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Linux 4.13.16
[linux/fpc-iii.git] / arch / ia64 / kernel / unwind.c
blob9704e2cd9878cfaf3ec91badec8c51d10299aac2
1 /*
2 * Copyright (C) 1999-2004 Hewlett-Packard Co
3 * David Mosberger-Tang <davidm@hpl.hp.com>
4 * Copyright (C) 2003 Fenghua Yu <fenghua.yu@intel.com>
5 * - Change pt_regs_off() to make it less dependent on pt_regs structure.
6 */
7 /*
8 * This file implements call frame unwind support for the Linux
9 * kernel. Parsing and processing the unwind information is
10 * time-consuming, so this implementation translates the unwind
11 * descriptors into unwind scripts. These scripts are very simple
12 * (basically a sequence of assignments) and efficient to execute.
13 * They are cached for later re-use. Each script is specific for a
14 * given instruction pointer address and the set of predicate values
15 * that the script depends on (most unwind descriptors are
16 * unconditional and scripts often do not depend on predicates at
17 * all). This code is based on the unwind conventions described in
18 * the "IA-64 Software Conventions and Runtime Architecture" manual.
19 *
20 * SMP conventions:
21 * o updates to the global unwind data (in structure "unw") are serialized
22 * by the unw.lock spinlock
23 * o each unwind script has its own read-write lock; a thread must acquire
24 * a read lock before executing a script and must acquire a write lock
25 * before modifying a script
26 * o if both the unw.lock spinlock and a script's read-write lock must be
27 * acquired, then the read-write lock must be acquired first.
28 */
29 #include <linux/module.h>
30 #include <linux/bootmem.h>
31 #include <linux/elf.h>
32 #include <linux/kernel.h>
33 #include <linux/sched.h>
34 #include <linux/slab.h>
35
36 #include <asm/unwind.h>
37
38 #include <asm/delay.h>
39 #include <asm/page.h>
40 #include <asm/ptrace.h>
41 #include <asm/ptrace_offsets.h>
42 #include <asm/rse.h>
43 #include <asm/sections.h>
44 #include <linux/uaccess.h>
45
46 #include "entry.h"
47 #include "unwind_i.h"
48
49 #define UNW_LOG_CACHE_SIZE 7 /* each unw_script is ~256 bytes in size */
50 #define UNW_CACHE_SIZE (1 << UNW_LOG_CACHE_SIZE)
51
52 #define UNW_LOG_HASH_SIZE (UNW_LOG_CACHE_SIZE + 1)
53 #define UNW_HASH_SIZE (1 << UNW_LOG_HASH_SIZE)
54
55 #define UNW_STATS 0 /* WARNING: this disabled interrupts for long time-spans!! */
56
57 #ifdef UNW_DEBUG
58 static unsigned int unw_debug_level = UNW_DEBUG;
59 # define UNW_DEBUG_ON(n) unw_debug_level >= n
60 /* Do not code a printk level, not all debug lines end in newline */
61 # define UNW_DPRINT(n, ...) if (UNW_DEBUG_ON(n)) printk(__VA_ARGS__)
62 # undef inline
63 # define inline
64 #else /* !UNW_DEBUG */
65 # define UNW_DEBUG_ON(n) 0
66 # define UNW_DPRINT(n, ...)
67 #endif /* UNW_DEBUG */
68
69 #if UNW_STATS
70 # define STAT(x...) x
71 #else
72 # define STAT(x...)
73 #endif
74
75 #define alloc_reg_state() kmalloc(sizeof(struct unw_reg_state), GFP_ATOMIC)
76 #define free_reg_state(usr) kfree(usr)
77 #define alloc_labeled_state() kmalloc(sizeof(struct unw_labeled_state), GFP_ATOMIC)
78 #define free_labeled_state(usr) kfree(usr)
79
80 typedef unsigned long unw_word;
81 typedef unsigned char unw_hash_index_t;
82
83 static struct {
84 spinlock_t lock; /* spinlock for unwind data */
85
86 /* list of unwind tables (one per load-module) */
87 struct unw_table *tables;
88
89 unsigned long r0; /* constant 0 for r0 */
90
91 /* table of registers that prologues can save (and order in which they're saved): */
92 const unsigned char save_order[8];
93
94 /* maps a preserved register index (preg_index) to corresponding switch_stack offset: */
95 unsigned short sw_off[sizeof(struct unw_frame_info) / 8];
96
97 unsigned short lru_head; /* index of lead-recently used script */
98 unsigned short lru_tail; /* index of most-recently used script */
99
100 /* index into unw_frame_info for preserved register i */
101 unsigned short preg_index[UNW_NUM_REGS];
102
103 short pt_regs_offsets[32];
104
105 /* unwind table for the kernel: */
106 struct unw_table kernel_table;
107
108 /* unwind table describing the gate page (kernel code that is mapped into user space): */
109 size_t gate_table_size;
110 unsigned long *gate_table;
111
112 /* hash table that maps instruction pointer to script index: */
113 unsigned short hash[UNW_HASH_SIZE];
114
115 /* script cache: */
116 struct unw_script cache[UNW_CACHE_SIZE];
117
118 # ifdef UNW_DEBUG
119 const char *preg_name[UNW_NUM_REGS];
120 # endif
121 # if UNW_STATS
122 struct {
123 struct {
124 int lookups;
125 int hinted_hits;
126 int normal_hits;
127 int collision_chain_traversals;
128 } cache;
129 struct {
130 unsigned long build_time;
131 unsigned long run_time;
132 unsigned long parse_time;
133 int builds;
134 int news;
135 int collisions;
136 int runs;
137 } script;
138 struct {
139 unsigned long init_time;
140 unsigned long unwind_time;
141 int inits;
142 int unwinds;
143 } api;
144 } stat;
145 # endif
146 } unw = {
147 .tables = &unw.kernel_table,
148 .lock = __SPIN_LOCK_UNLOCKED(unw.lock),
149 .save_order = {
150 UNW_REG_RP, UNW_REG_PFS, UNW_REG_PSP, UNW_REG_PR,
151 UNW_REG_UNAT, UNW_REG_LC, UNW_REG_FPSR, UNW_REG_PRI_UNAT_GR
152 },
153 .preg_index = {
154 offsetof(struct unw_frame_info, pri_unat_loc)/8, /* PRI_UNAT_GR */
155 offsetof(struct unw_frame_info, pri_unat_loc)/8, /* PRI_UNAT_MEM */
156 offsetof(struct unw_frame_info, bsp_loc)/8,
157 offsetof(struct unw_frame_info, bspstore_loc)/8,
158 offsetof(struct unw_frame_info, pfs_loc)/8,
159 offsetof(struct unw_frame_info, rnat_loc)/8,
160 offsetof(struct unw_frame_info, psp)/8,
161 offsetof(struct unw_frame_info, rp_loc)/8,
162 offsetof(struct unw_frame_info, r4)/8,
163 offsetof(struct unw_frame_info, r5)/8,
164 offsetof(struct unw_frame_info, r6)/8,
165 offsetof(struct unw_frame_info, r7)/8,
166 offsetof(struct unw_frame_info, unat_loc)/8,
167 offsetof(struct unw_frame_info, pr_loc)/8,
168 offsetof(struct unw_frame_info, lc_loc)/8,
169 offsetof(struct unw_frame_info, fpsr_loc)/8,
170 offsetof(struct unw_frame_info, b1_loc)/8,
171 offsetof(struct unw_frame_info, b2_loc)/8,
172 offsetof(struct unw_frame_info, b3_loc)/8,
173 offsetof(struct unw_frame_info, b4_loc)/8,
174 offsetof(struct unw_frame_info, b5_loc)/8,
175 offsetof(struct unw_frame_info, f2_loc)/8,
176 offsetof(struct unw_frame_info, f3_loc)/8,
177 offsetof(struct unw_frame_info, f4_loc)/8,
178 offsetof(struct unw_frame_info, f5_loc)/8,
179 offsetof(struct unw_frame_info, fr_loc[16 - 16])/8,
180 offsetof(struct unw_frame_info, fr_loc[17 - 16])/8,
181 offsetof(struct unw_frame_info, fr_loc[18 - 16])/8,
182 offsetof(struct unw_frame_info, fr_loc[19 - 16])/8,
183 offsetof(struct unw_frame_info, fr_loc[20 - 16])/8,
184 offsetof(struct unw_frame_info, fr_loc[21 - 16])/8,
185 offsetof(struct unw_frame_info, fr_loc[22 - 16])/8,
186 offsetof(struct unw_frame_info, fr_loc[23 - 16])/8,
187 offsetof(struct unw_frame_info, fr_loc[24 - 16])/8,
188 offsetof(struct unw_frame_info, fr_loc[25 - 16])/8,
189 offsetof(struct unw_frame_info, fr_loc[26 - 16])/8,
190 offsetof(struct unw_frame_info, fr_loc[27 - 16])/8,
191 offsetof(struct unw_frame_info, fr_loc[28 - 16])/8,
192 offsetof(struct unw_frame_info, fr_loc[29 - 16])/8,
193 offsetof(struct unw_frame_info, fr_loc[30 - 16])/8,
194 offsetof(struct unw_frame_info, fr_loc[31 - 16])/8,
195 },
196 .pt_regs_offsets = {
197 [0] = -1,
198 offsetof(struct pt_regs, r1),
199 offsetof(struct pt_regs, r2),
200 offsetof(struct pt_regs, r3),
201 [4] = -1, [5] = -1, [6] = -1, [7] = -1,
202 offsetof(struct pt_regs, r8),
203 offsetof(struct pt_regs, r9),
204 offsetof(struct pt_regs, r10),
205 offsetof(struct pt_regs, r11),
206 offsetof(struct pt_regs, r12),
207 offsetof(struct pt_regs, r13),
208 offsetof(struct pt_regs, r14),
209 offsetof(struct pt_regs, r15),
210 offsetof(struct pt_regs, r16),
211 offsetof(struct pt_regs, r17),
212 offsetof(struct pt_regs, r18),
213 offsetof(struct pt_regs, r19),
214 offsetof(struct pt_regs, r20),
215 offsetof(struct pt_regs, r21),
216 offsetof(struct pt_regs, r22),
217 offsetof(struct pt_regs, r23),
218 offsetof(struct pt_regs, r24),
219 offsetof(struct pt_regs, r25),
220 offsetof(struct pt_regs, r26),
221 offsetof(struct pt_regs, r27),
222 offsetof(struct pt_regs, r28),
223 offsetof(struct pt_regs, r29),
224 offsetof(struct pt_regs, r30),
225 offsetof(struct pt_regs, r31),
226 },
227 .hash = { [0 ... UNW_HASH_SIZE - 1] = -1 },
228 #ifdef UNW_DEBUG
229 .preg_name = {
230 "pri_unat_gr", "pri_unat_mem", "bsp", "bspstore", "ar.pfs", "ar.rnat", "psp", "rp",
231 "r4", "r5", "r6", "r7",
232 "ar.unat", "pr", "ar.lc", "ar.fpsr",
233 "b1", "b2", "b3", "b4", "b5",
234 "f2", "f3", "f4", "f5",
235 "f16", "f17", "f18", "f19", "f20", "f21", "f22", "f23",
236 "f24", "f25", "f26", "f27", "f28", "f29", "f30", "f31"
237 }
238 #endif
239 };
240
241 static inline int
242 read_only (void *addr)
243 {
244 return (unsigned long) ((char *) addr - (char *) &unw.r0) < sizeof(unw.r0);
245 }
246
247 /*
248 * Returns offset of rREG in struct pt_regs.
