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12#include <linux/mm.h>
13#include <linux/proc_fs.h>
14#include <linux/user.h>
15#include <linux/capability.h>
16#include <linux/elf.h>
17#include <linux/elfcore.h>
18#include <linux/vmalloc.h>
19#include <linux/highmem.h>
20#include <linux/bootmem.h>
21#include <linux/init.h>
22#include <asm/uaccess.h>
23#include <asm/io.h>
24#include <linux/list.h>
25#include <linux/ioport.h>
26#include <linux/memory.h>
27#include <asm/sections.h>
28
29#define CORE_STR "CORE"
30
31#ifndef ELF_CORE_EFLAGS
32#define ELF_CORE_EFLAGS 0
33#endif
34
35static struct proc_dir_entry *proc_root_kcore;
36
37
38#ifndef kc_vaddr_to_offset
39#define kc_vaddr_to_offset(v) ((v) - PAGE_OFFSET)
40#endif
41#ifndef kc_offset_to_vaddr
42#define kc_offset_to_vaddr(o) ((o) + PAGE_OFFSET)
43#endif
44
45
46struct memelfnote
47{
48 const char *name;
49 int type;
50 unsigned int datasz;
51 void *data;
52};
53
54static LIST_HEAD(kclist_head);
55static DEFINE_RWLOCK(kclist_lock);
56static int kcore_need_update = 1;
57
58void
59kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
60{
61 new->addr = (unsigned long)addr;
62 new->size = size;
63 new->type = type;
64
65 write_lock(&kclist_lock);
66 list_add_tail(&new->list, &kclist_head);
67 write_unlock(&kclist_lock);
68}
69
70static size_t get_kcore_size(int *nphdr, size_t *elf_buflen)
71{
72 size_t try, size;
73 struct kcore_list *m;
74
75 *nphdr = 1;
76 size = 0;
77
78 list_for_each_entry(m, &kclist_head, list) {
79 try = kc_vaddr_to_offset((size_t)m->addr + m->size);
80 if (try > size)
81 size = try;
82 *nphdr = *nphdr + 1;
83 }
84 *elf_buflen = sizeof(struct elfhdr) +
85 (*nphdr + 2)*sizeof(struct elf_phdr) +
86 3 * ((sizeof(struct elf_note)) +
87 roundup(sizeof(CORE_STR), 4)) +
88 roundup(sizeof(struct elf_prstatus), 4) +
89 roundup(sizeof(struct elf_prpsinfo), 4) +
90 roundup(sizeof(struct task_struct), 4);
91 *elf_buflen = PAGE_ALIGN(*elf_buflen);
92 return size + *elf_buflen;
93}
94
95static void free_kclist_ents(struct list_head *head)
96{
97 struct kcore_list *tmp, *pos;
98
99 list_for_each_entry_safe(pos, tmp, head, list) {
100 list_del(&pos->list);
101 kfree(pos);
102 }
103}
104
105
106
107static void __kcore_update_ram(struct list_head *list)
108{
109 int nphdr;
110 size_t size;
111 struct kcore_list *tmp, *pos;
112 LIST_HEAD(garbage);
113
114 write_lock(&kclist_lock);
115 if (kcore_need_update) {
116 list_for_each_entry_safe(pos, tmp, &kclist_head, list) {
117 if (pos->type == KCORE_RAM
118 || pos->type == KCORE_VMEMMAP)
119 list_move(&pos->list, &garbage);
120 }
121 list_splice_tail(list, &kclist_head);
122 } else
123 list_splice(list, &garbage);
124 kcore_need_update = 0;
125 proc_root_kcore->size = get_kcore_size(&nphdr, &size);
126 write_unlock(&kclist_lock);
127
128 free_kclist_ents(&garbage);
129}
130
131
132#ifdef CONFIG_HIGHMEM
133
134
135
136
137
138static int kcore_update_ram(void)
139{
140 LIST_HEAD(head);
141 struct kcore_list *ent;
142 int ret = 0;
143
144 ent = kmalloc(sizeof(*ent), GFP_KERNEL);
145 if (!ent)
146 return -ENOMEM;
147 ent->addr = (unsigned long)__va(0);
148 ent->size = max_low_pfn << PAGE_SHIFT;
149 ent->type = KCORE_RAM;
150 list_add(&ent->list, &head);
151 __kcore_update_ram(&head);
152 return ret;
153}
154
155#else
156
157#ifdef CONFIG_SPARSEMEM_VMEMMAP
158
159int get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)
160{
161 unsigned long pfn = __pa(ent->addr) >> PAGE_SHIFT;
162 unsigned long nr_pages = ent->size >> PAGE_SHIFT;
