check_dma_mapping_error.c

   1 /*
   2  * Copyright (C) 2015 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 "smatch.h"
  19 #include "smatch_slist.h"
  20 #include "smatch_extra.h"
  21
  22 static int my_id;
  23
  24 STATE(positive);
  25 STATE(ok);
  26
  27 static void ok_to_use(struct sm_state *sm, struct expression *mod_expr)
  28 {
  29         if (sm->state != &ok)
  30                 set_state(my_id, sm->name, sm->sym, &ok);
  31 }
  32
  33 static void match_assign(const char *fn, struct expression *expr, void *unused)
  34 {
  35         set_state_expr(my_id, expr->left, &positive);
  36 }
  37
  38 static void match_condition(struct expression *expr)
  39 {
  40         if (!get_state_expr(my_id, expr))
  41                 return;
  42         /* If the variable is zero that's ok */
  43         set_true_false_states_expr(my_id, expr, NULL, &ok);
  44 }
  45
  46 static void match_return(struct expression *ret_value)
  47 {
  48         struct smatch_state *state;
  49         struct sm_state *sm;
  50         sval_t min;
  51
  52         sm = get_sm_state_expr(my_id, ret_value);
  53         if (!sm)
  54                 return;
  55         if (!slist_has_state(sm->possible, &positive))
  56                 return;
  57         state = get_state_expr(SMATCH_EXTRA, ret_value);
  58         if (!state)
  59                 return;
  60         if (!get_absolute_min(ret_value, &min))
  61                 return;
  62         if (min.value == 0)
  63                 return;
  64         sm_msg("warn: warn: dma_mapping_error() doesn't return an error code");
  65 }
  66
  67 void check_dma_mapping_error(int id)
  68 {
  69         if (option_project != PROJ_KERNEL)
  70                 return;
  71
  72         my_id = id;
  73         add_function_assign_hook("dma_mapping_error", &match_assign, NULL);
  74         add_hook(&match_condition, CONDITION_HOOK);
  75         add_hook(&match_return, RETURN_HOOK);
  76         add_modification_hook(my_id, &ok_to_use);
  77 }