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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * fs/proc/kcore.c kernel ELF core dumper
3 *
4 * Modelled on fs/exec.c:aout_core_dump()
5 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
6 * ELF version written by David Howells <David.Howells@nexor.co.uk>
7 * Modified and incorporated into 2.3.x by Tigran Aivazian <tigran@veritas.com>
8 * Support to dump vmalloc'd areas (ELF only), Tigran Aivazian <tigran@veritas.com>
9 * Safe accesses to vmalloc/direct-mapped discontiguous areas, Kanoj Sarcar <kanoj@sgi.com>
10 */
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/mm.h>
13#include <linux/proc_fs.h>
14#include <linux/user.h>
Randy Dunlap16f7e0f2006-01-11 12:17:46 -080015#include <linux/capability.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/elf.h>
17#include <linux/elfcore.h>
18#include <linux/vmalloc.h>
19#include <linux/highmem.h>
Andrew Morton87ebdc02013-02-27 17:03:16 -080020#include <linux/printk.h>
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -070021#include <linux/bootmem.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/init.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/uaccess.h>
25#include <asm/io.h>
KAMEZAWA Hiroyuki2ef43ec2009-09-22 16:45:41 -070026#include <linux/list.h>
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -070027#include <linux/ioport.h>
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -070028#include <linux/memory.h>
KAMEZAWA Hiroyuki94925872009-09-22 16:45:45 -070029#include <asm/sections.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Magnus Damm36027602006-12-06 20:38:00 -080031#define CORE_STR "CORE"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Edgar E. Iglesias79885b22008-07-25 01:48:10 -070033#ifndef ELF_CORE_EFLAGS
34#define ELF_CORE_EFLAGS 0
35#endif
36
Alexey Dobriyan97ce5d62008-10-06 14:14:19 +040037static struct proc_dir_entry *proc_root_kcore;
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40#ifndef kc_vaddr_to_offset
41#define kc_vaddr_to_offset(v) ((v) - PAGE_OFFSET)
42#endif
43#ifndef kc_offset_to_vaddr
44#define kc_offset_to_vaddr(o) ((o) + PAGE_OFFSET)
45#endif
46
Linus Torvalds1da177e2005-04-16 15:20:36 -070047/* An ELF note in memory */
48struct memelfnote
49{
50 const char *name;
51 int type;
52 unsigned int datasz;
53 void *data;
54};
55
KAMEZAWA Hiroyuki2ef43ec2009-09-22 16:45:41 -070056static LIST_HEAD(kclist_head);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057static DEFINE_RWLOCK(kclist_lock);
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -070058static int kcore_need_update = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60void
KAMEZAWA Hiroyukic30bb2a2009-09-22 16:45:43 -070061kclist_add(struct kcore_list *new, void *addr, size_t size, int type)
Linus Torvalds1da177e2005-04-16 15:20:36 -070062{
63 new->addr = (unsigned long)addr;
64 new->size = size;
KAMEZAWA Hiroyukic30bb2a2009-09-22 16:45:43 -070065 new->type = type;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67 write_lock(&kclist_lock);
KAMEZAWA Hiroyuki2ef43ec2009-09-22 16:45:41 -070068 list_add_tail(&new->list, &kclist_head);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 write_unlock(&kclist_lock);
70}
71
72static size_t get_kcore_size(int *nphdr, size_t *elf_buflen)
73{
74 size_t try, size;
75 struct kcore_list *m;
76
77 *nphdr = 1; /* PT_NOTE */
78 size = 0;
79
KAMEZAWA Hiroyuki2ef43ec2009-09-22 16:45:41 -070080 list_for_each_entry(m, &kclist_head, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 try = kc_vaddr_to_offset((size_t)m->addr + m->size);
82 if (try > size)
83 size = try;
84 *nphdr = *nphdr + 1;
85 }
86 *elf_buflen = sizeof(struct elfhdr) +
87 (*nphdr + 2)*sizeof(struct elf_phdr) +
Magnus Damm36027602006-12-06 20:38:00 -080088 3 * ((sizeof(struct elf_note)) +
89 roundup(sizeof(CORE_STR), 4)) +
90 roundup(sizeof(struct elf_prstatus), 4) +
91 roundup(sizeof(struct elf_prpsinfo), 4) +
92 roundup(sizeof(struct task_struct), 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 *elf_buflen = PAGE_ALIGN(*elf_buflen);
94 return size + *elf_buflen;
95}
96
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -070097static void free_kclist_ents(struct list_head *head)
98{
99 struct kcore_list *tmp, *pos;
100
101 list_for_each_entry_safe(pos, tmp, head, list) {
102 list_del(&pos->list);
103 kfree(pos);
104 }
105}
106/*
KAMEZAWA Hiroyuki26562c52009-09-22 16:45:49 -0700107 * Replace all KCORE_RAM/KCORE_VMEMMAP information with passed list.
