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, char *global_static, 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, char *global_static, 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 static = 0 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 '$$' min-max %s",
 140                name, is_static(expr->fn) ? "static" : "global");
 141         free_string(name);
 142 }
 143
 144 static void print_struct_members(char *fn, char *global_static, struct expression *expr, int param, struct state_list *slist,
 145         void (*callback)(char *fn, char *global_static, int param, char *printed_name, struct smatch_state *state))
 146 {
 147         struct sm_state *sm;
 148         char *name;
 149         struct symbol *sym;
 150         int len;
 151         char printed_name[256];
 152         int is_address = 0;
 153
 154         expr = strip_expr(expr);
 155         if (expr->type == EXPR_PREOP && expr->op == '&') {
 156                 expr = strip_expr(expr->unop);
 157                 is_address = 1;
 158         }
 159
 160         name = get_variable_from_expr(expr, &sym);
 161         if (!name || !sym)
 162                 goto free;
 163
 164         len = strlen(name);
 165         FOR_EACH_PTR(slist, sm) {
 166                 if (sm->sym != sym)
 167                         continue;
 168                 if (strncmp(name, sm->name, len) || sm->name[len] == '\0')
 169                         continue;
 170                 if (is_address)
 171                         snprintf(printed_name, sizeof(printed_name), "$$->%s", sm->name + len + 1);
 172                 else
 173                         snprintf(printed_name, sizeof(printed_name), "$$%s", sm->name + len);
 174                 callback(fn, global_static, param, printed_name, sm->state);
 175         } END_FOR_EACH_PTR(sm);
 176 free:
 177         free_string(name);
 178 }
 179
 180 static void match_call_info(struct expression *expr)
 181 {
 182         struct member_info_callback *cb;
 183         struct expression *arg;
 184         struct state_list *slist;
 185         char *name;
 186         int i;
 187         char *gs;
 188
 189         name = get_fnptr_name(expr->fn);
 190         if (!name)
 191                 return;
 192
 193         if (is_static(expr->fn))
 194                 gs = (char *)"static";
 195         else
 196                 gs = (char *)"global";
 197
 198         FOR_EACH_PTR(member_callbacks, cb) {
 199                 slist = get_all_states(cb->owner);
 200                 i = 0;
 201                 FOR_EACH_PTR(expr->args, arg) {
 202                         print_struct_members(name, gs, arg, i, slist, cb->callback);
 203                         i++;
 204                 } END_FOR_EACH_PTR(arg);
 205         } END_FOR_EACH_PTR(cb);
 206
 207         free_string(name);
 208         free_slist(&slist);
 209 }
 210
 211 static int get_param(int param, char **name, struct symbol **sym)
 212 {
 213         struct symbol *arg;
 214         int i;
 215
 216         i = 0;
 217         FOR_EACH_PTR(cur_func_sym->ctype.base_type->arguments, arg) {
 218                 /*
 219                  * this is a temporary hack to work around a bug (I think in sparse?)
 220                  * 2.6.37-rc1:fs/reiserfs/journal.o
 221                  * If there is a function definition without parameter name found
 222                  * after a function implementation then it causes a crash.
