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