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d757b8c9 | 1 | /* Subroutines needed for unwinding stack frames for exception handling. */ |
0ba508e4 | 2 | /* Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 |
3 | Free Software Foundation, Inc. | |
d757b8c9 | 4 | Contributed by Jason Merrill <jason@cygnus.com>. |
5 | ||
f12b58b3 | 6 | This file is part of GCC. |
d757b8c9 | 7 | |
f12b58b3 | 8 | GCC is free software; you can redistribute it and/or modify it under |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 2, or (at your option) any later | |
11 | version. | |
d757b8c9 | 12 | |
4c9b6e71 | 13 | In addition to the permissions in the GNU General Public License, the |
14 | Free Software Foundation gives you unlimited permission to link the | |
15 | compiled version of this file into combinations with other programs, | |
16 | and to distribute those combinations without any restriction coming | |
17 | from the use of this file. (The General Public License restrictions | |
18 | do apply in other respects; for example, they cover modification of | |
19 | the file, and distribution when not linked into a combine | |
20 | executable.) | |
21 | ||
f12b58b3 | 22 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
23 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
24 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
25 | for more details. | |
d757b8c9 | 26 | |
27 | You should have received a copy of the GNU General Public License | |
f12b58b3 | 28 | along with GCC; see the file COPYING. If not, write to the Free |
29 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
30 | 02111-1307, USA. */ | |
d757b8c9 | 31 | |
0d6378a9 | 32 | #ifndef _Unwind_Find_FDE |
df4b504c | 33 | #include "tconfig.h" |
34 | #include "tsystem.h" | |
805e22b2 | 35 | #include "coretypes.h" |
36 | #include "tm.h" | |
9b84bf7d | 37 | #include "dwarf2.h" |
38 | #include "unwind.h" | |
8e7f75ad | 39 | #define NO_BASE_OF_ENCODED_VALUE |
9b84bf7d | 40 | #include "unwind-pe.h" |
df4b504c | 41 | #include "unwind-dw2-fde.h" |
42 | #include "gthr.h" | |
0d6378a9 | 43 | #endif |
df4b504c | 44 | |
9b84bf7d | 45 | /* The unseen_objects list contains objects that have been registered |
46 | but not yet categorized in any way. The seen_objects list has had | |
47 | it's pc_begin and count fields initialized at minimum, and is sorted | |
48 | by decreasing value of pc_begin. */ | |
49 | static struct object *unseen_objects; | |
50 | static struct object *seen_objects; | |
df4b504c | 51 | |
52 | #ifdef __GTHREAD_MUTEX_INIT | |
53 | static __gthread_mutex_t object_mutex = __GTHREAD_MUTEX_INIT; | |
54 | #else | |
55 | static __gthread_mutex_t object_mutex; | |
56 | #endif | |
57 | ||
58 | #ifdef __GTHREAD_MUTEX_INIT_FUNCTION | |
6c34d0c2 | 59 | static void |
df4b504c | 60 | init_object_mutex (void) |
61 | { | |
62 | __GTHREAD_MUTEX_INIT_FUNCTION (&object_mutex); | |
63 | } | |
64 | ||
65 | static void | |
66 | init_object_mutex_once (void) | |
67 | { | |
68 | static __gthread_once_t once = __GTHREAD_ONCE_INIT; | |
69 | __gthread_once (&once, init_object_mutex); | |
70 | } | |
71 | #else | |
72 | #define init_object_mutex_once() | |
73 | #endif | |
74 | ||
75 | /* Called from crtbegin.o to register the unwind info for an object. */ | |
76 | ||
77 | void | |
49856054 | 78 | __register_frame_info_bases (const void *begin, struct object *ob, |
9b84bf7d | 79 | void *tbase, void *dbase) |
df4b504c | 80 | { |
1093a4f3 | 81 | /* If .eh_frame is empty, don't register at all. */ |
c1251e69 | 82 | if ((uword *) begin == 0 || *(uword *) begin == 0) |
1093a4f3 | 83 | return; |
84 | ||
9b84bf7d | 85 | ob->pc_begin = (void *)-1; |
86 | ob->tbase = tbase; | |
87 | ob->dbase = dbase; | |
88 | ob->u.single = begin; | |
89 | ob->s.i = 0; | |
90 | ob->s.b.encoding = DW_EH_PE_omit; | |
a0c3f574 | 91 | #ifdef DWARF2_OBJECT_END_PTR_EXTENSION |
92 | ob->fde_end = NULL; | |
93 | #endif | |
df4b504c | 94 | |
95 | init_object_mutex_once (); | |
96 | __gthread_mutex_lock (&object_mutex); | |
97 | ||
9b84bf7d | 98 | ob->next = unseen_objects; |
99 | unseen_objects = ob; | |
df4b504c | 100 | |
101 | __gthread_mutex_unlock (&object_mutex); | |
102 | } | |
103 | ||
9b84bf7d | 104 | void |
49856054 | 105 | __register_frame_info (const void *begin, struct object *ob) |
9b84bf7d | 106 | { |
107 | __register_frame_info_bases (begin, ob, 0, 0); | |
108 | } | |
109 | ||
df4b504c | 110 | void |
111 | __register_frame (void *begin) | |
112 | { | |
1093a4f3 | 113 | struct object *ob; |
114 | ||
115 | /* If .eh_frame is empty, don't register at all. */ | |
188879e7 | 116 | if (*(uword *) begin == 0) |
1093a4f3 | 117 | return; |
118 | ||
f0af5a88 | 119 | ob = malloc (sizeof (struct object)); |
6c34d0c2 | 120 | __register_frame_info (begin, ob); |
df4b504c | 121 | } |