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700108 */
109static void __kcore_update_ram(struct list_head *list)
110{
KAMEZAWA Hiroyuki678ad5d2009-09-22 16:45:51 -0700111 int nphdr;
112 size_t size;
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700113 struct kcore_list *tmp, *pos;
114 LIST_HEAD(garbage);
115
116 write_lock(&kclist_lock);
117 if (kcore_need_update) {
118 list_for_each_entry_safe(pos, tmp, &kclist_head, list) {
KAMEZAWA Hiroyuki26562c52009-09-22 16:45:49 -0700119 if (pos->type == KCORE_RAM
120 || pos->type == KCORE_VMEMMAP)
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700121 list_move(&pos->list, &garbage);
122 }
123 list_splice_tail(list, &kclist_head);
124 } else
125 list_splice(list, &garbage);
126 kcore_need_update = 0;
KAMEZAWA Hiroyuki678ad5d2009-09-22 16:45:51 -0700127 proc_root_kcore->size = get_kcore_size(&nphdr, &size);
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700128 write_unlock(&kclist_lock);
129
130 free_kclist_ents(&garbage);
131}
132
133
134#ifdef CONFIG_HIGHMEM
135/*
136 * If no highmem, we can assume [0...max_low_pfn) continuous range of memory
137 * because memory hole is not as big as !HIGHMEM case.
138 * (HIGHMEM is special because part of memory is _invisible_ from the kernel.)
139 */
140static int kcore_update_ram(void)
141{
142 LIST_HEAD(head);
143 struct kcore_list *ent;
144 int ret = 0;
145
146 ent = kmalloc(sizeof(*ent), GFP_KERNEL);
147 if (!ent)
148 return -ENOMEM;
149 ent->addr = (unsigned long)__va(0);
150 ent->size = max_low_pfn << PAGE_SHIFT;
151 ent->type = KCORE_RAM;
152 list_add(&ent->list, &head);
153 __kcore_update_ram(&head);
154 return ret;
155}
156
157#else /* !CONFIG_HIGHMEM */
158
KAMEZAWA Hiroyuki26562c52009-09-22 16:45:49 -0700159#ifdef CONFIG_SPARSEMEM_VMEMMAP
160/* calculate vmemmap's address from given system ram pfn and register it */
Djalal Harounib9082432012-03-23 15:02:52 -0700161static int
162get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)
KAMEZAWA Hiroyuki26562c52009-09-22 16:45:49 -0700163{
164 unsigned long pfn = __pa(ent->addr) >> PAGE_SHIFT;
165 unsigned long nr_pages = ent->size >> PAGE_SHIFT;
166 unsigned long start, end;
167 struct kcore_list *vmm, *tmp;
168
169
170 start = ((unsigned long)pfn_to_page(pfn)) & PAGE_MASK;
171 end = ((unsigned long)pfn_to_page(pfn + nr_pages)) - 1;
172 end = ALIGN(end, PAGE_SIZE);
173 /* overlap check (because we have to align page */
174 list_for_each_entry(tmp, head, list) {
175 if (tmp->type != KCORE_VMEMMAP)
176 continue;
177 if (start < tmp->addr + tmp->size)
178 if (end > tmp->addr)
179 end = tmp->addr;
180 }
181 if (start < end) {
182 vmm = kmalloc(sizeof(*vmm), GFP_KERNEL);
183 if (!vmm)
184 return 0;
185 vmm->addr = start;
186 vmm->size = end - start;
187 vmm->type = KCORE_VMEMMAP;
188 list_add_tail(&vmm->list, head);
189 }
190 return 1;
191
192}
193#else
Djalal Harounib9082432012-03-23 15:02:52 -0700194static int
195get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head)
KAMEZAWA Hiroyuki26562c52009-09-22 16:45:49 -0700196{
197 return 1;
198}
199
200#endif
201
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700202static int
203kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg)
204{
205 struct list_head *head = (struct list_head *)arg;
206 struct kcore_list *ent;
207
208 ent = kmalloc(sizeof(*ent), GFP_KERNEL);
209 if (!ent)
210 return -ENOMEM;
211 ent->addr = (unsigned long)__va((pfn << PAGE_SHIFT));
