Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 LT |
2 | /* |
3 | * fs/proc/kcore.c kernel ELF core dumper | |
4 | * | |
5 | * Modelled on fs/exec.c:aout_core_dump() | |
6 | * Jeremy Fitzhardinge <jeremy@sw.oz.au> | |
7 | * ELF version written by David Howells <David.Howells@nexor.co.uk> | |
8 | * Modified and incorporated into 2.3.x by Tigran Aivazian <tigran@veritas.com> | |
9 | * Support to dump vmalloc'd areas (ELF only), Tigran Aivazian <tigran@veritas.com> | |
10 | * Safe accesses to vmalloc/direct-mapped discontiguous areas, Kanoj Sarcar <kanoj@sgi.com> | |
11 | */ | |
12 | ||
1da177e4 LT |
13 | #include <linux/mm.h> |
14 | #include <linux/proc_fs.h> | |
2f96b8c1 | 15 | #include <linux/kcore.h> |
1da177e4 | 16 | #include <linux/user.h> |
16f7e0fe | 17 | #include <linux/capability.h> |
1da177e4 LT |
18 | #include <linux/elf.h> |
19 | #include <linux/elfcore.h> | |
3c743a7f | 20 | #include <linux/notifier.h> |
1da177e4 LT |
21 | #include <linux/vmalloc.h> |
22 | #include <linux/highmem.h> | |
87ebdc00 | 23 | #include <linux/printk.h> |
3089aa1b | 24 | #include <linux/bootmem.h> |
1da177e4 | 25 | #include <linux/init.h> |
5a0e3ad6 | 26 | #include <linux/slab.h> |
7c0f6ba6 | 27 | #include <linux/uaccess.h> |
1da177e4 | 28 | #include <asm/io.h> |
2ef43ec7 | 29 | #include <linux/list.h> |
3089aa1b | 30 | #include <linux/ioport.h> |
3089aa1b | 31 | #include <linux/memory.h> |
29930025 | 32 | #include <linux/sched/task.h> |
9492587c | 33 | #include <asm/sections.h> |
59d8053f | 34 | #include "internal.h" |
1da177e4 | 35 | |
36027604 | 36 | #define CORE_STR "CORE" |
1da177e4 | 37 | |
79885b22 EI |
38 | #ifndef ELF_CORE_EFLAGS |
39 | #define ELF_CORE_EFLAGS 0 | |
40 | #endif | |
41 | ||
97ce5d6d AD |
42 | static struct proc_dir_entry *proc_root_kcore; |
43 | ||
1da177e4 LT |
44 | |
45 | #ifndef kc_vaddr_to_offset | |
46 | #define kc_vaddr_to_offset(v) ((v) - PAGE_OFFSET) | |
47 | #endif | |
48 | #ifndef kc_offset_to_vaddr | |
49 | #define kc_offset_to_vaddr(o) ((o) + PAGE_OFFSET) | |
50 | #endif | |
51 | ||
1da177e4 LT |
52 | /* An ELF note in memory */ |
53 | struct memelfnote | |
54 | { | |
55 | const char *name; | |
56 | int type; | |
57 | unsigned int datasz; | |
58 | void *data; | |
59 | }; | |
60 | ||
2ef43ec7 | 61 | static LIST_HEAD(kclist_head); |
1da177e4 | 62 | static DEFINE_RWLOCK(kclist_lock); |
3089aa1b | 63 | static int kcore_need_update = 1; |
1da177e4 | 64 | |
a8dd9c4d OS |
65 | /* This doesn't grab kclist_lock, so it should only be used at init time. */ |
66 | void __init kclist_add(struct kcore_list *new, void *addr, size_t size, | |
67 | int type) | |
1da177e4 LT |
68 | { |
69 | new->addr = (unsigned long)addr; | |
70 | new->size = size; | |
c30bb2a2 | 71 | new->type = type; |
1da177e4 | 72 | |
2ef43ec7 | 73 | list_add_tail(&new->list, &kclist_head); |
1da177e4 LT |
74 | } |
75 | ||
76 | static size_t get_kcore_size(int *nphdr, size_t *elf_buflen) | |
77 | { | |
