1 /* libunwind - a platform-independent unwind library
2    Copyright (C) 2001-2005 Hewlett-Packard Co
3    Copyright (C) 2007 David Mosberger-Tang
4 	Contributed by David Mosberger-Tang <dmosberger@gmail.com>
5 
6 This file is part of libunwind.
7 
8 Permission is hereby granted, free of charge, to any person obtaining
9 a copy of this software and associated documentation files (the
10 "Software"), to deal in the Software without restriction, including
11 without limitation the rights to use, copy, modify, merge, publish,
12 distribute, sublicense, and/or sell copies of the Software, and to
13 permit persons to whom the Software is furnished to do so, subject to
14 the following conditions:
15 
16 The above copyright notice and this permission notice shall be
17 included in all copies or substantial portions of the Software.
18 
19 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
23 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
24 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
25 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
26 
27 /* This files contains libunwind-internal definitions which are
28    subject to frequent change and are not to be exposed to
29    libunwind-users.  */
30 
31 #ifndef libunwind_i_h
32 #define libunwind_i_h
33 
34 #ifdef HAVE_CONFIG_H
35 # include "config.h"
36 #endif
37 
38 #include "compiler.h"
39 
40 #ifdef HAVE___THREAD
41   /* For now, turn off per-thread caching.  It uses up too much TLS
42      memory per thread even when the thread never uses libunwind at
43      all.  */
44 # undef HAVE___THREAD
45 #endif
46 
47 /* Platform-independent libunwind-internal declarations.  */
48 
49 #include <sys/types.h>	/* HP-UX needs this before include of pthread.h */
50 
51 #include <assert.h>
52 #include <libunwind.h>
53 #include <pthread.h>
54 #include <signal.h>
55 #include <stdbool.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 #include <sys/mman.h>
60 
61 #if defined(HAVE_ELF_H)
62 # include <elf.h>
63 #elif defined(HAVE_SYS_ELF_H)
64 # include <sys/elf.h>
65 #else
66 # error Could not locate <elf.h>
67 #endif
68 
69 #if defined(HAVE_ENDIAN_H)
70 # include <endian.h>
71 #elif defined(HAVE_SYS_ENDIAN_H)
72 # include <sys/endian.h>
73 #else
74 # define __LITTLE_ENDIAN	1234
75 # define __BIG_ENDIAN		4321
76 # if defined(__hpux)
77 #   define __BYTE_ORDER __BIG_ENDIAN
78 # elif defined(__QNX__)
79 #   if defined(__BIGENDIAN__)
80 #     define __BYTE_ORDER __BIG_ENDIAN
81 #   elif defined(__LITTLEENDIAN__)
82 #     define __BYTE_ORDER __LITTLE_ENDIAN
83 #   else
84 #     error Host has unknown byte-order.
85 #   endif
86 # else
87 #   error Host has unknown byte-order.
88 # endif
89 #endif
90 
91 #if defined(HAVE__BUILTIN_UNREACHABLE)
92 # define unreachable() __builtin_unreachable()
93 #else
94 # define unreachable() do { } while (1)
95 #endif
96 
97 #ifdef DEBUG
98 # define UNW_DEBUG	1
99 #else
100 # define UNW_DEBUG	0
101 #endif
102 
103 /* Make it easy to write thread-safe code which may or may not be
104    linked against libpthread.  The macros below can be used
105    unconditionally and if -lpthread is around, they'll call the
106    corresponding routines otherwise, they do nothing.  */
107 
108 #pragma weak pthread_mutex_init
109 #pragma weak pthread_mutex_lock
110 #pragma weak pthread_mutex_unlock
111 
112 #define mutex_init(l)							\
113 	(pthread_mutex_init != NULL ? pthread_mutex_init ((l), NULL) : 0)
114 #define mutex_lock(l)							\