249 */
250 static inline unsigned long
251 pt_regs_off (unsigned long reg)
252 {
253 short off = -1;
254
255 if (reg < ARRAY_SIZE(unw.pt_regs_offsets))
256 off = unw.pt_regs_offsets[reg];
257
258 if (off < 0) {
259 UNW_DPRINT(0, "unwind.%s: bad scratch reg r%lu\n", __func__, reg);
260 off = 0;
261 }
262 return (unsigned long) off;
263 }
264
265 static inline struct pt_regs *
266 get_scratch_regs (struct unw_frame_info *info)
267 {
268 if (!info->pt) {
269 /* This should not happen with valid unwind info. */
270 UNW_DPRINT(0, "unwind.%s: bad unwind info: resetting info->pt\n", __func__);
271 if (info->flags & UNW_FLAG_INTERRUPT_FRAME)
272 info->pt = (unsigned long) ((struct pt_regs *) info->psp - 1);
273 else
274 info->pt = info->sp - 16;
275 }
276 UNW_DPRINT(3, "unwind.%s: sp 0x%lx pt 0x%lx\n", __func__, info->sp, info->pt);
277 return (struct pt_regs *) info->pt;
278 }
279
280 /* Unwind accessors. */
281
282 int
283 unw_access_gr (struct unw_frame_info *info, int regnum, unsigned long *val, char *nat, int write)
284 {
285 unsigned long *addr, *nat_addr, nat_mask = 0, dummy_nat;
286 struct unw_ireg *ireg;
287 struct pt_regs *pt;
288
289 if ((unsigned) regnum - 1 >= 127) {
290 if (regnum == 0 && !write) {
291 *val = 0; /* read r0 always returns 0 */
292 *nat = 0;
293 return 0;
294 }
295 UNW_DPRINT(0, "unwind.%s: trying to access non-existent r%u\n",
296 __func__, regnum);
297 return -1;
298 }
299
300 if (regnum < 32) {
301 if (regnum >= 4 && regnum <= 7) {
302 /* access a preserved register */
303 ireg = &info->r4 + (regnum - 4);
304 addr = ireg->loc;
305 if (addr) {
306 nat_addr = addr + ireg->nat.off;
307 switch (ireg->nat.type) {
308 case UNW_NAT_VAL:
309 /* simulate getf.sig/setf.sig */
310 if (write) {
311 if (*nat) {
312 /* write NaTVal and be done with it */
313 addr[0] = 0;
314 addr[1] = 0x1fffe;
315 return 0;
316 }
317 addr[1] = 0x1003e;
318 } else {
319 if (addr[0] == 0 && addr[1] == 0x1ffe) {
320 /* return NaT and be done with it */
321 *val = 0;
322 *nat = 1;
323 return 0;
324 }
325 }
326 /* fall through */
327 case UNW_NAT_NONE:
328 dummy_nat = 0;
329 nat_addr = &dummy_nat;
330 break;
331
332 case UNW_NAT_MEMSTK:
333 nat_mask = (1UL << ((long) addr & 0x1f8)/8);
334 break;
335
336 case UNW_NAT_REGSTK:
337 nat_addr = ia64_rse_rnat_addr(addr);
338 if ((unsigned long) addr < info->regstk.limit
339 || (unsigned long) addr >= info->regstk.top)
340 {
341 UNW_DPRINT(0, "unwind.%s: %p outside of regstk "
342 "[0x%lx-0x%lx)\n",
343 __func__, (void *) addr,
344 info->regstk.limit,
345 info->regstk.top);
346 return -1;
347 }
348 if ((unsigned long) nat_addr >= info->regstk.top)
349 nat_addr = &info->sw->ar_rnat;
350 nat_mask = (1UL << ia64_rse_slot_num(addr));
351 break;
352 }
353 } else {
354 addr = &info->sw->r4 + (regnum - 4);
355 nat_addr = &info->sw->ar_unat;
356 nat_mask = (1UL << ((long) addr & 0x1f8)/8);
357 }
358 } else {
359 /* access a scratch register */
360 pt = get_scratch_regs(info);
361 addr = (unsigned long *) ((unsigned long)pt + pt_regs_off(regnum));
362 if (info->pri_unat_loc)
363 nat_addr = info->pri_unat_loc;
364 else
365 nat_addr = &info->sw->caller_unat;
366 nat_mask = (1UL << ((long) addr & 0x1f8)/8);
367 }
368 } else {
369 /* access a stacked register */
370 addr = ia64_rse_skip_regs((unsigned long *) info->bsp, regnum - 32);
371 nat_addr = ia64_rse_rnat_addr(addr);
372 if ((unsigned long) addr < info->regstk.limit
373 || (unsigned long) addr >= info->regstk.top)
374 {
375 UNW_DPRINT(0, "unwind.%s: ignoring attempt to access register outside "
376 "of rbs\n", __func__);
377 return -1;
378 }
379 if ((unsigned long) nat_addr >= info->regstk.top)
380 nat_addr = &info->sw->ar_rnat;
381 nat_mask = (1UL << ia64_rse_slot_num(addr));
382 }
383
384 if (write) {
385 if (read_only(addr)) {
386 UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
387 __func__);
388 } else {
389 *addr = *val;
390 if (*nat)
391 *nat_addr |= nat_mask;
392 else
393 *nat_addr &= ~nat_mask;
394 }
395 } else {
396 if ((*nat_addr & nat_mask) == 0) {
397 *val = *addr;
398 *nat = 0;
399 } else {
400 *val = 0; /* if register is a NaT, *addr may contain kernel data! */
401 *nat = 1;
402 }
403 }
404 return 0;
405 }
406 EXPORT_SYMBOL(unw_access_gr);
407
408 int
409 unw_access_br (struct unw_frame_info *info, int regnum, unsigned long *val, int write)
410 {
411 unsigned long *addr;
412 struct pt_regs *pt;
413
414 switch (regnum) {
415 /* scratch: */
416 case 0: pt = get_scratch_regs(info); addr = &pt->b0; break;
417 case 6: pt = get_scratch_regs(info); addr = &pt->b6; break;
418 case 7: pt = get_scratch_regs(info); addr = &pt->b7; break;
419
420 /* preserved: */
421 case 1: case 2: case 3: case 4: case 5:
422 addr = *(&info->b1_loc + (regnum - 1));
423 if (!addr)
424 addr = &info->sw->b1 + (regnum - 1);
425 break;
426
427 default:
428 UNW_DPRINT(0, "unwind.%s: trying to access non-existent b%u\n",
429 __func__, regnum);
430 return -1;
431 }
432 if (write)
433 if (read_only(addr)) {
434 UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
435 __func__);
436 } else
437 *addr = *val;
438 else
439 *val = *addr;
440 return 0;
441 }
442 EXPORT_SYMBOL(unw_access_br);
443
444 int
445 unw_access_fr (struct unw_frame_info *info, int regnum, struct ia64_fpreg *val, int write)
446 {
447 struct ia64_fpreg *addr = NULL;
448 struct pt_regs *pt;
449
450 if ((unsigned) (regnum - 2) >= 126) {
451 UNW_DPRINT(0, "unwind.%s: trying to access non-existent f%u\n",
452 __func__, regnum);
453 return -1;
454 }
455
456 if (regnum <= 5) {
457 addr = *(&info->f2_loc + (regnum - 2));
458 if (!addr)
459 addr = &info->sw->f2 + (regnum - 2);
460 } else if (regnum <= 15) {
461 if (regnum <= 11) {
462 pt = get_scratch_regs(info);
463 addr = &pt->f6 + (regnum - 6);
464 }
465 else
466 addr = &info->sw->f12 + (regnum - 12);
467 } else if (regnum <= 31) {
468 addr = info->fr_loc[regnum - 16];
469 if (!addr)
470 addr = &info->sw->f16 + (regnum - 16);
471 } else {
472 struct task_struct *t = info->task;
473
474 if (write)
475 ia64_sync_fph(t);
476 else
477 ia64_flush_fph(t);
478 addr = t->thread.fph + (regnum - 32);
479 }
480
481 if (write)
482 if (read_only(addr)) {
483 UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
484 __func__);
485 } else
486 *addr = *val;
487 else
488 *val = *addr;
489 return 0;
490 }
491 EXPORT_SYMBOL(unw_access_fr);
492
493 int
494 unw_access_ar (struct unw_frame_info *info, int regnum, unsigned long *val, int write)
495 {
496 unsigned long *addr;
497 struct pt_regs *pt;
498
499 switch (regnum) {
500 case UNW_AR_BSP:
501 addr = info->bsp_loc;
502 if (!addr)
503 addr = &info->sw->ar_bspstore;
504 break;
505
506 case UNW_AR_BSPSTORE:
507 addr = info->bspstore_loc;
508 if (!addr)
509 addr = &info->sw->ar_bspstore;
510 break;
511
512 case UNW_AR_PFS:
513 addr = info->pfs_loc;
514 if (!addr)
515 addr = &info->sw->ar_pfs;
516 break;
517
518 case UNW_AR_RNAT:
519 addr = info->rnat_loc;
520 if (!addr)
521 addr = &info->sw->ar_rnat;
522 break;
523
524 case UNW_AR_UNAT:
525 addr = info->unat_loc;
526 if (!addr)
527 addr = &info->sw->caller_unat;
528 break;
529
530 case UNW_AR_LC:
531 addr = info->lc_loc;
532 if (!addr)
533 addr = &info->sw->ar_lc;
534 break;
535
536 case UNW_AR_EC:
537 if (!info->cfm_loc)
538 return -1;
539 if (write)
540 *info->cfm_loc =
541 (*info->cfm_loc & ~(0x3fUL << 52)) | ((*val & 0x3f) << 52);
542 else
543 *val = (*info->cfm_loc >> 52) & 0x3f;
544 return 0;
545
546 case UNW_AR_FPSR:
547 addr = info->fpsr_loc;
548 if (!addr)
549 addr = &info->sw->ar_fpsr;
550 break;
551
552 case UNW_AR_RSC:
553 pt = get_scratch_regs(info);
554 addr = &pt->ar_rsc;
555 break;
556
557 case UNW_AR_CCV:
558 pt = get_scratch_regs(info);
559 addr = &pt->ar_ccv;
560 break;
561
562 case UNW_AR_CSD:
563 pt = get_scratch_regs(info);
564 addr = &pt->ar_csd;
565 break;
566
567 case UNW_AR_SSD:
568 pt = get_scratch_regs(info);
569 addr = &pt->ar_ssd;
570 break;
571
572 default:
573 UNW_DPRINT(0, "unwind.%s: trying to access non-existent ar%u\n",
574 __func__, regnum);
575 return -1;
576 }
577
578 if (write) {
579 if (read_only(addr)) {
580 UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
581 __func__);
582 } else
583 *addr = *val;
584 } else
585 *val = *addr;
586 return 0;
587 }
588 EXPORT_SYMBOL(unw_access_ar);
589
590 int
591 unw_access_pr (struct unw_frame_info *info, unsigned long *val, int write)
592 {
593 unsigned long *addr;
594
595 addr = info->pr_loc;
596 if (!addr)
597 addr = &info->sw->pr;
598
599 if (write) {
600 if (read_only(addr)) {
601 UNW_DPRINT(0, "unwind.%s: ignoring attempt to write read-only location\n",
602 __func__);
603 } else
604 *addr = *val;
605 } else
606 *val = *addr;
607 return 0;
608 }
609 EXPORT_SYMBOL(unw_access_pr);
610
611 \f
612 /* Routines to manipulate the state stack. */
613
614 static inline void
615 push (struct unw_state_record *sr)
616 {
617 struct unw_reg_state *rs;
618
619 rs = alloc_reg_state();
620 if (!rs) {
621 printk(KERN_ERR "unwind: cannot stack reg state!\n");
622 return;
623 }
624 memcpy(rs, &sr->curr, sizeof(*rs));
625 sr->curr.next = rs;
626 }
627
628 static void
629 pop (struct unw_state_record *sr)
630 {
631 struct unw_reg_state *rs = sr->curr.next;
632
633 if (!rs) {
634 printk(KERN_ERR "unwind: stack underflow!\n");
635 return;
636 }
637 memcpy(&sr->curr, rs, sizeof(*rs));
638 free_reg_state(rs);
639 }
640
641 /* Make a copy of the state stack. Non-recursive to avoid stack overflows. */
642 static struct unw_reg_state *
643 dup_state_stack (struct unw_reg_state *rs)
644 {
645 struct unw_reg_state *copy, *prev = NULL, *first = NULL;
646
647 while (rs) {
648 copy = alloc_reg_state();
649 if (!copy) {
650 printk(KERN_ERR "unwind.dup_state_stack: out of memory\n");
651 return NULL;
652 }
653 memcpy(copy, rs, sizeof(*copy));
654 if (first)
655 prev->next = copy;
656 else
657 first = copy;
658 rs = rs->next;
659 prev = copy;
