1/* internal.h -- Internal header file for stack backtrace library.
2   Copyright (C) 2012-2020 Free Software Foundation, Inc.
3   Written by Ian Lance Taylor, Google.
4
5Redistribution and use in source and binary forms, with or without
6modification, are permitted provided that the following conditions are
7met:
8
9    (1) Redistributions of source code must retain the above copyright
10    notice, this list of conditions and the following disclaimer.
11
12    (2) Redistributions in binary form must reproduce the above copyright
13    notice, this list of conditions and the following disclaimer in
14    the documentation and/or other materials provided with the
15    distribution.
16
17    (3) The name of the author may not be used to
18    endorse or promote products derived from this software without
19    specific prior written permission.
20
21THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
25INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
29STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31POSSIBILITY OF SUCH DAMAGE.  */
32
33#ifndef BACKTRACE_INTERNAL_H
34#define BACKTRACE_INTERNAL_H
35
36/* We assume that <sys/types.h> and "backtrace.h" have already been
37   included.  */
38
39#ifndef GCC_VERSION
40# define GCC_VERSION (__GNUC__ * 1000 + __GNUC_MINOR__)
41#endif
42
43#if (GCC_VERSION < 2007)
44# define __attribute__(x)
45#endif
46
47#ifndef ATTRIBUTE_UNUSED
48# define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
49#endif
50
51#ifndef ATTRIBUTE_MALLOC
52# if (GCC_VERSION >= 2096)
53#  define ATTRIBUTE_MALLOC __attribute__ ((__malloc__))
54# else
55#  define ATTRIBUTE_MALLOC
56# endif
57#endif
58
59#ifndef HAVE_SYNC_FUNCTIONS
60
61/* Define out the sync functions.  These should never be called if
62   they are not available.  */
63
64#define __sync_bool_compare_and_swap(A, B, C) (abort(), 1)
65#define __sync_lock_test_and_set(A, B) (abort(), 0)
66#define __sync_lock_release(A) abort()
67
68#endif /* !defined (HAVE_SYNC_FUNCTIONS) */
69
70#ifdef HAVE_ATOMIC_FUNCTIONS
71
72/* We have the atomic builtin functions.  */
73
74#define backtrace_atomic_load_pointer(p) \
75    __atomic_load_n ((p), __ATOMIC_ACQUIRE)
76#define backtrace_atomic_load_int(p) \
77    __atomic_load_n ((p), __ATOMIC_ACQUIRE)
78#define backtrace_atomic_store_pointer(p, v) \
79    __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
80#define backtrace_atomic_store_size_t(p, v) \
81    __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
82#define backtrace_atomic_store_int(p, v) \
83    __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
84
85#else /* !defined (HAVE_ATOMIC_FUNCTIONS) */
86#ifdef HAVE_SYNC_FUNCTIONS
87
88/* We have the sync functions but not the atomic functions.  Define
89   the atomic ones in terms of the sync ones.  */
90
91extern void *backtrace_atomic_load_pointer (void *);
92extern int backtrace_atomic_load_int (int *);
93extern void backtrace_atomic_store_pointer (void *, void *);
94extern void backtrace_atomic_store_size_t (size_t *, size_t);
95extern void backtrace_atomic_store_int (int *, int);
96
97#else /* !defined (HAVE_SYNC_FUNCTIONS) */
98
99/* We have neither the sync nor the atomic functions.  These will
100   never be called.  */
101
102#define backtrace_atomic_load_pointer(p) (abort(), (void *) NULL)
103#define backtrace_atomic_load_int(p) (abort(), 0)
104#define backtrace_atomic_store_pointer(p, v) abort()
105#define backtrace_atomic_store_size_t(p, v) abort()
106#define backtrace_atomic_store_int(p, v) abort()
107
108#endif /* !defined (HAVE_SYNC_FUNCTIONS) */
109#endif /* !defined (HAVE_ATOMIC_FUNCTIONS) */
110
111/* The type of the function that collects file/line information.  This
112   is like backtrace_pcinfo.  */
113
114typedef int (*fileline) (struct backtrace_state *state, uintptr_t pc,
115			 backtrace_full_callback callback,
116			 backtrace_error_callback error_callback, void *data);
117
118/* The type of the function that collects symbol information.  This is