163 unsigned long start, end;
164 struct kcore_list *vmm, *tmp;
165
166
167 start = ((unsigned long)pfn_to_page(pfn)) & PAGE_MASK;
168 end = ((unsigned long)pfn_to_page(pfn + nr_pages)) - 1;
169 end = ALIGN(end, PAGE_SIZE);
170
171 list_for_each_entry(tmp, head, list) {
172 if (tmp->type != KCORE_VMEMMAP)
173 continue;
174 if (start < tmp->addr + tmp->size)
175 if (end > tmp->addr)
176 end = tmp->addr;
177 }
178 if (start < end) {
179 vmm = kmalloc(sizeof(*vmm), GFP_KERNEL);
180 if (!vmm)
181 return 0;
182 vmm->addr = start;
183 vmm->size = end - start;
184 vmm->type = KCORE_VMEMMAP;
185 list_add_tail(&vmm->list, head);
186 }
187 return 1;
188
189}
190#else
191int get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)
192{
193 return 1;
194}
195
196#endif
197
198static int
199kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)
200{
201 struct list_head *head = (struct list_head *)arg;
202 struct kcore_list *ent;
203
204 ent = kmalloc(sizeof(*ent), GFP_KERNEL);
205 if (!ent)
206 return -ENOMEM;
207 ent->addr = (unsigned long)__va((pfn << PAGE_SHIFT));
208 ent->size = nr_pages << PAGE_SHIFT;
209
210
211 if (ent->addr < (unsigned long) __va(0))
212 goto free_out;
213
214
215 if (ULONG_MAX - ent->addr < ent->size)
216 ent->size = ULONG_MAX - ent->addr;
217
218
219 if (VMALLOC_START > (unsigned long)__va(0)) {
220 if (ent->addr > VMALLOC_START)
221 goto free_out;
222 if (VMALLOC_START - ent->addr < ent->size)
223 ent->size = VMALLOC_START - ent->addr;
224 }
225
226 ent->type = KCORE_RAM;
227 list_add_tail(&ent->list, head);
228
229 if (!get_sparsemem_vmemmap_info(ent, head)) {
230 list_del(&ent->list);
231 goto free_out;
232 }
233
234 return 0;
235free_out:
236 kfree(ent);
237 return 1;
238}
239
240static int kcore_update_ram(void)
241{
242 int nid, ret;
243 unsigned long end_pfn;
244 LIST_HEAD(head);
245
246
247
248 end_pfn = 0;
249 for_each_node_state(nid, N_HIGH_MEMORY) {
250 unsigned long node_end;
251 node_end = NODE_DATA(nid)->node_start_pfn +
252 NODE_DATA(nid)->node_spanned_pages;
253 if (end_pfn < node_end)
254 end_pfn = node_end;
255 }
256
257 ret = walk_system_ram_range(0, end_pfn, &head, kclist_add_private);
258 if (ret) {
259 free_kclist_ents(&head);
260 return -ENOMEM;
261 }
262 __kcore_update_ram(&head);
263 return ret;
264}
265#endif
266
267
268
269
270
271static int notesize(struct memelfnote *en)
272{
273 int sz;
274
275 sz = sizeof(struct elf_note);
276 sz += roundup((strlen(en->name) + 1), 4);
277 sz += roundup(en->datasz, 4);
278
279 return sz;
280}
281
282
283
284
285
286static char *storenote(struct memelfnote *men, char *bufp)
287{
288 struct elf_note en;
289
290#define DUMP_WRITE(addr,nr) do { memcpy(bufp,addr,nr); bufp += nr; } while(0)
291
292 en.n_namesz = strlen(men->name) + 1;
293 en.n_descsz = men->datasz;
294 en.n_type = men->type;
295
296 DUMP_WRITE(&en, sizeof(en));
297 DUMP_WRITE(men->name, en.n_namesz);
298
299
300 bufp = (char*) roundup((unsigned long)bufp,4);
301 DUMP_WRITE(men->data, men->datasz);
302 bufp = (char*) roundup((unsigned long)bufp,4);
303
304#undef DUMP_WRITE
305
306 return bufp;
307}
308
309
310
311
312
313static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff)
314{
315 struct elf_prstatus prstatus;
316 struct elf_prpsinfo prpsinfo;
317 struct elf_phdr *nhdr, *phdr;
318 struct elfhdr *elf;
319 struct memelfnote notes[3];
320 off_t offset = 0;
321 struct kcore_list *m;
322
323
324 elf = (struct elfhdr *) bufp;
325 bufp += sizeof(struct elfhdr);
