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
6This file is part of libunwind.
7
8Permission is hereby granted, free of charge, to any person obtaining
9a copy of this software and associated documentation files (the
10"Software"), to deal in the Software without restriction, including
11without limitation the rights to use, copy, modify, merge, publish,
12distribute, sublicense, and/or sell copies of the Software, and to
13permit persons to whom the Software is furnished to do so, subject to
14the following conditions:
15
16The above copyright notice and this permission notice shall be
17included in all copies or substantial portions of the Software.
18
19THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
23LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
24OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
25WITH 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>
121static inline int
122cmpxchg_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
145static inline int
146cmpxchg_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.  */
174typedef sigset_t intrmask_t;
175
176extern 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 */
180static 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)	\
192do {							\
193  SIGPROCMASK (SIG_SETMASK, &unwi_full_mask, &(m));	\
194  acquire_func (l);					\
195} while (0)
196#define __lock_release_internal(l, m, release_func)	\
197do {							\
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)				    		    \
229do {									    \
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
244extern 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);
248extern 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);
254extern 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
260extern 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);
265extern void unwi_dyn_remote_put_unwind_info (unw_addr_space_t as,
266					     unw_proc_info_t *pi,
267					     void *arg);
268extern int unwi_dyn_validate_cache (unw_addr_space_t as, void *arg);
269
270extern unw_dyn_info_list_t _U_dyn_info_list;
271extern pthread_mutex_t _U_dyn_info_list_lock;
272
273#if UNW_DEBUG
274# define unwi_debug_level		UNWI_ARCH_OBJ(debug_level)
275extern long unwi_debug_level;
276
277# ifdef ANDROID
278# define LOG_TAG "libunwind"
279# include <log/log.h>
280
281# define Debug(level, format, ...)					\
282do {									\
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...)						\
293do {									\
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
314static ALWAYS_INLINE int
315print_error (const char *string)
316{
317  return write (2, string, strlen (string));
318}
319
320#define mi_init		UNWI_ARCH_OBJ(mi_init)
321
322extern void mi_init (void);	/* machine-independent initializations */
323extern unw_word_t _U_dyn_info_list_addr (void);
324
325/* This is needed/used by ELF targets only.  */
326
327/* This structure should contain memory that will not change during local
328 * unwinds. For example, if a new member is added, then the function
329 * move_cached_elf_data must be updated to make sure that the data is
330 * properly copied. Any pointers in this structures must persist until
331 * the map is destroyed in map_destroy_list and moved in the previously
332 * mentioned move_cached_elf_data.
333 */
334struct elf_image
335  {
336    bool valid;			/* true if the image is a valid elf image */
337    bool load_attempted;	/* true if we've already attempted to load the elf */
338    bool mapped;		/* true if the elf image was mmap'd in */
339    void* mini_debug_info_data;  /* decompressed .gnu_debugdata section */
340    size_t mini_debug_info_size;
341    union
342      {
343        struct
344          {
345            void *image;		/* pointer to mmap'd image */
346            size_t size;		/* (file-) size of the image */
347          }
348        mapped;
349        struct
350          {
351            unw_addr_space_t as;	/* address space containing the access_mem function */
352            void *as_arg;		/* arg used with access_mem */
353            uintptr_t start;		/* The map start address. */
354            uintptr_t end;		/* The map end address. */
355          }
356        memory;
357      }
358    u;
359  };
360
361struct elf_dyn_info
362  {
363    /* ANDROID support update.*/
364    /* Removed: struct elf_image ei; */
365    /* End of ANDROID update. */
366    unw_dyn_info_t di_cache;
367    unw_dyn_info_t di_debug;    /* additional table info for .debug_frame */
368#if UNW_TARGET_IA64
369    unw_dyn_info_t ktab;
370#endif
371#if UNW_TARGET_ARM
372    unw_dyn_info_t di_arm;      /* additional table info for .ARM.exidx */
373#endif
374  };
375
376static inline void invalidate_edi (struct elf_dyn_info *edi)
377{
378  /* ANDROID support update.*/
379  /* Removed: if (edi->ei.image) */
380  /*            munmap (edi->ei.image, edi->ei.size); */
381  /* End of ANDROID update. */
382  memset (edi, 0, sizeof (*edi));
383  edi->di_cache.format = -1;
384  edi->di_debug.format = -1;
385#if UNW_TARGET_ARM
386  edi->di_arm.format = -1;
387#endif
388}
389
390
391/* Provide a place holder for architecture to override for fast access
392   to memory when known not to need to validate and know the access
393   will be local to the process. A suitable override will improve
394   unw_tdep_trace() performance in particular. */
395#define ACCESS_MEM_FAST(ret,validate,cur,addr,to) \
396  do { (ret) = dwarf_get ((cur), DWARF_MEM_LOC ((cur), (addr)), &(to)); } \
397  while (0)
398
399/* Define GNU and processor specific values for the Phdr p_type field in case
400   they aren't defined by <elf.h>.  */
401#ifndef PT_GNU_EH_FRAME
402# define PT_GNU_EH_FRAME	0x6474e550
403#endif /* !PT_GNU_EH_FRAME */
404#ifndef PT_ARM_EXIDX
405# define PT_ARM_EXIDX		0x70000001	/* ARM unwind segment */
406#endif /* !PT_ARM_EXIDX */
407
408#include "tdep/libunwind_i.h"
409
410#ifndef tdep_get_func_addr
411# define tdep_get_func_addr(as,addr,v)		(*(v) = addr, 0)
412#endif
413
414#define UNW_ALIGN(x,a) (((x)+(a)-1UL)&~((a)-1UL))
415
416#endif /* libunwind_i_h */
417