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867e359b CM |
1 | /* |
2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation, version 2. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or | |
11 | * NON INFRINGEMENT. See the GNU General Public License for | |
12 | * more details. | |
13 | */ | |
14 | ||
15 | #include <linux/sched.h> | |
16 | #include <linux/kernel.h> | |
17 | #include <linux/kprobes.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/pfn.h> | |
20 | #include <linux/kallsyms.h> | |
21 | #include <linux/stacktrace.h> | |
22 | #include <linux/uaccess.h> | |
23 | #include <linux/mmzone.h> | |
5f639fdc CM |
24 | #include <linux/dcache.h> |
25 | #include <linux/fs.h> | |
0cc96a74 | 26 | #include <linux/string.h> |
867e359b CM |
27 | #include <asm/backtrace.h> |
28 | #include <asm/page.h> | |
867e359b | 29 | #include <asm/ucontext.h> |
34f2c0ac | 30 | #include <asm/switch_to.h> |
867e359b CM |
31 | #include <asm/sigframe.h> |
32 | #include <asm/stack.h> | |
4a556f4f | 33 | #include <asm/vdso.h> |
867e359b CM |
34 | #include <arch/abi.h> |
35 | #include <arch/interrupts.h> | |
36 | ||
dabe98c9 CM |
37 | #define KBT_ONGOING 0 /* Backtrace still ongoing */ |
38 | #define KBT_DONE 1 /* Backtrace cleanly completed */ | |
39 | #define KBT_RUNNING 2 /* Can't run backtrace on a running task */ | |
40 | #define KBT_LOOP 3 /* Backtrace entered a loop */ | |
867e359b CM |
41 | |
42 | /* Is address on the specified kernel stack? */ | |
93013a0f | 43 | static int in_kernel_stack(struct KBacktraceIterator *kbt, unsigned long sp) |
867e359b CM |
44 | { |
45 | ulong kstack_base = (ulong) kbt->task->stack; | |
46 | if (kstack_base == 0) /* corrupt task pointer; just follow stack... */ | |
47 | return sp >= PAGE_OFFSET && sp < (unsigned long)high_memory; | |
48 | return sp >= kstack_base && sp < kstack_base + THREAD_SIZE; | |
49 | } | |
50 | ||
867e359b | 51 | /* Callback for backtracer; basically a glorified memcpy */ |
93013a0f | 52 | static bool read_memory_func(void *result, unsigned long address, |
867e359b CM |
53 | unsigned int size, void *vkbt) |
54 | { | |
55 | int retval; | |
56 | struct KBacktraceIterator *kbt = (struct KBacktraceIterator *)vkbt; | |
5f639fdc CM |
57 | |
58 | if (address == 0) | |
59 | return 0; | |
3cebbafd | 60 | if (__kernel_text_address(address)) { |
867e359b CM |
61 | /* OK to read kernel code. */ |
62 | } else if (address >= PAGE_OFFSET) { | |
63 | /* We only tolerate kernel-space reads of this task's stack */ | |
64 | if (!in_kernel_stack(kbt, address)) | |
65 | return 0; | |
5f639fdc CM |
66 | } else if (!kbt->is_current) { |
67 | return 0; /* can't read from other user address spaces */ | |
867e359b CM |
68 | } |
69 | pagefault_disable(); | |
0707ad30 CM |
70 | retval = __copy_from_user_inatomic(result, |
71 | (void __user __force *)address, | |
867e359b CM |
72 | size); |
73 | pagefault_enable(); | |
74 | return (retval == 0); | |
75 | } | |
76 | ||
77 | /* Return a pt_regs pointer for a valid fault handler frame */ | |
78 | static struct pt_regs *valid_fault_handler(struct KBacktraceIterator* kbt) | |
79 | { | |
867e359b CM |
80 | const char *fault = NULL; /* happy compiler */ |
81 | char fault_buf[64]; | |
93013a0f | 82 | unsigned long sp = kbt->it.sp; |
867e359b CM |
83 | struct pt_regs *p; |