119   like backtrace_syminfo.  */
120
121typedef void (*syminfo) (struct backtrace_state *state, uintptr_t pc,
122			 backtrace_syminfo_callback callback,
123			 backtrace_error_callback error_callback, void *data);
124
125/* What the backtrace state pointer points to.  */
126
127struct backtrace_state
128{
129  /* The name of the executable.  */
130  const char *filename;
131  /* Non-zero if threaded.  */
132  int threaded;
133  /* The master lock for fileline_fn, fileline_data, syminfo_fn,
134     syminfo_data, fileline_initialization_failed and everything the
135     data pointers point to.  */
136  void *lock;
137  /* The function that returns file/line information.  */
138  fileline fileline_fn;
139  /* The data to pass to FILELINE_FN.  */
140  void *fileline_data;
141  /* The function that returns symbol information.  */
142  syminfo syminfo_fn;
143  /* The data to pass to SYMINFO_FN.  */
144  void *syminfo_data;
145  /* Whether initializing the file/line information failed.  */
146  int fileline_initialization_failed;
147  /* The lock for the freelist.  */
148  int lock_alloc;
149  /* The freelist when using mmap.  */
150  struct backtrace_freelist_struct *freelist;
151};
152
153/* Open a file for reading.  Returns -1 on error.  If DOES_NOT_EXIST
154   is not NULL, *DOES_NOT_EXIST will be set to 0 normally and set to 1
155   if the file does not exist.  If the file does not exist and
156   DOES_NOT_EXIST is not NULL, the function will return -1 and will
157   not call ERROR_CALLBACK.  On other errors, or if DOES_NOT_EXIST is
158   NULL, the function will call ERROR_CALLBACK before returning.  */
159extern int backtrace_open (const char *filename,
160			   backtrace_error_callback error_callback,
161			   void *data,
162			   int *does_not_exist);
163
164/* A view of the contents of a file.  This supports mmap when
165   available.  A view will remain in memory even after backtrace_close
166   is called on the file descriptor from which the view was
167   obtained.  */
168
169struct backtrace_view
170{
171  /* The data that the caller requested.  */
172  const void *data;
173  /* The base of the view.  */
174  void *base;
175  /* The total length of the view.  */
176  size_t len;
177};
178
179/* Create a view of SIZE bytes from DESCRIPTOR at OFFSET.  Store the
180   result in *VIEW.  Returns 1 on success, 0 on error.  */
181extern int backtrace_get_view (struct backtrace_state *state, int descriptor,
182			       off_t offset, uint64_t size,
183			       backtrace_error_callback error_callback,
184			       void *data, struct backtrace_view *view);
185
186/* Release a view created by backtrace_get_view.  */
187extern void backtrace_release_view (struct backtrace_state *state,
188				    struct backtrace_view *view,
189				    backtrace_error_callback error_callback,
190				    void *data);
191
192/* Close a file opened by backtrace_open.  Returns 1 on success, 0 on
193   error.  */
194
195extern int backtrace_close (int descriptor,
196			    backtrace_error_callback error_callback,
197			    void *data);
198
199/* Sort without using memory.  */
200
201extern void backtrace_qsort (void *base, size_t count, size_t size,
202			     int (*compar) (const void *, const void *));
203
204/* Allocate memory.  This is like malloc.  If ERROR_CALLBACK is NULL,
205   this does not report an error, it just returns NULL.  */
206
207extern void *backtrace_alloc (struct backtrace_state *state, size_t size,
208			      backtrace_error_callback error_callback,
209			      void *data) ATTRIBUTE_MALLOC;
210
211/* Free memory allocated by backtrace_alloc.  If ERROR_CALLBACK is
212   NULL, this does not report an error.  */
213
214extern void backtrace_free (struct backtrace_state *state, void *mem,
215			    size_t size,
216			    backtrace_error_callback error_callback,
217			    void *data);
218
219/* A growable vector of some struct.  This is used for more efficient
220   allocation when we don't know the final size of some group of data