78 | size_t try, size; | |
79 | struct kcore_list *m; | |
80 | ||
81 | *nphdr = 1; /* PT_NOTE */ | |
82 | size = 0; | |
83 | ||
2ef43ec7 | 84 | list_for_each_entry(m, &kclist_head, list) { |
1da177e4 LT |
85 | try = kc_vaddr_to_offset((size_t)m->addr + m->size); |
86 | if (try > size) | |
87 | size = try; | |
88 | *nphdr = *nphdr + 1; | |
89 | } | |
90 | *elf_buflen = sizeof(struct elfhdr) + | |
91 | (*nphdr + 2)*sizeof(struct elf_phdr) + | |
36027604 MD |
92 | 3 * ((sizeof(struct elf_note)) + |
93 | roundup(sizeof(CORE_STR), 4)) + | |
94 | roundup(sizeof(struct elf_prstatus), 4) + | |
95 | roundup(sizeof(struct elf_prpsinfo), 4) + | |
5aaeb5c0 | 96 | roundup(arch_task_struct_size, 4); |
1da177e4 LT |
97 | *elf_buflen = PAGE_ALIGN(*elf_buflen); |
98 | return size + *elf_buflen; | |
99 | } | |
100 | ||
3089aa1b KH |
101 | static void free_kclist_ents(struct list_head *head) |
102 | { | |
103 | struct kcore_list *tmp, *pos; | |
104 | ||
105 | list_for_each_entry_safe(pos, tmp, head, list) { | |
106 | list_del(&pos->list); | |
107 | kfree(pos); | |
108 | } | |
109 | } | |
110 | /* | |
26562c59 | 111 | * Replace all KCORE_RAM/KCORE_VMEMMAP information with passed list. |
3089aa1b KH |
112 | */ |
113 | static void __kcore_update_ram(struct list_head *list) | |
114 | { | |
678ad5d8 KH |
115 | int nphdr; |
116 | size_t size; | |
3089aa1b KH |
117 | struct kcore_list *tmp, *pos; |
118 | LIST_HEAD(garbage); | |
119 | ||
120 | write_lock(&kclist_lock); | |
bf531831 | 121 | if (xchg(&kcore_need_update, 0)) { |
3089aa1b | 122 | list_for_each_entry_safe(pos, tmp, &kclist_head, list) { |
26562c59 KH |
123 | if (pos->type == KCORE_RAM |
124 | || pos->type == KCORE_VMEMMAP) | |
3089aa1b KH |
125 | list_move(&pos->list, &garbage); |
126 | } | |
127 | list_splice_tail(list, &kclist_head); | |
128 | } else | |
129 | list_splice(list, &garbage); | |
678ad5d8 | 130 | proc_root_kcore->size = get_kcore_size(&nphdr, &size); |
3089aa1b KH |
131 | write_unlock(&kclist_lock); |
132 | ||
133 | free_kclist_ents(&garbage); | |
134 | } | |
135 | ||
136 | ||
137 | #ifdef CONFIG_HIGHMEM | |
138 | /* | |
139 | * If no highmem, we can assume [0...max_low_pfn) continuous range of memory | |
140 | * because memory hole is not as big as !HIGHMEM case. | |
141 | * (HIGHMEM is special because part of memory is _invisible_ from the kernel.) | |
142 | */ | |
143 | static int kcore_update_ram(void) | |
144 | { | |
145 | LIST_HEAD(head); | |
146 | struct kcore_list *ent; | |
147 | int ret = 0; | |
148 | ||
149 | ent = kmalloc(sizeof(*ent), GFP_KERNEL); | |
150 | if (!ent) | |
151 | return -ENOMEM; | |
152 | ent->addr = (unsigned long)__va(0); | |
153 | ent->size = max_low_pfn << PAGE_SHIFT; | |
154 | ent->type = KCORE_RAM; | |
155 | list_add(&ent->list, &head); | |
156 | __kcore_update_ram(&head); | |
157 | return ret; | |
158 | } | |
159 | ||
160 | #else /* !CONFIG_HIGHMEM */ | |
161 | ||
26562c59 KH |
162 | #ifdef CONFIG_SPARSEMEM_VMEMMAP |
