1 //===-- sanitizer_flags.cc ------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a part of ThreadSanitizer/AddressSanitizer runtime.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "sanitizer_flags.h"
15
16 #include "sanitizer_common.h"
17 #include "sanitizer_libc.h"
18 #include "sanitizer_list.h"
19
20 namespace __sanitizer {
21
22 CommonFlags common_flags_dont_use;
23
24 struct FlagDescription {
25 const char *name;
26 const char *description;
27 FlagDescription *next;
28 };
29
30 IntrusiveList<FlagDescription> flag_descriptions;
31
32 // If set, the tool will install its own SEGV signal handler by default.
33 #ifndef SANITIZER_NEEDS_SEGV
34 # define SANITIZER_NEEDS_SEGV 1
35 #endif
36
SetCommonFlagsDefaults(CommonFlags * f)37 void SetCommonFlagsDefaults(CommonFlags *f) {
38 f->symbolize = true;
39 f->external_symbolizer_path = 0;
40 f->allow_addr2line = false;
41 f->strip_path_prefix = "";
42 f->fast_unwind_on_fatal = false;
43 f->fast_unwind_on_malloc = true;
44 f->handle_ioctl = false;
45 f->malloc_context_size = 1;
46 f->log_path = "stderr";
47 f->verbosity = 0;
48 f->detect_leaks = true;
49 f->leak_check_at_exit = true;
50 f->allocator_may_return_null = false;
51 f->print_summary = true;
52 f->check_printf = true;
53 // TODO(glider): tools may want to set different defaults for handle_segv.
54 f->handle_segv = SANITIZER_NEEDS_SEGV;
55 f->allow_user_segv_handler = false;
56 f->use_sigaltstack = true;
57 f->detect_deadlocks = false;
58 f->clear_shadow_mmap_threshold = 64 * 1024;
59 f->color = "auto";
60 f->legacy_pthread_cond = false;
61 f->intercept_tls_get_addr = false;
62 f->coverage = false;
63 f->coverage_direct = SANITIZER_ANDROID;
64 f->coverage_dir = ".";
65 f->full_address_space = false;
66 }
67
ParseCommonFlagsFromString(CommonFlags * f,const char * str)68 void ParseCommonFlagsFromString(CommonFlags *f, const char *str) {
69 ParseFlag(str, &f->symbolize, "symbolize",
70 "If set, use the online symbolizer from common sanitizer runtime to turn "
71 "virtual addresses to file/line locations.");
72 ParseFlag(str, &f->external_symbolizer_path, "external_symbolizer_path",
73 "Path to external symbolizer. If empty, the tool will search $PATH for "
74 "the symbolizer.");
75 ParseFlag(str, &f->allow_addr2line, "allow_addr2line",
76 "If set, allows online symbolizer to run addr2line binary to symbolize "
77 "stack traces (addr2line will only be used if llvm-symbolizer binary is "
78 "unavailable.");
79 ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix",
80 "Strips this prefix from file paths in error reports.");
81 ParseFlag(str, &f->fast_unwind_on_fatal, "fast_unwind_on_fatal",
82 "If available, use the fast frame-pointer-based unwinder on fatal "
83 "errors.");
84 ParseFlag(str, &f->fast_unwind_on_malloc, "fast_unwind_on_malloc",
85 "If available, use the fast frame-pointer-based unwinder on "
86 "malloc/free.");
87 ParseFlag(str, &f->handle_ioctl, "handle_ioctl",
88 "Intercept and handle ioctl requests.");
89 ParseFlag(str, &f->malloc_context_size, "malloc_context_size",
90 "Max number of stack frames kept for each allocation/deallocation.");
91 ParseFlag(str, &f->log_path, "log_path",
92 "Write logs to \"log_path.pid\". The special values are \"stdout\" and "
93 "\"stderr\". The default is \"stderr\".");
94 ParseFlag(str, &f->verbosity, "verbosity",
95 "Verbosity level (0 - silent, 1 - a bit of output, 2+ - more output).");
96 ParseFlag(str, &f->detect_leaks, "detect_leaks",
97 "Enable memory leak detection.");
98 ParseFlag(str, &f->leak_check_at_exit, "leak_check_at_exit",
99 "Invoke leak checking in an atexit handler. Has no effect if "
