xref: /illumos-gate/usr/src/tools/smatch/src/smatch_array_values.c (revision c85f09cc92abd00c84e58ec9f0f5d942906cb713)
1 /*
2  * Copyright (C) 2018 Oracle.  All rights reserved.
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 struct db_info {
25 	int count;
26 	struct symbol *type;
27 	struct range_list *rl;
28 };
29 
get_vals(void * _db_info,int argc,char ** argv,char ** azColName)30 static int get_vals(void *_db_info, int argc, char **argv, char **azColName)
31 {
32 	struct db_info *db_info = _db_info;
33 	struct range_list *rl;
34 
35 	str_to_rl(db_info->type, argv[0], &rl);
36 	db_info->rl = rl_union(db_info->rl, rl);
37 
38 	return 0;
39 }
40 
is_file_local(struct expression * array)41 static int is_file_local(struct expression *array)
42 {
43 	struct symbol *sym = NULL;
44 	char *name;
45 
46 	name = expr_to_str_sym(array, &sym);
47 	free_string(name);
48 	if (!sym)
49 		return 0;
50 
51 	if ((sym->ctype.modifiers & MOD_TOPLEVEL) &&
52 	    (sym->ctype.modifiers & MOD_STATIC))
53 		return 1;
54 	return 0;
55 }
56 
get_toplevel_name(struct expression * array)57 static char *get_toplevel_name(struct expression *array)
58 {
59 	char *name;
60 	char buf[128];
61 
62 	if (is_array(array))
63 		array = get_array_base(array);
64 
65 	if (!array || array->type != EXPR_SYMBOL)
66 		return NULL;
67 	if (!is_file_local(array))
68 		return NULL;
69 
70 	name = expr_to_str(array);
71 	snprintf(buf, sizeof(buf), "%s[]", name);
72 	free_string(name);
73 
74 	return alloc_sname(buf);
75 }
76 
get_member_array(struct expression * array)77 static char *get_member_array(struct expression *array)
78 {
79 	char *name;
80 	char buf[128];
81 
82 	name = get_member_name(array);
83 	if (!name)
84 		return NULL;
85 	snprintf(buf, sizeof(buf), "%s[]", name);
86 	free_string(name);
87 	return alloc_sname(buf);
88 }
89 
get_array_name(struct expression * array)90 static char *get_array_name(struct expression *array)
91 {
92 	struct symbol *type;
93 	char *name;
94 
95 	type = get_type(array);
96 	if (!type || type->type != SYM_ARRAY)
97 		return NULL;
98 
99 	name = get_toplevel_name(array);
100 	if (name)
101 		return name;
102 	name = get_member_array(array);
103 	if (name)
104 		return name;
105 
106 	return NULL;
107 }
108 
get_array_rl(struct expression * expr,struct range_list ** rl)109 int get_array_rl(struct expression *expr, struct range_list **rl)
110 {
111 	struct expression *array;
112 	struct symbol *type;
113 	struct db_info db_info = {};
114 	char *name;
115 
116 	type = get_type(expr);
117 	if (!type || type->type != SYM_BASETYPE)
118 		return 0;
119 	db_info.type = type;
120 
121 	array = get_array_base(expr);
122 	name = get_array_name(array);
123 	if (!name)
124 		return 0;
125 
126 	if (is_file_local(array)) {
127 		run_sql(&get_vals, &db_info,
128 			"select value from sink_info where file = '%s' and static = 1 and sink_name = '%s' and type = %d;",
129 			get_filename(), name, DATA_VALUE);
130 	} else {
131 		run_sql(&get_vals, &db_info,
132 			"select value from sink_info where sink_name = '%s' and type = %d limit 10;",
133 			name, DATA_VALUE);
134 	}
135 	if (!db_info.rl || db_info.count >= 10)
136 		return 0;
137 
138 	*rl = db_info.rl;
139 	return 1;
140 }
141 
get_saved_rl(struct symbol * type,char * name)142 static struct range_list *get_saved_rl(struct symbol *type, char *name)
143 {
144 	struct db_info db_info = {.type = type};
145 
146 	cache_sql(&get_vals, &db_info, "select value from sink_info where sink_name = '%s' and type = %d;",
147 		  name, DATA_VALUE);
148 	return db_info.rl;
149 }
150 
update_cache(char * name,int is_static,struct range_list * rl)151 static void update_cache(char *name, int is_static, struct range_list *rl)
152 {
153 	cache_sql(NULL, NULL, "delete from sink_info where sink_name = '%s' and type = %d;",
154 		  name, DATA_VALUE);
155 	cache_sql(NULL, NULL, "insert into sink_info values ('%s', %d, '%s', %d, '', '%s');",
156 		  get_filename(), is_static, name, DATA_VALUE, show_rl(rl));
157 }
158 
match_assign(struct expression * expr)159 static void match_assign(struct expression *expr)
160 {
161 	struct expression *left, *array;
162 	struct range_list *orig_rl, *rl;
163 	struct symbol *type;
164 	char *name;
165 
166 	type = get_type(expr->left);
167 	if (!type || type->type != SYM_BASETYPE)
168 		return;
169 
170 	left = strip_expr(expr->left);
171 	if (!is_array(left))
172 		return;
173 	array = get_array_base(left);
174 	name = get_array_name(array);
175 	if (!name)
176 		return;
177 
178 	if (expr->op != '=') {
179 		rl = alloc_whole_rl(get_type(expr->right));
180 		rl = cast_rl(type, rl);
181 	} else {
182 		get_absolute_rl(expr->right, &rl);
183 		rl = cast_rl(type, rl);
184 		orig_rl = get_saved_rl(type, name);
185 		rl = rl_union(orig_rl, rl);
186 	}
187 
188 	update_cache(name, is_file_local(array), rl);
189 }
190 
mark_strings_unknown(const char * fn,struct expression * expr,void * _arg)191 static void mark_strings_unknown(const char *fn, struct expression *expr, void *_arg)
192 {
193 	struct expression *dest;
194 	struct symbol *type;
195 	int arg = PTR_INT(_arg);
196 	char *name;
197 
198 	dest = get_argument_from_call_expr(expr->args, arg);
199 	if (!dest)
200 		return;
201 	name = get_array_name(dest);
202 	if (!name)
203 		return;
204 	type = get_type(dest);
205 	if (type_is_ptr(type))
206 		type = get_real_base_type(type);
207 	update_cache(name, is_file_local(dest), alloc_whole_rl(type));
208 }
209 
register_array_values(int id)210 void register_array_values(int id)
211 {
212 	my_id = id;
213 
214 	add_hook(&match_assign, ASSIGNMENT_HOOK);
215 	add_hook(&match_assign, GLOBAL_ASSIGNMENT_HOOK);
216 
217 	add_function_hook("sprintf", &mark_strings_unknown, INT_PTR(0));
218 	add_function_hook("snprintf", &mark_strings_unknown, INT_PTR(0));
219 
220 	add_function_hook("strcpy", &mark_strings_unknown, INT_PTR(0));
221 	add_function_hook("strncpy", &mark_strings_unknown, INT_PTR(0));
222 	add_function_hook("strlcpy", &mark_strings_unknown, INT_PTR(0));
223 	add_function_hook("strscpy", &mark_strings_unknown, INT_PTR(0));
224 }
225