660 }
661 return first;
662 }
663
664 /* Free all stacked register states (but not RS itself). */
665 static void
666 free_state_stack (struct unw_reg_state *rs)
667 {
668 struct unw_reg_state *p, *next;
669
670 for (p = rs->next; p != NULL; p = next) {
671 next = p->next;
672 free_reg_state(p);
673 }
674 rs->next = NULL;
675 }
676 \f
677 /* Unwind decoder routines */
678
679 static enum unw_register_index __attribute_const__
680 decode_abreg (unsigned char abreg, int memory)
681 {
682 switch (abreg) {
683 case 0x04 ... 0x07: return UNW_REG_R4 + (abreg - 0x04);
684 case 0x22 ... 0x25: return UNW_REG_F2 + (abreg - 0x22);
685 case 0x30 ... 0x3f: return UNW_REG_F16 + (abreg - 0x30);
686 case 0x41 ... 0x45: return UNW_REG_B1 + (abreg - 0x41);
687 case 0x60: return UNW_REG_PR;
688 case 0x61: return UNW_REG_PSP;
689 case 0x62: return memory ? UNW_REG_PRI_UNAT_MEM : UNW_REG_PRI_UNAT_GR;
690 case 0x63: return UNW_REG_RP;
691 case 0x64: return UNW_REG_BSP;
692 case 0x65: return UNW_REG_BSPSTORE;
693 case 0x66: return UNW_REG_RNAT;
694 case 0x67: return UNW_REG_UNAT;
695 case 0x68: return UNW_REG_FPSR;
696 case 0x69: return UNW_REG_PFS;
697 case 0x6a: return UNW_REG_LC;
698 default:
699 break;
700 }
701 UNW_DPRINT(0, "unwind.%s: bad abreg=0x%x\n", __func__, abreg);
702 return UNW_REG_LC;
703 }
704
705 static void
706 set_reg (struct unw_reg_info *reg, enum unw_where where, int when, unsigned long val)
707 {
708 reg->val = val;
709 reg->where = where;
710 if (reg->when == UNW_WHEN_NEVER)
711 reg->when = when;
712 }
713
714 static void
715 alloc_spill_area (unsigned long *offp, unsigned long regsize,
716 struct unw_reg_info *lo, struct unw_reg_info *hi)
717 {
718 struct unw_reg_info *reg;
719
720 for (reg = hi; reg >= lo; --reg) {
721 if (reg->where == UNW_WHERE_SPILL_HOME) {
722 reg->where = UNW_WHERE_PSPREL;
723 *offp -= regsize;
724 reg->val = *offp;
725 }
726 }
727 }
728
729 static inline void
730 spill_next_when (struct unw_reg_info **regp, struct unw_reg_info *lim, unw_word t)
731 {
732 struct unw_reg_info *reg;
733
734 for (reg = *regp; reg <= lim; ++reg) {
735 if (reg->where == UNW_WHERE_SPILL_HOME) {
736 reg->when = t;
737 *regp = reg + 1;
738 return;
739 }
740 }
741 UNW_DPRINT(0, "unwind.%s: excess spill!\n", __func__);
742 }
743
744 static inline void
745 finish_prologue (struct unw_state_record *sr)
746 {
747 struct unw_reg_info *reg;
748 unsigned long off;
749 int i;
750
751 /*
752 * First, resolve implicit register save locations (see Section "11.4.2.3 Rules
753 * for Using Unwind Descriptors", rule 3):
754 */
755 for (i = 0; i < (int) ARRAY_SIZE(unw.save_order); ++i) {
756 reg = sr->curr.reg + unw.save_order[i];
757 if (reg->where == UNW_WHERE_GR_SAVE) {
758 reg->where = UNW_WHERE_GR;
759 reg->val = sr->gr_save_loc++;
760 }
761 }
762
763 /*
764 * Next, compute when the fp, general, and branch registers get
765 * saved. This must come before alloc_spill_area() because
766 * we need to know which registers are spilled to their home
767 * locations.
768 */
769 if (sr->imask) {
770 unsigned char kind, mask = 0, *cp = sr->imask;
771 int t;
772 static const unsigned char limit[3] = {
773 UNW_REG_F31, UNW_REG_R7, UNW_REG_B5
774 };
775 struct unw_reg_info *(regs[3]);
776
777 regs[0] = sr->curr.reg + UNW_REG_F2;
778 regs[1] = sr->curr.reg + UNW_REG_R4;
779 regs[2] = sr->curr.reg + UNW_REG_B1;
780
781 for (t = 0; t < sr->region_len; ++t) {
782 if ((t & 3) == 0)
783 mask = *cp++;
784 kind = (mask >> 2*(3-(t & 3))) & 3;
785 if (kind > 0)
786 spill_next_when(&regs[kind - 1], sr->curr.reg + limit[kind - 1],
787 sr->region_start + t);
788 }
789 }
790 /*
791 * Next, lay out the memory stack spill area:
792 */
793 if (sr->any_spills) {
794 off = sr->spill_offset;
795 alloc_spill_area(&off, 16, sr->curr.reg + UNW_REG_F2, sr->curr.reg + UNW_REG_F31);
796 alloc_spill_area(&off, 8, sr->curr.reg + UNW_REG_B1, sr->curr.reg + UNW_REG_B5);
797 alloc_spill_area(&off, 8, sr->curr.reg + UNW_REG_R4, sr->curr.reg + UNW_REG_R7);
798 }
799 }
800
801 /*
802 * Region header descriptors.
803 */
804
805 static void
806 desc_prologue (int body, unw_word rlen, unsigned char mask, unsigned char grsave,
807 struct unw_state_record *sr)
808 {
809 int i, region_start;
810
811 if (!(sr->in_body || sr->first_region))
812 finish_prologue(sr);
813 sr->first_region = 0;
814
815 /* check if we're done: */
816 if (sr->when_target < sr->region_start + sr->region_len) {
817 sr->done = 1;
818 return;
819 }
820
821 region_start = sr->region_start + sr->region_len;
822
823 for (i = 0; i < sr->epilogue_count; ++i)
824 pop(sr);
825 sr->epilogue_count = 0;
826 sr->epilogue_start = UNW_WHEN_NEVER;
827
828 sr->region_start = region_start;
829 sr->region_len = rlen;
830 sr->in_body = body;
831
832 if (!body) {
833 push(sr);
834
835 for (i = 0; i < 4; ++i) {
836 if (mask & 0x8)
837 set_reg(sr->curr.reg + unw.save_order[i], UNW_WHERE_GR,
838 sr->region_start + sr->region_len - 1, grsave++);
839 mask <<= 1;
840 }
841 sr->gr_save_loc = grsave;
842 sr->any_spills = 0;
843 sr->imask = NULL;
844 sr->spill_offset = 0x10; /* default to psp+16 */
845 }
846 }
847
848 /*
849 * Prologue descriptors.
850 */
851
852 static inline void
853 desc_abi (unsigned char abi, unsigned char context, struct unw_state_record *sr)
854 {
855 if (abi == 3 && context == 'i') {
856 sr->flags |= UNW_FLAG_INTERRUPT_FRAME;
857 UNW_DPRINT(3, "unwind.%s: interrupt frame\n", __func__);
858 }
859 else
860 UNW_DPRINT(0, "unwind%s: ignoring unwabi(abi=0x%x,context=0x%x)\n",
861 __func__, abi, context);
862 }
863
864 static inline void
865 desc_br_gr (unsigned char brmask, unsigned char gr, struct unw_state_record *sr)
866 {
867 int i;
868
869 for (i = 0; i < 5; ++i) {
870 if (brmask & 1)
871 set_reg(sr->curr.reg + UNW_REG_B1 + i, UNW_WHERE_GR,
872 sr->region_start + sr->region_len - 1, gr++);
873 brmask >>= 1;
874 }
875 }
876
877 static inline void
878 desc_br_mem (unsigned char brmask, struct unw_state_record *sr)
879 {
880 int i;
881
882 for (i = 0; i < 5; ++i) {
883 if (brmask & 1) {
884 set_reg(sr->curr.reg + UNW_REG_B1 + i, UNW_WHERE_SPILL_HOME,
885 sr->region_start + sr->region_len - 1, 0);
886 sr->any_spills = 1;
887 }
888 brmask >>= 1;
889 }
890 }
891
892 static inline void
893 desc_frgr_mem (unsigned char grmask, unw_word frmask, struct unw_state_record *sr)
894 {
895 int i;
896
897 for (i = 0; i < 4; ++i) {
898 if ((grmask & 1) != 0) {
899 set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_SPILL_HOME,
900 sr->region_start + sr->region_len - 1, 0);
901 sr->any_spills = 1;
902 }
903 grmask >>= 1;
904 }
905 for (i = 0; i < 20; ++i) {
906 if ((frmask & 1) != 0) {
907 int base = (i < 4) ? UNW_REG_F2 : UNW_REG_F16 - 4;
908 set_reg(sr->curr.reg + base + i, UNW_WHERE_SPILL_HOME,
909 sr->region_start + sr->region_len - 1, 0);
910 sr->any_spills = 1;
911 }
912 frmask >>= 1;
913 }
914 }
915
916 static inline void
917 desc_fr_mem (unsigned char frmask, struct unw_state_record *sr)
918 {
919 int i;
920
921 for (i = 0; i < 4; ++i) {
922 if ((frmask & 1) != 0) {
923 set_reg(sr->curr.reg + UNW_REG_F2 + i, UNW_WHERE_SPILL_HOME,
924 sr->region_start + sr->region_len - 1, 0);
925 sr->any_spills = 1;
926 }
927 frmask >>= 1;
928 }
929 }
930
931 static inline void
932 desc_gr_gr (unsigned char grmask, unsigned char gr, struct unw_state_record *sr)
933 {
934 int i;
935
936 for (i = 0; i < 4; ++i) {
937 if ((grmask & 1) != 0)
938 set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_GR,
939 sr->region_start + sr->region_len - 1, gr++);
940 grmask >>= 1;
941 }
942 }
943
944 static inline void
945 desc_gr_mem (unsigned char grmask, struct unw_state_record *sr)
946 {
947 int i;
948
949 for (i = 0; i < 4; ++i) {
950 if ((grmask & 1) != 0) {
951 set_reg(sr->curr.reg + UNW_REG_R4 + i, UNW_WHERE_SPILL_HOME,
952 sr->region_start + sr->region_len - 1, 0);
953 sr->any_spills = 1;
954 }
955 grmask >>= 1;
956 }
957 }
958
959 static inline void
960 desc_mem_stack_f (unw_word t, unw_word size, struct unw_state_record *sr)
961 {
962 set_reg(sr->curr.reg + UNW_REG_PSP, UNW_WHERE_NONE,
963 sr->region_start + min_t(int, t, sr->region_len - 1), 16*size);
964 }
965
966 static inline void
967 desc_mem_stack_v (unw_word t, struct unw_state_record *sr)
968 {
969 sr->curr.reg[UNW_REG_PSP].when = sr->region_start + min_t(int, t, sr->region_len - 1);
970 }
971
972 static inline void
973 desc_reg_gr (unsigned char reg, unsigned char dst, struct unw_state_record *sr)
974 {
975 set_reg(sr->curr.reg + reg, UNW_WHERE_GR, sr->region_start + sr->region_len - 1, dst);
976 }
977
978 static inline void
979 desc_reg_psprel (unsigned char reg, unw_word pspoff, struct unw_state_record *sr)
980 {
981 set_reg(sr->curr.reg + reg, UNW_WHERE_PSPREL, sr->region_start + sr->region_len - 1,
982 0x10 - 4*pspoff);
983 }
984
985 static inline void
986 desc_reg_sprel (unsigned char reg, unw_word spoff, struct unw_state_record *sr)
987 {
988 set_reg(sr->curr.reg + reg, UNW_WHERE_SPREL, sr->region_start + sr->region_len - 1,
989 4*spoff);
990 }
991
992 static inline void
993 desc_rp_br (unsigned char dst, struct unw_state_record *sr)
994 {
995 sr->return_link_reg = dst;
996 }
997
998 static inline void
999 desc_reg_when (unsigned char regnum, unw_word t, struct unw_state_record *sr)
1000 {
1001 struct unw_reg_info *reg = sr->curr.reg + regnum;
1002
1003 if (reg->where == UNW_WHERE_NONE)
1004 reg->where = UNW_WHERE_GR_SAVE;
1005 reg->when = sr->region_start + min_t(int, t, sr->region_len - 1);
1006 }
1007
1008 static inline void
1009 desc_spill_base (unw_word pspoff, struct unw_state_record *sr)
1010 {
1011 sr->spill_offset = 0x10 - 4*pspoff;
1012 }
1013
1014 static inline unsigned char *
1015 desc_spill_mask (unsigned char *imaskp, struct unw_state_record *sr)
1016 {
1017 sr->imask = imaskp;
1018 return imaskp + (2*sr->region_len + 7)/8;
1019 }
1020
1021 /*
1022 * Body descriptors.
