1 /* internal.h -- Internal header file for stack backtrace library.
2    Copyright (C) 2012-2018 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 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 
91 extern void *backtrace_atomic_load_pointer (void *);
92 extern int backtrace_atomic_load_int (int *);
93 extern void backtrace_atomic_store_pointer (void *, void *);
94 extern void backtrace_atomic_store_size_t (size_t *, size_t);
95 extern 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 
114 typedef 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 
121 typedef 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 
127 struct 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.  */
159 extern 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 
169 struct 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.  */
181 extern int backtrace_get_view (struct backtrace_state *state, int descriptor,
182 			       off_t offset, size_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.  */
187 extern 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 
195 extern int backtrace_close (int descriptor,
196 			    backtrace_error_callback error_callback,
197 			    void *data);
198 
199 /* Sort without using memory.  */
200 
201 extern 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 
207 extern 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 
214 extern 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 
223 struct 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 
237 extern 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 
247 extern 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 
255 extern int backtrace_vector_release (struct backtrace_state *state,
256 				     struct backtrace_vector *vec,
257 				     backtrace_error_callback error_callback,
258 				     void *data);
259 
260 /* Read initial debug data from a descriptor, and set the
261    fileline_data, syminfo_fn, and syminfo_data fields of STATE.
262    Return the fileln_fn field in *FILELN_FN--this is done this way so
263    that the synchronization code is only implemented once.  This is
264    called after the descriptor has first been opened.  It will close
265    the descriptor if it is no longer needed.  Returns 1 on success, 0
266    on error.  There will be multiple implementations of this function,
267    for different file formats.  Each system will compile the
268    appropriate one.  */
269 
270 extern int backtrace_initialize (struct backtrace_state *state,
271 				 const char *filename,
272 				 int descriptor,
273 				 backtrace_error_callback error_callback,
274 				 void *data,
275 				 fileline *fileline_fn);
276 
277 /* Add file/line information for a DWARF module.  */
278 
279 extern int backtrace_dwarf_add (struct backtrace_state *state,
280 				uintptr_t base_address,
281 				const unsigned char* dwarf_info,
282 				size_t dwarf_info_size,
283 				const unsigned char *dwarf_line,
284 				size_t dwarf_line_size,
285 				const unsigned char *dwarf_abbrev,
286 				size_t dwarf_abbrev_size,
287 				const unsigned char *dwarf_ranges,
288 				size_t dwarf_range_size,
289 				const unsigned char *dwarf_str,
290 				size_t dwarf_str_size,
291 				int is_bigendian,
292 				backtrace_error_callback error_callback,
293 				void *data, fileline *fileline_fn);
294 
295 /* A test-only hook for elf_uncompress_zdebug.  */
296 
297 extern int backtrace_uncompress_zdebug (struct backtrace_state *,
298 					const unsigned char *compressed,
299 					size_t compressed_size,
300 					backtrace_error_callback, void *data,
301 					unsigned char **uncompressed,
302 					size_t *uncompressed_size);
303 
304 #endif
305