 223                  * int foo() {}
 224                  * int bar(char *);
 225                  */
 226                 if (arg->ident->name < (char *)100)
 227                         continue;
 228                 if (i == param && arg->ident->name) {
 229                         *name = arg->ident->name;
 230                         *sym = arg;
 231                         return TRUE;
 232                 }
 233                 i++;
 234         } END_FOR_EACH_PTR(arg);
 235
 236         return FALSE;
 237 }
 238
 239 static struct state_list *final_states;
 240 static int prev_func_id = -1;
 241 static int db_callback(void *unused, int argc, char **argv, char **azColName)
 242 {
 243         int func_id;
 244         long type;
 245         long param;
 246         char *name;
 247         struct symbol *sym;
 248         struct def_callback *def_callback;
 249
 250         if (argc != 5)
 251                 return 0;
 252
 253         func_id = atoi(argv[0]);
 254         errno = 0;
 255         type = strtol(argv[1], NULL, 10);
 256         param = strtol(argv[2], NULL, 10);
 257         if (errno)
 258                 return 0;
 259
 260         if (prev_func_id == -1)
 261                 prev_func_id = func_id;
 262         if (func_id != prev_func_id) {
 263                 merge_slist(&final_states, __pop_fake_cur_slist());
 264                 __push_fake_cur_slist();
 265                 __unnullify_path();
 266                 prev_func_id = func_id;
 267         }
 268
 269         if (param == -1 || !get_param(param, &name, &sym))
 270                 return 0;
 271
 272         FOR_EACH_PTR(callbacks, def_callback) {
 273                 if (def_callback->hook_type == type)
 274                         def_callback->callback(name, sym, argv[3], argv[4]);
 275         } END_FOR_EACH_PTR(def_callback);
 276
 277         return 0;
 278 }
 279
 280 static void get_direct_callers(struct symbol *sym)
 281 {
 282         char sql_filter[1024];
 283
 284         if (sym->ctype.modifiers & MOD_STATIC) {
 285                 snprintf(sql_filter, 1024,
 286                          "file = '%s' and function = '%s' order by function_id;",
 287                          get_filename(), sym->ident->name);
 288         } else {
 289                 snprintf(sql_filter, 1024,
 290                          "function = '%s' and static = 0 order by function_id;",
 291                          sym->ident->name);
 292         }
 293
 294         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 295                 " where %s", sql_filter);
 296 }
 297
 298 static char *ptr_name;
 299 static int get_ptr_name(void *unused, int argc, char **argv, char **azColName)
 300 {
 301         if (!ptr_name)
 302                 ptr_name = alloc_string(argv[0]);
 303         return 0;
 304 }
 305
 306 static void get_function_pointer_callers(struct symbol *sym)
 307 {
 308         ptr_name = NULL;
 309         run_sql(get_ptr_name, "select ptr from function_ptr where function = '%s'",
 310                 sym->ident->name);
 311         if (!ptr_name)
 312                 return;
 313
 314         run_sql(db_callback, "select function_id, type, parameter, key, value from caller_info"
 315                 " where function = '%s' order by function_id", ptr_name);
 316 }
 317
 318 static void match_data_from_db(struct symbol *sym)
 319 {
 320         struct sm_state *sm;
 321
 322         if (!sym || !sym->ident || !sym->ident->name)
 323                 return;
 324
 325         __push_fake_cur_slist();
 326         __unnullify_path();
 327         prev_func_id = -1;
 328
 329         get_direct_callers(sym);
 330         get_function_pointer_callers(sym);
 331
 332         merge_slist(&final_states, __pop_fake_cur_slist());
 333
 334         FOR_EACH_PTR(final_states, sm) {
 335                 __set_sm(sm);
 336         } END_FOR_EACH_PTR(sm);
 337
 338         free_slist(&final_states);
 339 }
 340
 341 static void match_function_assign(struct expression *expr)
 342 {
 343         struct expression *right = expr->right;
 344         struct symbol *sym;
 345         char *fn_name;
 346         char *ptr_name;
 347
 348         if (right->type == EXPR_PREOP && right->op == '&')
 349                 right = right->unop;
 350         if (right->type != EXPR_SYMBOL)
 351                 return;
 352         sym = get_type(right);
 353         if (!sym || sym->type != SYM_FN)
 354                 return;
 355
 356         fn_name = get_variable_from_expr(right, NULL);
 357         ptr_name = get_fnptr_name(expr->left);
 358         if (!fn_name || !ptr_name)
 359                 goto free;
 360
 361         sm_msg("info: sets_fn_ptr '%s' '%s'", ptr_name, fn_name);
 362
 363 free:
 364         free_string(fn_name);
 365         free_string(ptr_name);
 366 }
 367
 368 static struct expression *call_implies_call_expr;