221   that we want to represent as an array.  */
222
223struct backtrace_vector
224{
225  /* The base of the vector.  */
226  void *base;
227  /* The number of bytes in the vector.  */
228  size_t size;
229  /* The number of bytes available at the current allocation.  */
230  size_t alc;
231};
232
233/* Grow VEC by SIZE bytes.  Return a pointer to the newly allocated
234   bytes.  Note that this may move the entire vector to a new memory
235   location.  Returns NULL on failure.  */
236
237extern void *backtrace_vector_grow (struct backtrace_state *state, size_t size,
238				    backtrace_error_callback error_callback,
239				    void *data,
240				    struct backtrace_vector *vec);
241
242/* Finish the current allocation on VEC.  Prepare to start a new
243   allocation.  The finished allocation will never be freed.  Returns
244   a pointer to the base of the finished entries, or NULL on
245   failure.  */
246
247extern void* backtrace_vector_finish (struct backtrace_state *state,
248				      struct backtrace_vector *vec,
249				      backtrace_error_callback error_callback,
250				      void *data);
251
252/* Release any extra space allocated for VEC.  This may change
253   VEC->base.  Returns 1 on success, 0 on failure.  */
254
255extern int backtrace_vector_release (struct backtrace_state *state,
256				     struct backtrace_vector *vec,
257				     backtrace_error_callback error_callback,
258				     void *data);
259
260/* Free the space managed by VEC.  This will reset VEC.  */
261
262static inline void
263backtrace_vector_free (struct backtrace_state *state,
264		       struct backtrace_vector *vec,
265		       backtrace_error_callback error_callback, void *data)
266{
267  vec->alc += vec->size;
268  vec->size = 0;
269  backtrace_vector_release (state, vec, error_callback, data);
270}
271
272/* Read initial debug data from a descriptor, and set the
273   fileline_data, syminfo_fn, and syminfo_data fields of STATE.
274   Return the fileln_fn field in *FILELN_FN--this is done this way so
275   that the synchronization code is only implemented once.  This is
276   called after the descriptor has first been opened.  It will close
277   the descriptor if it is no longer needed.  Returns 1 on success, 0
278   on error.  There will be multiple implementations of this function,
279   for different file formats.  Each system will compile the
280   appropriate one.  */
281
282extern int backtrace_initialize (struct backtrace_state *state,
283				 const char *filename,
284				 int descriptor,
285				 backtrace_error_callback error_callback,
286				 void *data,
287				 fileline *fileline_fn);
288
289/* An enum for the DWARF sections we care about.  */
290
291enum dwarf_section
292{
293  DEBUG_INFO,
294  DEBUG_LINE,
295  DEBUG_ABBREV,
296  DEBUG_RANGES,
297  DEBUG_STR,
298  DEBUG_ADDR,
299  DEBUG_STR_OFFSETS,
300  DEBUG_LINE_STR,
301  DEBUG_RNGLISTS,
302
303  DEBUG_MAX
304};
305
306/* Data for the DWARF sections we care about.  */
307
308struct dwarf_sections
309{
310  const unsigned char *data[DEBUG_MAX];
311  size_t size[DEBUG_MAX];
312};
313
314/* DWARF data read from a file, used for .gnu_debugaltlink.  */
315
316struct dwarf_data;
317
318/* Add file/line information for a DWARF module.  */
319
320extern int backtrace_dwarf_add (struct backtrace_state *state,
321				uintptr_t base_address,
322				const struct dwarf_sections *dwarf_sections,
323				int is_bigendian,
324				struct dwarf_data *fileline_altlink,
325				backtrace_error_callback error_callback,
326				void *data, fileline *fileline_fn,
327				struct dwarf_data **fileline_entry);
328
329/* A test-only hook for elf_uncompress_zdebug.  */
330
331extern int backtrace_uncompress_zdebug (struct backtrace_state *,
332					const unsigned char *compressed,
333					size_t compressed_size,
334					backtrace_error_callback, void *data,
335					unsigned char **uncompressed,
336					size_t *uncompressed_size);
337
338#endif
339