1 /*
2 * Copyright (c) 2015, 2021, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "runtime/flags/jvmFlag.hpp"
30 #include "runtime/flags/jvmFlagAccess.hpp"
31 #include "runtime/flags/jvmFlagLimit.hpp"
32 #include "runtime/java.hpp"
33 #include "runtime/jniHandles.hpp"
34 #include "services/writeableFlags.hpp"
35
36 #define TEMP_BUF_SIZE 80
37
buffer_concat(char * buffer,const char * src)38 static void buffer_concat(char* buffer, const char* src) {
39 strncat(buffer, src, TEMP_BUF_SIZE - 1 - strlen(buffer));
40 }
41
print_flag_error_message_bounds(const JVMFlag * flag,char * buffer)42 static void print_flag_error_message_bounds(const JVMFlag* flag, char* buffer) {
43 if (JVMFlagLimit::get_range(flag) != NULL) {
44 buffer_concat(buffer, "must have value in range ");
45
46 stringStream stream;
47 JVMFlagAccess::print_range(&stream, flag);
48 const char* range_string = stream.as_string();
49 size_t j = strlen(buffer);
50 for (size_t i=0; j<TEMP_BUF_SIZE-1; i++) {
51 if (range_string[i] == '\0') {
52 break;
53 } else if (range_string[i] != ' ') {
54 buffer[j] = range_string[i];
55 j++;
56 }
57 }
58 buffer[j] = '\0';
59 }
60 }
61
print_flag_error_message_if_needed(JVMFlag::Error error,const JVMFlag * flag,FormatBuffer<80> & err_msg)62 static void print_flag_error_message_if_needed(JVMFlag::Error error, const JVMFlag* flag, FormatBuffer<80>& err_msg) {
63 if (error == JVMFlag::SUCCESS) {
64 return;
65 }
66
67 const char* name = flag->name();
68 char buffer[TEMP_BUF_SIZE] = {'\0'};
69 if ((error != JVMFlag::MISSING_NAME) && (name != NULL)) {
70 buffer_concat(buffer, name);
71 buffer_concat(buffer, " error: ");
72 } else {
73 buffer_concat(buffer, "Error: ");
74 }
75 switch (error) {
76 case JVMFlag::MISSING_NAME:
77 buffer_concat(buffer, "flag name is missing."); break;
78 case JVMFlag::MISSING_VALUE:
79 buffer_concat(buffer, "parsing the textual form of the value."); break;
80 case JVMFlag::NON_WRITABLE:
81 buffer_concat(buffer, "flag is not writeable."); break;
82 case JVMFlag::OUT_OF_BOUNDS:
83 if (name != NULL) { print_flag_error_message_bounds(flag, buffer); } break;
84 case JVMFlag::VIOLATES_CONSTRAINT:
85 buffer_concat(buffer, "value violates its flag's constraint."); break;
86 case JVMFlag::INVALID_FLAG:
87 buffer_concat(buffer, "there is no flag with the given name."); break;
88 case JVMFlag::ERR_OTHER:
89 buffer_concat(buffer, "other, unspecified error related to setting the flag."); break;
90 case JVMFlag::SUCCESS:
91 break;
92 default:
93 break;
94 }
95
96 err_msg.print("%s", buffer);
97 }
98
99 template <typename T, int type_enum>
set_flag_impl(const char * name,T value,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)100 JVMFlag::Error WriteableFlags::set_flag_impl(const char* name, T value, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
101 JVMFlag* flag = JVMFlag::find_flag(name);
102 JVMFlag::Error err = JVMFlagAccess::set<T, type_enum>(flag, &value, origin);
103 print_flag_error_message_if_needed(err, flag, err_msg);
104 return err;
105 }
106
107
108 // set a boolean global flag
set_bool_flag(const char * name,const char * arg,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)109 JVMFlag::Error WriteableFlags::set_bool_flag(const char* name, const char* arg, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
110 if ((strcasecmp(arg, "true") == 0) || (*arg == '1' && *(arg + 1) == 0)) {
111 return set_flag_impl<JVM_FLAG_TYPE(bool)>(name, true, origin, err_msg);
112 } else if ((strcasecmp(arg, "false") == 0) || (*arg == '0' && *(arg + 1) == 0)) {
113 return set_flag_impl<JVM_FLAG_TYPE(bool)>(name, false, origin, err_msg);
114 }
115 err_msg.print("flag value must be a boolean (1/0 or true/false)");
116 return JVMFlag::WRONG_FORMAT;
117 }
118
119 // set a int global flag
set_int_flag(const char * name,const char * arg,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)120 JVMFlag::Error WriteableFlags::set_int_flag(const char* name, const char* arg, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
121 int value;
122
123 if (sscanf(arg, "%d", &value) == 1) {
124 return set_flag_impl<JVM_FLAG_TYPE(int)>(name, value, origin, err_msg);
125 }
126 err_msg.print("flag value must be an integer");
127 return JVMFlag::WRONG_FORMAT;
128 }
129
130 // set a uint global flag
set_uint_flag(const char * name,const char * arg,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)131 JVMFlag::Error WriteableFlags::set_uint_flag(const char* name, const char* arg, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
132 uint value;