84 | ||
5f639fdc CM |
85 | if (sp % sizeof(long) != 0) |
86 | return NULL; | |
867e359b CM |
87 | if (!in_kernel_stack(kbt, sp)) |
88 | return NULL; | |
89 | if (!in_kernel_stack(kbt, sp + C_ABI_SAVE_AREA_SIZE + PTREGS_SIZE-1)) | |
90 | return NULL; | |
91 | p = (struct pt_regs *)(sp + C_ABI_SAVE_AREA_SIZE); | |
92 | if (p->faultnum == INT_SWINT_1 || p->faultnum == INT_SWINT_1_SIGRETURN) | |
93 | fault = "syscall"; | |
94 | else { | |
95 | if (kbt->verbose) { /* else we aren't going to use it */ | |
96 | snprintf(fault_buf, sizeof(fault_buf), | |
97 | "interrupt %ld", p->faultnum); | |
98 | fault = fault_buf; | |
99 | } | |
100 | } | |
101 | if (EX1_PL(p->ex1) == KERNEL_PL && | |
3cebbafd | 102 | __kernel_text_address(p->pc) && |
867e359b CM |
103 | in_kernel_stack(kbt, p->sp) && |
104 | p->sp >= sp) { | |
105 | if (kbt->verbose) | |
0707ad30 | 106 | pr_err(" <%s while in kernel mode>\n", fault); |
051168df | 107 | } else if (user_mode(p) && |
3ef23111 | 108 | p->sp < PAGE_OFFSET && p->sp != 0) { |
867e359b | 109 | if (kbt->verbose) |
0707ad30 | 110 | pr_err(" <%s while in user mode>\n", fault); |
9088616f CIK |
111 | } else { |
112 | if (kbt->verbose) | |
113 | pr_err(" (odd fault: pc %#lx, sp %#lx, ex1 %#lx?)\n", | |
114 | p->pc, p->sp, p->ex1); | |
115 | return NULL; | |
867e359b | 116 | } |
9088616f CIK |
117 | if (kbt->profile && ((1ULL << p->faultnum) & QUEUED_INTERRUPTS) != 0) |
118 | return NULL; | |
119 | return p; | |
867e359b CM |
120 | } |
121 | ||
122 | /* Is the pc pointing to a sigreturn trampoline? */ | |
93013a0f | 123 | static int is_sigreturn(unsigned long pc) |
867e359b | 124 | { |
4a556f4f | 125 | return current->mm && (pc == VDSO_SYM(&__vdso_rt_sigreturn)); |
867e359b CM |
126 | } |
127 | ||
128 | /* Return a pt_regs pointer for a valid signal handler frame */ | |
5f639fdc CM |
129 | static struct pt_regs *valid_sigframe(struct KBacktraceIterator* kbt, |
130 | struct rt_sigframe* kframe) | |
867e359b CM |
131 | { |
132 | BacktraceIterator *b = &kbt->it; | |
133 | ||
4a556f4f | 134 | if (is_sigreturn(b->pc) && b->sp < PAGE_OFFSET && |
5f639fdc CM |
135 | b->sp % sizeof(long) == 0) { |
136 | int retval; | |
137 | pagefault_disable(); | |
138 | retval = __copy_from_user_inatomic( | |
139 | kframe, (void __user __force *)b->sp, | |
140 | sizeof(*kframe)); | |
141 | pagefault_enable(); | |
142 | if (retval != 0 || | |
143 | (unsigned int)(kframe->info.si_signo) >= _NSIG) | |
867e359b | 144 | return NULL; |
867e359b | 145 | if (kbt->verbose) { |
0707ad30 | 146 | pr_err(" <received signal %d>\n", |
5f639fdc | 147 | kframe->info.si_signo); |
867e359b | 148 | } |
5f639fdc | 149 | return (struct pt_regs *)&kframe->uc.uc_mcontext; |
867e359b CM |
150 | } |
151 | return NULL; | |
152 | } | |
153 | ||
0707ad30 | 154 | static int KBacktraceIterator_is_sigreturn(struct KBacktraceIterator *kbt) |
867e359b CM |
155 | { |
156 | return is_sigreturn(kbt->it.pc); | |
157 | } | |
158 | ||
159 | static int KBacktraceIterator_restart(struct KBacktraceIterator *kbt) | |
160 | { | |
161 | struct pt_regs *p; | |
5f639fdc | 162 | struct rt_sigframe kframe; |
867e359b CM |
163 | |
164 | p = valid_fault_handler(kbt); | |
165 | if (p == NULL) | |
5f639fdc | 166 | p = valid_sigframe(kbt, &kframe); |
867e359b CM |
167 | if (p == NULL) |