163 | /* calculate vmemmap's address from given system ram pfn and register it */ | |
b908243c DH |
164 | static int |
165 | get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head) | |
26562c59 KH |
166 | { |
167 | unsigned long pfn = __pa(ent->addr) >> PAGE_SHIFT; | |
168 | unsigned long nr_pages = ent->size >> PAGE_SHIFT; | |
169 | unsigned long start, end; | |
170 | struct kcore_list *vmm, *tmp; | |
171 | ||
172 | ||
173 | start = ((unsigned long)pfn_to_page(pfn)) & PAGE_MASK; | |
174 | end = ((unsigned long)pfn_to_page(pfn + nr_pages)) - 1; | |
108a8a11 | 175 | end = PAGE_ALIGN(end); |
26562c59 KH |
176 | /* overlap check (because we have to align page */ |
177 | list_for_each_entry(tmp, head, list) { | |
178 | if (tmp->type != KCORE_VMEMMAP) | |
179 | continue; | |
180 | if (start < tmp->addr + tmp->size) | |
181 | if (end > tmp->addr) | |
182 | end = tmp->addr; | |
183 | } | |
184 | if (start < end) { | |
185 | vmm = kmalloc(sizeof(*vmm), GFP_KERNEL); | |
186 | if (!vmm) | |
187 | return 0; | |
188 | vmm->addr = start; | |
189 | vmm->size = end - start; | |
190 | vmm->type = KCORE_VMEMMAP; | |
191 | list_add_tail(&vmm->list, head); | |
192 | } | |
193 | return 1; | |
194 | ||
195 | } | |
196 | #else | |
b908243c DH |
197 | static int |
198 | get_sparsemem_vmemmap_info(struct kcore_list *ent, struct list_head *head) | |
26562c59 KH |
199 | { |
200 | return 1; | |
201 | } | |
202 | ||
203 | #endif | |
204 | ||
3089aa1b KH |
205 | static int |
206 | kclist_add_private(unsigned long pfn, unsigned long nr_pages, void *arg) | |
207 | { | |
208 | struct list_head *head = (struct list_head *)arg; | |
209 | struct kcore_list *ent; | |
3955333d LA |
210 | struct page *p; |
211 | ||
212 | if (!pfn_valid(pfn)) | |
213 | return 1; | |
214 | ||
215 | p = pfn_to_page(pfn); | |
216 | if (!memmap_valid_within(pfn, p, page_zone(p))) | |
217 | return 1; | |
3089aa1b KH |
218 | |
219 | ent = kmalloc(sizeof(*ent), GFP_KERNEL); | |
220 | if (!ent) | |
221 | return -ENOMEM; | |
3955333d | 222 | ent->addr = (unsigned long)page_to_virt(p); |
3089aa1b KH |
223 | ent->size = nr_pages << PAGE_SHIFT; |
224 | ||
3955333d | 225 | if (!virt_addr_valid(ent->addr)) |
3089aa1b KH |
226 | goto free_out; |
227 | ||
228 | /* cut not-mapped area. ....from ppc-32 code. */ | |
229 | if (ULONG_MAX - ent->addr < ent->size) | |
230 | ent->size = ULONG_MAX - ent->addr; | |
231 | ||
3955333d LA |
232 | /* |
233 | * We've already checked virt_addr_valid so we know this address | |
234 | * is a valid pointer, therefore we can check against it to determine | |
235 | * if we need to trim | |
236 | */ | |
237 | if (VMALLOC_START > ent->addr) { | |
3089aa1b KH |
238 | if (VMALLOC_START - ent->addr < ent->size) |
239 | ent->size = VMALLOC_START - ent->addr; | |
240 | } | |
241 | ||
242 | ent->type = KCORE_RAM; | |
243 | list_add_tail(&ent->list, head); | |
26562c59 KH |
244 | |
245 | if (!get_sparsemem_vmemmap_info(ent, head)) { | |