115 	(pthread_mutex_lock != NULL ? pthread_mutex_lock (l) : 0)
116 #define mutex_unlock(l)							\
117 	(pthread_mutex_unlock != NULL ? pthread_mutex_unlock (l) : 0)
118 
119 #ifdef HAVE_ATOMIC_OPS_H
120 # include <atomic_ops.h>
121 static inline int
cmpxchg_ptr(void * addr,void * old,void * new)122 cmpxchg_ptr (void *addr, void *old, void *new)
123 {
124   union
125     {
126       void *vp;
127       AO_t *aop;
128     }
129   u;
130 
131   u.vp = addr;
132   return AO_compare_and_swap(u.aop, (AO_t) old, (AO_t) new);
133 }
134 # define fetch_and_add1(_ptr)		AO_fetch_and_add1(_ptr)
135 # define fetch_and_add(_ptr, value)	AO_fetch_and_add(_ptr, value)
136    /* GCC 3.2.0 on HP-UX crashes on cmpxchg_ptr() */
137 #  if !(defined(__hpux) && __GNUC__ == 3 && __GNUC_MINOR__ == 2)
138 #   define HAVE_CMPXCHG
139 #  endif
140 # define HAVE_FETCH_AND_ADD
141 #elif defined(HAVE_SYNC_ATOMICS) || defined(HAVE_IA64INTRIN_H)
142 # ifdef HAVE_IA64INTRIN_H
143 #  include <ia64intrin.h>
144 # endif
145 static inline int
cmpxchg_ptr(void * addr,void * old,void * new)146 cmpxchg_ptr (void *addr, void *old, void *new)
147 {
148   union
149     {
150       void *vp;
151       long *vlp;
152     }
153   u;
154 
155   u.vp = addr;
156   return __sync_bool_compare_and_swap(u.vlp, (long) old, (long) new);
157 }
158 # define fetch_and_add1(_ptr)		__sync_fetch_and_add(_ptr, 1)
159 # define fetch_and_add(_ptr, value)	__sync_fetch_and_add(_ptr, value)
160 # define HAVE_CMPXCHG
161 # define HAVE_FETCH_AND_ADD
162 #endif
163 #define atomic_read(ptr)	(*(ptr))
164 
165 #define UNWI_OBJ(fn)	  UNW_PASTE(UNW_PREFIX,UNW_PASTE(I,fn))
166 #define UNWI_ARCH_OBJ(fn) UNW_PASTE(UNW_PASTE(UNW_PASTE(_UI,UNW_TARGET),_), fn)
167 
168 #define unwi_full_mask    UNWI_ARCH_OBJ(full_mask)
169 
170 /* Type of a mask that can be used to inhibit preemption.  At the
171    userlevel, preemption is caused by signals and hence sigset_t is
172    appropriate.  In constrast, the Linux kernel uses "unsigned long"
173    to hold the processor "flags" instead.  */
174 typedef sigset_t intrmask_t;
175 
176 extern intrmask_t unwi_full_mask;
177 
178 /* Silence compiler warnings about variables which are used only if libunwind
179    is configured in a certain way */
mark_as_used(void * v UNUSED)180 static inline void mark_as_used(void *v UNUSED) {
181 }
182 
183 #if defined(CONFIG_BLOCK_SIGNALS)
184 # define SIGPROCMASK(how, new_mask, old_mask) \
185   sigprocmask((how), (new_mask), (old_mask))
186 #else
187 # define SIGPROCMASK(how, new_mask, old_mask) mark_as_used(old_mask)
188 #endif
189 
190 /* ANDROID support update. */
191 #define __lock_acquire_internal(l, m, acquire_func)	\
192 do {							\
193   SIGPROCMASK (SIG_SETMASK, &unwi_full_mask, &(m));	\
194   acquire_func (l);					\
195 } while (0)
196 #define __lock_release_internal(l, m, release_func)	\
197 do {							\
198   release_func (l);					\
199   SIGPROCMASK (SIG_SETMASK, &(m), NULL);		\
200 } while (0)
201 
202 #define lock_rdwr_var(name)				\
203   pthread_rwlock_t name
204 #define lock_rdwr_init(l)	pthread_rwlock_init (l, NULL)
205 #define lock_rdwr_wr_acquire(l, m)			\
206   __lock_acquire_internal(l, m, pthread_rwlock_wrlock)
207 #define lock_rdwr_rd_acquire(l, m)			\
208   __lock_acquire_internal(l, m, pthread_rwlock_rdlock)
209 #define lock_rdwr_release(l, m)				\
210   __lock_release_internal(l, m, pthread_rwlock_unlock)
211 
212 #define lock_var(name) \
213   pthread_mutex_t name
214 #define define_lock(name) \
215   lock_var (name) = PTHREAD_MUTEX_INITIALIZER