 369 static int call_implies_callbacks(void *unused, int argc, char **argv, char **azColName)
 370 {
 371         struct call_implies_callback *cb;
 372         struct expression *arg;
 373         int type;
 374         int param;
 375
 376         if (argc != 4)
 377                 return 0;
 378
 379         type = atoi(argv[1]);
 380         param = atoi(argv[2]);
 381
 382         FOR_EACH_PTR(call_implies_cb_list, cb) {
 383                 if (cb->type != type)
 384                         continue;
 385                 arg = get_argument_from_call_expr(call_implies_call_expr->args, param);
 386                 if (!arg)
 387                         continue;
 388                 cb->callback(arg, argv[3]);
 389         } END_FOR_EACH_PTR(cb);
 390
 391         return 0;
 392 }
 393
 394 static void match_call_implies(struct expression *expr)
 395 {
 396         struct symbol *sym;
 397         static char sql_filter[1024];
 398
 399         if (expr->fn->type != EXPR_SYMBOL)
 400                 return;
 401         sym = expr->fn->symbol;
 402         if (!sym)
 403                 return;
 404
 405         if (sym->ctype.modifiers & MOD_STATIC) {
 406                 snprintf(sql_filter, 1024, "file = '%s' and function = '%s';",
 407                          get_filename(), sym->ident->name);
 408         } else {
 409                 snprintf(sql_filter, 1024, "function = '%s' and static = 0;",
 410                                 sym->ident->name);
 411         }
 412
 413         call_implies_call_expr = expr;
 414         run_sql(call_implies_callbacks,
 415                 "select function, type, parameter, value from call_implies where %s",
 416                 sql_filter);
 417         return;
 418 }
 419
 420 static void print_initializer_list(struct expression_list *expr_list,
 421                 struct symbol *struct_type)
 422 {
 423         struct expression *expr;
 424         struct symbol *base_type;
 425
 426         FOR_EACH_PTR(expr_list, expr) {
 427                 if (expr->type == EXPR_INDEX && expr->idx_expression && expr->idx_expression->type == EXPR_INITIALIZER) {
 428                         print_initializer_list(expr->idx_expression->expr_list, struct_type);
 429                         continue;
 430                 }
 431                 if (expr->type != EXPR_IDENTIFIER)
 432                         continue;
 433                 if (!expr->expr_ident)
 434                         continue;
 435                 if (!expr->ident_expression || !expr->ident_expression->symbol_name)
 436                         continue;
 437                 base_type = get_type(expr->ident_expression);
 438                 if (!base_type || base_type->type != SYM_FN)
 439                         continue;
 440                 sm_msg("info: sets_fn_ptr '(struct %s)->%s' '%s'", struct_type->ident->name,
 441                        expr->expr_ident->name,
 442                        expr->ident_expression->symbol_name->name);
 443         } END_FOR_EACH_PTR(expr);
 444
 445 }
 446
 447 static void global_variable(struct symbol *sym)
 448 {
 449         struct symbol *struct_type;
 450
 451         if (!sym->ident)
 452                 return;
 453         if (!sym->initializer || sym->initializer->type != EXPR_INITIALIZER)
 454                 return;
 455         struct_type = get_base_type(sym);
 456         if (!struct_type)
 457                 return;
 458         if (struct_type->type == SYM_ARRAY) {
 459                 struct_type = get_base_type(struct_type);
 460                 if (!struct_type)
 461                         return;
 462         }
 463         if (struct_type->type != SYM_STRUCT || !struct_type->ident)
 464                 return;
 465         print_initializer_list(sym->initializer->expr_list, struct_type);
 466 }
 467
 468 void open_smatch_db(void)
 469 {
 470 #ifdef SQLITE_OPEN_READONLY
 471         int rc;
 472
 473         if (option_no_db)
 474                 return;
 475
 476         rc = sqlite3_open_v2("smatch_db.sqlite", &db, SQLITE_OPEN_READONLY, NULL);
 477         if (rc != SQLITE_OK) {
 478                 option_no_db = 1;
 479                 return;
 480         }
 481         return;
 482 #else
 483         option_no_db = 1;
 484         return;
 485 #endif
 486 }
 487
 488 void register_definition_db_callbacks(int id)
 489 {
 490         if (option_info) {
 491                 add_hook(&match_call_info, FUNCTION_CALL_HOOK);
 492                 add_hook(&match_call_hack, FUNCTION_CALL_HOOK);
 493                 add_hook(&match_function_assign, ASSIGNMENT_HOOK);
 494                 add_hook(&global_variable, BASE_HOOK);
 495                 add_hook(&global_variable, DECLARATION_HOOK);
 496         }
 497
 498         if (option_no_db)
 499                 return;
 500
 501         add_hook(&match_data_from_db, FUNC_DEF_HOOK);
 502         add_hook(&match_call_implies, FUNCTION_CALL_HOOK);
 503 }