122 | ||
123 | /* Similar, but BEGIN is actually a pointer to a table of unwind entries | |
124 | for different translation units. Called from the file generated by | |
125 | collect2. */ | |
126 | ||
127 | void | |
9b84bf7d | 128 | __register_frame_info_table_bases (void *begin, struct object *ob, |
129 | void *tbase, void *dbase) | |
df4b504c | 130 | { |
9b84bf7d | 131 | ob->pc_begin = (void *)-1; |
132 | ob->tbase = tbase; | |
133 | ob->dbase = dbase; | |
134 | ob->u.array = begin; | |
135 | ob->s.i = 0; | |
136 | ob->s.b.from_array = 1; | |
137 | ob->s.b.encoding = DW_EH_PE_omit; | |
df4b504c | 138 | |
139 | init_object_mutex_once (); | |
140 | __gthread_mutex_lock (&object_mutex); | |
141 | ||
9b84bf7d | 142 | ob->next = unseen_objects; |
143 | unseen_objects = ob; | |
df4b504c | 144 | |
145 | __gthread_mutex_unlock (&object_mutex); | |
146 | } | |
147 | ||
9b84bf7d | 148 | void |
149 | __register_frame_info_table (void *begin, struct object *ob) | |
150 | { | |
151 | __register_frame_info_table_bases (begin, ob, 0, 0); | |
152 | } | |
153 | ||
df4b504c | 154 | void |
155 | __register_frame_table (void *begin) | |
156 | { | |
f0af5a88 | 157 | struct object *ob = malloc (sizeof (struct object)); |
df4b504c | 158 | __register_frame_info_table (begin, ob); |
159 | } | |
160 | ||
161 | /* Called from crtbegin.o to deregister the unwind info for an object. */ | |
ce32d35f | 162 | /* ??? Glibc has for a while now exported __register_frame_info and |
163 | __deregister_frame_info. If we call __register_frame_info_bases | |
164 | from crtbegin (wherein it is declared weak), and this object does | |
165 | not get pulled from libgcc.a for other reasons, then the | |
166 | invocation of __deregister_frame_info will be resolved from glibc. | |
167 | Since the registration did not happen there, we'll abort. | |
168 | ||
169 | Therefore, declare a new deregistration entry point that does the | |
6c34d0c2 | 170 | exact same thing, but will resolve to the same library as |
ce32d35f | 171 | implements __register_frame_info_bases. */ |
df4b504c | 172 | |
173 | void * | |
49856054 | 174 | __deregister_frame_info_bases (const void *begin) |
df4b504c | 175 | { |
176 | struct object **p; | |
9b84bf7d | 177 | struct object *ob = 0; |
df4b504c | 178 | |
1093a4f3 | 179 | /* If .eh_frame is empty, we haven't registered. */ |
c1251e69 | 180 | if ((uword *) begin == 0 || *(uword *) begin == 0) |
d984cc45 | 181 | return ob; |
1093a4f3 | 182 | |
df4b504c | 183 | init_object_mutex_once (); |
184 | __gthread_mutex_lock (&object_mutex); | |
185 | ||
9b84bf7d | 186 | for (p = &unseen_objects; *p ; p = &(*p)->next) |
187 | if ((*p)->u.single == begin) | |
188 | { | |
189 | ob = *p; | |
190 | *p = ob->next; | |
191 | goto out; | |
192 | } | |
193 | ||
194 | for (p = &seen_objects; *p ; p = &(*p)->next) | |
195 | if ((*p)->s.b.sorted) | |
196 | { | |
197 | if ((*p)->u.sort->orig_data == begin) | |
198 | { | |
199 | ob = *p; | |
200 | *p = ob->next; | |
201 | free (ob->u.sort); | |
202 | goto out; | |
203 | } | |
204 | } | |
205 | else | |
206 | { | |
207 | if ((*p)->u.single == begin) | |
208 | { | |
209 | ob = *p; | |
210 | *p = ob->next; | |
211 | goto out; | |
212 | } | |
213 | } | |
df4b504c | 214 | |
215 | __gthread_mutex_unlock (&object_mutex); | |
216 | abort (); | |
9b84bf7d | 217 | |
218 | out: | |
219 | __gthread_mutex_unlock (&object_mutex); | |
220 | return (void *) ob; | |
df4b504c | 221 | } |
222 | ||
ce32d35f | 223 | void * |
49856054 | 224 | __deregister_frame_info (const void *begin) |
ce32d35f | 225 | { |
226 | return __deregister_frame_info_bases (begin); | |
227 | } | |
ce32d35f | 228 | |
df4b504c | 229 | void |
230 | __deregister_frame (void *begin) | |
231 | { | |
1093a4f3 | 232 | /* If .eh_frame is empty, we haven't registered. */ |
188879e7 | 233 | if (*(uword *) begin != 0) |
1093a4f3 | 234 | free (__deregister_frame_info (begin)); |
df4b504c | 235 | } |
236 | ||
9b84bf7d | 237 | \f |
238 | /* Like base_of_encoded_value, but take the base from a struct object | |
239 | instead of an _Unwind_Context. */ | |
240 | ||
241 | static _Unwind_Ptr | |
242 | base_from_object (unsigned char encoding, struct object *ob) | |
243 | { | |
244 | if (encoding == DW_EH_PE_omit) | |
245 | return 0; | |
246 | ||
247 | switch (encoding & 0x70) | |
248 | { | |
249 | case DW_EH_PE_absptr: | |
250 | case DW_EH_PE_pcrel: | |
9a4d22ba | 251 | case DW_EH_PE_aligned: |
9b84bf7d | 252 | return 0; |
253 | ||
254 | case DW_EH_PE_textrel: | |
255 | return (_Unwind_Ptr) ob->tbase; | |
256 | case DW_EH_PE_datarel: | |
257 | return (_Unwind_Ptr) ob->dbase; | |
258 | } | |
259 | abort (); | |
260 | } | |
261 | ||
262 | /* Return the FDE pointer encoding from the CIE. */ | |
263 | /* ??? This is a subset of extract_cie_info from unwind-dw2.c. */ | |
