check_sleep_info.c

   1 /*
   2  * Copyright (C) 2021 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_extra.h"
  20 #include "smatch_slist.h"
  21
  22 static struct void_fn_list *hooks;
  23 static int my_id;
  24
  25 STATE(sleep);
  26
  27 unsigned long GFP_DIRECT_RECLAIM(void)
  28 {
  29         static unsigned long saved_flags = -1;
  30         struct symbol *macro_sym;
  31
  32         if (saved_flags != -1)
  33                 return saved_flags;
  34
  35         macro_sym = lookup_macro_symbol("___GFP_DIRECT_RECLAIM");
  36         if (!macro_sym || !macro_sym->expansion)
  37                 return 0;
  38         if (token_type(macro_sym->expansion) != TOKEN_NUMBER)
  39                 return 0;
  40
  41         saved_flags = strtoul(macro_sym->expansion->number, NULL, 0);
  42         return saved_flags;
  43 }
  44
  45 static void do_sleep(void)
  46 {
  47         void_fn *fn;
  48
  49         FOR_EACH_PTR(hooks, fn) {
  50                 fn();
  51         } END_FOR_EACH_PTR(fn);
  52
  53         set_state(my_id, "sleep", NULL, &sleep);
  54         clear_preempt_cnt();
  55 }
  56
  57 static void match_sleep(const char *fn, struct expression *expr, void *unused)
  58 {
  59         do_sleep();
  60 }
  61
  62 static void match_might_sleep_fn(const char *fn, struct expression *expr, void *unused)
  63 {
  64         struct range_list *rl;
  65         sval_t sval;
  66
  67         if (!get_implied_rl_from_call_str(expr, "$0", &rl))
  68                 return;
  69         if (!rl_to_sval(rl, &sval) || sval.value != 0)
  70                 return;
  71
  72         do_sleep();
  73 }
  74
  75 static void match_might_sleep_macro(struct statement *stmt)
  76 {
  77         const char *macro;
  78
  79         macro = get_macro_name(stmt->pos);
  80         if (!macro ||
  81             strcmp(macro, "might_sleep") != 0)
  82                 return;
  83
  84         do_sleep();
  85 }
  86
  87 static void select_sleep(struct expression *call, struct expression *arg, char *key, char *unused)
  88 {
  89         do_sleep();
  90 }
  91
  92 static void match_gfp_t(struct expression *expr)
  93 {
  94         struct expression *arg;
  95         char *name;
  96         sval_t sval;
  97         int param;
  98
  99         param = get_gfp_param(expr);
 100         if (param < 0)
 101                 return;
 102         arg = get_argument_from_call_expr(expr->args, param);
 103         if (!get_implied_value(arg, &sval))
 104                 return;
 105
 106         if (!(sval.value & GFP_DIRECT_RECLAIM()))
 107                 return;
 108
 109         name = expr_to_str(expr->fn);
 110         if (name &&
 111             (strncmp(name, "__xa_", 5) == 0 ||
 112              strncmp(name, "xa_", 3) == 0 ||
 113              strcmp(name, "ttm_bo_swapout") == 0)) {
 114                 free_string(name);
 115                 return;
 116         }
 117         free_string(name);
 118
 119         do_sleep();
 120 }
 121
 122 static void insert_sleep(void)
 123 {
 124         if (function_decrements_preempt())
 125                 return;
 126         if (get_state(my_id, "sleep", NULL) != &sleep)
 127                 return;
 128         sql_insert_return_implies(SLEEP, -1, "", "");
 129 }
 130
 131 void add_sleep_callback(void_fn *fn)
 132 {
 133         add_ptr_list(&hooks, fn);
 134 }
 135
 136 void check_sleep_info(int id)
 137 {
 138         my_id = id;
 139
 140         if (option_project != PROJ_KERNEL)
 141                 return;
 142
 143         add_function_hook("schedule", &match_sleep, NULL);
 144         add_function_hook("msleep", &match_sleep, NULL);
 145         add_function_hook("might_resched", &match_sleep, NULL);
 146         add_function_hook("vfree", &match_sleep, NULL);
 147         add_function_hook("__might_sleep", &match_might_sleep_fn, NULL);
 148         add_function_hook("___might_sleep", &match_might_sleep_fn, NULL);
 149         add_hook(&match_might_sleep_macro, STMT_HOOK);
 150
 151         add_hook(&match_gfp_t, FUNCTION_CALL_HOOK);
 152
 153         all_return_states_hook(&insert_sleep);
 154         select_return_implies_hook_early(SLEEP, &select_sleep);
 155 }