1 /* internal.h -- Internal header file for stack backtrace library.
2 Copyright (C) 2012-2023 Free Software Foundation, Inc.
3 Written by Ian Lance Taylor, Google.
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions are
7 met:
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
21 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24 DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
25 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
26 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
27 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
29 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30 IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 POSSIBILITY 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 ATTRIBUTE_FALLTHROUGH
60 # if (GCC_VERSION >= 7000)
61 # define ATTRIBUTE_FALLTHROUGH __attribute__ ((__fallthrough__))
62 # else
63 # define ATTRIBUTE_FALLTHROUGH
64 # endif
65 #endif
66
67 #ifndef HAVE_SYNC_FUNCTIONS
68
69 /* Define out the sync functions. These should never be called if
70 they are not available. */
71
72 #define __sync_bool_compare_and_swap(A, B, C) (abort(), 1)
73 #define __sync_lock_test_and_set(A, B) (abort(), 0)
74 #define __sync_lock_release(A) abort()
75
76 #endif /* !defined (HAVE_SYNC_FUNCTIONS) */
77
78 #ifdef HAVE_ATOMIC_FUNCTIONS
79
80 /* We have the atomic builtin functions. */
81
82 #define backtrace_atomic_load_pointer(p) \
83 __atomic_load_n ((p), __ATOMIC_ACQUIRE)
84 #define backtrace_atomic_load_int(p) \
85 __atomic_load_n ((p), __ATOMIC_ACQUIRE)
86 #define backtrace_atomic_store_pointer(p, v) \
87 __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
88 #define backtrace_atomic_store_size_t(p, v) \
89 __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
90 #define backtrace_atomic_store_int(p, v) \
91 __atomic_store_n ((p), (v), __ATOMIC_RELEASE)
92
93 #else /* !defined (HAVE_ATOMIC_FUNCTIONS) */
94 #ifdef HAVE_SYNC_FUNCTIONS
95
96 /* We have the sync functions but not the atomic functions. Define
97 the atomic ones in terms of the sync ones. */
98
99 extern void *backtrace_atomic_load_pointer (void *);
100 extern int backtrace_atomic_load_int (int *);
101 extern void backtrace_atomic_store_pointer (void *, void *);
102 extern void backtrace_atomic_store_size_t (size_t *, size_t);
103 extern void backtrace_atomic_store_int (int *, int);
104
105 #else /* !defined (HAVE_SYNC_FUNCTIONS) */
106
107 /* We have neither the sync nor the atomic functions. These will
108 never be called. */
109
110 #define backtrace_atomic_load_pointer(p) (abort(), (void *) NULL)
111 #define backtrace_atomic_load_int(p) (abort(), 0)
112 #define backtrace_atomic_store_pointer(p, v) abort()
113 #define backtrace_atomic_store_size_t(p, v) abort()
114 #define backtrace_atomic_store_int(p, v) abort()
115
116 #endif /* !defined (HAVE_SYNC_FUNCTIONS) */
117 #endif /* !defined (HAVE_ATOMIC_FUNCTIONS) */
118
119 /* The type of the function that collects file/line information. This
120 is like backtrace_pcinfo. */
121
122 typedef int (*fileline) (struct backtrace_state *state, uintptr_t pc,
123 backtrace_full_callback callback,
124 backtrace_error_callback error_callback, void *data);
125
126 /* The type of the function that collects symbol information. This is
127 like backtrace_syminfo. */
128
129 typedef void (*syminfo) (struct backtrace_state *state, uintptr_t pc,
130 backtrace_syminfo_callback callback,
131 backtrace_error_callback error_callback, void *data);
132
133 /* What the backtrace state pointer points to. */
134
135 struct backtrace_state
136 {
137 /* The name of the executable. */
138 const char *filename;
139 /* Non-zero if threaded. */
140 int threaded;
141 /* The master lock for fileline_fn, fileline_data, syminfo_fn,
142 syminfo_data, fileline_initialization_failed and everything the
143 data pointers point to. */
144 void *lock;
145 /* The function that returns file/line information. */
146 fileline fileline_fn;
147 /* The data to pass to FILELINE_FN. */
148 void *fileline_data;
149 /* The function that returns symbol information. */
150 syminfo syminfo_fn;
151 /* The data to pass to SYMINFO_FN. */
152 void *syminfo_data;
153 /* Whether initializing the file/line information failed. */
154 int fileline_initialization_failed;
155 /* The lock for the freelist. */
156 int lock_alloc;
157 /* The freelist when using mmap. */
158 struct backtrace_freelist_struct *freelist;
159 };
160