264 | ||
265 | static int | |
49856054 | 266 | get_cie_encoding (const struct dwarf_cie *cie) |
9b84bf7d | 267 | { |
268 | const unsigned char *aug, *p; | |
269 | _Unwind_Ptr dummy; | |
a6398abe | 270 | _Unwind_Word utmp; |
271 | _Unwind_Sword stmp; | |
9b84bf7d | 272 | |
273 | aug = cie->augmentation; | |
274 | if (aug[0] != 'z') | |
275 | return DW_EH_PE_absptr; | |
276 | ||
88cbb18b | 277 | p = aug + strlen ((const char *)aug) + 1; /* Skip the augmentation string. */ |
a6398abe | 278 | p = read_uleb128 (p, &utmp); /* Skip code alignment. */ |
279 | p = read_sleb128 (p, &stmp); /* Skip data alignment. */ | |
c0d45e55 | 280 | if (cie->version == 1) /* Skip return address column. */ |
281 | p++; | |
282 | else | |
283 | p = read_uleb128 (p, &utmp); | |
9b84bf7d | 284 | |
285 | aug++; /* Skip 'z' */ | |
a6398abe | 286 | p = read_uleb128 (p, &utmp); /* Skip augmentation length. */ |
9b84bf7d | 287 | while (1) |
288 | { | |
289 | /* This is what we're looking for. */ | |
290 | if (*aug == 'R') | |
291 | return *p; | |
292 | /* Personality encoding and pointer. */ | |
293 | else if (*aug == 'P') | |
9a4d22ba | 294 | { |
295 | /* ??? Avoid dereferencing indirect pointers, since we're | |
296 | faking the base address. Gotta keep DW_EH_PE_aligned | |
297 | intact, however. */ | |
298 | p = read_encoded_value_with_base (*p & 0x7F, 0, p + 1, &dummy); | |
299 | } | |
9b84bf7d | 300 | /* LSDA encoding. */ |
301 | else if (*aug == 'L') | |
302 | p++; | |
303 | /* Otherwise end of string, or unknown augmentation. */ | |
304 | else | |
305 | return DW_EH_PE_absptr; | |
306 | aug++; | |
307 | } | |
308 | } | |
309 | ||
310 | static inline int | |
49856054 | 311 | get_fde_encoding (const struct dwarf_fde *f) |
9b84bf7d | 312 | { |
313 | return get_cie_encoding (get_cie (f)); | |
314 | } | |
315 | ||
df4b504c | 316 | \f |
30f345ee | 317 | /* Sorting an array of FDEs by address. |
318 | (Ideally we would have the linker sort the FDEs so we don't have to do | |
319 | it at run time. But the linkers are not yet prepared for this.) */ | |
320 | ||
9b84bf7d | 321 | /* Comparison routines. Three variants of increasing complexity. */ |
322 | ||
5bc5b545 | 323 | static int |
9b84bf7d | 324 | fde_unencoded_compare (struct object *ob __attribute__((unused)), |
49856054 | 325 | const fde *x, const fde *y) |
9b84bf7d | 326 | { |
183c0b2a | 327 | _Unwind_Ptr x_ptr = *(_Unwind_Ptr *) x->pc_begin; |
328 | _Unwind_Ptr y_ptr = *(_Unwind_Ptr *) y->pc_begin; | |
329 | ||
330 | if (x_ptr > y_ptr) | |
5bc5b545 | 331 | return 1; |
183c0b2a | 332 | if (x_ptr < y_ptr) |
5bc5b545 | 333 | return -1; |
334 | return 0; | |
9b84bf7d | 335 | } |
336 | ||
5bc5b545 | 337 | static int |
49856054 | 338 | fde_single_encoding_compare (struct object *ob, const fde *x, const fde *y) |
9b84bf7d | 339 | { |
340 | _Unwind_Ptr base, x_ptr, y_ptr; | |
341 | ||
342 | base = base_from_object (ob->s.b.encoding, ob); | |
343 | read_encoded_value_with_base (ob->s.b.encoding, base, x->pc_begin, &x_ptr); | |
344 | read_encoded_value_with_base (ob->s.b.encoding, base, y->pc_begin, &y_ptr); | |
345 | ||
5bc5b545 | 346 | if (x_ptr > y_ptr) |
347 | return 1; | |
348 | if (x_ptr < y_ptr) | |
349 | return -1; | |
350 | return 0; | |
9b84bf7d | 351 | } |
352 | ||
5bc5b545 | 353 | static int |
49856054 | 354 | fde_mixed_encoding_compare (struct object *ob, const fde *x, const fde *y) |
9b84bf7d | 355 | { |
356 | int x_encoding, y_encoding; | |
357 | _Unwind_Ptr x_ptr, y_ptr; | |
358 | ||
359 | x_encoding = get_fde_encoding (x); | |
360 | read_encoded_value_with_base (x_encoding, base_from_object (x_encoding, ob), | |
361 | x->pc_begin, &x_ptr); | |
362 | ||
363 | y_encoding = get_fde_encoding (y); | |
364 | read_encoded_value_with_base (y_encoding, base_from_object (y_encoding, ob), | |
365 | y->pc_begin, &y_ptr); | |
366 | ||
5bc5b545 | 367 | if (x_ptr > y_ptr) |
368 | return 1; | |
369 | if (x_ptr < y_ptr) | |
370 | return -1; | |
371 | return 0; | |
9b84bf7d | 372 | } |
373 | ||
49856054 | 374 | typedef int (*fde_compare_t) (struct object *, const fde *, const fde *); |
9b84bf7d | 375 | |
376 | ||
30f345ee | 377 | /* This is a special mix of insertion sort and heap sort, optimized for |
378 | the data sets that actually occur. They look like | |
379 | 101 102 103 127 128 105 108 110 190 111 115 119 125 160 126 129 130. | |
380 | I.e. a linearly increasing sequence (coming from functions in the text | |
381 | section), with additionally a few unordered elements (coming from functions | |
382 | in gnu_linkonce sections) whose values are higher than the values in the | |
383 | surrounding linear sequence (but not necessarily higher than the values | |
384 | at the end of the linear sequence!). | |
385 | The worst-case total run time is O(N) + O(n log (n)), where N is the | |