246 | list_del(&ent->list); | |
247 | goto free_out; | |
248 | } | |
249 | ||
3089aa1b KH |
250 | return 0; |
251 | free_out: | |
252 | kfree(ent); | |
253 | return 1; | |
254 | } | |
255 | ||
256 | static int kcore_update_ram(void) | |
257 | { | |
258 | int nid, ret; | |
259 | unsigned long end_pfn; | |
260 | LIST_HEAD(head); | |
261 | ||
262 | /* Not inialized....update now */ | |
263 | /* find out "max pfn" */ | |
264 | end_pfn = 0; | |
4ff1b2c2 | 265 | for_each_node_state(nid, N_MEMORY) { |
3089aa1b | 266 | unsigned long node_end; |
83285c72 | 267 | node_end = node_end_pfn(nid); |
3089aa1b KH |
268 | if (end_pfn < node_end) |
269 | end_pfn = node_end; | |
270 | } | |
271 | /* scan 0 to max_pfn */ | |
272 | ret = walk_system_ram_range(0, end_pfn, &head, kclist_add_private); | |
273 | if (ret) { | |
274 | free_kclist_ents(&head); | |
275 | return -ENOMEM; | |
276 | } | |
277 | __kcore_update_ram(&head); | |
278 | return ret; | |
279 | } | |
280 | #endif /* CONFIG_HIGHMEM */ | |
1da177e4 LT |
281 | |
282 | /*****************************************************************************/ | |
283 | /* | |
284 | * determine size of ELF note | |
285 | */ | |
286 | static int notesize(struct memelfnote *en) | |
287 | { | |
288 | int sz; | |
289 | ||
290 | sz = sizeof(struct elf_note); | |
632dd205 | 291 | sz += roundup((strlen(en->name) + 1), 4); |
1da177e4 LT |
292 | sz += roundup(en->datasz, 4); |
293 | ||
294 | return sz; | |
295 | } /* end notesize() */ | |
296 | ||
297 | /*****************************************************************************/ | |
298 | /* | |
299 | * store a note in the header buffer | |
300 | */ | |
301 | static char *storenote(struct memelfnote *men, char *bufp) | |
302 | { | |
303 | struct elf_note en; | |
304 | ||
305 | #define DUMP_WRITE(addr,nr) do { memcpy(bufp,addr,nr); bufp += nr; } while(0) | |
306 | ||
632dd205 | 307 | en.n_namesz = strlen(men->name) + 1; |
1da177e4 LT |
308 | en.n_descsz = men->datasz; |
309 | en.n_type = men->type; | |
310 | ||
311 | DUMP_WRITE(&en, sizeof(en)); | |
312 | DUMP_WRITE(men->name, en.n_namesz); | |
313 | ||
314 | /* XXX - cast from long long to long to avoid need for libgcc.a */ | |
315 | bufp = (char*) roundup((unsigned long)bufp,4); | |
316 | DUMP_WRITE(men->data, men->datasz); | |
317 | bufp = (char*) roundup((unsigned long)bufp,4); | |
318 | ||
319 | #undef DUMP_WRITE | |
320 | ||
321 | return bufp; | |
322 | } /* end storenote() */ | |
323 | ||
324 | /* | |
325 | * store an ELF coredump header in the supplied buffer | |
326 | * nphdr is the number of elf_phdr to insert | |
327 | */ | |
328 | static void elf_kcore_store_hdr(char *bufp, int nphdr, int dataoff) | |
329 | { | |
330 | struct elf_prstatus prstatus; /* NT_PRSTATUS */ | |
331 | struct elf_prpsinfo prpsinfo; /* NT_PRPSINFO */ | |
332 | struct elf_phdr *nhdr, *phdr; | |
333 | struct elfhdr *elf; | |
334 | struct memelfnote notes[3]; | |
335 | off_t offset = 0; | |