100 "detect_leaks=false, or if __lsan_do_leak_check() is called before the "
101 "handler has a chance to run.");
102 ParseFlag(str, &f->allocator_may_return_null, "allocator_may_return_null",
103 "If false, the allocator will crash instead of returning 0 on "
104 "out-of-memory.");
105 ParseFlag(str, &f->print_summary, "print_summary",
106 "If false, disable printing error summaries in addition to error "
107 "reports.");
108 ParseFlag(str, &f->check_printf, "check_printf",
109 "Check printf arguments.");
110 ParseFlag(str, &f->handle_segv, "handle_segv",
111 "If set, registers the tool's custom SEGV handler (both SIGBUS and "
112 "SIGSEGV on OSX).");
113 ParseFlag(str, &f->allow_user_segv_handler, "allow_user_segv_handler",
114 "If set, allows user to register a SEGV handler even if the tool "
115 "registers one.");
116 ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack",
117 "If set, uses alternate stack for signal handling.");
118 ParseFlag(str, &f->detect_deadlocks, "detect_deadlocks",
119 "If set, deadlock detection is enabled.");
120 ParseFlag(str, &f->clear_shadow_mmap_threshold,
121 "clear_shadow_mmap_threshold",
122 "Large shadow regions are zero-filled using mmap(NORESERVE) instead of "
123 "memset(). This is the threshold size in bytes.");
124 ParseFlag(str, &f->color, "color",
125 "Colorize reports: (always|never|auto).");
126 ParseFlag(str, &f->legacy_pthread_cond, "legacy_pthread_cond",
127 "Enables support for dynamic libraries linked with libpthread 2.2.5.");
128 ParseFlag(str, &f->intercept_tls_get_addr, "intercept_tls_get_addr",
129 "Intercept __tls_get_addr.");
130 ParseFlag(str, &f->help, "help", "Print the flag descriptions.");
131 ParseFlag(str, &f->mmap_limit_mb, "mmap_limit_mb",
132 "Limit the amount of mmap-ed memory (excluding shadow) in Mb; "
133 "not a user-facing flag, used mosly for testing the tools");
134 ParseFlag(str, &f->coverage, "coverage",
135 "If set, coverage information will be dumped at program shutdown (if the "
136 "coverage instrumentation was enabled at compile time).");
137 ParseFlag(str, &f->coverage_direct, "coverage_direct",
138 "If set, coverage information will be dumped directly to a memory "
139 "mapped file. This way data is not lost even if the process is "
140 "suddenly killed.");
141 ParseFlag(str, &f->coverage_dir, "coverage_dir",
142 "Target directory for coverage dumps. Defaults to the current "
143 "directory.");
144 ParseFlag(str, &f->full_address_space, "full_address_space",
145 "Sanitize complete address space; "
146 "by default kernel area on 32-bit platforms will not be sanitized");
147
148 // Do a sanity check for certain flags.
149 if (f->malloc_context_size < 1)
150 f->malloc_context_size = 1;
151 }
152
GetFlagValue(const char * env,const char * name,const char ** value,int * value_length)153 static bool GetFlagValue(const char *env, const char *name,
154 const char **value, int *value_length) {
155 if (env == 0)
156 return false;
157 const char *pos = 0;
158 for (;;) {
159 pos = internal_strstr(env, name);
160 if (pos == 0)
161 return false;
162 const char *name_end = pos + internal_strlen(name);
163 if ((pos != env &&
164 ((pos[-1] >= 'a' && pos[-1] <= 'z') || pos[-1] == '_')) ||
165 *name_end != '=') {
166 // Seems to be middle of another flag name or value.
167 env = pos + 1;
168 continue;
169 }
170 pos = name_end;
171 break;
172 }
173 const char *end;
174 if (pos[0] != '=') {
175 end = pos;
176 } else {
177 pos += 1;
178 if (pos[0] == '"') {
179 pos += 1;
180 end = internal_strchr(pos, '"');
181 } else if (pos[0] == '\'') {
182 pos += 1;
183 end = internal_strchr(pos, '\'');
184 } else {
185 // Read until the next space or colon.