216 #define lock_init(l)		mutex_init (l)
217 #define lock_acquire(l,m)				\
218   __lock_acquire_internal(l, m, mutex_lock)
219 #define lock_release(l,m)			\
220   __lock_release_internal(l, m, mutex_unlock)
221 /* End of ANDROID update. */
222 
223 #define SOS_MEMORY_SIZE 16384	/* see src/mi/mempool.c */
224 
225 #ifndef MAP_ANONYMOUS
226 # define MAP_ANONYMOUS MAP_ANON
227 #endif
228 #define GET_MEMORY(mem, size)				    		    \
229 do {									    \
230   /* Hopefully, mmap() goes straight through to a system call stub...  */   \
231   mem = mmap (NULL, size, PROT_READ | PROT_WRITE,			    \
232 	      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);			    \
233   if (mem == MAP_FAILED)						    \
234     mem = NULL;								    \
235 } while (0)
236 
237 #define unwi_find_dynamic_proc_info	UNWI_OBJ(find_dynamic_proc_info)
238 #define unwi_extract_dynamic_proc_info	UNWI_OBJ(extract_dynamic_proc_info)
239 #define unwi_put_dynamic_unwind_info	UNWI_OBJ(put_dynamic_unwind_info)
240 #define unwi_dyn_remote_find_proc_info	UNWI_OBJ(dyn_remote_find_proc_info)
241 #define unwi_dyn_remote_put_unwind_info	UNWI_OBJ(dyn_remote_put_unwind_info)
242 #define unwi_dyn_validate_cache		UNWI_OBJ(dyn_validate_cache)
243 
244 extern int unwi_find_dynamic_proc_info (unw_addr_space_t as,
245 					unw_word_t ip,
246 					unw_proc_info_t *pi,
247 					int need_unwind_info, void *arg);
248 extern int unwi_extract_dynamic_proc_info (unw_addr_space_t as,
249 					   unw_word_t ip,
250 					   unw_proc_info_t *pi,
251 					   unw_dyn_info_t *di,
252 					   int need_unwind_info,
253 					   void *arg);
254 extern void unwi_put_dynamic_unwind_info (unw_addr_space_t as,
255 					  unw_proc_info_t *pi, void *arg);
256 
257 /* These handle the remote (cross-address-space) case of accessing
258    dynamic unwind info. */
259 
260 extern int unwi_dyn_remote_find_proc_info (unw_addr_space_t as,
261 					   unw_word_t ip,
262 					   unw_proc_info_t *pi,
263 					   int need_unwind_info,
264 					   void *arg);
265 extern void unwi_dyn_remote_put_unwind_info (unw_addr_space_t as,
266 					     unw_proc_info_t *pi,
267 					     void *arg);
268 extern int unwi_dyn_validate_cache (unw_addr_space_t as, void *arg);
269 
270 extern unw_dyn_info_list_t _U_dyn_info_list;
271 extern pthread_mutex_t _U_dyn_info_list_lock;
272 
273 #if UNW_DEBUG
274 # define unwi_debug_level		UNWI_ARCH_OBJ(debug_level)
275 extern long unwi_debug_level;
276 
277 # ifdef ANDROID
278 # define LOG_TAG "libunwind"
279 # include <log/log.h>
280 
281 # define Debug(level, format, ...)					\
282 do {									\
283   if (unwi_debug_level >= (level))					\
284     { 									\
285       ALOGI("%*c>%s: " format, ((level) <= 16) ? (level) : 16, ' ',	\
286             __FUNCTION__, ##__VA_ARGS__);				\
287     } 									\
288 } while (0)
289 # define Dprintf(format, ...) ALOGI(format, ##__VA_ARGS__);
290 #else
291 # include <stdio.h>
292 # define Debug(level,format...)						\
293 do {									\
294   if (unwi_debug_level >= level)					\
295     {									\
296       int _n = level;							\
297       if (_n > 16)							\
298 	_n = 16;							\
299       fprintf (stderr, "%*c>%s: ", _n, ' ', __FUNCTION__);		\
300       fprintf (stderr, format);						\
301     }									\
302 } while (0)
303 # define Dprintf(format...) 	    fprintf (stderr, format)
304 # ifdef __GNUC__
305 #  undef inline
306 #  define inline	UNUSED
307 # endif
308 # endif
309 #else
310 # define Debug(level,format...)
