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1 /**************************************************************************
2  *
3  * Copyright 2009 VMware, Inc.
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
27 
28 /**
29  * @file
30  * Symbol lookup.
31  *
32  * @author Jose Fonseca <jfonseca@vmware.com>
33  */
34 
35 #include "pipe/p_compiler.h"
36 #include "os/os_thread.h"
37 #include "u_string.h"
38 
39 #include "u_debug.h"
40 #include "u_debug_symbol.h"
41 #include "u_hash_table.h"
42 
43 
44 #if defined(PIPE_OS_WINDOWS)
45 
46 #include <windows.h>
47 #include <stddef.h>
48 
49 #include "dbghelp.h"
50 
51 
52 /**
53  * SymInitialize() must be called once for each process (in this case, the
54  * current process), before any of the other functions can be called.
55  */
56 static BOOL g_bSymInitialized = FALSE;
57 
58 
59 /**
60  * Lookup the address of a DbgHelp function.
61  */
62 static FARPROC WINAPI
getDbgHelpProcAddress(LPCSTR lpProcName)63 getDbgHelpProcAddress(LPCSTR lpProcName)
64 {
65    static HMODULE hModule = NULL;
66 
67    if (!hModule) {
68       static boolean bail = FALSE;
69 
70       if (bail) {
71          return NULL;
72       }
73 
74 #ifdef PIPE_CC_GCC
75       /*
76        * DbgHelp does not understand the debug information generated by MinGW toolchain.
77        *
78        * mgwhelp.dll is a dbghelp.dll look-alike replacement, which is able to
79        * understand MinGW symbols, including on 64-bit builds.
80        */
81       if (!hModule) {
82          hModule = LoadLibraryA("mgwhelp.dll");
83          if (!hModule) {
84             _debug_printf("warning: mgwhelp.dll not found: symbol names will not be resolved\n"
85                           "warning: download it from https://github.com/jrfonseca/drmingw/#mgwhelp\n");
86          }
87       }
88 #endif
89 
90       /*
91        * Fallback to the real DbgHelp.
92        */
93       if (!hModule) {
94          hModule = LoadLibraryA("dbghelp.dll");
95       }
96 
97       if (!hModule) {
98          bail = TRUE;
99          return NULL;
100       }
101    }
102 
103    return GetProcAddress(hModule, lpProcName);
104 }
105 
106 
107 /**
108  * Generic macro to dispatch a DbgHelp functions.
109  */
110 #define DBGHELP_DISPATCH(_name, _ret_type, _ret_default, _arg_types, _arg_names) \
111    static _ret_type WINAPI \
112    j_##_name _arg_types \
113    { \
114       typedef BOOL (WINAPI *PFN) _arg_types; \
115       static PFN pfn = NULL; \
116       if (!pfn) { \
117          pfn = (PFN) getDbgHelpProcAddress(#_name); \
118          if (!pfn) { \
119             return _ret_default; \
120          } \
121       } \
122       return pfn _arg_names; \
123    }
124 
125 DBGHELP_DISPATCH(SymInitialize,
126                  BOOL, 0,
127                  (HANDLE hProcess, PSTR UserSearchPath, BOOL fInvadeProcess),
128                  (hProcess, UserSearchPath, fInvadeProcess))
129 
130 DBGHELP_DISPATCH(SymSetOptions,
131                  DWORD, FALSE,
132                  (DWORD SymOptions),
133                  (SymOptions))
134 
135 DBGHELP_DISPATCH(SymFromAddr,
136                  BOOL, FALSE,
137                  (HANDLE hProcess, DWORD64 Address, PDWORD64 Displacement, PSYMBOL_INFO Symbol),
138                  (hProcess, Address, Displacement, Symbol))
139 
140 DBGHELP_DISPATCH(SymGetLineFromAddr64,
141                  BOOL, FALSE,
142                  (HANDLE hProcess, DWORD64 dwAddr, PDWORD pdwDisplacement, PIMAGEHLP_LINE64 Line),
143                  (hProcess, dwAddr, pdwDisplacement, Line))
144 
145 
146 #undef DBGHELP_DISPATCH
147 
148 
149 static inline boolean
debug_symbol_name_dbghelp(const void * addr,char * buf,unsigned size)150 debug_symbol_name_dbghelp(const void *addr, char* buf, unsigned size)
151 {
152    DWORD64 dwAddr = (DWORD64)(uintptr_t)addr;
153    HANDLE hProcess = GetCurrentProcess();
154 
155    /* General purpose buffer, to back pSymbol and other temporary stuff.
156     * Must not be too memory hungry here to avoid stack overflows.