161 /* Open a file for reading. Returns -1 on error. If DOES_NOT_EXIST
162 is not NULL, *DOES_NOT_EXIST will be set to 0 normally and set to 1
163 if the file does not exist. If the file does not exist and
164 DOES_NOT_EXIST is not NULL, the function will return -1 and will
165 not call ERROR_CALLBACK. On other errors, or if DOES_NOT_EXIST is
166 NULL, the function will call ERROR_CALLBACK before returning. */
167 extern int backtrace_open (const char *filename,
168 backtrace_error_callback error_callback,
169 void *data,
170 int *does_not_exist);
171
172 /* A view of the contents of a file. This supports mmap when
173 available. A view will remain in memory even after backtrace_close
174 is called on the file descriptor from which the view was
175 obtained. */
176
177 struct backtrace_view
178 {
179 /* The data that the caller requested. */
180 const void *data;
181 /* The base of the view. */
182 void *base;
183 /* The total length of the view. */
184 size_t len;
185 };
186
187 /* Create a view of SIZE bytes from DESCRIPTOR at OFFSET. Store the
188 result in *VIEW. Returns 1 on success, 0 on error. */
189 extern int backtrace_get_view (struct backtrace_state *state, int descriptor,
190 off_t offset, uint64_t size,
191 backtrace_error_callback error_callback,
192 void *data, struct backtrace_view *view);
193
194 /* Release a view created by backtrace_get_view. */
195 extern void backtrace_release_view (struct backtrace_state *state,
196 struct backtrace_view *view,
197 backtrace_error_callback error_callback,
198 void *data);
199
200 /* Close a file opened by backtrace_open. Returns 1 on success, 0 on
201 error. */
202
203 extern int backtrace_close (int descriptor,
204 backtrace_error_callback error_callback,
205 void *data);
206
207 /* Sort without using memory. */
208
209 extern void backtrace_qsort (void *base, size_t count, size_t size,
210 int (*compar) (const void *, const void *));
211
212 /* Allocate memory. This is like malloc. If ERROR_CALLBACK is NULL,
213 this does not report an error, it just returns NULL. */
214
215 extern void *backtrace_alloc (struct backtrace_state *state, size_t size,
216 backtrace_error_callback error_callback,
217 void *data) ATTRIBUTE_MALLOC;
218
219 /* Free memory allocated by backtrace_alloc. If ERROR_CALLBACK is
220 NULL, this does not report an error. */
221
222 extern void backtrace_free (struct backtrace_state *state, void *mem,
223 size_t size,
224 backtrace_error_callback error_callback,
225 void *data);
226
227 /* A growable vector of some struct. This is used for more efficient
228 allocation when we don't know the final size of some group of data
229 that we want to represent as an array. */
230
231 struct backtrace_vector
232 {
233 /* The base of the vector. */
234 void *base;
235 /* The number of bytes in the vector. */
236 size_t size;
237 /* The number of bytes available at the current allocation. */
238 size_t alc;
239 };
240
241 /* Grow VEC by SIZE bytes. Return a pointer to the newly allocated
242 bytes. Note that this may move the entire vector to a new memory
243 location. Returns NULL on failure. */
244
245 extern void *backtrace_vector_grow (struct backtrace_state *state, size_t size,
246 backtrace_error_callback error_callback,
247 void *data,
248 struct backtrace_vector *vec);
249
250 /* Finish the current allocation on VEC. Prepare to start a new
251 allocation. The finished allocation will never be freed. Returns
252 a pointer to the base of the finished entries, or NULL on
253 failure. */
254
255 extern void* backtrace_vector_finish (struct backtrace_state *state,
256 struct backtrace_vector *vec,
257 backtrace_error_callback error_callback,
258 void *data);
259
260 /* Release any extra space allocated for VEC. This may change
261 VEC->base. Returns 1 on success, 0 on failure. */
262
263 extern int backtrace_vector_release (struct backtrace_state *state,
264 struct backtrace_vector *vec,
265 backtrace_error_callback error_callback,
266 void *data);
267
268 /* Free the space managed by VEC. This will reset VEC. */
269
270 static inline void
271 backtrace_vector_free (struct backtrace_state *state,
272 struct backtrace_vector *vec,
273 backtrace_error_callback error_callback, void *data)
274 {
275 vec->alc += vec->size;
276 vec->size = 0;
277 backtrace_vector_release (state, vec, error_callback, data);
278 }
279
280 /* Read initial debug data from a descriptor, and set the
281 fileline_data, syminfo_fn, and syminfo_data fields of STATE.