326 offset += sizeof(struct elfhdr);
327 memcpy(elf->e_ident, ELFMAG, SELFMAG);
328 elf->e_ident[EI_CLASS] = ELF_CLASS;
329 elf->e_ident[EI_DATA] = ELF_DATA;
330 elf->e_ident[EI_VERSION]= EV_CURRENT;
331 elf->e_ident[EI_OSABI] = ELF_OSABI;
332 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
333 elf->e_type = ET_CORE;
334 elf->e_machine = ELF_ARCH;
335 elf->e_version = EV_CURRENT;
336 elf->e_entry = 0;
337 elf->e_phoff = sizeof(struct elfhdr);
338 elf->e_shoff = 0;
339 elf->e_flags = ELF_CORE_EFLAGS;
340 elf->e_ehsize = sizeof(struct elfhdr);
341 elf->e_phentsize= sizeof(struct elf_phdr);
342 elf->e_phnum = nphdr;
343 elf->e_shentsize= 0;
344 elf->e_shnum = 0;
345 elf->e_shstrndx = 0;
346
347
348 nhdr = (struct elf_phdr *) bufp;
349 bufp += sizeof(struct elf_phdr);
350 offset += sizeof(struct elf_phdr);
351 nhdr->p_type = PT_NOTE;
352 nhdr->p_offset = 0;
353 nhdr->p_vaddr = 0;
354 nhdr->p_paddr = 0;
355 nhdr->p_filesz = 0;
356 nhdr->p_memsz = 0;
357 nhdr->p_flags = 0;
358 nhdr->p_align = 0;
359
360
361 list_for_each_entry(m, &kclist_head, list) {
362 phdr = (struct elf_phdr *) bufp;
363 bufp += sizeof(struct elf_phdr);
364 offset += sizeof(struct elf_phdr);
365
366 phdr->p_type = PT_LOAD;
367 phdr->p_flags = PF_R|PF_W|PF_X;
368 phdr->p_offset = kc_vaddr_to_offset(m->addr) + dataoff;
369 phdr->p_vaddr = (size_t)m->addr;
370 phdr->p_paddr = 0;
371 phdr->p_filesz = phdr->p_memsz = m->size;
372 phdr->p_align = PAGE_SIZE;
373 }
374
375
376
377
378
379 nhdr->p_offset = offset;
380
381
382 notes[0].name = CORE_STR;
383 notes[0].type = NT_PRSTATUS;
384 notes[0].datasz = sizeof(struct elf_prstatus);
385 notes[0].data = &prstatus;
386
387 memset(&prstatus, 0, sizeof(struct elf_prstatus));
388
389 nhdr->p_filesz = notesize(¬es[0]);
390 bufp = storenote(¬es[0], bufp);
391
392
393 notes[1].name = CORE_STR;
394 notes[1].type = NT_PRPSINFO;
395 notes[1].datasz = sizeof(struct elf_prpsinfo);
396 notes[1].data = &prpsinfo;
397
398 memset(&prpsinfo, 0, sizeof(struct elf_prpsinfo));
399 prpsinfo.pr_state = 0;
400 prpsinfo.pr_sname = 'R';
401 prpsinfo.pr_zomb = 0;
402
403 strcpy(prpsinfo.pr_fname, "vmlinux");
404 strncpy(prpsinfo.pr_psargs, saved_command_line, ELF_PRARGSZ);
405
406 nhdr->p_filesz += notesize(¬es[1]);
407 bufp = storenote(¬es[1], bufp);
408
409
410 notes[2].name = CORE_STR;
411 notes[2].type = NT_TASKSTRUCT;
412 notes[2].datasz = sizeof(struct task_struct);
413 notes[2].data = current;
414
415 nhdr->p_filesz += notesize(¬es[2]);
416 bufp = storenote(¬es[2], bufp);
417
418}
419
420
421
422
423
424static ssize_t
425read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
426{
427 ssize_t acc = 0;
428 size_t size, tsz;
429 size_t elf_buflen;
430 int nphdr;
431 unsigned long start;
432
433 read_lock(&kclist_lock);
434 size = get_kcore_size(&nphdr, &elf_buflen);
435
436 if (buflen == 0 || *fpos >= size) {
437 read_unlock(&kclist_lock);
438 return 0;
439 }
440
441
442 if (buflen > size - *fpos)
443 buflen = size - *fpos;
444
445
446 if (*fpos < elf_buflen) {
447 char * elf_buf;
448
449 tsz = elf_buflen - *fpos;
450 if (buflen < tsz)
451 tsz = buflen;
452 elf_buf = kzalloc(elf_buflen, GFP_ATOMIC);
453 if (!elf_buf) {
454 read_unlock(&kclist_lock);
455 return -ENOMEM;
456 }
457 elf_kcore_store_hdr(elf_buf, nphdr, elf_buflen);
458 read_unlock(&kclist_lock);
459 if (copy_to_user(buffer, elf_buf + *fpos, tsz)) {
460 kfree(elf_buf);
461 return -EFAULT;
462 }
463 kfree(elf_buf);
464 buflen -= tsz;
465 *fpos += tsz;