336 | struct kcore_list *m; | |
337 | ||
338 | /* setup ELF header */ | |
339 | elf = (struct elfhdr *) bufp; | |
340 | bufp += sizeof(struct elfhdr); | |
341 | offset += sizeof(struct elfhdr); | |
342 | memcpy(elf->e_ident, ELFMAG, SELFMAG); | |
343 | elf->e_ident[EI_CLASS] = ELF_CLASS; | |
344 | elf->e_ident[EI_DATA] = ELF_DATA; | |
345 | elf->e_ident[EI_VERSION]= EV_CURRENT; | |
346 | elf->e_ident[EI_OSABI] = ELF_OSABI; | |
347 | memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); | |
348 | elf->e_type = ET_CORE; | |
349 | elf->e_machine = ELF_ARCH; | |
350 | elf->e_version = EV_CURRENT; | |
351 | elf->e_entry = 0; | |
352 | elf->e_phoff = sizeof(struct elfhdr); | |
353 | elf->e_shoff = 0; | |
79885b22 | 354 | elf->e_flags = ELF_CORE_EFLAGS; |
1da177e4 LT |
355 | elf->e_ehsize = sizeof(struct elfhdr); |
356 | elf->e_phentsize= sizeof(struct elf_phdr); | |
357 | elf->e_phnum = nphdr; | |
358 | elf->e_shentsize= 0; | |
359 | elf->e_shnum = 0; | |
360 | elf->e_shstrndx = 0; | |
361 | ||
362 | /* setup ELF PT_NOTE program header */ | |
363 | nhdr = (struct elf_phdr *) bufp; | |
364 | bufp += sizeof(struct elf_phdr); | |
365 | offset += sizeof(struct elf_phdr); | |
366 | nhdr->p_type = PT_NOTE; | |
367 | nhdr->p_offset = 0; | |
368 | nhdr->p_vaddr = 0; | |
369 | nhdr->p_paddr = 0; | |
370 | nhdr->p_filesz = 0; | |
371 | nhdr->p_memsz = 0; | |
372 | nhdr->p_flags = 0; | |
373 | nhdr->p_align = 0; | |
374 | ||
375 | /* setup ELF PT_LOAD program header for every area */ | |
2ef43ec7 | 376 | list_for_each_entry(m, &kclist_head, list) { |
1da177e4 LT |
377 | phdr = (struct elf_phdr *) bufp; |
378 | bufp += sizeof(struct elf_phdr); | |
379 | offset += sizeof(struct elf_phdr); | |
380 | ||
381 | phdr->p_type = PT_LOAD; | |
382 | phdr->p_flags = PF_R|PF_W|PF_X; | |
383 | phdr->p_offset = kc_vaddr_to_offset(m->addr) + dataoff; | |
384 | phdr->p_vaddr = (size_t)m->addr; | |
df865e83 | 385 | if (m->type == KCORE_RAM) |
46492010 | 386 | phdr->p_paddr = __pa(m->addr); |
df865e83 JM |
387 | else if (m->type == KCORE_TEXT) |
388 | phdr->p_paddr = __pa_symbol(m->addr); | |
46492010 PA |
389 | else |
390 | phdr->p_paddr = (elf_addr_t)-1; | |
1da177e4 LT |
391 | phdr->p_filesz = phdr->p_memsz = m->size; |
392 | phdr->p_align = PAGE_SIZE; | |
393 | } | |
394 | ||
395 | /* | |
396 | * Set up the notes in similar form to SVR4 core dumps made | |
397 | * with info from their /proc. | |
398 | */ | |
399 | nhdr->p_offset = offset; | |
400 | ||
401 | /* set up the process status */ | |
36027604 | 402 | notes[0].name = CORE_STR; |
1da177e4 LT |
403 | notes[0].type = NT_PRSTATUS; |
404 | notes[0].datasz = sizeof(struct elf_prstatus); | |
405 | notes[0].data = &prstatus; | |
406 | ||
407 | memset(&prstatus, 0, sizeof(struct elf_prstatus)); | |
408 | ||
409 | nhdr->p_filesz = notesize(¬es[0]); | |
410 | bufp = storenote(¬es[0], bufp); | |
411 | ||
412 | /* set up the process info */ | |
36027604 | 413 | notes[1].name = CORE_STR; |