282 Return the fileln_fn field in *FILELN_FN--this is done this way so
283 that the synchronization code is only implemented once. This is
284 called after the descriptor has first been opened. It will close
285 the descriptor if it is no longer needed. Returns 1 on success, 0
286 on error. There will be multiple implementations of this function,
287 for different file formats. Each system will compile the
288 appropriate one. */
289
290 extern int backtrace_initialize (struct backtrace_state *state,
291 const char *filename,
292 int descriptor,
293 backtrace_error_callback error_callback,
294 void *data,
295 fileline *fileline_fn);
296
297 /* An enum for the DWARF sections we care about. */
298
299 enum dwarf_section
300 {
301 DEBUG_INFO,
302 DEBUG_LINE,
303 DEBUG_ABBREV,
304 DEBUG_RANGES,
305 DEBUG_STR,
306 DEBUG_ADDR,
307 DEBUG_STR_OFFSETS,
308 DEBUG_LINE_STR,
309 DEBUG_RNGLISTS,
310
311 DEBUG_MAX
312 };
313
314 /* Data for the DWARF sections we care about. */
315
316 struct dwarf_sections
317 {
318 const unsigned char *data[DEBUG_MAX];
319 size_t size[DEBUG_MAX];
320 };
321
322 /* DWARF data read from a file, used for .gnu_debugaltlink. */
323
324 struct dwarf_data;
325
326 /* Add file/line information for a DWARF module. */
327
328 extern int backtrace_dwarf_add (struct backtrace_state *state,
329 uintptr_t base_address,
330 const struct dwarf_sections *dwarf_sections,
331 int is_bigendian,
332 struct dwarf_data *fileline_altlink,
333 backtrace_error_callback error_callback,
334 void *data, fileline *fileline_fn,
335 struct dwarf_data **fileline_entry);
336
337 /* A data structure to pass to backtrace_syminfo_to_full. */
338
339 struct backtrace_call_full
340 {
341 backtrace_full_callback full_callback;
342 backtrace_error_callback full_error_callback;
343 void *full_data;
344 int ret;
345 };
346
347 /* A backtrace_syminfo_callback that can call into a
348 backtrace_full_callback, used when we have a symbol table but no
349 debug info. */
350
351 extern void backtrace_syminfo_to_full_callback (void *data, uintptr_t pc,
352 const char *symname,
353 uintptr_t symval,
354 uintptr_t symsize);
355
356 /* An error callback that corresponds to
357 backtrace_syminfo_to_full_callback. */
358
359 extern void backtrace_syminfo_to_full_error_callback (void *, const char *,
360 int);
361
362 /* A test-only hook for elf_uncompress_zdebug. */
363
364 extern int backtrace_uncompress_zdebug (struct backtrace_state *,
365 const unsigned char *compressed,
366 size_t compressed_size,
367 backtrace_error_callback, void *data,
368 unsigned char **uncompressed,
369 size_t *uncompressed_size);
370
371 /* A test-only hook for elf_zstd_decompress. */
372
373 extern int backtrace_uncompress_zstd (struct backtrace_state *,
374 const unsigned char *compressed,
375 size_t compressed_size,
376 backtrace_error_callback, void *data,
377 unsigned char *uncompressed,
378 size_t uncompressed_size);
379
380 /* A test-only hook for elf_uncompress_lzma. */
381
382 extern int backtrace_uncompress_lzma (struct backtrace_state *,
383 const unsigned char *compressed,
384 size_t compressed_size,
385 backtrace_error_callback, void *data,
386 unsigned char **uncompressed,
387 size_t *uncompressed_size);
388
389 #endif