311 # define Dprintf(format...)
312 #endif
313 
314 static ALWAYS_INLINE int
print_error(const char * string)315 print_error (const char *string)
316 {
317   return write (2, string, strlen (string));
318 }
319 
320 #define mi_init		UNWI_ARCH_OBJ(mi_init)
321 
322 extern void mi_init (void);	/* machine-independent initializations */
323 extern unw_word_t _U_dyn_info_list_addr (void);
324 
325 /* This is needed/used by ELF targets only.  */
326 
327 struct elf_image
328   {
329     bool valid;			/* true if the image is a valid elf image */
330     bool load_attempted;	/* true if we've already attempted to load the elf */
331     bool mapped;		/* true if the elf image was mmap'd in */
332     union
333       {
334         struct
335           {
336             void *image;		/* pointer to mmap'd image */
337             size_t size;		/* (file-) size of the image */
338           }
339         mapped;
340         struct
341           {
342             unw_addr_space_t as;	/* address space containing the access_mem function */
343             void *as_arg;		/* arg used with access_mem */
344             struct map_info *map;	/* map data associated with the elf data */
345           }
346         memory;
347       }
348     u;
349   };
350 
351 struct elf_dyn_info
352   {
353     /* ANDROID support update.*/
354     /* Removed: struct elf_image ei; */
355     /* End of ANDROID update. */
356     unw_dyn_info_t di_cache;
357     unw_dyn_info_t di_debug;    /* additional table info for .debug_frame */
358 #if UNW_TARGET_IA64
359     unw_dyn_info_t ktab;
360 #endif
361 #if UNW_TARGET_ARM
362     unw_dyn_info_t di_arm;      /* additional table info for .ARM.exidx */
363 #endif
364   };
365 
invalidate_edi(struct elf_dyn_info * edi)366 static inline void invalidate_edi (struct elf_dyn_info *edi)
367 {
368   /* ANDROID support update.*/
369   /* Removed: if (edi->ei.image) */
370   /*            munmap (edi->ei.image, edi->ei.size); */
371   /* End of ANDROID update. */
372   memset (edi, 0, sizeof (*edi));
373   edi->di_cache.format = -1;
374   edi->di_debug.format = -1;
375 #if UNW_TARGET_ARM
376   edi->di_arm.format = -1;
377 #endif
378 }
379 
380 
381 /* Provide a place holder for architecture to override for fast access
382    to memory when known not to need to validate and know the access
383    will be local to the process. A suitable override will improve
384    unw_tdep_trace() performance in particular. */
385 #define ACCESS_MEM_FAST(ret,validate,cur,addr,to) \
386   do { (ret) = dwarf_get ((cur), DWARF_MEM_LOC ((cur), (addr)), &(to)); } \
387   while (0)
388 
389 /* Define GNU and processor specific values for the Phdr p_type field in case
390    they aren't defined by <elf.h>.  */
391 #ifndef PT_GNU_EH_FRAME
392 # define PT_GNU_EH_FRAME	0x6474e550
393 #endif /* !PT_GNU_EH_FRAME */
394 #ifndef PT_ARM_EXIDX
395 # define PT_ARM_EXIDX		0x70000001	/* ARM unwind segment */
396 #endif /* !PT_ARM_EXIDX */
397 
398 #include "tdep/libunwind_i.h"
399 
400 #ifndef tdep_get_func_addr
401 # define tdep_get_func_addr(as,addr,v)		(*(v) = addr, 0)
402 #endif
403 
404 #define UNW_ALIGN(x,a) (((x)+(a)-1UL)&~((a)-1UL))
405 
406 #endif /* libunwind_i_h */
407