK);
 488                 add_hook(&global_variable, DECLARATION_HOOK);
 489         }
 490
 491         if (option_no_db)
 492                 return;
 493
 494         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 495         add_hook(&match_call_implies, FUNCTION_CALL_HOOK);
 496 }