1da177e4 LT |
414 | notes[1].type = NT_PRPSINFO; |
415 | notes[1].datasz = sizeof(struct elf_prpsinfo); | |
416 | notes[1].data = &prpsinfo; | |
417 | ||
418 | memset(&prpsinfo, 0, sizeof(struct elf_prpsinfo)); | |
419 | prpsinfo.pr_state = 0; | |
420 | prpsinfo.pr_sname = 'R'; | |
421 | prpsinfo.pr_zomb = 0; | |
422 | ||
423 | strcpy(prpsinfo.pr_fname, "vmlinux"); | |
30bc30df | 424 | strlcpy(prpsinfo.pr_psargs, saved_command_line, sizeof(prpsinfo.pr_psargs)); |
1da177e4 LT |
425 | |
426 | nhdr->p_filesz += notesize(¬es[1]); | |
427 | bufp = storenote(¬es[1], bufp); | |
428 | ||
429 | /* set up the task structure */ | |
36027604 | 430 | notes[2].name = CORE_STR; |
1da177e4 | 431 | notes[2].type = NT_TASKSTRUCT; |
5aaeb5c0 | 432 | notes[2].datasz = arch_task_struct_size; |
1da177e4 LT |
433 | notes[2].data = current; |
434 | ||
435 | nhdr->p_filesz += notesize(¬es[2]); | |
436 | bufp = storenote(¬es[2], bufp); | |
437 | ||
438 | } /* end elf_kcore_store_hdr() */ | |
439 | ||
440 | /*****************************************************************************/ | |
441 | /* | |
442 | * read from the ELF header and then kernel memory | |
443 | */ | |
444 | static ssize_t | |
445 | read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) | |
446 | { | |
f5beeb18 | 447 | char *buf = file->private_data; |
1da177e4 LT |
448 | ssize_t acc = 0; |
449 | size_t size, tsz; | |
450 | size_t elf_buflen; | |
451 | int nphdr; | |
452 | unsigned long start; | |
453 | ||
454 | read_lock(&kclist_lock); | |
678ad5d8 KH |
455 | size = get_kcore_size(&nphdr, &elf_buflen); |
456 | ||
1da177e4 LT |
457 | if (buflen == 0 || *fpos >= size) { |
458 | read_unlock(&kclist_lock); | |
459 | return 0; | |
460 | } | |
461 | ||
462 | /* trim buflen to not go beyond EOF */ | |
463 | if (buflen > size - *fpos) | |
464 | buflen = size - *fpos; | |
465 | ||
466 | /* construct an ELF core header if we'll need some of it */ | |
467 | if (*fpos < elf_buflen) { | |
468 | char * elf_buf; | |
469 | ||
470 | tsz = elf_buflen - *fpos; | |
471 | if (buflen < tsz) | |
472 | tsz = buflen; | |
f8314dc6 | 473 | elf_buf = kzalloc(elf_buflen, GFP_ATOMIC); |
1da177e4 LT |
474 | if (!elf_buf) { |
475 | read_unlock(&kclist_lock); | |
476 | return -ENOMEM; | |
477 | } | |
1da177e4 LT |
478 | elf_kcore_store_hdr(elf_buf, nphdr, elf_buflen); |
479 | read_unlock(&kclist_lock); | |
480 | if (copy_to_user(buffer, elf_buf + *fpos, tsz)) { | |
481 | kfree(elf_buf); | |
482 | return -EFAULT; | |
483 | } | |
484 | kfree(elf_buf); | |
485 | buflen -= tsz; | |
486 | *fpos += tsz; | |
487 | buffer += tsz; | |
488 | acc += tsz; | |
489 | ||
490 | /* leave now if filled buffer already */ | |
491 | if (buflen == 0) | |
492 | return acc; | |
493 | } else | |
494 | read_unlock(&kclist_lock); | |
495 | ||
496 | /* | |
497 | * Check to see if our file offset matches with any of | |
498 | * the addresses in the elf_phdr on our list. | |
499 | */ | |
