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