133
134 if (sscanf(arg, "%u", &value) == 1) {
135 return set_flag_impl<JVM_FLAG_TYPE(uint)>(name, value, origin, err_msg);
136 }
137 err_msg.print("flag value must be an unsigned integer");
138 return JVMFlag::WRONG_FORMAT;
139 }
140
141 // set a intx global flag
set_intx_flag(const char * name,const char * arg,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)142 JVMFlag::Error WriteableFlags::set_intx_flag(const char* name, const char* arg, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
143 intx value;
144
145 if (sscanf(arg, INTX_FORMAT, &value) == 1) {
146 return set_flag_impl<JVM_FLAG_TYPE(intx)>(name, value, origin, err_msg);
147 }
148 err_msg.print("flag value must be an integer");
149 return JVMFlag::WRONG_FORMAT;
150 }
151
152 // set a uintx global flag
set_uintx_flag(const char * name,const char * arg,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)153 JVMFlag::Error WriteableFlags::set_uintx_flag(const char* name, const char* arg, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
154 uintx value;
155
156 if (sscanf(arg, UINTX_FORMAT, &value) == 1) {
157 return set_flag_impl<JVM_FLAG_TYPE(uintx)>(name, value, origin, err_msg);
158 }
159 err_msg.print("flag value must be an unsigned integer");
160 return JVMFlag::WRONG_FORMAT;
161 }
162
163 // set a uint64_t global flag
set_uint64_t_flag(const char * name,const char * arg,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)164 JVMFlag::Error WriteableFlags::set_uint64_t_flag(const char* name, const char* arg, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
165 uint64_t value;
166
167 if (sscanf(arg, UINT64_FORMAT, &value) == 1) {
168 return set_flag_impl<JVM_FLAG_TYPE(uint64_t)>(name, value, origin, err_msg);
169 }
170 err_msg.print("flag value must be an unsigned 64-bit integer");
171 return JVMFlag::WRONG_FORMAT;
172 }
173
174 // set a size_t global flag
set_size_t_flag(const char * name,const char * arg,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)175 JVMFlag::Error WriteableFlags::set_size_t_flag(const char* name, const char* arg, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
176 size_t value;
177
178 if (sscanf(arg, SIZE_FORMAT, &value) == 1) {
179 return set_flag_impl<JVM_FLAG_TYPE(size_t)>(name, value, origin, err_msg);
180 }
181 err_msg.print("flag value must be an unsigned integer");
182 return JVMFlag::WRONG_FORMAT;
183 }
184
185 // set a double global flag
set_double_flag(const char * name,const char * arg,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)186 JVMFlag::Error WriteableFlags::set_double_flag(const char* name, const char* arg, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
187 double value;
188
189 if (sscanf(arg, "%lf", &value) == 1) {
190 return set_flag_impl<JVM_FLAG_TYPE(double)>(name, value, origin, err_msg);
191 }
192 err_msg.print("flag value must be a double");
193 return JVMFlag::WRONG_FORMAT;
194 }
195
196 // set a string global flag using value from AttachOperation
set_ccstr_flag(const char * name,const char * value,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)197 JVMFlag::Error WriteableFlags::set_ccstr_flag(const char* name, const char* value, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
198 JVMFlag* flag = JVMFlag::find_flag(name);
199 JVMFlag::Error err = JVMFlagAccess::set_ccstr(flag, &value, origin);
200 if (err == JVMFlag::SUCCESS) {
201 assert(value == NULL, "old value is freed automatically and not returned");
202 }
203 print_flag_error_message_if_needed(err, flag, err_msg);
204 return err;
205 }
206
207 /* sets a writeable flag to the provided value
208 *
209 * - return status is one of the WriteableFlags::err enum values
210 * - an eventual error message will be generated to the provided err_msg buffer
211 */
set_flag(const char * flag_name,const char * flag_value,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)212 JVMFlag::Error WriteableFlags::set_flag(const char* flag_name, const char* flag_value, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
213 return set_flag(flag_name, &flag_value, set_flag_from_char, origin, err_msg);
214 }
215
216 /* sets a writeable flag to the provided value
217 *
218 * - return status is one of the WriteableFlags::err enum values
219 * - an eventual error message will be generated to the provided err_msg buffer
220 */
set_flag(const char * flag_name,jvalue flag_value,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)221 JVMFlag::Error WriteableFlags::set_flag(const char* flag_name, jvalue flag_value, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
