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