168 | return 0; | |
169 | backtrace_init(&kbt->it, read_memory_func, kbt, | |
170 | p->pc, p->lr, p->sp, p->regs[52]); | |
171 | kbt->new_context = 1; | |
172 | return 1; | |
173 | } | |
174 | ||
175 | /* Find a frame that isn't a sigreturn, if there is one. */ | |
176 | static int KBacktraceIterator_next_item_inclusive( | |
177 | struct KBacktraceIterator *kbt) | |
178 | { | |
179 | for (;;) { | |
180 | do { | |
181 | if (!KBacktraceIterator_is_sigreturn(kbt)) | |
dabe98c9 | 182 | return KBT_ONGOING; |
867e359b CM |
183 | } while (backtrace_next(&kbt->it)); |
184 | ||
185 | if (!KBacktraceIterator_restart(kbt)) | |
dabe98c9 | 186 | return KBT_DONE; |
867e359b CM |
187 | } |
188 | } | |
189 | ||
190 | /* | |
191 | * If the current sp is on a page different than what we recorded | |
192 | * as the top-of-kernel-stack last time we context switched, we have | |
193 | * probably blown the stack, and nothing is going to work out well. | |
194 | * If we can at least get out a warning, that may help the debug, | |
195 | * though we probably won't be able to backtrace into the code that | |
196 | * actually did the recursive damage. | |
197 | */ | |
198 | static void validate_stack(struct pt_regs *regs) | |
199 | { | |
bc1a298f | 200 | int cpu = raw_smp_processor_id(); |
867e359b | 201 | unsigned long ksp0 = get_current_ksp0(); |
35f05976 | 202 | unsigned long ksp0_base = ksp0 & -THREAD_SIZE; |
867e359b CM |
203 | unsigned long sp = stack_pointer; |
204 | ||
205 | if (EX1_PL(regs->ex1) == KERNEL_PL && regs->sp >= ksp0) { | |
35f05976 | 206 | pr_err("WARNING: cpu %d: kernel stack %#lx..%#lx underrun!\n" |
867e359b | 207 | " sp %#lx (%#lx in caller), caller pc %#lx, lr %#lx\n", |
35f05976 | 208 | cpu, ksp0_base, ksp0, sp, regs->sp, regs->pc, regs->lr); |
867e359b CM |
209 | } |
210 | ||
211 | else if (sp < ksp0_base + sizeof(struct thread_info)) { | |
35f05976 | 212 | pr_err("WARNING: cpu %d: kernel stack %#lx..%#lx overrun!\n" |
867e359b | 213 | " sp %#lx (%#lx in caller), caller pc %#lx, lr %#lx\n", |
35f05976 | 214 | cpu, ksp0_base, ksp0, sp, regs->sp, regs->pc, regs->lr); |
867e359b CM |
215 | } |
216 | } | |
217 | ||
218 | void KBacktraceIterator_init(struct KBacktraceIterator *kbt, | |
219 | struct task_struct *t, struct pt_regs *regs) | |
220 | { | |
93013a0f | 221 | unsigned long pc, lr, sp, r52; |
867e359b CM |
222 | int is_current; |
223 | ||
224 | /* | |
225 | * Set up callback information. We grab the kernel stack base | |
5f639fdc | 226 | * so we will allow reads of that address range. |
867e359b | 227 | */ |
5f639fdc | 228 | is_current = (t == NULL || t == current); |
867e359b CM |
229 | kbt->is_current = is_current; |
230 | if (is_current) | |
231 | t = validate_current(); | |
232 | kbt->task = t; | |
867e359b CM |
233 | kbt->verbose = 0; /* override in caller if desired */ |
234 | kbt->profile = 0; /* override in caller if desired */ | |
dabe98c9 | 235 | kbt->end = KBT_ONGOING; |
5f639fdc CM |
236 | kbt->new_context = 1; |
237 | if (is_current) | |
867e359b | 238 | validate_stack(regs); |
867e359b CM |
239 | |
240 | if (regs == NULL) { | |
867e359b CM |
241 | if (is_current || t->state == TASK_RUNNING) { |
242 | /* Can't do this; we need registers */ | |
dabe98c9 | 243 | kbt->end = KBT_RUNNING; |
867e359b CM |
244 | return; |
