smatch_mtag_data.c

   1 /*
   2  * Copyright (C) 2016 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 /*
  19  * What we're doing here is saving all the possible values for static variables.
  20  * Later on we might do globals as well.
  21  *
  22  */
  23
  24 #include "smatch.h"
  25 #include "smatch_slist.h"
  26 #include "smatch_extra.h"
  27
  28 static int my_id;
  29 static struct stree *vals;
  30
  31 static int save_rl(void *_rl, int argc, char **argv, char **azColName)
  32 {
  33         unsigned long *rl = _rl;
  34
  35         *rl = strtoul(argv[0], NULL, 10);
  36         return 0;
  37 }
  38
  39 static struct range_list *select_orig_rl(sval_t sval)
  40 {
  41         struct range_list *rl = NULL;
  42         mtag_t tag = sval.uvalue & ~MTAG_OFFSET_MASK;
  43         int offset = sval.uvalue & MTAG_OFFSET_MASK;
  44
  45         mem_sql(&save_rl, &rl, "select value from mtag_data where tag = %lld and offset = %d;",
  46                 tag, offset);
  47         return rl;
  48 }
  49
  50 static int is_kernel_param(const char *name)
  51 {
  52         struct sm_state *tmp;
  53         char buf[256];
  54
  55         /*
  56          * I'm ignoring these because otherwise Smatch thinks that kernel
  57          * parameters are always set to the default.
  58          *
  59          */
  60
  61         if (option_project != PROJ_KERNEL)
  62                 return 0;
  63
  64         snprintf(buf, sizeof(buf), "__param_%s.arg", name);
  65
  66         FOR_EACH_SM(vals, tmp) {
  67                 if (strcmp(tmp->name, buf) == 0)
  68                         return 1;
  69         } END_FOR_EACH_SM(tmp);
  70
  71         return 0;
  72 }
  73
  74 void insert_mtag_data(sval_t sval, struct range_list *rl)
  75 {
  76         mtag_t tag = sval.uvalue & ~MTAG_OFFSET_MASK;
  77         int offset = sval.uvalue & MTAG_OFFSET_MASK;
  78
  79         rl = clone_rl_permanent(rl);
  80
  81         mem_sql(NULL, NULL, "delete from mtag_data where tag = %lld and offset = %d and type = %d",
  82                 tag, offset, DATA_VALUE);
  83         mem_sql(NULL, NULL, "insert into mtag_data values (%lld, %d, %d, '%lu');",
  84                 tag, offset, DATA_VALUE, (unsigned long)rl);
  85 }
  86
  87 void update_mtag_data(struct expression *expr)
  88 {
  89         struct range_list *orig, *new, *rl;
  90         char *name;
  91         sval_t sval;
  92
  93         name = expr_to_var(expr);
  94         if (is_kernel_param(name)) {
  95                 free_string(name);
  96                 return;
  97         }
  98         free_string(name);
  99
 100         if (!get_mtag_addr_sval(expr, &sval))
 101                 return;
 102
 103         get_absolute_rl(expr, &rl);
 104
 105         orig = select_orig_rl(sval);
 106         new = rl_union(orig, rl);
 107         insert_mtag_data(sval, new);
 108 }
 109
 110 static void match_global_assign(struct expression *expr)
 111 {
 112         struct range_list *rl;
 113         sval_t sval;
 114         char *name;
 115
 116         name = expr_to_var(expr->left);
 117         if (is_kernel_param(name)) {
 118                 free_string(name);
 119                 return;
 120         }
 121         free_string(name);
 122
 123         if (!get_mtag_addr_sval(expr->left, &sval))
 124                 return;
 125
 126         get_absolute_rl(expr->right, &rl);
 127         insert_mtag_data(sval, rl);
 128 }
 129
 130 static int save_mtag_data(void *_unused, int argc, char **argv, char **azColName)
 131 {
 132         struct range_list *rl;
 133
 134         if (argc != 4) {
 135                 sm_msg("Error saving mtag data");
 136                 return 0;
