1 /* 2 * Copyright (C) 2018 Oracle. 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 <stdlib.h> 19 #include "parse.h" 20 #include "smatch.h" 21 #include "smatch_slist.h" 22 #include "smatch_extra.h" 23 24 static int my_id; 25 static int barrier_id; 26 27 STATE(nospec); 28 29 static bool in_nospec_stmt; 30 31 static struct smatch_state *unmatched_state(struct sm_state *sm) 32 { 33 struct range_list *rl; 34 35 if (__in_function_def && !get_user_rl_var_sym(sm->name, sm->sym, &rl)) 36 return &nospec; 37 return &undefined; 38 } 39 40 bool is_nospec(struct expression *expr) 41 { 42 char *macro; 43 44 if (in_nospec_stmt) 45 return true; 46 if (!expr) 47 return false; 48 if (get_state_expr(my_id, expr) == &nospec) 49 return true; 50 macro = get_macro_name(expr->pos); 51 if (macro && strcmp(macro, "array_index_nospec") == 0) 52 return true; 53 return false; 54 } 55 56 static void nospec_assign(struct expression *expr) 57 { 58 if (is_nospec(expr->right)) 59 set_state_expr(my_id, expr->left, &nospec); 60 } 61 62 static void set_param_nospec(const char *name, struct symbol *sym, char *key, char *value) 63 { 64 char fullname[256]; 65 66 if (strcmp(key, "*$") == 0) 67 snprintf(fullname, sizeof(fullname), "*%s", name); 68 else if (strncmp(key, "$", 1) == 0) 69 snprintf(fullname, 256, "%s%s", name, key + 1); 70 else 71 return; 72 73 set_state(my_id, fullname, sym, &nospec); 74 } 75 76 static void match_call_info(struct expression *expr) 77 { 78 struct expression *arg; 79 int i = 0; 80 81 FOR_EACH_PTR(expr->args, arg) { 82 if (get_state_expr(my_id, arg) == &nospec) 83 sql_insert_caller_info(expr, NOSPEC, i, "$", ""); 84 i++; 85 } END_FOR_EACH_PTR(arg); 86 } 87 88 static void struct_member_callback(struct expression *call, int param, char *printed_name, struct sm_state *sm) 89 { 90 struct range_list *rl; 91 92 if (!get_user_rl_var_sym(sm->name, sm->sym, &rl)) 93 return; 94 sql_insert_caller_info(call, NOSPEC, param, printed_name, ""); 95 } 96 97 static void returned_struct_members(int return_id, char *return_ranges, struct expression *expr) 98 { 99 struct symbol *returned_sym; 100 struct sm_state *sm; 101 const char *param_name; 102 struct range_list *rl; 103 int param; 104 105 returned_sym = expr_to_sym(expr); 106 107 FOR_EACH_MY_SM(my_id, __get_cur_stree(), sm) { 108 param = get_param_num_from_sym(sm->sym); 109 if (param < 0) { 110 if (!returned_sym || returned_sym != sm->sym) 111 continue; 112 param = -1; 113 } 114 115 param_name = get_param_name(sm); 116 if (!param_name) 117 continue; 118 if (param != -1 && strcmp(param_name, "$") == 0) 119 continue; 120 121 if (!get_user_rl_var_sym(sm->name, sm->sym, &rl)) 122 continue; 123 124 sql_insert_return_states(return_id, return_ranges, NOSPEC, param, param_name, ""); 125 } END_FOR_EACH_SM(sm); 126 127 if (is_nospec(expr) && get_user_rl(expr, &rl)) 128 sql_insert_return_states(return_id, return_ranges, NOSPEC, -1, "$", ""); 129 130 if (get_state(barrier_id, "barrier", NULL) == &nospec) 131 sql_insert_return_states(return_id, return_ranges, NOSPEC_WB, -1, "", ""); 132 } 133 134 static int is_return_statement(void) 135 { 136 if (__cur_stmt && __cur_stmt->type == STMT_RETURN) 137 return 1; 138 return 0; 139 } 140 141 static void db_returns_nospec(struct expression *expr, int param, char *key, char *value) 142 { 143 struct expression *call; 144 struct expression *arg; 145 char *name; 146 struct symbol *sym; 147 148 call = expr; 149 while (call->type == EXPR_ASSIGNMENT) 150 call = strip_expr(call->right); 151 if (call->type != EXPR_CALL) 152 return; 153 154 if (param == -1 && expr->type == EXPR_ASSIGNMENT) { 155 name = get_variable_from_key(expr->left, key, &sym); 156 } else if (param == -1 && is_return_statement()) { 157 in_nospec_stmt = true; 158 return; 159 } else { 160 arg = get_argument_from_call_expr(call->args, param); 161 if (!arg) 162 return; 163 name = get_variable_from_key(arg, key, &sym); 164 } 165 if (!name || !sym) 166 goto free; 167 168 set_state(my_id, name, sym, &nospec); 169 free: 170 free_string(name); 171 } 172 173 static int is_nospec_asm(struct statement *stmt) 174 { 175 char *macro; 176 177 if (!stmt || stmt->type != STMT_ASM) 178 return 0; 179 macro = get_macro_name(stmt->asm_string->pos); 180 if (!macro || strcmp(macro, "CALL_NOSPEC") != 0) 181 return 0; 182 return 1; 183 } 184 185 static void match_asm(struct statement *stmt) 186 { 187 if (is_nospec_asm(stmt)) 188 in_nospec_stmt = true; 189 } 190 191 static void match_after_nospec_asm(struct statement *stmt) 192 { 193 in_nospec_stmt = false; 194 } 195 196 static void mark_user_data_as_nospec(void) 197 { 198 struct stree *stree; 199 struct symbol *type; 200 struct sm_state *sm; 201 202 stree = get_user_stree(); 203 FOR_EACH_SM(stree, sm) { 204 if (is_whole_rl(estate_rl(sm->state))) 205 continue; 206 type = estate_type(sm->state); 207 if (!type || type->type != SYM_BASETYPE) 208 continue; 209 if (!is_capped_var_sym(sm->name, sm->sym)) 210 continue; 211 set_state(my_id, sm->name, sm->sym, &nospec); 212 } END_FOR_EACH_SM(sm); 213 free_stree(&stree); 214 } 215 216 static void match_barrier(struct statement *stmt) 217 { 218 char *macro; 219 220 macro = get_macro_name(stmt->pos); 221 if (!macro) 222 return; 223 if (strcmp(macro, "rmb") != 0 && 224 strcmp(macro, "smp_rmb") != 0 && 225 strcmp(macro, "barrier_nospec") != 0) 226 return; 227 228 set_state(barrier_id, "barrier", NULL, &nospec); 229 mark_user_data_as_nospec(); 230 } 231 232 static void db_returns_barrier(struct expression *expr, int param, char *key, char *value) 233 { 234 mark_user_data_as_nospec(); 235 } 236 237 void check_nospec(int id) 238 { 239 my_id = id; 240 241 add_hook(&nospec_assign, ASSIGNMENT_HOOK); 242 243 select_caller_info_hook(set_param_nospec, NOSPEC); 244 add_unmatched_state_hook(my_id, &unmatched_state); 245 246 add_hook(&match_call_info, FUNCTION_CALL_HOOK); 247 add_member_info_callback(my_id, struct_member_callback); 248 add_split_return_callback(&returned_struct_members); 249 select_return_states_hook(NOSPEC, &db_returns_nospec); 250 select_return_states_hook(NOSPEC_WB, &db_returns_barrier); 251 252 add_hook(&match_asm, ASM_HOOK); 253 add_hook(&match_after_nospec_asm, STMT_HOOK_AFTER); 254 } 255 256 void check_nospec_barrier(int id) 257 { 258 barrier_id = id; 259 260 add_hook(&match_barrier, ASM_HOOK); 261 }