212 ent->size = nr_pages << PAGE_SHIFT;
213
214 /* Sanity check: Can happen in 32bit arch...maybe */
215 if (ent->addr < (unsigned long) __va(0))
216 goto free_out;
217
218 /* cut not-mapped area. ....from ppc-32 code. */
219 if (ULONG_MAX - ent->addr < ent->size)
220 ent->size = ULONG_MAX - ent->addr;
221
222 /* cut when vmalloc() area is higher than direct-map area */
223 if (VMALLOC_START > (unsigned long)__va(0)) {
224 if (ent->addr > VMALLOC_START)
225 goto free_out;
226 if (VMALLOC_START - ent->addr < ent->size)
227 ent->size = VMALLOC_START - ent->addr;
228 }
229
230 ent->type = KCORE_RAM;
231 list_add_tail(&ent->list, head);
KAMEZAWA Hiroyuki26562c52009-09-22 16:45:49 -0700232
233 if (!get_sparsemem_vmemmap_info(ent, head)) {
234 list_del(&ent->list);
235 goto free_out;
236 }
237
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700238 return 0;
239free_out:
240 kfree(ent);
241 return 1;
242}
243
244static int kcore_update_ram(void)
245{
246 int nid, ret;
247 unsigned long end_pfn;
248 LIST_HEAD(head);
249
250 /* Not inialized....update now */
251 /* find out "max pfn" */
252 end_pfn = 0;
Lai Jiangshan4ff1b2c2012-12-12 13:51:25 -0800253 for_each_node_state(nid, N_MEMORY) {
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700254 unsigned long node_end;
255 node_end = NODE_DATA(nid)->node_start_pfn +
256 NODE_DATA(nid)->node_spanned_pages;
257 if (end_pfn < node_end)
258 end_pfn = node_end;
259 }
260 /* scan 0 to max_pfn */
261 ret = walk_system_ram_range(0, end_pfn, &head, kclist_add_private);
262 if (ret) {
263 free_kclist_ents(&head);
264 return -ENOMEM;
265 }
266 __kcore_update_ram(&head);
267 return ret;
268}
269#endif /* CONFIG_HIGHMEM */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
271/*****************************************************************************/
272/*
273 * determine size of ELF note
274 */
275static int notesize(struct memelfnote *en)
276{
277 int sz;
278
279 sz = sizeof(struct elf_note);
Vivek Goyal632dd202006-09-29 02:01:45 -0700280 sz += roundup((strlen(en->name) + 1), 4);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 sz += roundup(en->datasz, 4);
282
283 return sz;
284} /* end notesize() */
285
286/*****************************************************************************/
287/*
288 * store a note in the header buffer
289 */
290static char *storenote(struct memelfnote *men, char *bufp)
291{
292 struct elf_note en;
293
294#define DUMP_WRITE(addr,nr) do { memcpy(bufp,addr,nr); bufp += nr; } while(0)
295
Vivek Goyal632dd202006-09-29 02:01:45 -0700296 en.n_namesz = strlen(men->name) + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 en.n_descsz = men->datasz;
298 en.n_type = men->type;
299
300 DUMP_WRITE(&en, sizeof(en));
301 DUMP_WRITE(men->name, en.n_namesz);
302
303 /* XXX - cast from long long to long to avoid need for libgcc.a */
304 bufp = (char*) roundup((unsigned long)bufp,4);
305 DUMP_WRITE(men->data, men->datasz);
306 bufp = (char*) roundup((unsigned long)bufp,4);
307
308#undef DUMP_WRITE
309
310 return bufp;
311} /* end storenote() */
312
313/*
314 * store an ELF coredump header in the supplied buffer
315 * nphdr is the number of elf_phdr to insert
316 */
317static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff)
318{
319 struct elf_prstatus prstatus; /* NT_PRSTATUS */
320 struct elf_prpsinfo prpsinfo; /* NT_PRPSINFO */
321 struct elf_phdr *nhdr, *phdr;
322 struct elfhdr *elf;
323 struct memelfnote notes[3];
324 off_t offset = 0;
