smatch_kernel_xa_err.c

   1 /*
   2  * Copyright 2024 Linaro Ltd.
   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_extra.h"
  20 #include "smatch_slist.h"
  21
  22 static int my_id;
  23
  24 static void match_xa_is_err_true(const char *fn, struct expression *call_expr,
  25                                  struct expression *assign_expr, void *unused)
  26 {
  27         struct expression *arg;
  28         struct smatch_state *pre_state;
  29         struct range_list *rl;
  30
  31         arg = get_argument_from_call_expr(call_expr->args, 0);
  32         pre_state = get_state_expr(SMATCH_EXTRA, arg);
  33         rl = estate_rl(pre_state);
  34         if (!rl)
  35                 rl = alloc_rl(ptr_xa_err_min, ptr_xa_err_max);
  36         rl = rl_intersection(rl, alloc_rl(ptr_xa_err_min, ptr_xa_err_max));
  37         rl = cast_rl(get_type(arg), rl);
  38         set_extra_expr_nomod(arg, alloc_estate_rl(rl));
  39 }
  40
  41 static void match_xa_is_err_false(const char *fn, struct expression *call_expr,
  42                                   struct expression *assign_expr, void *unused)
  43 {
  44         struct expression *arg;
  45         struct smatch_state *pre_state;
  46         struct range_list *rl;
  47
  48         arg = get_argument_from_call_expr(call_expr->args, 0);
  49         pre_state = get_state_expr(SMATCH_EXTRA, arg);
  50         if (pre_state) {
  51                 rl = estate_rl(pre_state);
  52                 rl = remove_range(rl, ptr_xa_err_min, ptr_xa_err_max);
  53         } else {
  54                 rl = alloc_rl(valid_ptr_min_sval, valid_ptr_max_sval);
  55         }
  56         rl = cast_rl(get_type(arg), rl);
  57         set_extra_expr_nomod(arg, alloc_estate_rl(rl));
  58 }
  59
  60 static int implied_xa_err_return(struct expression *call, void *unused, struct range_list **rl)
  61 {
  62         struct expression *arg;
  63         struct range_list *param_rl;
  64
  65         arg = get_argument_from_call_expr(call->args, 0);
  66         if (!get_implied_rl(arg, &param_rl))
  67                 return false;
  68         if (sval_cmp(rl_min(param_rl), ptr_xa_err_min) >= 0 &&
  69             sval_cmp(rl_max(param_rl), ptr_xa_err_max) <= 0) {
  70                 *rl = alloc_rl(err_min, err_max);
  71                 return true;
  72         }
  73
  74         return false;
  75 }
  76
  77 void register_kernel_xa_err(int id)
  78 {
  79         my_id = id;
  80
  81         if (option_project != PROJ_KERNEL)
  82                 return;
  83
  84         return_implies_state("xa_is_err", 1, 1, &match_xa_is_err_true, NULL);
  85         return_implies_state("xa_is_err", 0, 0, &match_xa_is_err_false, NULL);
  86
  87         add_implied_return_hook("xa_err", &implied_xa_err_return, NULL);
  88 }