1 /* 2 * Copyright (C) 2009 Dan Carpenter. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 2 7 * of the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt 16 */ 17 18 #include "smatch.h" 19 #include "smatch_slist.h" 20 21 static int my_id; 22 23 static int err_ptr = 0; 24 static int returns_null = 0; 25 26 static void match_err_ptr(struct expression *expr) 27 { 28 expr = strip_expr(expr); 29 if (!expr) 30 return; 31 if (expr->type != EXPR_CALL) 32 return; 33 34 if (expr->fn->type != EXPR_SYMBOL || !expr->fn->symbol) 35 return; 36 if (!strcmp(expr->fn->symbol->ident->name, "ERR_PTR")) 37 err_ptr = 1; 38 } 39 40 static void match_return(struct expression *ret_value) 41 { 42 struct state_list *slist; 43 struct sm_state *tmp; 44 sval_t sval; 45 46 if (__inline_fn) 47 return; 48 match_err_ptr(ret_value); 49 slist = get_possible_states_expr(check_assigned_expr_id, ret_value); 50 FOR_EACH_PTR(slist, tmp) { 51 if (tmp->state == &undefined || tmp->state == &merged) 52 continue; 53 match_err_ptr((struct expression *)tmp->state->data); 54 } END_FOR_EACH_PTR(tmp); 55 56 if (get_implied_value(ret_value, &sval)) { 57 if (sval.value == 0) 58 returns_null = 1; 59 } 60 } 61 62 static void match_end_func(struct symbol *sym) 63 { 64 if (__inline_fn) 65 return; 66 if (err_ptr) 67 sm_info("returns_err_ptr"); 68 err_ptr = 0; 69 returns_null = 0; 70 } 71 72 void check_err_ptr(int id) 73 { 74 if (option_project != PROJ_KERNEL) 75 return; 76 if (!option_info) 77 return; 78 79 my_id = id; 80 add_hook(&match_return, RETURN_HOOK); 81 add_hook(&match_end_func, END_FUNC_HOOK); 82 } 83