1023 */
1024 static inline void
1025 desc_epilogue (unw_word t, unw_word ecount, struct unw_state_record *sr)
1026 {
1027 sr->epilogue_start = sr->region_start + sr->region_len - 1 - t;
1028 sr->epilogue_count = ecount + 1;
1029 }
1030
1031 static inline void
1032 desc_copy_state (unw_word label, struct unw_state_record *sr)
1033 {
1034 struct unw_labeled_state *ls;
1035
1036 for (ls = sr->labeled_states; ls; ls = ls->next) {
1037 if (ls->label == label) {
1038 free_state_stack(&sr->curr);
1039 memcpy(&sr->curr, &ls->saved_state, sizeof(sr->curr));
1040 sr->curr.next = dup_state_stack(ls->saved_state.next);
1041 return;
1042 }
1043 }
1044 printk(KERN_ERR "unwind: failed to find state labeled 0x%lx\n", label);
1045 }
1046
1047 static inline void
1048 desc_label_state (unw_word label, struct unw_state_record *sr)
1049 {
1050 struct unw_labeled_state *ls;
1051
1052 ls = alloc_labeled_state();
1053 if (!ls) {
1054 printk(KERN_ERR "unwind.desc_label_state(): out of memory\n");
1055 return;
1056 }
1057 ls->label = label;
1058 memcpy(&ls->saved_state, &sr->curr, sizeof(ls->saved_state));
1059 ls->saved_state.next = dup_state_stack(sr->curr.next);
1060
1061 /* insert into list of labeled states: */
1062 ls->next = sr->labeled_states;
1063 sr->labeled_states = ls;
1064 }
1065
1066 /*
1067 * General descriptors.
1068 */
1069
1070 static inline int
1071 desc_is_active (unsigned char qp, unw_word t, struct unw_state_record *sr)
1072 {
1073 if (sr->when_target <= sr->region_start + min_t(int, t, sr->region_len - 1))
1074 return 0;
1075 if (qp > 0) {
1076 if ((sr->pr_val & (1UL << qp)) == 0)
1077 return 0;
1078 sr->pr_mask |= (1UL << qp);
1079 }
1080 return 1;
1081 }
1082
1083 static inline void
1084 desc_restore_p (unsigned char qp, unw_word t, unsigned char abreg, struct unw_state_record *sr)
1085 {
1086 struct unw_reg_info *r;
1087
1088 if (!desc_is_active(qp, t, sr))
1089 return;
1090
1091 r = sr->curr.reg + decode_abreg(abreg, 0);
1092 r->where = UNW_WHERE_NONE;
1093 r->when = UNW_WHEN_NEVER;
1094 r->val = 0;
1095 }
1096
1097 static inline void
1098 desc_spill_reg_p (unsigned char qp, unw_word t, unsigned char abreg, unsigned char x,
1099 unsigned char ytreg, struct unw_state_record *sr)
1100 {
1101 enum unw_where where = UNW_WHERE_GR;
1102 struct unw_reg_info *r;
1103
1104 if (!desc_is_active(qp, t, sr))
1105 return;
1106
1107 if (x)
1108 where = UNW_WHERE_BR;
1109 else if (ytreg & 0x80)
1110 where = UNW_WHERE_FR;
1111
1112 r = sr->curr.reg + decode_abreg(abreg, 0);
1113 r->where = where;
1114 r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
1115 r->val = (ytreg & 0x7f);
1116 }
1117
1118 static inline void
1119 desc_spill_psprel_p (unsigned char qp, unw_word t, unsigned char abreg, unw_word pspoff,
1120 struct unw_state_record *sr)
1121 {
1122 struct unw_reg_info *r;
1123
1124 if (!desc_is_active(qp, t, sr))
1125 return;
1126
1127 r = sr->curr.reg + decode_abreg(abreg, 1);
1128 r->where = UNW_WHERE_PSPREL;
1129 r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
1130 r->val = 0x10 - 4*pspoff;
1131 }
1132
1133 static inline void
1134 desc_spill_sprel_p (unsigned char qp, unw_word t, unsigned char abreg, unw_word spoff,
1135 struct unw_state_record *sr)
1136 {
1137 struct unw_reg_info *r;
1138
1139 if (!desc_is_active(qp, t, sr))
1140 return;
1141
1142 r = sr->curr.reg + decode_abreg(abreg, 1);
1143 r->where = UNW_WHERE_SPREL;
1144 r->when = sr->region_start + min_t(int, t, sr->region_len - 1);
1145 r->val = 4*spoff;
1146 }
1147
1148 #define UNW_DEC_BAD_CODE(code) printk(KERN_ERR "unwind: unknown code 0x%02x\n", \
1149 code);
1150
1151 /*
1152 * region headers:
1153 */
1154 #define UNW_DEC_PROLOGUE_GR(fmt,r,m,gr,arg) desc_prologue(0,r,m,gr,arg)
1155 #define UNW_DEC_PROLOGUE(fmt,b,r,arg) desc_prologue(b,r,0,32,arg)
1156 /*
1157 * prologue descriptors:
1158 */
1159 #define UNW_DEC_ABI(fmt,a,c,arg) desc_abi(a,c,arg)
1160 #define UNW_DEC_BR_GR(fmt,b,g,arg) desc_br_gr(b,g,arg)
1161 #define UNW_DEC_BR_MEM(fmt,b,arg) desc_br_mem(b,arg)
1162 #define UNW_DEC_FRGR_MEM(fmt,g,f,arg) desc_frgr_mem(g,f,arg)
1163 #define UNW_DEC_FR_MEM(fmt,f,arg) desc_fr_mem(f,arg)
1164 #define UNW_DEC_GR_GR(fmt,m,g,arg) desc_gr_gr(m,g,arg)
1165 #define UNW_DEC_GR_MEM(fmt,m,arg) desc_gr_mem(m,arg)
1166 #define UNW_DEC_MEM_STACK_F(fmt,t,s,arg) desc_mem_stack_f(t,s,arg)
1167 #define UNW_DEC_MEM_STACK_V(fmt,t,arg) desc_mem_stack_v(t,arg)
1168 #define UNW_DEC_REG_GR(fmt,r,d,arg) desc_reg_gr(r,d,arg)
1169 #define UNW_DEC_REG_PSPREL(fmt,r,o,arg) desc_reg_psprel(r,o,arg)
1170 #define UNW_DEC_REG_SPREL(fmt,r,o,arg) desc_reg_sprel(r,o,arg)
1171 #define UNW_DEC_REG_WHEN(fmt,r,t,arg) desc_reg_when(r,t,arg)
1172 #define UNW_DEC_PRIUNAT_WHEN_GR(fmt,t,arg) desc_reg_when(UNW_REG_PRI_UNAT_GR,t,arg)
1173 #define UNW_DEC_PRIUNAT_WHEN_MEM(fmt,t,arg) desc_reg_when(UNW_REG_PRI_UNAT_MEM,t,arg)
1174 #define UNW_DEC_PRIUNAT_GR(fmt,r,arg) desc_reg_gr(UNW_REG_PRI_UNAT_GR,r,arg)
1175 #define UNW_DEC_PRIUNAT_PSPREL(fmt,o,arg) desc_reg_psprel(UNW_REG_PRI_UNAT_MEM,o,arg)
1176 #define UNW_DEC_PRIUNAT_SPREL(fmt,o,arg) desc_reg_sprel(UNW_REG_PRI_UNAT_MEM,o,arg)
1177 #define UNW_DEC_RP_BR(fmt,d,arg) desc_rp_br(d,arg)
1178 #define UNW_DEC_SPILL_BASE(fmt,o,arg) desc_spill_base(o,arg)
1179 #define UNW_DEC_SPILL_MASK(fmt,m,arg) (m = desc_spill_mask(m,arg))
1180 /*
1181 * body descriptors:
1182 */
1183 #define UNW_DEC_EPILOGUE(fmt,t,c,arg) desc_epilogue(t,c,arg)
1184 #define UNW_DEC_COPY_STATE(fmt,l,arg) desc_copy_state(l,arg)
1185 #define UNW_DEC_LABEL_STATE(fmt,l,arg) desc_label_state(l,arg)
1186 /*
1187 * general unwind descriptors:
1188 */
1189 #define UNW_DEC_SPILL_REG_P(f,p,t,a,x,y,arg) desc_spill_reg_p(p,t,a,x,y,arg)
1190 #define UNW_DEC_SPILL_REG(f,t,a,x,y,arg) desc_spill_reg_p(0,t,a,x,y,arg)
1191 #define UNW_DEC_SPILL_PSPREL_P(f,p,t,a,o,arg) desc_spill_psprel_p(p,t,a,o,arg)
1192 #define UNW_DEC_SPILL_PSPREL(f,t,a,o,arg) desc_spill_psprel_p(0,t,a,o,arg)
1193 #define UNW_DEC_SPILL_SPREL_P(f,p,t,a,o,arg) desc_spill_sprel_p(p,t,a,o,arg)
1194 #define UNW_DEC_SPILL_SPREL(f,t,a,o,arg) desc_spill_sprel_p(0,t,a,o,arg)
1195 #define UNW_DEC_RESTORE_P(f,p,t,a,arg) desc_restore_p(p,t,a,arg)
1196 #define UNW_DEC_RESTORE(f,t,a,arg) desc_restore_p(0,t,a,arg)
1197
1198 #include "unwind_decoder.c"
1199
1200 \f
1201 /* Unwind scripts. */
1202
1203 static inline unw_hash_index_t
1204 hash (unsigned long ip)
1205 {
1206 /* magic number = ((sqrt(5)-1)/2)*2^64 */
1207 static const unsigned long hashmagic = 0x9e3779b97f4a7c16UL;
1208
1209 return (ip >> 4) * hashmagic >> (64 - UNW_LOG_HASH_SIZE);
1210 }
1211
1212 static inline long
1213 cache_match (struct unw_script *script, unsigned long ip, unsigned long pr)
1214 {
1215 read_lock(&script->lock);
1216 if (ip == script->ip && ((pr ^ script->pr_val) & script->pr_mask) == 0)
1217 /* keep the read lock... */
1218 return 1;
1219 read_unlock(&script->lock);
1220 return 0;
1221 }
1222
1223 static inline struct unw_script *
1224 script_lookup (struct unw_frame_info *info)
1225 {
1226 struct unw_script *script = unw.cache + info->hint;
1227 unsigned short index;
1228 unsigned long ip, pr;
1229
1230 if (UNW_DEBUG_ON(0))
1231 return NULL; /* Always regenerate scripts in debug mode */
1232
1233 STAT(++unw.stat.cache.lookups);
1234
1235 ip = info->ip;
1236 pr = info->pr;
1237
1238 if (cache_match(script, ip, pr)) {
1239 STAT(++unw.stat.cache.hinted_hits);
1240 return script;
1241 }
1242
1243 index = unw.hash[hash(ip)];
1244 if (index >= UNW_CACHE_SIZE)
1245 return NULL;
1246
1247 script = unw.cache + index;
1248 while (1) {
1249 if (cache_match(script, ip, pr)) {
1250 /* update hint; no locking required as single-word writes are atomic */
1251 STAT(++unw.stat.cache.normal_hits);
1252 unw.cache[info->prev_script].hint = script - unw.cache;
1253 return script;
1254 }
1255 if (script->coll_chain >= UNW_HASH_SIZE)
1256 return NULL;
1257 script = unw.cache + script->coll_chain;
1258 STAT(++unw.stat.cache.collision_chain_traversals);
1259 }
1260 }
1261
1262 /*
1263 * On returning, a write lock for the SCRIPT is still being held.