500 | start = kc_offset_to_vaddr(*fpos - elf_buflen); | |
501 | if ((tsz = (PAGE_SIZE - (start & ~PAGE_MASK))) > buflen) | |
502 | tsz = buflen; | |
503 | ||
504 | while (buflen) { | |
505 | struct kcore_list *m; | |
506 | ||
507 | read_lock(&kclist_lock); | |
2ef43ec7 | 508 | list_for_each_entry(m, &kclist_head, list) { |
1da177e4 LT |
509 | if (start >= m->addr && start < (m->addr+m->size)) |
510 | break; | |
511 | } | |
512 | read_unlock(&kclist_lock); | |
513 | ||
4fd2c20d | 514 | if (&m->list == &kclist_head) { |
1da177e4 LT |
515 | if (clear_user(buffer, tsz)) |
516 | return -EFAULT; | |
737326aa | 517 | } else if (m->type == KCORE_VMALLOC) { |
f5beeb18 | 518 | vread(buf, (char *)start, tsz); |
73d7c33e | 519 | /* we have to zero-fill user buffer even if no read */ |
f5beeb18 | 520 | if (copy_to_user(buffer, buf, tsz)) |
1da177e4 | 521 | return -EFAULT; |
595dd46e JZ |
522 | } else if (m->type == KCORE_USER) { |
523 | /* User page is handled prior to normal kernel page: */ | |
524 | if (copy_to_user(buffer, (char *)start, tsz)) | |
525 | return -EFAULT; | |
1da177e4 LT |
526 | } else { |
527 | if (kern_addr_valid(start)) { | |
df04abfd JO |
528 | /* |
529 | * Using bounce buffer to bypass the | |
530 | * hardened user copy kernel text checks. | |
531 | */ | |
d0290bc2 HC |
532 | if (probe_kernel_read(buf, (void *) start, tsz)) { |
533 | if (clear_user(buffer, tsz)) | |
534 | return -EFAULT; | |
535 | } else { | |
536 | if (copy_to_user(buffer, buf, tsz)) | |
1da177e4 LT |
537 | return -EFAULT; |
538 | } | |
539 | } else { | |
540 | if (clear_user(buffer, tsz)) | |
541 | return -EFAULT; | |
542 | } | |
543 | } | |
544 | buflen -= tsz; | |
545 | *fpos += tsz; | |
546 | buffer += tsz; | |
547 | acc += tsz; | |
548 | start += tsz; | |
549 | tsz = (buflen > PAGE_SIZE ? PAGE_SIZE : buflen); | |
550 | } | |
551 | ||
552 | return acc; | |
553 | } | |
97ce5d6d | 554 | |
3089aa1b KH |
555 | |
556 | static int open_kcore(struct inode *inode, struct file *filp) | |
557 | { | |
558 | if (!capable(CAP_SYS_RAWIO)) | |
559 | return -EPERM; | |
f5beeb18 JO |
560 | |
561 | filp->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
562 | if (!filp->private_data) | |
563 | return -ENOMEM; | |
564 | ||
3089aa1b KH |
565 | if (kcore_need_update) |
566 | kcore_update_ram(); | |
0d4c36a9 | 567 | if (i_size_read(inode) != proc_root_kcore->size) { |
5955102c | 568 | inode_lock(inode); |
0d4c36a9 | 569 | i_size_write(inode, proc_root_kcore->size); |
5955102c | 570 | inode_unlock(inode); |
0d4c36a9 | 571 | } |
3089aa1b KH |
572 | return 0; |
573 | } | |
574 | ||
f5beeb18 JO |
575 | static int release_kcore(struct inode *inode, struct file *file) |
576 | { | |
577 | kfree(file->private_data); | |
578 | return 0; | |
579 | } | |
3089aa1b KH |
580 | |
581 | static const struct file_operations proc_kcore_operations = { | |
582 | .read = read_kcore, | |
583 | .open = open_kcore, | |
f5beeb18 | 584 | .release = release_kcore, |