222 return set_flag(flag_name, &flag_value, set_flag_from_jvalue, origin, err_msg);
223 }
224
225 // a writeable flag setter accepting either 'jvalue' or 'char *' values
226 JVMFlag::Error WriteableFlags::set_flag(const char* name, const void* value, JVMFlag::Error(*setter)(JVMFlag*,const void*,JVMFlagOrigin,FormatBuffer<80>&), JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
227 if (name == NULL) {
228 err_msg.print("flag name is missing");
229 return JVMFlag::MISSING_NAME;
230 }
231 if (value == NULL) {
232 err_msg.print("flag value is missing");
233 return JVMFlag::MISSING_VALUE;
234 }
235
236 JVMFlag* f = JVMFlag::find_flag(name);
237 if (f) {
238 // only writeable flags are allowed to be set
239 if (f->is_writeable()) {
240 return setter(f, value, origin, err_msg);
241 } else {
242 err_msg.print("only 'writeable' flags can be set");
243 return JVMFlag::NON_WRITABLE;
244 }
245 }
246
247 err_msg.print("flag %s does not exist", name);
248 return JVMFlag::INVALID_FLAG;
249 }
250
251 // a writeable flag setter accepting 'char *' values
set_flag_from_char(JVMFlag * f,const void * value,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)252 JVMFlag::Error WriteableFlags::set_flag_from_char(JVMFlag* f, const void* value, JVMFlagOrigin origin, FormatBuffer<80>& err_msg) {
253 char* flag_value = *(char**)value;
254 if (flag_value == NULL) {
255 err_msg.print("flag value is missing");
256 return JVMFlag::MISSING_VALUE;
257 }
258 if (f->is_bool()) {
259 return set_bool_flag(f->name(), flag_value, origin, err_msg);
260 } else if (f->is_int()) {
261 return set_int_flag(f->name(), flag_value, origin, err_msg);
262 } else if (f->is_uint()) {
263 return set_uint_flag(f->name(), flag_value, origin, err_msg);
264 } else if (f->is_intx()) {
265 return set_intx_flag(f->name(), flag_value, origin, err_msg);
266 } else if (f->is_uintx()) {
267 return set_uintx_flag(f->name(), flag_value, origin, err_msg);
268 } else if (f->is_uint64_t()) {
269 return set_uint64_t_flag(f->name(), flag_value, origin, err_msg);
270 } else if (f->is_size_t()) {
271 return set_size_t_flag(f->name(), flag_value, origin, err_msg);
272 } else if (f->is_double()) {
273 return set_double_flag(f->name(), flag_value, origin, err_msg);
274 } else if (f->is_ccstr()) {
275 return set_ccstr_flag(f->name(), flag_value, origin, err_msg);
276 } else {
277 ShouldNotReachHere();
278 }
279 return JVMFlag::ERR_OTHER;
280 }
281
282 // a writeable flag setter accepting 'jvalue' values
set_flag_from_jvalue(JVMFlag * f,const void * value,JVMFlagOrigin origin,FormatBuffer<80> & err_msg)283 JVMFlag::Error WriteableFlags::set_flag_from_jvalue(JVMFlag* f, const void* value, JVMFlagOrigin origin,
284 FormatBuffer<80>& err_msg) {
285 jvalue new_value = *(jvalue*)value;
286 if (f->is_bool()) {
287 bool bvalue = (new_value.z == JNI_TRUE ? true : false);
288 return set_flag_impl<JVM_FLAG_TYPE(bool)>(f->name(), bvalue, origin, err_msg);
289 } else if (f->is_int()) {
290 int ivalue = (int)new_value.j;
291 return set_flag_impl<JVM_FLAG_TYPE(int)>(f->name(), ivalue, origin, err_msg);
292 } else if (f->is_uint()) {
293 uint uvalue = (uint)new_value.j;
294 return set_flag_impl<JVM_FLAG_TYPE(uint)>(f->name(), uvalue, origin, err_msg);
295 } else if (f->is_intx()) {
296 intx ivalue = (intx)new_value.j;
297 return set_flag_impl<JVM_FLAG_TYPE(intx)>(f->name(), ivalue, origin, err_msg);
298 } else if (f->is_uintx()) {
299 uintx uvalue = (uintx)new_value.j;
300 return set_flag_impl<JVM_FLAG_TYPE(uintx)>(f->name(), uvalue, origin, err_msg);
301 } else if (f->is_uint64_t()) {
302 uint64_t uvalue = (uint64_t)new_value.j;
303 return set_flag_impl<JVM_FLAG_TYPE(uint64_t)>(f->name(), uvalue, origin, err_msg);
304 } else if (f->is_size_t()) {
305 size_t svalue = (size_t)new_value.j;
306 return set_flag_impl<JVM_FLAG_TYPE(size_t)>(f->name(), svalue, origin, err_msg);
307 } else if (f->is_double()) {
308 double dvalue = (double)new_value.d;
309 return set_flag_impl<JVM_FLAG_TYPE(double)>(f->name(), dvalue, origin, err_msg);
310 } else if (f->is_ccstr()) {
311 oop str = JNIHandles::resolve_external_guard(new_value.l);
312 if (str == NULL) {
313 err_msg.print("flag value is missing");
314 return JVMFlag::MISSING_VALUE;
315 }
316 ResourceMark rm;
317 ccstr svalue = java_lang_String::as_utf8_string(str);
318 JVMFlag::Error ret = WriteableFlags::set_ccstr_flag(f->name(), svalue, origin, err_msg);
319 return ret;
320 } else {
321 ShouldNotReachHere();
322 }
323 return JVMFlag::ERR_OTHER;
324 }
325