466 buffer += tsz;
467 acc += tsz;
468
469
470 if (buflen == 0)
471 return acc;
472 } else
473 read_unlock(&kclist_lock);
474
475
476
477
478
479 start = kc_offset_to_vaddr(*fpos - elf_buflen);
480 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
481 tsz = buflen;
482
483 while (buflen) {
484 struct kcore_list *m;
485
486 read_lock(&kclist_lock);
487 list_for_each_entry(m, &kclist_head, list) {
488 if (start >= m->addr && start < (m->addr+m->size))
489 break;
490 }
491 read_unlock(&kclist_lock);
492
493 if (m == NULL) {
494 if (clear_user(buffer, tsz))
495 return -EFAULT;
496 } else if (is_vmalloc_or_module_addr((void *)start)) {
497 char * elf_buf;
498
499 elf_buf = kzalloc(tsz, GFP_KERNEL);
500 if (!elf_buf)
501 return -ENOMEM;
502 vread(elf_buf, (char *)start, tsz);
503
504 if (copy_to_user(buffer, elf_buf, tsz)) {
505 kfree(elf_buf);
506 return -EFAULT;
507 }
508 kfree(elf_buf);
509 } else {
510 if (kern_addr_valid(start)) {
511 unsigned long n;
512
513 n = copy_to_user(buffer, (char *)start, tsz);
514
515
516
517
518
519
520 if (n) {
521 if (clear_user(buffer + tsz - n,
522 n))
523 return -EFAULT;
524 }
525 } else {
526 if (clear_user(buffer, tsz))
527 return -EFAULT;
528 }
529 }
530 buflen -= tsz;
531 *fpos += tsz;
532 buffer += tsz;
533 acc += tsz;
534 start += tsz;
535 tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen);
536 }
537
538 return acc;
539}
540
541
542static int open_kcore(struct inode *inode, struct file *filp)
543{
544 if (!capable(CAP_SYS_RAWIO))
545 return -EPERM;
546 if (kcore_need_update)
547 kcore_update_ram();
548 if (i_size_read(inode) != proc_root_kcore->size) {
549 mutex_lock(&inode->i_mutex);
550 i_size_write(inode, proc_root_kcore->size);
551 mutex_unlock(&inode->i_mutex);
552 }
553 return 0;
554}
555
556
557static const struct file_operations proc_kcore_operations = {
558 .read = read_kcore,
559 .open = open_kcore,
560};
561
562#ifdef CONFIG_MEMORY_HOTPLUG
563
564static int __meminit kcore_callback(struct notifier_block *self,
565 unsigned long action, void *arg)
566{
567 switch (action) {
568 case MEM_ONLINE:
569 case MEM_OFFLINE:
570 write_lock(&kclist_lock);
571 kcore_need_update = 1;
572 write_unlock(&kclist_lock);
573 }
574 return NOTIFY_OK;
575}
576#endif
577
578
579static struct kcore_list kcore_vmalloc;
580
581#ifdef CONFIG_ARCH_PROC_KCORE_TEXT
582static struct kcore_list kcore_text;
583
584
585
586
587static void __init proc_kcore_text_init(void)
588{
589 kclist_add(&kcore_text, _stext, _end - _stext, KCORE_TEXT);
590}
591#else
592static void __init proc_kcore_text_init(void)
593{
594}
595#endif
596
597#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
598
599
600
601struct kcore_list kcore_modules;
602static void __init add_modules_range(void)
603{
604 kclist_add(&kcore_modules, (void *)MODULES_VADDR,
605 MODULES_END - MODULES_VADDR, KCORE_VMALLOC);
606}
607#else
608static void __init add_modules_range(void)
609{
610}
611#endif
612
613static int __init proc_kcore_init(void)
614{
615 proc_root_kcore = proc_create("kcore", S_IRUSR, NULL,
616 &proc_kcore_operations);
617 if (!proc_root_kcore) {
618 printk(KERN_ERR "couldn't create /proc/kcore\n");
619 return 0;
620 }
621
622 proc_kcore_text_init();
623
624 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
625 VMALLOC_END - VMALLOC_START, KCORE_VMALLOC);
626 add_modules_range();
627
628 kcore_update_ram();
629 hotplug_memory_notifier(kcore_callback, 0);
630
631 return 0;
632}
633module_init(proc_kcore_init);
634