386 | total number of FDEs and n is the number of erratic ones. */ | |
387 | ||
9b84bf7d | 388 | struct fde_accumulator |
30f345ee | 389 | { |
9b84bf7d | 390 | struct fde_vector *linear; |
391 | struct fde_vector *erratic; | |
392 | }; | |
df4b504c | 393 | |
8f44897f | 394 | static inline int |
9b84bf7d | 395 | start_fde_sort (struct fde_accumulator *accu, size_t count) |
30f345ee | 396 | { |
9b84bf7d | 397 | size_t size; |
398 | if (! count) | |
399 | return 0; | |
400 | ||
49856054 | 401 | size = sizeof (struct fde_vector) + sizeof (const fde *) * count; |
f0af5a88 | 402 | if ((accu->linear = malloc (size))) |
9b84bf7d | 403 | { |
404 | accu->linear->count = 0; | |
f0af5a88 | 405 | if ((accu->erratic = malloc (size))) |
9b84bf7d | 406 | accu->erratic->count = 0; |
407 | return 1; | |
408 | } | |
409 | else | |
6c34d0c2 | 410 | return 0; |
30f345ee | 411 | } |
d757b8c9 | 412 | |
30f345ee | 413 | static inline void |
49856054 | 414 | fde_insert (struct fde_accumulator *accu, const fde *this_fde) |
30f345ee | 415 | { |
9b84bf7d | 416 | if (accu->linear) |
417 | accu->linear->array[accu->linear->count++] = this_fde; | |
30f345ee | 418 | } |
419 | ||
420 | /* Split LINEAR into a linear sequence with low values and an erratic | |
421 | sequence with high values, put the linear one (of longest possible | |
205c3938 | 422 | length) into LINEAR and the erratic one into ERRATIC. This is O(N). |
6c34d0c2 | 423 | |
205c3938 | 424 | Because the longest linear sequence we are trying to locate within the |
425 | incoming LINEAR array can be interspersed with (high valued) erratic | |
426 | entries. We construct a chain indicating the sequenced entries. | |
427 | To avoid having to allocate this chain, we overlay it onto the space of | |
428 | the ERRATIC array during construction. A final pass iterates over the | |
429 | chain to determine what should be placed in the ERRATIC array, and | |
430 | what is the linear sequence. This overlay is safe from aliasing. */ | |
9b84bf7d | 431 | |
30f345ee | 432 | static inline void |
9b84bf7d | 433 | fde_split (struct object *ob, fde_compare_t fde_compare, |
434 | struct fde_vector *linear, struct fde_vector *erratic) | |
30f345ee | 435 | { |
49856054 | 436 | static const fde *marker; |
30f345ee | 437 | size_t count = linear->count; |
49856054 | 438 | const fde **chain_end = ▮ |
205c3938 | 439 | size_t i, j, k; |
440 | ||
441 | /* This should optimize out, but it is wise to make sure this assumption | |
442 | is correct. Should these have different sizes, we cannot cast between | |
443 | them and the overlaying onto ERRATIC will not work. */ | |
49856054 | 444 | if (sizeof (const fde *) != sizeof (const fde **)) |
205c3938 | 445 | abort (); |
6c34d0c2 | 446 | |
30f345ee | 447 | for (i = 0; i < count; i++) |
448 | { | |
49856054 | 449 | const fde **probe; |
6c34d0c2 | 450 | |
205c3938 | 451 | for (probe = chain_end; |
6c34d0c2 | 452 | probe != &marker && fde_compare (ob, linear->array[i], *probe) < 0; |
453 | probe = chain_end) | |
454 | { | |
49856054 | 455 | chain_end = (const fde **) erratic->array[probe - linear->array]; |
6c34d0c2 | 456 | erratic->array[probe - linear->array] = NULL; |
457 | } | |
49856054 | 458 | erratic->array[i] = (const fde *) chain_end; |
205c3938 | 459 | chain_end = &linear->array[i]; |
30f345ee | 460 | } |
461 | ||
205c3938 | 462 | /* Each entry in LINEAR which is part of the linear sequence we have |
463 | discovered will correspond to a non-NULL entry in the chain we built in | |
464 | the ERRATIC array. */ | |
465 | for (i = j = k = 0; i < count; i++) | |
466 | if (erratic->array[i]) | |
30f345ee | 467 | linear->array[j++] = linear->array[i]; |
205c3938 | 468 | else |
469 | erratic->array[k++] = linear->array[i]; | |
30f345ee | 470 | linear->count = j; |
205c3938 | 471 | erratic->count = k; |
30f345ee | 472 | } |
473 | ||
49856054 | 474 | #define SWAP(x,y) do { const fde * tmp = x; x = y; y = tmp; } while (0) |
ae2ff033 | 475 | |
476 | /* Convert a semi-heap to a heap. A semi-heap is a heap except possibly | |
477 | for the first (root) node; push it down to its rightful place. */ | |
478 | ||
479 | static void | |
49856054 | 480 | frame_downheap (struct object *ob, fde_compare_t fde_compare, const fde **a, |
ae2ff033 | 481 | int lo, int hi) |
482 | { | |
483 | int i, j; | |
484 | ||
485 | for (i = lo, j = 2*i+1; | |
486 | j < hi; | |
487 | j = 2*i+1) | |
488 | { | |
489 | if (j+1 < hi && fde_compare (ob, a[j], a[j+1]) < 0) | |
490 | ++j; | |
491 | ||
492 | if (fde_compare (ob, a[i], a[j]) < 0) | |
493 | { | |
494 | SWAP (a[i], a[j]); | |
495 | i = j; | |
496 | } | |
497 | else | |
498 | break; | |
499 | } | |
500 | } | |
501 | ||
1e530549 | 502 | /* This is O(n log(n)). BSD/OS defines heapsort in stdlib.h, so we must |