325 struct kcore_list *m;
326
327 /* setup ELF header */
328 elf = (struct elfhdr *) bufp;
329 bufp += sizeof(struct elfhdr);
330 offset += sizeof(struct elfhdr);
331 memcpy(elf->e_ident, ELFMAG, SELFMAG);
332 elf->e_ident[EI_CLASS] = ELF_CLASS;
333 elf->e_ident[EI_DATA] = ELF_DATA;
334 elf->e_ident[EI_VERSION]= EV_CURRENT;
335 elf->e_ident[EI_OSABI] = ELF_OSABI;
336 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
337 elf->e_type = ET_CORE;
338 elf->e_machine = ELF_ARCH;
339 elf->e_version = EV_CURRENT;
340 elf->e_entry = 0;
341 elf->e_phoff = sizeof(struct elfhdr);
342 elf->e_shoff = 0;
Edgar E. Iglesias79885b22008-07-25 01:48:10 -0700343 elf->e_flags = ELF_CORE_EFLAGS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344 elf->e_ehsize = sizeof(struct elfhdr);
345 elf->e_phentsize= sizeof(struct elf_phdr);
346 elf->e_phnum = nphdr;
347 elf->e_shentsize= 0;
348 elf->e_shnum = 0;
349 elf->e_shstrndx = 0;
350
351 /* setup ELF PT_NOTE program header */
352 nhdr = (struct elf_phdr *) bufp;
353 bufp += sizeof(struct elf_phdr);
354 offset += sizeof(struct elf_phdr);
355 nhdr->p_type = PT_NOTE;
356 nhdr->p_offset = 0;
357 nhdr->p_vaddr = 0;
358 nhdr->p_paddr = 0;
359 nhdr->p_filesz = 0;
360 nhdr->p_memsz = 0;
361 nhdr->p_flags = 0;
362 nhdr->p_align = 0;
363
364 /* setup ELF PT_LOAD program header for every area */
KAMEZAWA Hiroyuki2ef43ec2009-09-22 16:45:41 -0700365 list_for_each_entry(m, &kclist_head, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 phdr = (struct elf_phdr *) bufp;
367 bufp += sizeof(struct elf_phdr);
368 offset += sizeof(struct elf_phdr);
369
370 phdr->p_type = PT_LOAD;
371 phdr->p_flags = PF_R|PF_W|PF_X;
372 phdr->p_offset = kc_vaddr_to_offset(m->addr) + dataoff;
373 phdr->p_vaddr = (size_t)m->addr;
374 phdr->p_paddr = 0;
375 phdr->p_filesz = phdr->p_memsz = m->size;
376 phdr->p_align = PAGE_SIZE;
377 }
378
379 /*
380 * Set up the notes in similar form to SVR4 core dumps made
381 * with info from their /proc.
382 */
383 nhdr->p_offset = offset;
384
385 /* set up the process status */
Magnus Damm36027602006-12-06 20:38:00 -0800386 notes[0].name = CORE_STR;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387 notes[0].type = NT_PRSTATUS;
388 notes[0].datasz = sizeof(struct elf_prstatus);
389 notes[0].data = &prstatus;
390
391 memset(&prstatus, 0, sizeof(struct elf_prstatus));
392
393 nhdr->p_filesz = notesize(&notes[0]);
394 bufp = storenote(&notes[0], bufp);
395
396 /* set up the process info */
Magnus Damm36027602006-12-06 20:38:00 -0800397 notes[1].name = CORE_STR;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 notes[1].type = NT_PRPSINFO;
399 notes[1].datasz = sizeof(struct elf_prpsinfo);
400 notes[1].data = &prpsinfo;
401
402 memset(&prpsinfo, 0, sizeof(struct elf_prpsinfo));
403 prpsinfo.pr_state = 0;
404 prpsinfo.pr_sname = 'R';
405 prpsinfo.pr_zomb = 0;
406
407 strcpy(prpsinfo.pr_fname, "vmlinux");
408 strncpy(prpsinfo.pr_psargs, saved_command_line, ELF_PRARGSZ);
409
410 nhdr->p_filesz += notesize(&notes[1]);
411 bufp = storenote(&notes[1], bufp);
412
413 /* set up the task structure */
Magnus Damm36027602006-12-06 20:38:00 -0800414 notes[2].name = CORE_STR;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 notes[2].type = NT_TASKSTRUCT;
416 notes[2].datasz = sizeof(struct task_struct);
417 notes[2].data = current;
418
419 nhdr->p_filesz += notesize(&notes[2]);
420 bufp = storenote(&notes[2], bufp);
421
422} /* end elf_kcore_store_hdr() */
423
