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         struct range_list *rl;
  36
  37         if (!get_implied_rl(expr->right, &rl))
  38                 return;
  39         if (rl_max(rl).value != 1)
  40                 return;
  41         set_state_expr(my_id, expr->left, &positive);
  42 }
  43
  44 static void match_condition(struct expression *expr)
  45 {
  46         if (!get_state_expr(my_id, expr))
  47                 return;
  48         /* If the variable is zero that's ok */
  49         set_true_false_states_expr(my_id, expr, NULL, &ok);
  50 }
  51
  52 static void match_return(struct expression *ret_value)
  53 {
  54         struct smatch_state *state;
  55         struct sm_state *sm;
  56         sval_t min;
  57
  58         sm = get_sm_state_expr(my_id, ret_value);
  59         if (!sm)
  60                 return;
  61         if (!slist_has_state(sm->possible, &positive))
  62                 return;
  63         state = get_state_expr(SMATCH_EXTRA, ret_value);
  64         if (!state)
  65                 return;
  66         if (!get_absolute_min(ret_value, &min))
  67                 return;
  68         if (min.value == 0)
  69                 return;
  70         sm_warning("dma_mapping_error() doesn't return an error code");
  71 }
  72
  73 void check_dma_mapping_error(int id)
  74 {
  75         if (option_project != PROJ_KERNEL)
  76                 return;
  77
  78         my_id = id;
  79         add_function_assign_hook("dma_mapping_error", &match_assign, NULL);
  80         add_function_assign_hook("pci_dma_mapping_error", &match_assign, NULL);
  81         add_hook(&match_condition, CONDITION_HOOK);
  82         add_hook(&match_return, RETURN_HOOK);
  83         add_modification_hook(my_id, &ok_to_use);
  84 }