503 | use a name that does not conflict. */ | |
9b84bf7d | 504 | |
505 | static void | |
506 | frame_heapsort (struct object *ob, fde_compare_t fde_compare, | |
507 | struct fde_vector *erratic) | |
30f345ee | 508 | { |
509 | /* For a description of this algorithm, see: | |
510 | Samuel P. Harbison, Guy L. Steele Jr.: C, a reference manual, 2nd ed., | |
1be87b72 | 511 | p. 60-61. */ |
49856054 | 512 | const fde ** a = erratic->array; |
30f345ee | 513 | /* A portion of the array is called a "heap" if for all i>=0: |
514 | If i and 2i+1 are valid indices, then a[i] >= a[2i+1]. | |
1be87b72 | 515 | If i and 2i+2 are valid indices, then a[i] >= a[2i+2]. */ |
30f345ee | 516 | size_t n = erratic->count; |
ae2ff033 | 517 | int m; |
518 | ||
519 | /* Expand our heap incrementally from the end of the array, heapifying | |
520 | each resulting semi-heap as we go. After each step, a[m] is the top | |
521 | of a heap. */ | |
522 | for (m = n/2-1; m >= 0; --m) | |
523 | frame_downheap (ob, fde_compare, a, m, n); | |
524 | ||
525 | /* Shrink our heap incrementally from the end of the array, first | |
526 | swapping out the largest element a[0] and then re-heapifying the | |
527 | resulting semi-heap. After each step, a[0..m) is a heap. */ | |
528 | for (m = n-1; m >= 1; --m) | |
30f345ee | 529 | { |
ae2ff033 | 530 | SWAP (a[0], a[m]); |
531 | frame_downheap (ob, fde_compare, a, 0, m); | |
30f345ee | 532 | } |
533 | #undef SWAP | |
534 | } | |
535 | ||
1be87b72 | 536 | /* Merge V1 and V2, both sorted, and put the result into V1. */ |
9b84bf7d | 537 | static inline void |
538 | fde_merge (struct object *ob, fde_compare_t fde_compare, | |
539 | struct fde_vector *v1, struct fde_vector *v2) | |
d757b8c9 | 540 | { |
30f345ee | 541 | size_t i1, i2; |
49856054 | 542 | const fde * fde2; |
d757b8c9 | 543 | |
30f345ee | 544 | i2 = v2->count; |
545 | if (i2 > 0) | |
d757b8c9 | 546 | { |
30f345ee | 547 | i1 = v1->count; |
ac0c7fb1 | 548 | do |
549 | { | |
550 | i2--; | |
551 | fde2 = v2->array[i2]; | |
552 | while (i1 > 0 && fde_compare (ob, v1->array[i1-1], fde2) > 0) | |
553 | { | |
554 | v1->array[i1+i2] = v1->array[i1-1]; | |
555 | i1--; | |
556 | } | |
6c34d0c2 | 557 | v1->array[i1+i2] = fde2; |
ac0c7fb1 | 558 | } |
559 | while (i2 > 0); | |
30f345ee | 560 | v1->count += v2->count; |
d757b8c9 | 561 | } |
562 | } | |
563 | ||
9b84bf7d | 564 | static inline void |
565 | end_fde_sort (struct object *ob, struct fde_accumulator *accu, size_t count) | |
30f345ee | 566 | { |
9b84bf7d | 567 | fde_compare_t fde_compare; |
568 | ||
569 | if (accu->linear && accu->linear->count != count) | |
30f345ee | 570 | abort (); |
9b84bf7d | 571 | |
572 | if (ob->s.b.mixed_encoding) | |
573 | fde_compare = fde_mixed_encoding_compare; | |
574 | else if (ob->s.b.encoding == DW_EH_PE_absptr) | |
575 | fde_compare = fde_unencoded_compare; | |
576 | else | |
577 | fde_compare = fde_single_encoding_compare; | |
578 | ||
579 | if (accu->erratic) | |
8f44897f | 580 | { |
9b84bf7d | 581 | fde_split (ob, fde_compare, accu->linear, accu->erratic); |
582 | if (accu->linear->count + accu->erratic->count != count) | |
8f44897f | 583 | abort (); |
9b84bf7d | 584 | frame_heapsort (ob, fde_compare, accu->erratic); |
585 | fde_merge (ob, fde_compare, accu->linear, accu->erratic); | |
586 | free (accu->erratic); | |
8f44897f | 587 | } |
588 | else | |
589 | { | |
9b84bf7d | 590 | /* We've not managed to malloc an erratic array, |
591 | so heap sort in the linear one. */ | |
592 | frame_heapsort (ob, fde_compare, accu->linear); | |
8f44897f | 593 | } |
30f345ee | 594 | } |
595 | ||
df4b504c | 596 | \f |
6c34d0c2 | 597 | /* Update encoding, mixed_encoding, and pc_begin for OB for the |
9b84bf7d | 598 | fde array beginning at THIS_FDE. Return the number of fdes |
599 | encountered along the way. */ | |
600 | ||
df4b504c | 601 | static size_t |
49856054 | 602 | classify_object_over_fdes (struct object *ob, const fde *this_fde) |
df4b504c | 603 | { |
49856054 | 604 | const struct dwarf_cie *last_cie = 0; |
9b84bf7d | 605 | size_t count = 0; |
606 | int encoding = DW_EH_PE_absptr; | |
607 | _Unwind_Ptr base = 0; | |
d757b8c9 | 608 | |
a0c3f574 | 609 | for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) |
9b84bf7d | 610 | { |
49856054 | 611 | const struct dwarf_cie *this_cie; |
9b84bf7d | 612 | _Unwind_Ptr mask, pc_begin; |
df4b504c | 613 | |
9b84bf7d | 614 | /* Skip CIEs. */ |
615 | if (this_fde->CIE_delta == 0) | |
616 | continue; | |
df4b504c | 617 | |
9b84bf7d | 618 | /* Determine the encoding for this FDE. Note mixed encoded |
619 | objects for later. */ | |
620 | this_cie = get_cie (this_fde); | |
621 | if (this_cie != last_cie) | |
622 | { | |
623 | last_cie = this_cie; | |
624 | encoding = get_cie_encoding (this_cie); | |
625 | base = base_from_object (encoding, ob); | |