245 | } | |
0707ad30 | 246 | pc = get_switch_to_pc(); |
867e359b CM |
247 | lr = t->thread.pc; |
248 | sp = t->thread.ksp; | |
249 | r52 = 0; | |
250 | } else { | |
251 | pc = regs->pc; | |
252 | lr = regs->lr; | |
253 | sp = regs->sp; | |
254 | r52 = regs->regs[52]; | |
255 | } | |
256 | ||
257 | backtrace_init(&kbt->it, read_memory_func, kbt, pc, lr, sp, r52); | |
dabe98c9 | 258 | kbt->end = KBacktraceIterator_next_item_inclusive(kbt); |
867e359b CM |
259 | } |
260 | EXPORT_SYMBOL(KBacktraceIterator_init); | |
261 | ||
262 | int KBacktraceIterator_end(struct KBacktraceIterator *kbt) | |
263 | { | |
dabe98c9 | 264 | return kbt->end != KBT_ONGOING; |
867e359b CM |
265 | } |
266 | EXPORT_SYMBOL(KBacktraceIterator_end); | |
267 | ||
268 | void KBacktraceIterator_next(struct KBacktraceIterator *kbt) | |
269 | { | |
93013a0f | 270 | unsigned long old_pc = kbt->it.pc, old_sp = kbt->it.sp; |
867e359b | 271 | kbt->new_context = 0; |
dabe98c9 CM |
272 | if (!backtrace_next(&kbt->it) && !KBacktraceIterator_restart(kbt)) { |
273 | kbt->end = KBT_DONE; | |
274 | return; | |
275 | } | |
276 | kbt->end = KBacktraceIterator_next_item_inclusive(kbt); | |
277 | if (old_pc == kbt->it.pc && old_sp == kbt->it.sp) { | |
278 | /* Trapped in a loop; give up. */ | |
279 | kbt->end = KBT_LOOP; | |
280 | } | |
867e359b CM |
281 | } |
282 | EXPORT_SYMBOL(KBacktraceIterator_next); | |
283 | ||
5f639fdc CM |
284 | static void describe_addr(struct KBacktraceIterator *kbt, |
285 | unsigned long address, | |
286 | int have_mmap_sem, char *buf, size_t bufsize) | |
287 | { | |
288 | struct vm_area_struct *vma; | |
289 | size_t namelen, remaining; | |
290 | unsigned long size, offset, adjust; | |
291 | char *p, *modname; | |
292 | const char *name; | |
293 | int rc; | |
294 | ||
295 | /* | |
296 | * Look one byte back for every caller frame (i.e. those that | |
297 | * aren't a new context) so we look up symbol data for the | |
298 | * call itself, not the following instruction, which may be on | |
299 | * a different line (or in a different function). | |
300 | */ | |
301 | adjust = !kbt->new_context; | |
302 | address -= adjust; | |
303 | ||
304 | if (address >= PAGE_OFFSET) { | |
305 | /* Handle kernel symbols. */ | |
306 | BUG_ON(bufsize < KSYM_NAME_LEN); | |
307 | name = kallsyms_lookup(address, &size, &offset, | |
308 | &modname, buf); | |
309 | if (name == NULL) { | |
310 | buf[0] = '\0'; | |
311 | return; | |
312 | } | |
313 | namelen = strlen(buf); | |
314 | remaining = (bufsize - 1) - namelen; | |
315 | p = buf + namelen; | |
316 | rc = snprintf(p, remaining, "+%#lx/%#lx ", | |
317 | offset + adjust, size); | |
318 | if (modname && rc < remaining) | |
319 | snprintf(p + rc, remaining - rc, "[%s] ", modname); | |
320 | buf[bufsize-1] = '\0'; | |
321 | return; | |
322 | } | |
323 | ||
324 | /* If we don't have the mmap_sem, we can't show any more info. */ | |
325 | buf[0] = '\0'; | |
326 | if (!have_mmap_sem) | |
327 | return; | |
328 | ||
329 | /* Find vma info. */ | |
330 | vma = find_vma(kbt->task->mm, address); | |
331 | if (vma == NULL || address < vma->vm_start) { | |
332 | snprintf(buf, bufsize, "[unmapped address] "); | |
333 | return; | |
334 | } | |
335 | ||
336 | if (vma->vm_file) { | |
9bf39ab2 | 337 | p = file_path(vma->vm_file, buf, bufsize); |