1264 */
1265 static inline struct unw_script *
1266 script_new (unsigned long ip)
1267 {
1268 struct unw_script *script, *prev, *tmp;
1269 unw_hash_index_t index;
1270 unsigned short head;
1271
1272 STAT(++unw.stat.script.news);
1273
1274 /*
1275 * Can't (easily) use cmpxchg() here because of ABA problem
1276 * that is intrinsic in cmpxchg()...
1277 */
1278 head = unw.lru_head;
1279 script = unw.cache + head;
1280 unw.lru_head = script->lru_chain;
1281
1282 /*
1283 * We'd deadlock here if we interrupted a thread that is holding a read lock on
1284 * script->lock. Thus, if the write_trylock() fails, we simply bail out. The
1285 * alternative would be to disable interrupts whenever we hold a read-lock, but
1286 * that seems silly.
1287 */
1288 if (!write_trylock(&script->lock))
1289 return NULL;
1290
1291 /* re-insert script at the tail of the LRU chain: */
1292 unw.cache[unw.lru_tail].lru_chain = head;
1293 unw.lru_tail = head;
1294
1295 /* remove the old script from the hash table (if it's there): */
1296 if (script->ip) {
1297 index = hash(script->ip);
1298 tmp = unw.cache + unw.hash[index];
1299 prev = NULL;
1300 while (1) {
1301 if (tmp == script) {
1302 if (prev)
1303 prev->coll_chain = tmp->coll_chain;
1304 else
1305 unw.hash[index] = tmp->coll_chain;
1306 break;
1307 } else
1308 prev = tmp;
1309 if (tmp->coll_chain >= UNW_CACHE_SIZE)
1310 /* old script wasn't in the hash-table */
1311 break;
1312 tmp = unw.cache + tmp->coll_chain;
1313 }
1314 }
1315
1316 /* enter new script in the hash table */
1317 index = hash(ip);
1318 script->coll_chain = unw.hash[index];
1319 unw.hash[index] = script - unw.cache;
1320
1321 script->ip = ip; /* set new IP while we're holding the locks */
1322
1323 STAT(if (script->coll_chain < UNW_CACHE_SIZE) ++unw.stat.script.collisions);
1324
1325 script->flags = 0;
1326 script->hint = 0;
1327 script->count = 0;
1328 return script;
1329 }
1330
1331 static void
1332 script_finalize (struct unw_script *script, struct unw_state_record *sr)
1333 {
1334 script->pr_mask = sr->pr_mask;
1335 script->pr_val = sr->pr_val;
1336 /*
1337 * We could down-grade our write-lock on script->lock here but
1338 * the rwlock API doesn't offer atomic lock downgrading, so
1339 * we'll just keep the write-lock and release it later when
1340 * we're done using the script.
1341 */
1342 }
1343
1344 static inline void
1345 script_emit (struct unw_script *script, struct unw_insn insn)
1346 {
1347 if (script->count >= UNW_MAX_SCRIPT_LEN) {
1348 UNW_DPRINT(0, "unwind.%s: script exceeds maximum size of %u instructions!\n",
1349 __func__, UNW_MAX_SCRIPT_LEN);
1350 return;
1351 }
1352 script->insn[script->count++] = insn;
1353 }
1354
1355 static inline void
1356 emit_nat_info (struct unw_state_record *sr, int i, struct unw_script *script)
1357 {
1358 struct unw_reg_info *r = sr->curr.reg + i;
1359 enum unw_insn_opcode opc;
1360 struct unw_insn insn;
1361 unsigned long val = 0;
1362
1363 switch (r->where) {
1364 case UNW_WHERE_GR:
1365 if (r->val >= 32) {
1366 /* register got spilled to a stacked register */
1367 opc = UNW_INSN_SETNAT_TYPE;
1368 val = UNW_NAT_REGSTK;
1369 } else
1370 /* register got spilled to a scratch register */
1371 opc = UNW_INSN_SETNAT_MEMSTK;
1372 break;
1373
1374 case UNW_WHERE_FR:
1375 opc = UNW_INSN_SETNAT_TYPE;
1376 val = UNW_NAT_VAL;
1377 break;
1378
1379 case UNW_WHERE_BR:
1380 opc = UNW_INSN_SETNAT_TYPE;
1381 val = UNW_NAT_NONE;
1382 break;
1383
1384 case UNW_WHERE_PSPREL:
1385 case UNW_WHERE_SPREL:
1386 opc = UNW_INSN_SETNAT_MEMSTK;
1387 break;
1388
1389 default:
1390 UNW_DPRINT(0, "unwind.%s: don't know how to emit nat info for where = %u\n",
1391 __func__, r->where);
1392 return;
1393 }
1394 insn.opc = opc;
1395 insn.dst = unw.preg_index[i];
1396 insn.val = val;
1397 script_emit(script, insn);
1398 }
1399
1400 static void
1401 compile_reg (struct unw_state_record *sr, int i, struct unw_script *script)
1402 {
1403 struct unw_reg_info *r = sr->curr.reg + i;
1404 enum unw_insn_opcode opc;
1405 unsigned long val, rval;
1406 struct unw_insn insn;
1407 long need_nat_info;
1408
1409 if (r->where == UNW_WHERE_NONE || r->when >= sr->when_target)
1410 return;
1411
1412 opc = UNW_INSN_MOVE;
1413 val = rval = r->val;
1414 need_nat_info = (i >= UNW_REG_R4 && i <= UNW_REG_R7);
1415
1416 switch (r->where) {
1417 case UNW_WHERE_GR:
1418 if (rval >= 32) {
1419 opc = UNW_INSN_MOVE_STACKED;
1420 val = rval - 32;
1421 } else if (rval >= 4 && rval <= 7) {
1422 if (need_nat_info) {
1423 opc = UNW_INSN_MOVE2;
1424 need_nat_info = 0;
1425 }
1426 val = unw.preg_index[UNW_REG_R4 + (rval - 4)];
1427 } else if (rval == 0) {
1428 opc = UNW_INSN_MOVE_CONST;
1429 val = 0;
1430 } else {
1431 /* register got spilled to a scratch register */
1432 opc = UNW_INSN_MOVE_SCRATCH;
1433 val = pt_regs_off(rval);
1434 }
1435 break;
1436
1437 case UNW_WHERE_FR:
1438 if (rval <= 5)
1439 val = unw.preg_index[UNW_REG_F2 + (rval - 2)];
1440 else if (rval >= 16 && rval <= 31)
1441 val = unw.preg_index[UNW_REG_F16 + (rval - 16)];
1442 else {
1443 opc = UNW_INSN_MOVE_SCRATCH;
1444 if (rval <= 11)
1445 val = offsetof(struct pt_regs, f6) + 16*(rval - 6);
1446 else
1447 UNW_DPRINT(0, "unwind.%s: kernel may not touch f%lu\n",
1448 __func__, rval);
1449 }
1450 break;
1451
1452 case UNW_WHERE_BR:
1453 if (rval >= 1 && rval <= 5)
1454 val = unw.preg_index[UNW_REG_B1 + (rval - 1)];
1455 else {
1456 opc = UNW_INSN_MOVE_SCRATCH;
1457 if (rval == 0)
1458 val = offsetof(struct pt_regs, b0);
1459 else if (rval == 6)
1460 val = offsetof(struct pt_regs, b6);
1461 else
1462 val = offsetof(struct pt_regs, b7);
1463 }
1464 break;
1465
1466 case UNW_WHERE_SPREL:
1467 opc = UNW_INSN_ADD_SP;
1468 break;
1469
1470 case UNW_WHERE_PSPREL:
1471 opc = UNW_INSN_ADD_PSP;
1472 break;
1473
1474 default:
1475 UNW_DPRINT(0, "unwind%s: register %u has unexpected `where' value of %u\n",
1476 __func__, i, r->where);
1477 break;
1478 }
1479 insn.opc = opc;
1480 insn.dst = unw.preg_index[i];
1481 insn.val = val;
1482 script_emit(script, insn);
1483 if (need_nat_info)
1484 emit_nat_info(sr, i, script);
1485
1486 if (i == UNW_REG_PSP) {
1487 /*
1488 * info->psp must contain the _value_ of the previous
1489 * sp, not it's save location. We get this by
1490 * dereferencing the value we just stored in
1491 * info->psp:
1492 */
1493 insn.opc = UNW_INSN_LOAD;
1494 insn.dst = insn.val = unw.preg_index[UNW_REG_PSP];
1495 script_emit(script, insn);
1496 }
1497 }
1498
1499 static inline const struct unw_table_entry *
1500 lookup (struct unw_table *table, unsigned long rel_ip)
1501 {
1502 const struct unw_table_entry *e = NULL;
1503 unsigned long lo, hi, mid;
1504
1505 /* do a binary search for right entry: */
1506 for (lo = 0, hi = table->length; lo < hi; ) {
1507 mid = (lo + hi) / 2;
1508 e = &table->array[mid];
1509 if (rel_ip < e->start_offset)
1510 hi = mid;
1511 else if (rel_ip >= e->end_offset)
1512 lo = mid + 1;
1513 else
1514 break;
1515 }
1516 if (rel_ip < e->start_offset || rel_ip >= e->end_offset)
1517 return NULL;
1518 return e;
1519 }
1520
1521 /*
1522 * Build an unwind script that unwinds from state OLD_STATE to the
1523 * entrypoint of the function that called OLD_STATE.