626 | if (ob->s.b.encoding == DW_EH_PE_omit) | |
627 | ob->s.b.encoding = encoding; | |
628 | else if (ob->s.b.encoding != encoding) | |
629 | ob->s.b.mixed_encoding = 1; | |
630 | } | |
d757b8c9 | 631 | |
9b84bf7d | 632 | read_encoded_value_with_base (encoding, base, this_fde->pc_begin, |
633 | &pc_begin); | |
d757b8c9 | 634 | |
9b84bf7d | 635 | /* Take care to ignore link-once functions that were removed. |
636 | In these cases, the function address will be NULL, but if | |
637 | the encoding is smaller than a pointer a true NULL may not | |
638 | be representable. Assume 0 in the representable bits is NULL. */ | |
639 | mask = size_of_encoded_value (encoding); | |
640 | if (mask < sizeof (void *)) | |
641 | mask = (1L << (mask << 3)) - 1; | |
642 | else | |
643 | mask = -1; | |
644 | ||
645 | if ((pc_begin & mask) == 0) | |
646 | continue; | |
732992fa | 647 | |
9b84bf7d | 648 | count += 1; |
188879e7 | 649 | if ((void *) pc_begin < ob->pc_begin) |
650 | ob->pc_begin = (void *) pc_begin; | |
df4b504c | 651 | } |
732992fa | 652 | |
9b84bf7d | 653 | return count; |
d757b8c9 | 654 | } |
655 | ||
9b84bf7d | 656 | static void |
49856054 | 657 | add_fdes (struct object *ob, struct fde_accumulator *accu, const fde *this_fde) |
cd236c08 | 658 | { |
49856054 | 659 | const struct dwarf_cie *last_cie = 0; |
9b84bf7d | 660 | int encoding = ob->s.b.encoding; |
661 | _Unwind_Ptr base = base_from_object (ob->s.b.encoding, ob); | |
662 | ||
a0c3f574 | 663 | for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) |
df4b504c | 664 | { |
49856054 | 665 | const struct dwarf_cie *this_cie; |
df4b504c | 666 | |
9b84bf7d | 667 | /* Skip CIEs. */ |
668 | if (this_fde->CIE_delta == 0) | |
669 | continue; | |
670 | ||
671 | if (ob->s.b.mixed_encoding) | |
672 | { | |
673 | /* Determine the encoding for this FDE. Note mixed encoded | |
674 | objects for later. */ | |
675 | this_cie = get_cie (this_fde); | |
676 | if (this_cie != last_cie) | |
677 | { | |
678 | last_cie = this_cie; | |
679 | encoding = get_cie_encoding (this_cie); | |
680 | base = base_from_object (encoding, ob); | |
681 | } | |
682 | } | |
683 | ||
684 | if (encoding == DW_EH_PE_absptr) | |
685 | { | |
188879e7 | 686 | if (*(_Unwind_Ptr *) this_fde->pc_begin == 0) |
9b84bf7d | 687 | continue; |
688 | } | |
689 | else | |
690 | { | |
691 | _Unwind_Ptr pc_begin, mask; | |
692 | ||
693 | read_encoded_value_with_base (encoding, base, this_fde->pc_begin, | |
694 | &pc_begin); | |
695 | ||
696 | /* Take care to ignore link-once functions that were removed. | |
697 | In these cases, the function address will be NULL, but if | |
698 | the encoding is smaller than a pointer a true NULL may not | |
699 | be representable. Assume 0 in the representable bits is NULL. */ | |
700 | mask = size_of_encoded_value (encoding); | |
701 | if (mask < sizeof (void *)) | |
702 | mask = (1L << (mask << 3)) - 1; | |
703 | else | |
704 | mask = -1; | |
705 | ||
706 | if ((pc_begin & mask) == 0) | |
707 | continue; | |
708 | } | |
709 | ||
710 | fde_insert (accu, this_fde); | |
df4b504c | 711 | } |
cd236c08 | 712 | } |
713 | ||
df4b504c | 714 | /* Set up a sorted array of pointers to FDEs for a loaded object. We |
715 | count up the entries before allocating the array because it's likely to | |
716 | be faster. We can be called multiple times, should we have failed to | |
717 | allocate a sorted fde array on a previous occasion. */ | |
d757b8c9 | 718 | |
9b84bf7d | 719 | static inline void |
720 | init_object (struct object* ob) | |
d757b8c9 | 721 | { |
9b84bf7d | 722 | struct fde_accumulator accu; |
df4b504c | 723 | size_t count; |
d757b8c9 | 724 | |
9b84bf7d | 725 | count = ob->s.b.count; |
726 | if (count == 0) | |
df4b504c | 727 | { |
9b84bf7d | 728 | if (ob->s.b.from_array) |
729 | { | |
730 | fde **p = ob->u.array; | |
731 | for (count = 0; *p; ++p) | |
732 | count += classify_object_over_fdes (ob, *p); | |
733 | } | |
734 | else | |
735 | count = classify_object_over_fdes (ob, ob->u.single); | |
736 | ||
737 | /* The count field we have in the main struct object is somewhat | |
738 | limited, but should suffice for virtually all cases. If the | |
739 | counted value doesn't fit, re-write a zero. The worst that | |
740 | happens is that we re-count next time -- admittedly non-trivial | |
741 | in that this implies some 2M fdes, but at least we function. */ | |
742 | ob->s.b.count = count; | |
743 | if (ob->s.b.count != count) | |
744 | ob->s.b.count = 0; | |
df4b504c | 745 | } |
732992fa | 746 | |
9b84bf7d | 747 | if (!start_fde_sort (&accu, count)) |
df4b504c | 748 | return; |
732992fa | 749 | |
9b84bf7d | 750 | if (ob->s.b.from_array) |
df4b504c | 751 | { |
9b84bf7d | 752 | fde **p; |
753 | for (p = ob->u.array; *p; ++p) | |
6c34d0c2 | 754 | add_fdes (ob, &accu, *p); |