5f639fdc CM |
338 | if (IS_ERR(p)) |
339 | p = "?"; | |
0cc96a74 | 340 | name = kbasename(p); |
5f639fdc | 341 | } else { |
0cc96a74 | 342 | name = "anon"; |
5f639fdc CM |
343 | } |
344 | ||
345 | /* Generate a string description of the vma info. */ | |
0cc96a74 | 346 | namelen = strlen(name); |
5f639fdc | 347 | remaining = (bufsize - 1) - namelen; |
0cc96a74 | 348 | memmove(buf, name, namelen); |
5f639fdc CM |
349 | snprintf(buf + namelen, remaining, "[%lx+%lx] ", |
350 | vma->vm_start, vma->vm_end - vma->vm_start); | |
351 | } | |
352 | ||
3ef23111 CM |
353 | /* |
354 | * Avoid possible crash recursion during backtrace. If it happens, it | |
355 | * makes it easy to lose the actual root cause of the failure, so we | |
356 | * put a simple guard on all the backtrace loops. | |
357 | */ | |
358 | static bool start_backtrace(void) | |
359 | { | |
360 | if (current->thread.in_backtrace) { | |
361 | pr_err("Backtrace requested while in backtrace!\n"); | |
362 | return false; | |
363 | } | |
364 | current->thread.in_backtrace = true; | |
365 | return true; | |
366 | } | |
367 | ||
368 | static void end_backtrace(void) | |
369 | { | |
370 | current->thread.in_backtrace = false; | |
371 | } | |
372 | ||
867e359b CM |
373 | /* |
374 | * This method wraps the backtracer's more generic support. | |
375 | * It is only invoked from the architecture-specific code; show_stack() | |
376 | * and dump_stack() (in entry.S) are architecture-independent entry points. | |
377 | */ | |
378 | void tile_show_stack(struct KBacktraceIterator *kbt, int headers) | |
379 | { | |
380 | int i; | |
5f639fdc | 381 | int have_mmap_sem = 0; |
867e359b | 382 | |
3ef23111 CM |
383 | if (!start_backtrace()) |
384 | return; | |
867e359b CM |
385 | if (headers) { |
386 | /* | |
387 | * Add a blank line since if we are called from panic(), | |
388 | * then bust_spinlocks() spit out a space in front of us | |
389 | * and it will mess up our KERN_ERR. | |
390 | */ | |
f4743673 | 391 | pr_err("Starting stack dump of tid %d, pid %d (%s) on cpu %d at cycle %lld\n", |
867e359b | 392 | kbt->task->pid, kbt->task->tgid, kbt->task->comm, |
bc1a298f | 393 | raw_smp_processor_id(), get_cycles()); |
867e359b | 394 | } |
867e359b CM |
395 | kbt->verbose = 1; |
396 | i = 0; | |
397 | for (; !KBacktraceIterator_end(kbt); KBacktraceIterator_next(kbt)) { | |
867e359b | 398 | char namebuf[KSYM_NAME_LEN+100]; |
5f639fdc | 399 | unsigned long address = kbt->it.pc; |
867e359b | 400 | |
5f639fdc CM |
401 | /* Try to acquire the mmap_sem as we pass into userspace. */ |
402 | if (address < PAGE_OFFSET && !have_mmap_sem && kbt->task->mm) | |
403 | have_mmap_sem = | |
404 | down_read_trylock(&kbt->task->mm->mmap_sem); | |
405 | ||
406 | describe_addr(kbt, address, have_mmap_sem, | |
407 | namebuf, sizeof(namebuf)); | |
867e359b | 408 | |
0707ad30 | 409 | pr_err(" frame %d: 0x%lx %s(sp 0x%lx)\n", |
867e359b CM |
410 | i++, address, namebuf, (unsigned long)(kbt->it.sp)); |
411 | ||
412 | if (i >= 100) { | |
f4743673 | 413 | pr_err("Stack dump truncated (%d frames)\n", i); |
867e359b CM |
414 | break; |
415 | } | |
416 | } | |
dabe98c9 CM |
417 | if (kbt->end == KBT_LOOP) |
418 | pr_err("Stack dump stopped; next frame identical to this one\n"); | |
867e359b | 419 | if (headers) |