424/*****************************************************************************/
425/*
426 * read from the ELF header and then kernel memory
427 */
428static ssize_t
429read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
430{
431 ssize_t acc = 0;
432 size_t size, tsz;
433 size_t elf_buflen;
434 int nphdr;
435 unsigned long start;
436
437 read_lock(&kclist_lock);
KAMEZAWA Hiroyuki678ad5d2009-09-22 16:45:51 -0700438 size = get_kcore_size(&nphdr, &elf_buflen);
439
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 if (buflen == 0 || *fpos >= size) {
441 read_unlock(&kclist_lock);
442 return 0;
443 }
444
445 /* trim buflen to not go beyond EOF */
446 if (buflen > size - *fpos)
447 buflen = size - *fpos;
448
449 /* construct an ELF core header if we'll need some of it */
450 if (*fpos < elf_buflen) {
451 char * elf_buf;
452
453 tsz = elf_buflen - *fpos;
454 if (buflen < tsz)
455 tsz = buflen;
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700456 elf_buf = kzalloc(elf_buflen, GFP_ATOMIC);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457 if (!elf_buf) {
458 read_unlock(&kclist_lock);
459 return -ENOMEM;
460 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 elf_kcore_store_hdr(elf_buf, nphdr, elf_buflen);
462 read_unlock(&kclist_lock);
463 if (copy_to_user(buffer, elf_buf + *fpos, tsz)) {
464 kfree(elf_buf);
465 return -EFAULT;
466 }
467 kfree(elf_buf);
468 buflen -= tsz;
469 *fpos += tsz;
470 buffer += tsz;
471 acc += tsz;
472
473 /* leave now if filled buffer already */
474 if (buflen == 0)
475 return acc;
476 } else
477 read_unlock(&kclist_lock);
478
479 /*
480 * Check to see if our file offset matches with any of
481 * the addresses in the elf_phdr on our list.
482 */
483 start = kc_offset_to_vaddr(*fpos - elf_buflen);
484 if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen)
485 tsz = buflen;
486
487 while (buflen) {
488 struct kcore_list *m;
489
490 read_lock(&kclist_lock);
KAMEZAWA Hiroyuki2ef43ec2009-09-22 16:45:41 -0700491 list_for_each_entry(m, &kclist_head, list) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 if (start >= m->addr && start < (m->addr+m->size))
493 break;
494 }
495 read_unlock(&kclist_lock);
496
Dan Carpenter4fd2c202010-03-23 13:35:42 -0700497 if (&m->list == &kclist_head) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498 if (clear_user(buffer, tsz))
499 return -EFAULT;
KAMEZAWA Hiroyuki81ac3ad2009-09-22 16:45:49 -0700500 } else if (is_vmalloc_or_module_addr((void *)start)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 char * elf_buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502
Panagiotis Issarisf8314dc2006-09-27 01:49:37 -0700503 elf_buf = kzalloc(tsz, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 if (!elf_buf)
505 return -ENOMEM;
KAMEZAWA Hiroyuki73d7c332009-09-21 17:02:35 -0700506 vread(elf_buf, (char *)start, tsz);
507 /* we have to zero-fill user buffer even if no read */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 if (copy_to_user(buffer, elf_buf, tsz)) {
509 kfree(elf_buf);
510 return -EFAULT;
511 }
512 kfree(elf_buf);
513 } else {
514 if (kern_addr_valid(start)) {
515 unsigned long n;
516
517 n = copy_to_user(buffer, (char *)start, tsz);
518 /*
Laura Vasilescuf1f996b2012-03-19 15:41:15 +0200519 * We cannot distinguish between fault on source
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 * and fault on destination. When this happens
521 * we clear too and hope it will trigger the
522 * EFAULT again.