1524 */
1525 static inline struct unw_script *
1526 build_script (struct unw_frame_info *info)
1527 {
1528 const struct unw_table_entry *e = NULL;
1529 struct unw_script *script = NULL;
1530 struct unw_labeled_state *ls, *next;
1531 unsigned long ip = info->ip;
1532 struct unw_state_record sr;
1533 struct unw_table *table, *prev;
1534 struct unw_reg_info *r;
1535 struct unw_insn insn;
1536 u8 *dp, *desc_end;
1537 u64 hdr;
1538 int i;
1539 STAT(unsigned long start, parse_start;)
1540
1541 STAT(++unw.stat.script.builds; start = ia64_get_itc());
1542
1543 /* build state record */
1544 memset(&sr, 0, sizeof(sr));
1545 for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r)
1546 r->when = UNW_WHEN_NEVER;
1547 sr.pr_val = info->pr;
1548
1549 UNW_DPRINT(3, "unwind.%s: ip 0x%lx\n", __func__, ip);
1550 script = script_new(ip);
1551 if (!script) {
1552 UNW_DPRINT(0, "unwind.%s: failed to create unwind script\n", __func__);
1553 STAT(unw.stat.script.build_time += ia64_get_itc() - start);
1554 return NULL;
1555 }
1556 unw.cache[info->prev_script].hint = script - unw.cache;
1557
1558 /* search the kernels and the modules' unwind tables for IP: */
1559
1560 STAT(parse_start = ia64_get_itc());
1561
1562 prev = NULL;
1563 for (table = unw.tables; table; table = table->next) {
1564 if (ip >= table->start && ip < table->end) {
1565 /*
1566 * Leave the kernel unwind table at the very front,
1567 * lest moving it breaks some assumption elsewhere.
1568 * Otherwise, move the matching table to the second
1569 * position in the list so that traversals can benefit
1570 * from commonality in backtrace paths.
1571 */
1572 if (prev && prev != unw.tables) {
1573 /* unw is safe - we're already spinlocked */
1574 prev->next = table->next;
1575 table->next = unw.tables->next;
1576 unw.tables->next = table;
1577 }
1578 e = lookup(table, ip - table->segment_base);
1579 break;
1580 }
1581 prev = table;
1582 }
1583 if (!e) {
1584 /* no info, return default unwinder (leaf proc, no mem stack, no saved regs) */
1585 UNW_DPRINT(1, "unwind.%s: no unwind info for ip=0x%lx (prev ip=0x%lx)\n",
1586 __func__, ip, unw.cache[info->prev_script].ip);
1587 sr.curr.reg[UNW_REG_RP].where = UNW_WHERE_BR;
1588 sr.curr.reg[UNW_REG_RP].when = -1;
1589 sr.curr.reg[UNW_REG_RP].val = 0;
1590 compile_reg(&sr, UNW_REG_RP, script);
1591 script_finalize(script, &sr);
1592 STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start);
1593 STAT(unw.stat.script.build_time += ia64_get_itc() - start);
1594 return script;
1595 }
1596
1597 sr.when_target = (3*((ip & ~0xfUL) - (table->segment_base + e->start_offset))/16
1598 + (ip & 0xfUL));
1599 hdr = *(u64 *) (table->segment_base + e->info_offset);
1600 dp = (u8 *) (table->segment_base + e->info_offset + 8);
1601 desc_end = dp + 8*UNW_LENGTH(hdr);
1602
1603 while (!sr.done && dp < desc_end)
1604 dp = unw_decode(dp, sr.in_body, &sr);
1605
1606 if (sr.when_target > sr.epilogue_start) {
1607 /*
1608 * sp has been restored and all values on the memory stack below
1609 * psp also have been restored.
1610 */
1611 sr.curr.reg[UNW_REG_PSP].val = 0;
1612 sr.curr.reg[UNW_REG_PSP].where = UNW_WHERE_NONE;
1613 sr.curr.reg[UNW_REG_PSP].when = UNW_WHEN_NEVER;
1614 for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r)
1615 if ((r->where == UNW_WHERE_PSPREL && r->val <= 0x10)
1616 || r->where == UNW_WHERE_SPREL)
1617 {
1618 r->val = 0;
1619 r->where = UNW_WHERE_NONE;
1620 r->when = UNW_WHEN_NEVER;
1621 }
1622 }
1623
1624 script->flags = sr.flags;
1625
1626 /*
1627 * If RP did't get saved, generate entry for the return link
1628 * register.
1629 */
1630 if (sr.curr.reg[UNW_REG_RP].when >= sr.when_target) {
1631 sr.curr.reg[UNW_REG_RP].where = UNW_WHERE_BR;
1632 sr.curr.reg[UNW_REG_RP].when = -1;
1633 sr.curr.reg[UNW_REG_RP].val = sr.return_link_reg;
1634 UNW_DPRINT(1, "unwind.%s: using default for rp at ip=0x%lx where=%d val=0x%lx\n",
1635 __func__, ip, sr.curr.reg[UNW_REG_RP].where,
1636 sr.curr.reg[UNW_REG_RP].val);
1637 }
1638
1639 #ifdef UNW_DEBUG
1640 UNW_DPRINT(1, "unwind.%s: state record for func 0x%lx, t=%u:\n",
1641 __func__, table->segment_base + e->start_offset, sr.when_target);
1642 for (r = sr.curr.reg; r < sr.curr.reg + UNW_NUM_REGS; ++r) {
1643 if (r->where != UNW_WHERE_NONE || r->when != UNW_WHEN_NEVER) {
1644 UNW_DPRINT(1, " %s <- ", unw.preg_name[r - sr.curr.reg]);
1645 switch (r->where) {
1646 case UNW_WHERE_GR: UNW_DPRINT(1, "r%lu", r->val); break;
1647 case UNW_WHERE_FR: UNW_DPRINT(1, "f%lu", r->val); break;
1648 case UNW_WHERE_BR: UNW_DPRINT(1, "b%lu", r->val); break;
1649 case UNW_WHERE_SPREL: UNW_DPRINT(1, "[sp+0x%lx]", r->val); break;
1650 case UNW_WHERE_PSPREL: UNW_DPRINT(1, "[psp+0x%lx]", r->val); break;
1651 case UNW_WHERE_NONE:
1652 UNW_DPRINT(1, "%s+0x%lx", unw.preg_name[r - sr.curr.reg], r->val);
1653 break;
1654
1655 default:
1656 UNW_DPRINT(1, "BADWHERE(%d)", r->where);
1657 break;
1658 }
1659 UNW_DPRINT(1, "\t\t%d\n", r->when);
1660 }
1661 }
1662 #endif
1663
1664 STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start);
1665
1666 /* translate state record into unwinder instructions: */
1667
1668 /*
1669 * First, set psp if we're dealing with a fixed-size frame;
1670 * subsequent instructions may depend on this value.
1671 */
1672 if (sr.when_target > sr.curr.reg[UNW_REG_PSP].when
1673 && (sr.curr.reg[UNW_REG_PSP].where == UNW_WHERE_NONE)
1674 && sr.curr.reg[UNW_REG_PSP].val != 0) {
1675 /* new psp is sp plus frame size */
1676 insn.opc = UNW_INSN_ADD;
1677 insn.dst = offsetof(struct unw_frame_info, psp)/8;
1678 insn.val = sr.curr.reg[UNW_REG_PSP].val; /* frame size */
1679 script_emit(script, insn);
1680 }
1681
1682 /* determine where the primary UNaT is: */
1683 if (sr.when_target < sr.curr.reg[UNW_REG_PRI_UNAT_GR].when)
1684 i = UNW_REG_PRI_UNAT_MEM;
1685 else if (sr.when_target < sr.curr.reg[UNW_REG_PRI_UNAT_MEM].when)
1686 i = UNW_REG_PRI_UNAT_GR;
1687 else if (sr.curr.reg[UNW_REG_PRI_UNAT_MEM].when > sr.curr.reg[UNW_REG_PRI_UNAT_GR].when)
1688 i = UNW_REG_PRI_UNAT_MEM;
1689 else
1690 i = UNW_REG_PRI_UNAT_GR;
1691
1692 compile_reg(&sr, i, script);
1693
1694 for (i = UNW_REG_BSP; i < UNW_NUM_REGS; ++i)
1695 compile_reg(&sr, i, script);
1696
1697 /* free labeled register states & stack: */
1698
1699 STAT(parse_start = ia64_get_itc());
1700 for (ls = sr.labeled_states; ls; ls = next) {
1701 next = ls->next;
1702 free_state_stack(&ls->saved_state);
1703 free_labeled_state(ls);
1704 }
1705 free_state_stack(&sr.curr);
1706 STAT(unw.stat.script.parse_time += ia64_get_itc() - parse_start);
1707
1708 script_finalize(script, &sr);
1709 STAT(unw.stat.script.build_time += ia64_get_itc() - start);
1710 return script;
1711 }
1712
1713 /*
1714 * Apply the unwinding actions represented by OPS and update SR to
1715 * reflect the state that existed upon entry to the function that this
1716 * unwinder represents.