0707ad30 | 420 | pr_err("Stack dump complete\n"); |
5f639fdc CM |
421 | if (have_mmap_sem) |
422 | up_read(&kbt->task->mm->mmap_sem); | |
3ef23111 | 423 | end_backtrace(); |
867e359b CM |
424 | } |
425 | EXPORT_SYMBOL(tile_show_stack); | |
426 | ||
427 | ||
428 | /* This is called from show_regs() and _dump_stack() */ | |
429 | void dump_stack_regs(struct pt_regs *regs) | |
430 | { | |
431 | struct KBacktraceIterator kbt; | |
432 | KBacktraceIterator_init(&kbt, NULL, regs); | |
433 | tile_show_stack(&kbt, 1); | |
434 | } | |
435 | EXPORT_SYMBOL(dump_stack_regs); | |
436 | ||
437 | static struct pt_regs *regs_to_pt_regs(struct pt_regs *regs, | |
438 | ulong pc, ulong lr, ulong sp, ulong r52) | |
439 | { | |
440 | memset(regs, 0, sizeof(struct pt_regs)); | |
441 | regs->pc = pc; | |
442 | regs->lr = lr; | |
443 | regs->sp = sp; | |
444 | regs->regs[52] = r52; | |
445 | return regs; | |
446 | } | |
447 | ||
448 | /* This is called from dump_stack() and just converts to pt_regs */ | |
449 | void _dump_stack(int dummy, ulong pc, ulong lr, ulong sp, ulong r52) | |
450 | { | |
451 | struct pt_regs regs; | |
452 | dump_stack_regs(regs_to_pt_regs(®s, pc, lr, sp, r52)); | |
453 | } | |
454 | ||
455 | /* This is called from KBacktraceIterator_init_current() */ | |
456 | void _KBacktraceIterator_init_current(struct KBacktraceIterator *kbt, ulong pc, | |
457 | ulong lr, ulong sp, ulong r52) | |
458 | { | |
459 | struct pt_regs regs; | |
460 | KBacktraceIterator_init(kbt, NULL, | |
461 | regs_to_pt_regs(®s, pc, lr, sp, r52)); | |
462 | } | |
463 | ||
0a0fca9d | 464 | /* This is called only from kernel/sched/core.c, with esp == NULL */ |
867e359b CM |
465 | void show_stack(struct task_struct *task, unsigned long *esp) |
466 | { | |
467 | struct KBacktraceIterator kbt; | |
468 | if (task == NULL || task == current) | |
469 | KBacktraceIterator_init_current(&kbt); | |
470 | else | |
471 | KBacktraceIterator_init(&kbt, task, NULL); | |
472 | tile_show_stack(&kbt, 0); | |
473 | } | |
474 | ||
475 | #ifdef CONFIG_STACKTRACE | |
476 | ||
477 | /* Support generic Linux stack API too */ | |
478 | ||
479 | void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace) | |
480 | { | |
481 | struct KBacktraceIterator kbt; | |
482 | int skip = trace->skip; | |
483 | int i = 0; | |
484 | ||
3ef23111 CM |
485 | if (!start_backtrace()) |
486 | goto done; | |
867e359b CM |
487 | if (task == NULL || task == current) |
488 | KBacktraceIterator_init_current(&kbt); | |
489 | else | |
490 | KBacktraceIterator_init(&kbt, task, NULL); | |
491 | for (; !KBacktraceIterator_end(&kbt); KBacktraceIterator_next(&kbt)) { | |
492 | if (skip) { | |
493 | --skip; | |
494 | continue; | |
495 | } | |
496 | if (i >= trace->max_entries || kbt.it.pc < PAGE_OFFSET) | |
497 | break; | |
498 | trace->entries[i++] = kbt.it.pc; | |
499 | } | |
3ef23111 CM |
500 | end_backtrace(); |
501 | done: | |
867e359b CM |
502 | trace->nr_entries = i; |
503 | } | |
504 | EXPORT_SYMBOL(save_stack_trace_tsk); | |
505 | ||
506 | void save_stack_trace(struct stack_trace *trace) | |
507 | { | |
508 | save_stack_trace_tsk(NULL, trace); | |
509 | } | |
7c63e1ee | 510 | EXPORT_SYMBOL_GPL(save_stack_trace); |
867e359b CM |
511 | |
512 | #endif | |
513 | ||
514 | /* In entry.S */ | |
515 | EXPORT_SYMBOL(KBacktraceIterator_init_current); |