523 */
524 if (n) {
525 if (clear_user(buffer + tsz - n,
Adam B. Jerome06351702006-07-12 09:03:07 -0700526 n))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 return -EFAULT;
528 }
529 } else {
530 if (clear_user(buffer, tsz))
531 return -EFAULT;
532 }
533 }
534 buflen -= tsz;
535 *fpos += tsz;
536 buffer += tsz;
537 acc += tsz;
538 start += tsz;
539 tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen);
540 }
541
542 return acc;
543}
Alexey Dobriyan97ce5d62008-10-06 14:14:19 +0400544
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700545
546static int open_kcore(struct inode *inode, struct file *filp)
547{
548 if (!capable(CAP_SYS_RAWIO))
549 return -EPERM;
550 if (kcore_need_update)
551 kcore_update_ram();
KAMEZAWA Hiroyuki0d4c36a2009-09-22 16:45:52 -0700552 if (i_size_read(inode) != proc_root_kcore->size) {
553 mutex_lock(&inode->i_mutex);
554 i_size_write(inode, proc_root_kcore->size);
555 mutex_unlock(&inode->i_mutex);
556 }
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700557 return 0;
558}
559
560
561static const struct file_operations proc_kcore_operations = {
562 .read = read_kcore,
563 .open = open_kcore,
Dave Andersonceff1a72011-01-12 17:00:36 -0800564 .llseek = default_llseek,
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700565};
566
567#ifdef CONFIG_MEMORY_HOTPLUG
568/* just remember that we have to update kcore */
569static int __meminit kcore_callback(struct notifier_block *self,
570 unsigned long action, void *arg)
571{
572 switch (action) {
573 case MEM_ONLINE:
574 case MEM_OFFLINE:
575 write_lock(&kclist_lock);
576 kcore_need_update = 1;
577 write_unlock(&kclist_lock);
578 }
579 return NOTIFY_OK;
580}
581#endif
582
583
KAMEZAWA Hiroyukia0614da2009-09-22 16:45:44 -0700584static struct kcore_list kcore_vmalloc;
585
KAMEZAWA Hiroyuki94925872009-09-22 16:45:45 -0700586#ifdef CONFIG_ARCH_PROC_KCORE_TEXT
587static struct kcore_list kcore_text;
588/*
589 * If defined, special segment is used for mapping kernel text instead of
590 * direct-map area. We need to create special TEXT section.
591 */
592static void __init proc_kcore_text_init(void)
593{
Wu Fengguang36e15262010-05-26 14:43:27 -0700594 kclist_add(&kcore_text, _text, _end - _text, KCORE_TEXT);
KAMEZAWA Hiroyuki94925872009-09-22 16:45:45 -0700595}
596#else
597static void __init proc_kcore_text_init(void)
598{
599}
600#endif
601
KAMEZAWA Hiroyuki81ac3ad2009-09-22 16:45:49 -0700602#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
603/*
604 * MODULES_VADDR has no intersection with VMALLOC_ADDR.
605 */
606struct kcore_list kcore_modules;
607static void __init add_modules_range(void)
608{
609 kclist_add(&kcore_modules, (void *)MODULES_VADDR,
610 MODULES_END - MODULES_VADDR, KCORE_VMALLOC);
611}
612#else
613static void __init add_modules_range(void)
614{
615}
616#endif
617
Alexey Dobriyan97ce5d62008-10-06 14:14:19 +0400618static int __init proc_kcore_init(void)
619{
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700620 proc_root_kcore = proc_create("kcore", S_IRUSR, NULL,
621 &proc_kcore_operations);
KAMEZAWA Hiroyuki90396f92009-09-22 16:45:50 -0700622 if (!proc_root_kcore) {
Andrew Morton87ebdc02013-02-27 17:03:16 -0800623 pr_err("couldn't create /proc/kcore\n");
KAMEZAWA Hiroyuki90396f92009-09-22 16:45:50 -0700624 return 0; /* Always returns 0. */
625 }
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700626 /* Store text area if it's special */
KAMEZAWA Hiroyuki94925872009-09-22 16:45:45 -0700627 proc_kcore_text_init();
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700628 /* Store vmalloc area */
KAMEZAWA Hiroyukia0614da2009-09-22 16:45:44 -0700629 kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
630 VMALLOC_END - VMALLOC_START, KCORE_VMALLOC);
KAMEZAWA Hiroyuki81ac3ad2009-09-22 16:45:49 -0700631 add_modules_range();
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700632 /* Store direct-map area from physical memory map */
633 kcore_update_ram();
634 hotplug_memory_notifier(kcore_callback, 0);
KAMEZAWA Hiroyuki3089aa12009-09-22 16:45:48 -0700635
Alexey Dobriyan97ce5d62008-10-06 14:14:19 +0400636 return 0;
637}
638module_init(proc_kcore_init);