ceff1a77 | 585 | .llseek = default_llseek, |
3089aa1b KH |
586 | }; |
587 | ||
3089aa1b KH |
588 | /* just remember that we have to update kcore */ |
589 | static int __meminit kcore_callback(struct notifier_block *self, | |
590 | unsigned long action, void *arg) | |
591 | { | |
592 | switch (action) { | |
593 | case MEM_ONLINE: | |
594 | case MEM_OFFLINE: | |
3089aa1b | 595 | kcore_need_update = 1; |
bf531831 | 596 | break; |
3089aa1b KH |
597 | } |
598 | return NOTIFY_OK; | |
599 | } | |
3089aa1b | 600 | |
3c743a7f AM |
601 | static struct notifier_block kcore_callback_nb __meminitdata = { |
602 | .notifier_call = kcore_callback, | |
603 | .priority = 0, | |
604 | }; | |
3089aa1b | 605 | |
a0614da8 KH |
606 | static struct kcore_list kcore_vmalloc; |
607 | ||
9492587c KH |
608 | #ifdef CONFIG_ARCH_PROC_KCORE_TEXT |
609 | static struct kcore_list kcore_text; | |
610 | /* | |
611 | * If defined, special segment is used for mapping kernel text instead of | |
612 | * direct-map area. We need to create special TEXT section. | |
613 | */ | |
614 | static void __init proc_kcore_text_init(void) | |
615 | { | |
36e15263 | 616 | kclist_add(&kcore_text, _text, _end - _text, KCORE_TEXT); |
9492587c KH |
617 | } |
618 | #else | |
619 | static void __init proc_kcore_text_init(void) | |
620 | { | |
621 | } | |
622 | #endif | |
623 | ||
81ac3ad9 KH |
624 | #if defined(CONFIG_MODULES) && defined(MODULES_VADDR) |
625 | /* | |
626 | * MODULES_VADDR has no intersection with VMALLOC_ADDR. | |
627 | */ | |
628 | struct kcore_list kcore_modules; | |
629 | static void __init add_modules_range(void) | |
630 | { | |
bf3e2692 BH |
631 | if (MODULES_VADDR != VMALLOC_START && MODULES_END != VMALLOC_END) { |
632 | kclist_add(&kcore_modules, (void *)MODULES_VADDR, | |
81ac3ad9 | 633 | MODULES_END - MODULES_VADDR, KCORE_VMALLOC); |
bf3e2692 | 634 | } |
81ac3ad9 KH |
635 | } |
636 | #else | |
637 | static void __init add_modules_range(void) | |
638 | { | |
639 | } | |
640 | #endif | |
641 | ||
97ce5d6d AD |
642 | static int __init proc_kcore_init(void) |
643 | { | |
3089aa1b KH |
644 | proc_root_kcore = proc_create("kcore", S_IRUSR, NULL, |
645 | &proc_kcore_operations); | |
90396f96 | 646 | if (!proc_root_kcore) { |
87ebdc00 | 647 | pr_err("couldn't create /proc/kcore\n"); |
90396f96 KH |
648 | return 0; /* Always returns 0. */ |
649 | } | |
3089aa1b | 650 | /* Store text area if it's special */ |
9492587c | 651 | proc_kcore_text_init(); |
3089aa1b | 652 | /* Store vmalloc area */ |
a0614da8 KH |
653 | kclist_add(&kcore_vmalloc, (void *)VMALLOC_START, |
654 | VMALLOC_END - VMALLOC_START, KCORE_VMALLOC); | |
81ac3ad9 | 655 | add_modules_range(); |
3089aa1b KH |
656 | /* Store direct-map area from physical memory map */ |
657 | kcore_update_ram(); | |
3c743a7f | 658 | register_hotmemory_notifier(&kcore_callback_nb); |
3089aa1b | 659 | |
97ce5d6d AD |
660 | return 0; |
661 | } | |
abaf3787 | 662 | fs_initcall(proc_kcore_init); |