1717 */
1718 static inline void
1719 run_script (struct unw_script *script, struct unw_frame_info *state)
1720 {
1721 struct unw_insn *ip, *limit, next_insn;
1722 unsigned long opc, dst, val, off;
1723 unsigned long *s = (unsigned long *) state;
1724 STAT(unsigned long start;)
1725
1726 STAT(++unw.stat.script.runs; start = ia64_get_itc());
1727 state->flags = script->flags;
1728 ip = script->insn;
1729 limit = script->insn + script->count;
1730 next_insn = *ip;
1731
1732 while (ip++ < limit) {
1733 opc = next_insn.opc;
1734 dst = next_insn.dst;
1735 val = next_insn.val;
1736 next_insn = *ip;
1737
1738 redo:
1739 switch (opc) {
1740 case UNW_INSN_ADD:
1741 s[dst] += val;
1742 break;
1743
1744 case UNW_INSN_MOVE2:
1745 if (!s[val])
1746 goto lazy_init;
1747 s[dst+1] = s[val+1];
1748 s[dst] = s[val];
1749 break;
1750
1751 case UNW_INSN_MOVE:
1752 if (!s[val])
1753 goto lazy_init;
1754 s[dst] = s[val];
1755 break;
1756
1757 case UNW_INSN_MOVE_SCRATCH:
1758 if (state->pt) {
1759 s[dst] = (unsigned long) get_scratch_regs(state) + val;
1760 } else {
1761 s[dst] = 0;
1762 UNW_DPRINT(0, "unwind.%s: no state->pt, dst=%ld, val=%ld\n",
1763 __func__, dst, val);
1764 }
1765 break;
1766
1767 case UNW_INSN_MOVE_CONST:
1768 if (val == 0)
1769 s[dst] = (unsigned long) &unw.r0;
1770 else {
1771 s[dst] = 0;
1772 UNW_DPRINT(0, "unwind.%s: UNW_INSN_MOVE_CONST bad val=%ld\n",
1773 __func__, val);
1774 }
1775 break;
1776
1777
1778 case UNW_INSN_MOVE_STACKED:
1779 s[dst] = (unsigned long) ia64_rse_skip_regs((unsigned long *)state->bsp,
1780 val);
1781 break;
1782
1783 case UNW_INSN_ADD_PSP:
1784 s[dst] = state->psp + val;
1785 break;
1786
1787 case UNW_INSN_ADD_SP:
1788 s[dst] = state->sp + val;
1789 break;
1790
1791 case UNW_INSN_SETNAT_MEMSTK:
1792 if (!state->pri_unat_loc)
1793 state->pri_unat_loc = &state->sw->caller_unat;
1794 /* register off. is a multiple of 8, so the least 3 bits (type) are 0 */
1795 s[dst+1] = ((unsigned long) state->pri_unat_loc - s[dst]) | UNW_NAT_MEMSTK;
1796 break;
1797
1798 case UNW_INSN_SETNAT_TYPE:
1799 s[dst+1] = val;
1800 break;
1801
1802 case UNW_INSN_LOAD:
1803 #ifdef UNW_DEBUG
1804 if ((s[val] & (local_cpu_data->unimpl_va_mask | 0x7)) != 0
1805 || s[val] < TASK_SIZE)
1806 {
1807 UNW_DPRINT(0, "unwind.%s: rejecting bad psp=0x%lx\n",
1808 __func__, s[val]);
1809 break;
1810 }
1811 #endif
1812 s[dst] = *(unsigned long *) s[val];
1813 break;
1814 }
1815 }
1816 STAT(unw.stat.script.run_time += ia64_get_itc() - start);
1817 return;
1818
1819 lazy_init:
1820 off = unw.sw_off[val];
1821 s[val] = (unsigned long) state->sw + off;
1822 if (off >= offsetof(struct switch_stack, r4) && off <= offsetof(struct switch_stack, r7))
1823 /*
1824 * We're initializing a general register: init NaT info, too. Note that
1825 * the offset is a multiple of 8 which gives us the 3 bits needed for
1826 * the type field.
1827 */
1828 s[val+1] = (offsetof(struct switch_stack, ar_unat) - off) | UNW_NAT_MEMSTK;
1829 goto redo;
1830 }
1831
1832 static int
1833 find_save_locs (struct unw_frame_info *info)
1834 {
1835 int have_write_lock = 0;
1836 struct unw_script *scr;
1837 unsigned long flags = 0;
1838
1839 if ((info->ip & (local_cpu_data->unimpl_va_mask | 0xf)) || info->ip < TASK_SIZE) {
1840 /* don't let obviously bad addresses pollute the cache */
1841 /* FIXME: should really be level 0 but it occurs too often. KAO */
1842 UNW_DPRINT(1, "unwind.%s: rejecting bad ip=0x%lx\n", __func__, info->ip);
1843 info->rp_loc = NULL;
1844 return -1;
1845 }
1846
1847 scr = script_lookup(info);
1848 if (!scr) {
1849 spin_lock_irqsave(&unw.lock, flags);
1850 scr = build_script(info);
1851 if (!scr) {
1852 spin_unlock_irqrestore(&unw.lock, flags);
1853 UNW_DPRINT(0,
1854 "unwind.%s: failed to locate/build unwind script for ip %lx\n",
1855 __func__, info->ip);
1856 return -1;
1857 }
1858 have_write_lock = 1;
1859 }
1860 info->hint = scr->hint;
1861 info->prev_script = scr - unw.cache;
1862
1863 run_script(scr, info);
1864
1865 if (have_write_lock) {
1866 write_unlock(&scr->lock);
1867 spin_unlock_irqrestore(&unw.lock, flags);
1868 } else
1869 read_unlock(&scr->lock);
1870 return 0;
1871 }
1872
1873 static int
1874 unw_valid(const struct unw_frame_info *info, unsigned long* p)
1875 {
1876 unsigned long loc = (unsigned long)p;
1877 return (loc >= info->regstk.limit && loc < info->regstk.top) ||
1878 (loc >= info->memstk.top && loc < info->memstk.limit);
1879 }
1880
1881 int
1882 unw_unwind (struct unw_frame_info *info)
1883 {
1884 unsigned long prev_ip, prev_sp, prev_bsp;
1885 unsigned long ip, pr, num_regs;
1886 STAT(unsigned long start, flags;)
1887 int retval;
1888
1889 STAT(local_irq_save(flags); ++unw.stat.api.unwinds; start = ia64_get_itc());
1890
1891 prev_ip = info->ip;
1892 prev_sp = info->sp;
1893 prev_bsp = info->bsp;
1894
1895 /* validate the return IP pointer */
1896 if (!unw_valid(info, info->rp_loc)) {
1897 /* FIXME: should really be level 0 but it occurs too often. KAO */
1898 UNW_DPRINT(1, "unwind.%s: failed to locate return link (ip=0x%lx)!\n",
1899 __func__, info->ip);
1900 STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
1901 return -1;
1902 }
1903 /* restore the ip */
1904 ip = info->ip = *info->rp_loc;
1905 if (ip < GATE_ADDR) {
1906 UNW_DPRINT(2, "unwind.%s: reached user-space (ip=0x%lx)\n", __func__, ip);
1907 STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
1908 return -1;
1909 }
1910
1911 /* validate the previous stack frame pointer */
1912 if (!unw_valid(info, info->pfs_loc)) {
1913 UNW_DPRINT(0, "unwind.%s: failed to locate ar.pfs!\n", __func__);
1914 STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
1915 return -1;
1916 }
1917 /* restore the cfm: */
1918 info->cfm_loc = info->pfs_loc;
1919
1920 /* restore the bsp: */
1921 pr = info->pr;
1922 num_regs = 0;
1923 if ((info->flags & UNW_FLAG_INTERRUPT_FRAME)) {
1924 info->pt = info->sp + 16;
1925 if ((pr & (1UL << PRED_NON_SYSCALL)) != 0)
1926 num_regs = *info->cfm_loc & 0x7f; /* size of frame */
1927 info->pfs_loc =
1928 (unsigned long *) (info->pt + offsetof(struct pt_regs, ar_pfs));
1929 UNW_DPRINT(3, "unwind.%s: interrupt_frame pt 0x%lx\n", __func__, info->pt);
1930 } else
1931 num_regs = (*info->cfm_loc >> 7) & 0x7f; /* size of locals */
1932 info->bsp = (unsigned long) ia64_rse_skip_regs((unsigned long *) info->bsp, -num_regs);
1933 if (info->bsp < info->regstk.limit || info->bsp > info->regstk.top) {
1934 UNW_DPRINT(0, "unwind.%s: bsp (0x%lx) out of range [0x%lx-0x%lx]\n",
1935 __func__, info->bsp, info->regstk.limit, info->regstk.top);
1936 STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
1937 return -1;
1938 }
1939
1940 /* restore the sp: */
1941 info->sp = info->psp;
1942 if (info->sp < info->memstk.top || info->sp > info->memstk.limit) {
1943 UNW_DPRINT(0, "unwind.%s: sp (0x%lx) out of range [0x%lx-0x%lx]\n",
1944 __func__, info->sp, info->memstk.top, info->memstk.limit);
1945 STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
1946 return -1;
1947 }
1948
1949 if (info->ip == prev_ip && info->sp == prev_sp && info->bsp == prev_bsp) {
1950 UNW_DPRINT(0, "unwind.%s: ip, sp, bsp unchanged; stopping here (ip=0x%lx)\n",
1951 __func__, ip);
1952 STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
1953 return -1;
1954 }
1955
1956 /* as we unwind, the saved ar.unat becomes the primary unat: */
1957 info->pri_unat_loc = info->unat_loc;
1958
1959 /* finally, restore the predicates: */
1960 unw_get_pr(info, &info->pr);
1961
1962 retval = find_save_locs(info);
1963 STAT(unw.stat.api.unwind_time += ia64_get_itc() - start; local_irq_restore(flags));
1964 return retval;
1965 }
1966 EXPORT_SYMBOL(unw_unwind);
1967
1968 int
1969 unw_unwind_to_user (struct unw_frame_info *info)
1970 {
1971 unsigned long ip, sp, pr = info->pr;
1972
1973 do {
1974 unw_get_sp(info, &sp);
1975 if ((long)((unsigned long)info->task + IA64_STK_OFFSET - sp)
1976 < IA64_PT_REGS_SIZE) {
1977 UNW_DPRINT(0, "unwind.%s: ran off the top of the kernel stack\n",
1978 __func__);
1979 break;
1980 }
1981 if (unw_is_intr_frame(info) &&
1982 (pr & (1UL << PRED_USER_STACK)))
1983 return 0;
1984 if (unw_get_pr (info, &pr) < 0) {
1985 unw_get_rp(info, &ip);
1986 UNW_DPRINT(0, "unwind.%s: failed to read "
1987 "predicate register (ip=0x%lx)\n",
1988 __func__, ip);
1989 return -1;
1990 }
1991 } while (unw_unwind(info) >= 0);
1992 unw_get_ip(info, &ip);
1993 UNW_DPRINT(0, "unwind.%s: failed to unwind to user-level (ip=0x%lx)\n",
1994 __func__, ip);
1995 return -1;
1996 }
1997 EXPORT_SYMBOL(unw_unwind_to_user);
1998
1999 static void
2000 init_frame_info (struct unw_frame_info *info, struct task_struct *t,
2001 struct switch_stack *sw, unsigned long stktop)
2002 {
2003 unsigned long rbslimit, rbstop, stklimit;
2004 STAT(unsigned long start, flags;)
2005
2006 STAT(local_irq_save(flags); ++unw.stat.api.inits; start = ia64_get_itc());
2007
2008 /*
2009 * Subtle stuff here: we _could_ unwind through the switch_stack frame but we
2010 * don't want to do that because it would be slow as each preserved register would
2011 * have to be processed. Instead, what we do here is zero out the frame info and
2012 * start the unwind process at the function that created the switch_stack frame.
2013 * When a preserved value in switch_stack needs to be accessed, run_script() will
2014 * initialize the appropriate pointer on demand.