186 end = pos + internal_strcspn(pos, " :");
187 }
188 if (end == 0)
189 end = pos + internal_strlen(pos);
190 }
191 *value = pos;
192 *value_length = end - pos;
193 return true;
194 }
195
StartsWith(const char * flag,int flag_length,const char * value)196 static bool StartsWith(const char *flag, int flag_length, const char *value) {
197 if (!flag || !value)
198 return false;
199 int value_length = internal_strlen(value);
200 return (flag_length >= value_length) &&
201 (0 == internal_strncmp(flag, value, value_length));
202 }
203
204 static LowLevelAllocator allocator_for_flags;
205
206 // The linear scan is suboptimal, but the number of flags is relatively small.
FlagInDescriptionList(const char * name)207 bool FlagInDescriptionList(const char *name) {
208 IntrusiveList<FlagDescription>::Iterator it(&flag_descriptions);
209 while (it.hasNext()) {
210 if (!internal_strcmp(it.next()->name, name)) return true;
211 }
212 return false;
213 }
214
AddFlagDescription(const char * name,const char * description)215 void AddFlagDescription(const char *name, const char *description) {
216 if (FlagInDescriptionList(name)) return;
217 FlagDescription *new_description = new(allocator_for_flags) FlagDescription;
218 new_description->name = name;
219 new_description->description = description;
220 flag_descriptions.push_back(new_description);
221 }
222
223 // TODO(glider): put the descriptions inside CommonFlags.
PrintFlagDescriptions()224 void PrintFlagDescriptions() {
225 IntrusiveList<FlagDescription>::Iterator it(&flag_descriptions);
226 Printf("Available flags for %s:\n", SanitizerToolName);
227 while (it.hasNext()) {
228 FlagDescription *descr = it.next();
229 Printf("\t%s\n\t\t- %s\n", descr->name, descr->description);
230 }
231 }
232
ParseFlag(const char * env,bool * flag,const char * name,const char * descr)233 void ParseFlag(const char *env, bool *flag,
234 const char *name, const char *descr) {
235 const char *value;
236 int value_length;
237 AddFlagDescription(name, descr);
238 if (!GetFlagValue(env, name, &value, &value_length))
239 return;
240 if (StartsWith(value, value_length, "0") ||
241 StartsWith(value, value_length, "no") ||
242 StartsWith(value, value_length, "false"))
243 *flag = false;
244 if (StartsWith(value, value_length, "1") ||
245 StartsWith(value, value_length, "yes") ||
246 StartsWith(value, value_length, "true"))
247 *flag = true;
248 }
249
ParseFlag(const char * env,int * flag,const char * name,const char * descr)250 void ParseFlag(const char *env, int *flag,
251 const char *name, const char *descr) {
252 const char *value;
253 int value_length;
254 AddFlagDescription(name, descr);
255 if (!GetFlagValue(env, name, &value, &value_length))
256 return;
257 *flag = static_cast<int>(internal_atoll(value));
258 }
259
ParseFlag(const char * env,uptr * flag,const char * name,const char * descr)260 void ParseFlag(const char *env, uptr *flag,
261 const char *name, const char *descr) {
262 const char *value;
263 int value_length;
264 AddFlagDescription(name, descr);
265 if (!GetFlagValue(env, name, &value, &value_length))
266 return;
267 *flag = static_cast<uptr>(internal_atoll(value));
268 }
269
ParseFlag(const char * env,const char ** flag,const char * name,const char * descr)270 void ParseFlag(const char *env, const char **flag,
271 const char *name, const char *descr) {
272 const char *value;
273 int value_length;
274 AddFlagDescription(name, descr);
275 if (!GetFlagValue(env, name, &value, &value_length))
276 return;
277 // Copy the flag value. Don't use locks here, as flags are parsed at
278 // tool startup.
279 char *value_copy = (char*)(allocator_for_flags.Allocate(value_length + 1));
280 internal_memcpy(value_copy, value, value_length);
281 value_copy[value_length] = '\0';
282 *flag = value_copy;
283 }
284
285 } // namespace __sanitizer
286