157     */
158    CHAR buffer[512];
159 
160    PSYMBOL_INFO pSymbol = (PSYMBOL_INFO) buffer;
161    DWORD64 dwDisplacement = 0;  /* Displacement of the input address, relative to the start of the symbol */
162    DWORD dwLineDisplacement = 0;
163    IMAGEHLP_LINE64 Line;
164 
165    memset(pSymbol, 0, sizeof *pSymbol);
166    pSymbol->SizeOfStruct = sizeof buffer;
167    pSymbol->MaxNameLen = sizeof buffer - offsetof(SYMBOL_INFO, Name);
168 
169    if (!g_bSymInitialized) {
170       j_SymSetOptions(/* SYMOPT_UNDNAME | */ SYMOPT_LOAD_LINES);
171       if (j_SymInitialize(hProcess, NULL, TRUE)) {
172          g_bSymInitialized = TRUE;
173       }
174    }
175 
176    /* Lookup symbol name */
177    if (!g_bSymInitialized ||
178        !j_SymFromAddr(hProcess, dwAddr, &dwDisplacement, pSymbol)) {
179       /*
180        * We couldn't obtain symbol information.  At least tell which module the address belongs.
181        */
182 
183       HMODULE hModule = NULL;
184 
185       if (!GetModuleHandleEx(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS,
186                              (LPCTSTR)addr,
187                              &hModule)) {
188          return FALSE;
189       }
190 
191       if (GetModuleFileNameA(hModule, buffer, sizeof buffer) == sizeof buffer) {
192          return FALSE;
193       }
194       util_snprintf(buf, size, "%p at %s+0x%lx",
195                     addr, buffer,
196                     (unsigned long)((uintptr_t)addr - (uintptr_t)hModule));
197 
198       return TRUE;
199    }
200 
201    /*
202     * Try to get filename and line number.
203     */
204    memset(&Line, 0, sizeof Line);
205    Line.SizeOfStruct = sizeof Line;
206    if (!j_SymGetLineFromAddr64(hProcess, dwAddr, &dwLineDisplacement, &Line)) {
207       Line.FileName = NULL;
208    }
209 
210    if (Line.FileName) {
211       util_snprintf(buf, size, "%s at %s:%lu", pSymbol->Name, Line.FileName, Line.LineNumber);
212    } else {
213       util_snprintf(buf, size, "%s", pSymbol->Name);
214    }
215 
216    return TRUE;
217 }
218 
219 #endif /* PIPE_OS_WINDOWS */
220 
221 
222 #if defined(__GLIBC__) && !defined(__UCLIBC__)
223 
224 #include <execinfo.h>
225 
226 /* This can only provide dynamic symbols, or binary offsets into a file.
227  *
228  * To fix this, post-process the output with tools/addr2line.sh
229  */
230 static inline boolean
debug_symbol_name_glibc(const void * addr,char * buf,unsigned size)231 debug_symbol_name_glibc(const void *addr, char* buf, unsigned size)
232 {
233    char** syms = backtrace_symbols((void**)&addr, 1);
234    if (!syms) {
235       return FALSE;
236    }
237    strncpy(buf, syms[0], size);
238    buf[size - 1] = 0;
239    free(syms);
240    return TRUE;
241 }
242 
243 #endif /* defined(__GLIBC__) && !defined(__UCLIBC__) */
244 
245 
246 void
debug_symbol_name(const void * addr,char * buf,unsigned size)247 debug_symbol_name(const void *addr, char* buf, unsigned size)
248 {
249 #if defined(PIPE_OS_WINDOWS)
250    if (debug_symbol_name_dbghelp(addr, buf, size)) {
251       return;
252    }
253 #endif
254 
255 #if defined(__GLIBC__) && !defined(__UCLIBC__)
256    if (debug_symbol_name_glibc(addr, buf, size)) {
257        return;
258    }
259 #endif
260 
261    util_snprintf(buf, size, "%p", addr);
262    buf[size - 1] = 0;
263 }
264 
265 void
debug_symbol_print(const void * addr)266 debug_symbol_print(const void *addr)
267 {
268    char buf[1024];
269    debug_symbol_name(addr, buf, sizeof(buf));
270    debug_printf("\t%s\n", buf);
271 }
272 
273 struct util_hash_table* symbols_hash;
274 pipe_static_mutex(symbols_mutex);
275 
hash_ptr(void * p)276 static unsigned hash_ptr(void* p)
277 {
278    return (unsigned)(uintptr_t)p;
279 }
280 
compare_ptr(void * a,void * b)281 static int compare_ptr(void* a, void* b)
282 {
283    if(a == b)
284       return 0;
285    else if(a < b)
286       return -1;
287    else
288       return 1;
289 }
290 
291 const char*
debug_symbol_name_cached(const void * addr)292 debug_symbol_name_cached(const void *addr)
293 {
294    const char* name;
295 #ifdef PIPE_SUBSYSTEM_WINDOWS_USER
296    static boolean first = TRUE;
297 
298    if (first) {
299       pipe_mutex_init(symbols_mutex);
300       first = FALSE;
301    }
302 #endif
303 
304    pipe_mutex_lock(symbols_mutex);
305    if(!symbols_hash)
306       symbols_hash = util_hash_table_create(hash_ptr, compare_ptr);
307    name = util_hash_table_get(symbols_hash, (void*)addr);
308    if(!name)
309    {
310       char buf[1024];
311       debug_symbol_name(addr, buf, sizeof(buf));
312       name = strdup(buf);
313 
314       util_hash_table_set(symbols_hash, (void*)addr, (void*)name);
315    }
316    pipe_mutex_unlock(symbols_mutex);
317    return name;
318 }
319