df4b504c | 755 | } |
756 | else | |
9b84bf7d | 757 | add_fdes (ob, &accu, ob->u.single); |
758 | ||
759 | end_fde_sort (ob, &accu, count); | |
760 | ||
761 | /* Save the original fde pointer, since this is the key by which the | |
762 | DSO will deregister the object. */ | |
763 | accu.linear->orig_data = ob->u.single; | |
764 | ob->u.sort = accu.linear; | |
765 | ||
766 | ob->s.b.sorted = 1; | |
cd236c08 | 767 | } |
768 | ||
9b84bf7d | 769 | /* A linear search through a set of FDEs for the given PC. This is |
770 | used when there was insufficient memory to allocate and sort an | |
771 | array. */ | |
772 | ||
49856054 | 773 | static const fde * |
774 | linear_search_fdes (struct object *ob, const fde *this_fde, void *pc) | |
d757b8c9 | 775 | { |
49856054 | 776 | const struct dwarf_cie *last_cie = 0; |
9b84bf7d | 777 | int encoding = ob->s.b.encoding; |
778 | _Unwind_Ptr base = base_from_object (ob->s.b.encoding, ob); | |
779 | ||
a0c3f574 | 780 | for (; ! last_fde (ob, this_fde); this_fde = next_fde (this_fde)) |
9b84bf7d | 781 | { |
49856054 | 782 | const struct dwarf_cie *this_cie; |
9b84bf7d | 783 | _Unwind_Ptr pc_begin, pc_range; |
784 | ||
785 | /* Skip CIEs. */ | |
786 | if (this_fde->CIE_delta == 0) | |
787 | continue; | |
788 | ||
789 | if (ob->s.b.mixed_encoding) | |
790 | { | |
791 | /* Determine the encoding for this FDE. Note mixed encoded | |
792 | objects for later. */ | |
793 | this_cie = get_cie (this_fde); | |
794 | if (this_cie != last_cie) | |
795 | { | |
796 | last_cie = this_cie; | |
797 | encoding = get_cie_encoding (this_cie); | |
798 | base = base_from_object (encoding, ob); | |
799 | } | |
800 | } | |
801 | ||
802 | if (encoding == DW_EH_PE_absptr) | |
803 | { | |
188879e7 | 804 | pc_begin = ((_Unwind_Ptr *) this_fde->pc_begin)[0]; |
805 | pc_range = ((_Unwind_Ptr *) this_fde->pc_begin)[1]; | |
9b84bf7d | 806 | if (pc_begin == 0) |
807 | continue; | |
808 | } | |
809 | else | |
810 | { | |
811 | _Unwind_Ptr mask; | |
88cbb18b | 812 | const unsigned char *p; |
9b84bf7d | 813 | |
814 | p = read_encoded_value_with_base (encoding, base, | |
815 | this_fde->pc_begin, &pc_begin); | |
816 | read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); | |
817 | ||
818 | /* Take care to ignore link-once functions that were removed. | |
819 | In these cases, the function address will be NULL, but if | |
820 | the encoding is smaller than a pointer a true NULL may not | |
821 | be representable. Assume 0 in the representable bits is NULL. */ | |
822 | mask = size_of_encoded_value (encoding); | |
823 | if (mask < sizeof (void *)) | |
824 | mask = (1L << (mask << 3)) - 1; | |
825 | else | |
826 | mask = -1; | |
827 | ||
828 | if ((pc_begin & mask) == 0) | |
829 | continue; | |
830 | } | |
831 | ||
188879e7 | 832 | if ((_Unwind_Ptr) pc - pc_begin < pc_range) |
6c34d0c2 | 833 | return this_fde; |
9b84bf7d | 834 | } |
835 | ||
836 | return NULL; | |
837 | } | |
838 | ||
839 | /* Binary search for an FDE containing the given PC. Here are three | |
840 | implementations of increasing complexity. */ | |
841 | ||
49856054 | 842 | static inline const fde * |
9b84bf7d | 843 | binary_search_unencoded_fdes (struct object *ob, void *pc) |
844 | { | |
845 | struct fde_vector *vec = ob->u.sort; | |
df4b504c | 846 | size_t lo, hi; |
6c34d0c2 | 847 | |
9b84bf7d | 848 | for (lo = 0, hi = vec->count; lo < hi; ) |
849 | { | |
850 | size_t i = (lo + hi) / 2; | |
49856054 | 851 | const fde *f = vec->array[i]; |
9b84bf7d | 852 | void *pc_begin; |
853 | uaddr pc_range; | |
854 | ||
188879e7 | 855 | pc_begin = ((void **) f->pc_begin)[0]; |
856 | pc_range = ((uaddr *) f->pc_begin)[1]; | |
9b84bf7d | 857 | |
858 | if (pc < pc_begin) | |
859 | hi = i; | |
860 | else if (pc >= pc_begin + pc_range) | |
861 | lo = i + 1; | |
862 | else | |
863 | return f; | |
864 | } | |
d757b8c9 | 865 | |
9b84bf7d | 866 | return NULL; |
867 | } | |
732992fa | 868 | |
49856054 | 869 | static inline const fde * |
9b84bf7d | 870 | binary_search_single_encoding_fdes (struct object *ob, void *pc) |
871 | { | |
872 | struct fde_vector *vec = ob->u.sort; | |
873 | int encoding = ob->s.b.encoding; | |
874 | _Unwind_Ptr base = base_from_object (encoding, ob); | |
875 | size_t lo, hi; | |
6c34d0c2 | 876 | |
9b84bf7d | 877 | for (lo = 0, hi = vec->count; lo < hi; ) |
d757b8c9 | 878 | { |
9b84bf7d | 879 | size_t i = (lo + hi) / 2; |
49856054 | 880 | const fde *f = vec->array[i]; |
9b84bf7d | 881 | _Unwind_Ptr pc_begin, pc_range; |
88cbb18b | 882 | const unsigned char *p; |
9b84bf7d | 883 | |
884 | p = read_encoded_value_with_base (encoding, base, f->pc_begin, | |
885 | &pc_begin); | |
886 | read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); | |
887 | ||
188879e7 | 888 | if ((_Unwind_Ptr) pc < pc_begin) |