2015 */
2016 memset(info, 0, sizeof(*info));
2017
2018 rbslimit = (unsigned long) t + IA64_RBS_OFFSET;
2019 stklimit = (unsigned long) t + IA64_STK_OFFSET;
2020
2021 rbstop = sw->ar_bspstore;
2022 if (rbstop > stklimit || rbstop < rbslimit)
2023 rbstop = rbslimit;
2024
2025 if (stktop <= rbstop)
2026 stktop = rbstop;
2027 if (stktop > stklimit)
2028 stktop = stklimit;
2029
2030 info->regstk.limit = rbslimit;
2031 info->regstk.top = rbstop;
2032 info->memstk.limit = stklimit;
2033 info->memstk.top = stktop;
2034 info->task = t;
2035 info->sw = sw;
2036 info->sp = info->psp = stktop;
2037 info->pr = sw->pr;
2038 UNW_DPRINT(3, "unwind.%s:\n"
2039 " task 0x%lx\n"
2040 " rbs = [0x%lx-0x%lx)\n"
2041 " stk = [0x%lx-0x%lx)\n"
2042 " pr 0x%lx\n"
2043 " sw 0x%lx\n"
2044 " sp 0x%lx\n",
2045 __func__, (unsigned long) t, rbslimit, rbstop, stktop, stklimit,
2046 info->pr, (unsigned long) info->sw, info->sp);
2047 STAT(unw.stat.api.init_time += ia64_get_itc() - start; local_irq_restore(flags));
2048 }
2049
2050 void
2051 unw_init_frame_info (struct unw_frame_info *info, struct task_struct *t, struct switch_stack *sw)
2052 {
2053 unsigned long sol;
2054
2055 init_frame_info(info, t, sw, (unsigned long) (sw + 1) - 16);
2056 info->cfm_loc = &sw->ar_pfs;
2057 sol = (*info->cfm_loc >> 7) & 0x7f;
2058 info->bsp = (unsigned long) ia64_rse_skip_regs((unsigned long *) info->regstk.top, -sol);
2059 info->ip = sw->b0;
2060 UNW_DPRINT(3, "unwind.%s:\n"
2061 " bsp 0x%lx\n"
2062 " sol 0x%lx\n"
2063 " ip 0x%lx\n",
2064 __func__, info->bsp, sol, info->ip);
2065 find_save_locs(info);
2066 }
2067
2068 EXPORT_SYMBOL(unw_init_frame_info);
2069
2070 void
2071 unw_init_from_blocked_task (struct unw_frame_info *info, struct task_struct *t)
2072 {
2073 struct switch_stack *sw = (struct switch_stack *) (t->thread.ksp + 16);
2074
2075 UNW_DPRINT(1, "unwind.%s\n", __func__);
2076 unw_init_frame_info(info, t, sw);
2077 }
2078 EXPORT_SYMBOL(unw_init_from_blocked_task);
2079
2080 static void
2081 init_unwind_table (struct unw_table *table, const char *name, unsigned long segment_base,
2082 unsigned long gp, const void *table_start, const void *table_end)
2083 {
2084 const struct unw_table_entry *start = table_start, *end = table_end;
2085
2086 table->name = name;
2087 table->segment_base = segment_base;
2088 table->gp = gp;
2089 table->start = segment_base + start[0].start_offset;
2090 table->end = segment_base + end[-1].end_offset;
2091 table->array = start;
2092 table->length = end - start;
2093 }
2094
2095 void *
2096 unw_add_unwind_table (const char *name, unsigned long segment_base, unsigned long gp,
2097 const void *table_start, const void *table_end)
2098 {
2099 const struct unw_table_entry *start = table_start, *end = table_end;
2100 struct unw_table *table;
2101 unsigned long flags;
2102
2103 if (end - start <= 0) {
2104 UNW_DPRINT(0, "unwind.%s: ignoring attempt to insert empty unwind table\n",
2105 __func__);
2106 return NULL;
2107 }
2108
2109 table = kmalloc(sizeof(*table), GFP_USER);
2110 if (!table)
2111 return NULL;
2112
2113 init_unwind_table(table, name, segment_base, gp, table_start, table_end);
2114
2115 spin_lock_irqsave(&unw.lock, flags);
2116 {
2117 /* keep kernel unwind table at the front (it's searched most commonly): */
2118 table->next = unw.tables->next;
2119 unw.tables->next = table;
2120 }
2121 spin_unlock_irqrestore(&unw.lock, flags);
2122
2123 return table;
2124 }
2125
2126 void
2127 unw_remove_unwind_table (void *handle)
2128 {
2129 struct unw_table *table, *prev;
2130 struct unw_script *tmp;
2131 unsigned long flags;
2132 long index;
2133
2134 if (!handle) {
2135 UNW_DPRINT(0, "unwind.%s: ignoring attempt to remove non-existent unwind table\n",
2136 __func__);
2137 return;
2138 }
2139
2140 table = handle;
2141 if (table == &unw.kernel_table) {
2142 UNW_DPRINT(0, "unwind.%s: sorry, freeing the kernel's unwind table is a "
2143 "no-can-do!\n", __func__);
2144 return;
2145 }
2146
2147 spin_lock_irqsave(&unw.lock, flags);
2148 {
2149 /* first, delete the table: */
2150
2151 for (prev = (struct unw_table *) &unw.tables; prev; prev = prev->next)
2152 if (prev->next == table)
2153 break;
2154 if (!prev) {
2155 UNW_DPRINT(0, "unwind.%s: failed to find unwind table %p\n",
2156 __func__, (void *) table);
2157 spin_unlock_irqrestore(&unw.lock, flags);
2158 return;
2159 }
2160 prev->next = table->next;
2161 }
2162 spin_unlock_irqrestore(&unw.lock, flags);
2163
2164 /* next, remove hash table entries for this table */
2165
2166 for (index = 0; index < UNW_HASH_SIZE; ++index) {
2167 tmp = unw.cache + unw.hash[index];
2168 if (unw.hash[index] >= UNW_CACHE_SIZE
2169 || tmp->ip < table->start || tmp->ip >= table->end)
2170 continue;
2171
2172 write_lock(&tmp->lock);
2173 {
2174 if (tmp->ip >= table->start && tmp->ip < table->end) {
2175 unw.hash[index] = tmp->coll_chain;
2176 tmp->ip = 0;
2177 }
2178 }
2179 write_unlock(&tmp->lock);
2180 }
2181
2182 kfree(table);
2183 }
2184
2185 static int __init
2186 create_gate_table (void)
2187 {
2188 const struct unw_table_entry *entry, *start, *end;
2189 unsigned long *lp, segbase = GATE_ADDR;
2190 size_t info_size, size;
2191 char *info;
2192 Elf64_Phdr *punw = NULL, *phdr = (Elf64_Phdr *) (GATE_ADDR + GATE_EHDR->e_phoff);
2193 int i;
2194
2195 for (i = 0; i < GATE_EHDR->e_phnum; ++i, ++phdr)
2196 if (phdr->p_type == PT_IA_64_UNWIND) {
2197 punw = phdr;
2198 break;
2199 }
2200
2201 if (!punw) {
2202 printk("%s: failed to find gate DSO's unwind table!\n", __func__);
2203 return 0;
2204 }
2205
2206 start = (const struct unw_table_entry *) punw->p_vaddr;
2207 end = (struct unw_table_entry *) ((char *) start + punw->p_memsz);
2208 size = 0;
2209
2210 unw_add_unwind_table("linux-gate.so", segbase, 0, start, end);
2211
2212 for (entry = start; entry < end; ++entry)
2213 size += 3*8 + 8 + 8*UNW_LENGTH(*(u64 *) (segbase + entry->info_offset));
2214 size += 8; /* reserve space for "end of table" marker */
2215
2216 unw.gate_table = kmalloc(size, GFP_KERNEL);
2217 if (!unw.gate_table) {
2218 unw.gate_table_size = 0;
2219 printk(KERN_ERR "%s: unable to create unwind data for gate page!\n", __func__);
2220 return 0;
2221 }
2222 unw.gate_table_size = size;
2223
2224 lp = unw.gate_table;
2225 info = (char *) unw.gate_table + size;
2226
2227 for (entry = start; entry < end; ++entry, lp += 3) {
2228 info_size = 8 + 8*UNW_LENGTH(*(u64 *) (segbase + entry->info_offset));
2229 info -= info_size;
2230 memcpy(info, (char *) segbase + entry->info_offset, info_size);
2231
2232 lp[0] = segbase + entry->start_offset; /* start */
2233 lp[1] = segbase + entry->end_offset; /* end */
2234 lp[2] = info - (char *) unw.gate_table; /* info */
2235 }
2236 *lp = 0; /* end-of-table marker */
2237 return 0;
2238 }
2239
2240 __initcall(create_gate_table);
2241
2242 void __init
2243 unw_init (void)
2244 {
2245 extern char __gp[];
2246 extern void unw_hash_index_t_is_too_narrow (void);
2247 long i, off;
2248
2249 if (8*sizeof(unw_hash_index_t) < UNW_LOG_HASH_SIZE)
2250 unw_hash_index_t_is_too_narrow();
2251
2252 unw.sw_off[unw.preg_index[UNW_REG_PRI_UNAT_GR]] = SW(CALLER_UNAT);
2253 unw.sw_off[unw.preg_index[UNW_REG_BSPSTORE]] = SW(AR_BSPSTORE);
2254 unw.sw_off[unw.preg_index[UNW_REG_PFS]] = SW(AR_PFS);
2255 unw.sw_off[unw.preg_index[UNW_REG_RP]] = SW(B0);
2256 unw.sw_off[unw.preg_index[UNW_REG_UNAT]] = SW(CALLER_UNAT);
2257 unw.sw_off[unw.preg_index[UNW_REG_PR]] = SW(PR);
2258 unw.sw_off[unw.preg_index[UNW_REG_LC]] = SW(AR_LC);
2259 unw.sw_off[unw.preg_index[UNW_REG_FPSR]] = SW(AR_FPSR);
2260 for (i = UNW_REG_R4, off = SW(R4); i <= UNW_REG_R7; ++i, off += 8)
2261 unw.sw_off[unw.preg_index[i]] = off;
2262 for (i = UNW_REG_B1, off = SW(B1); i <= UNW_REG_B5; ++i, off += 8)
2263 unw.sw_off[unw.preg_index[i]] = off;
2264 for (i = UNW_REG_F2, off = SW(F2); i <= UNW_REG_F5; ++i, off += 16)
2265 unw.sw_off[unw.preg_index[i]] = off;
2266 for (i = UNW_REG_F16, off = SW(F16); i <= UNW_REG_F31; ++i, off += 16)
2267 unw.sw_off[unw.preg_index[i]] = off;
2268
2269 for (i = 0; i < UNW_CACHE_SIZE; ++i) {
2270 if (i > 0)
2271 unw.cache[i].lru_chain = (i - 1);
2272 unw.cache[i].coll_chain = -1;
2273 rwlock_init(&unw.cache[i].lock);
2274 }
2275 unw.lru_head = UNW_CACHE_SIZE - 1;
2276 unw.lru_tail = 0;
2277
2278 init_unwind_table(&unw.kernel_table, "kernel", KERNEL_START, (unsigned long) __gp,
2279 __start_unwind, __end_unwind);
2280 }
2281
2282 /*
2283 * DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED
2284 *
2285 * This system call has been deprecated. The new and improved way to get
2286 * at the kernel's unwind info is via the gate DSO. The address of the
2287 * ELF header for this DSO is passed to user-level via AT_SYSINFO_EHDR.
2288 *
2289 * DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED DEPRECATED
2290 *
2291 * This system call copies the unwind data into the buffer pointed to by BUF and returns
2292 * the size of the unwind data. If BUF_SIZE is smaller than the size of the unwind data
2293 * or if BUF is NULL, nothing is copied, but the system call still returns the size of the
2294 * unwind data.
2295 *
2296 * The first portion of the unwind data contains an unwind table and rest contains the
2297 * associated unwind info (in no particular order). The unwind table consists of a table
2298 * of entries of the form:
2299 *
2300 * u64 start; (64-bit address of start of function)
2301 * u64 end; (64-bit address of start of function)
2302 * u64 info; (BUF-relative offset to unwind info)
2303 *
2304 * The end of the unwind table is indicated by an entry with a START address of zero.
2305 *
2306 * Please see the IA-64 Software Conventions and Runtime Architecture manual for details
2307 * on the format of the unwind info.
2308 *
2309 * ERRORS
2310 * EFAULT BUF points outside your accessible address space.
2311 */
2312 asmlinkage long
2313 sys_getunwind (void __user *buf, size_t buf_size)
2314 {
2315 if (buf && buf_size >= unw.gate_table_size)
2316 if (copy_to_user(buf, unw.gate_table, unw.gate_table_size) != 0)
2317 return -EFAULT;
2318 return unw.gate_table_size;
2319 }
Linux with added FPC-III support