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