9b84bf7d | 889 | hi = i; |
188879e7 | 890 | else if ((_Unwind_Ptr) pc >= pc_begin + pc_range) |
9b84bf7d | 891 | lo = i + 1; |
892 | else | |
893 | return f; | |
df4b504c | 894 | } |
d757b8c9 | 895 | |
9b84bf7d | 896 | return NULL; |
897 | } | |
898 | ||
49856054 | 899 | static inline const fde * |
9b84bf7d | 900 | binary_search_mixed_encoding_fdes (struct object *ob, void *pc) |
901 | { | |
902 | struct fde_vector *vec = ob->u.sort; | |
903 | size_t lo, hi; | |
6c34d0c2 | 904 | |
9b84bf7d | 905 | for (lo = 0, hi = vec->count; lo < hi; ) |
df4b504c | 906 | { |
9b84bf7d | 907 | size_t i = (lo + hi) / 2; |
49856054 | 908 | const fde *f = vec->array[i]; |
9b84bf7d | 909 | _Unwind_Ptr pc_begin, pc_range; |
88cbb18b | 910 | const unsigned char *p; |
9b84bf7d | 911 | int encoding; |
912 | ||
913 | encoding = get_fde_encoding (f); | |
914 | p = read_encoded_value_with_base (encoding, | |
915 | base_from_object (encoding, ob), | |
916 | f->pc_begin, &pc_begin); | |
917 | read_encoded_value_with_base (encoding & 0x0F, 0, p, &pc_range); | |
918 | ||
188879e7 | 919 | if ((_Unwind_Ptr) pc < pc_begin) |
9b84bf7d | 920 | hi = i; |
188879e7 | 921 | else if ((_Unwind_Ptr) pc >= pc_begin + pc_range) |
9b84bf7d | 922 | lo = i + 1; |
923 | else | |
924 | return f; | |
df4b504c | 925 | } |
d757b8c9 | 926 | |
9b84bf7d | 927 | return NULL; |
928 | } | |
df4b504c | 929 | |
49856054 | 930 | static const fde * |
9b84bf7d | 931 | search_object (struct object* ob, void *pc) |
932 | { | |
933 | /* If the data hasn't been sorted, try to do this now. We may have | |
934 | more memory available than last time we tried. */ | |
935 | if (! ob->s.b.sorted) | |
df4b504c | 936 | { |
9b84bf7d | 937 | init_object (ob); |
df4b504c | 938 | |
9b84bf7d | 939 | /* Despite the above comment, the normal reason to get here is |
940 | that we've not processed this object before. A quick range | |
941 | check is in order. */ | |
942 | if (pc < ob->pc_begin) | |
943 | return NULL; | |
944 | } | |
945 | ||
946 | if (ob->s.b.sorted) | |
947 | { | |
948 | if (ob->s.b.mixed_encoding) | |
949 | return binary_search_mixed_encoding_fdes (ob, pc); | |
950 | else if (ob->s.b.encoding == DW_EH_PE_absptr) | |
951 | return binary_search_unencoded_fdes (ob, pc); | |
952 | else | |
953 | return binary_search_single_encoding_fdes (ob, pc); | |
d757b8c9 | 954 | } |
df4b504c | 955 | else |
956 | { | |
9b84bf7d | 957 | /* Long slow labourious linear search, cos we've no memory. */ |
958 | if (ob->s.b.from_array) | |
6c34d0c2 | 959 | { |
960 | fde **p; | |
9b84bf7d | 961 | for (p = ob->u.array; *p ; p++) |
962 | { | |
49856054 | 963 | const fde *f = linear_search_fdes (ob, *p, pc); |
6c34d0c2 | 964 | if (f) |
9b84bf7d | 965 | return f; |
6c34d0c2 | 966 | } |
9b84bf7d | 967 | return NULL; |
968 | } | |
df4b504c | 969 | else |
9b84bf7d | 970 | return linear_search_fdes (ob, ob->u.single, pc); |
971 | } | |
972 | } | |
973 | ||
49856054 | 974 | const fde * |
9b84bf7d | 975 | _Unwind_Find_FDE (void *pc, struct dwarf_eh_bases *bases) |
976 | { | |
977 | struct object *ob; | |
49856054 | 978 | const fde *f = NULL; |
9b84bf7d | 979 | |
980 | init_object_mutex_once (); | |
981 | __gthread_mutex_lock (&object_mutex); | |
982 | ||
983 | /* Linear search through the classified objects, to find the one | |
b9fe4edd | 984 | containing the pc. Note that pc_begin is sorted descending, and |
9b84bf7d | 985 | we expect objects to be non-overlapping. */ |
986 | for (ob = seen_objects; ob; ob = ob->next) | |
987 | if (pc >= ob->pc_begin) | |
988 | { | |
989 | f = search_object (ob, pc); | |
990 | if (f) | |
991 | goto fini; | |
992 | break; | |
993 | } | |
994 | ||
995 | /* Classify and search the objects we've not yet processed. */ | |
996 | while ((ob = unseen_objects)) | |
997 | { | |
998 | struct object **p; | |
999 | ||
1000 | unseen_objects = ob->next; | |
1001 | f = search_object (ob, pc); | |
1002 | ||
1003 | /* Insert the object into the classified list. */ | |
1004 | for (p = &seen_objects; *p ; p = &(*p)->next) | |
1005 | if ((*p)->pc_begin < ob->pc_begin) | |
1006 | break; | |
1007 | ob->next = *p; | |
1008 | *p = ob; | |
1009 | ||
1010 | if (f) | |
1011 | goto fini; | |
1012 | } | |
1013 | ||
1014 | fini: | |
1015 | __gthread_mutex_unlock (&object_mutex); | |
1016 | ||
1017 | if (f) | |
1018 | { | |
1019 | int encoding; | |
1020 | ||
1021 | bases->tbase = ob->tbase; | |
1022 | bases->dbase = ob->dbase; | |
732992fa | 1023 | |
9b84bf7d | 1024 | encoding = ob->s.b.encoding; |
1025 | if (ob->s.b.mixed_encoding) | |
1026 | encoding = get_fde_encoding (f); | |
1027 | read_encoded_value_with_base (encoding, base_from_object (encoding, ob), | |
1028 | f->pc_begin, (_Unwind_Ptr *)&bases->func); | |
df4b504c | 1029 | } |
d757b8c9 | 1030 | |
9b84bf7d | 1031 | return f; |
cd236c08 | 1032 | } |