 137         }
 138         if (!option_info)
 139                 return 0;
 140
 141         rl = (struct range_list *)strtoul(argv[3], NULL, 10);
 142         sm_msg("SQL: insert into mtag_data values ('%s', '%s', '%s', '%s');",
 143                argv[0], argv[1], argv[2], show_rl(rl));
 144
 145         return 0;
 146 }
 147
 148 static void match_end_file(struct symbol_list *sym_list)
 149 {
 150         mem_sql(&save_mtag_data, NULL, "select * from mtag_data where type = %d;",
 151                 DATA_VALUE);
 152 }
 153
 154 struct db_info {
 155         struct symbol *type;
 156         struct range_list *rl;
 157 };
 158
 159 static int get_vals(void *_db_info, int argc, char **argv, char **azColName)
 160 {
 161         struct db_info *db_info = _db_info;
 162         struct range_list *tmp;
 163
 164         str_to_rl(db_info->type, argv[0], &tmp);
 165         if (db_info->rl)
 166                 db_info->rl = rl_union(db_info->rl, tmp);
 167         else
 168                 db_info->rl = tmp;
 169
 170         return 0;
 171 }
 172
 173 struct db_cache_results {
 174         sval_t sval;
 175         struct range_list *rl;
 176 };
 177 static struct db_cache_results cached_results[8];
 178
 179 static int get_rl_from_mtag_sval(sval_t sval, struct symbol *type, struct range_list **rl)
 180 {
 181         struct db_info db_info = {};
 182         mtag_t tag;
 183         int offset;
 184         static int idx;
 185         int ret;
 186         int i;
 187
 188         for (i = 0; i < ARRAY_SIZE(cached_results); i++) {
 189                 if (sval.uvalue == cached_results[i].sval.uvalue) {
 190                         if (cached_results[i].rl) {
 191                                 *rl = cached_results[i].rl;
 192                                 return 1;
 193                         }
 194                         return 0;
 195                 }
 196         }
 197
 198         tag = sval.uvalue & ~MTAG_OFFSET_MASK;
 199         offset = sval.uvalue & MTAG_OFFSET_MASK;
 200         if (offset == MTAG_OFFSET_MASK) {
 201                 ret = 0;
 202                 goto update_cache;
 203         }
 204         db_info.type = type;
 205
 206         run_sql(get_vals, &db_info,
 207                 "select value from mtag_data where tag = %lld and offset = %d and type = %d;",
 208                 tag, offset, DATA_VALUE);
 209         if (!db_info.rl || is_whole_rl(db_info.rl)) {
 210                 db_info.rl = NULL;
 211                 ret = 0;
 212                 goto update_cache;
 213         }
 214
 215         *rl = db_info.rl;
 216         ret = 1;
 217
 218 update_cache:
 219         cached_results[idx].sval = sval;
 220         cached_results[idx].rl = db_info.rl;
 221         idx = (idx + 1) % ARRAY_SIZE(cached_results);
 222
 223         return ret;
 224 }
 225
 226 static void clear_cache(struct symbol *sym)
 227 {
 228         memset(cached_results, 0, sizeof(cached_results));
 229 }
 230
 231 int get_mtag_rl(struct expression *expr, struct range_list **rl)
 232 {
 233         struct symbol *type;
 234         sval_t sval;
 235
 236         if (!get_mtag_addr_sval(expr, &sval))
 237                 return 0;
 238
 239         type = get_type(expr);
 240         if (!type)
 241                 return 0;
 242
 243         return get_rl_from_mtag_sval(sval, type, rl);
 244 }
 245
 246 void register_mtag_data(int id)
 247 {
 248         my_id = id;
 249
 250         add_hook(&clear_cache, FUNC_DEF_HOOK);
 251
 252 //      if (!option_info)
 253 //              return;
 254         add_hook(&match_global_assign, GLOBAL_ASSIGNMENT_HOOK);
 255         add_hook(&match_end_file, END_FILE_HOOK);
 256 }
 257