Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/mem.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * Added devfs support. | |
7 | * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu> | |
8 | * Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com> | |
9 | */ | |
10 | ||
1da177e4 LT |
11 | #include <linux/mm.h> |
12 | #include <linux/miscdevice.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/vmalloc.h> | |
15 | #include <linux/mman.h> | |
16 | #include <linux/random.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/raw.h> | |
19 | #include <linux/tty.h> | |
20 | #include <linux/capability.h> | |
1da177e4 LT |
21 | #include <linux/ptrace.h> |
22 | #include <linux/device.h> | |
50b1fdbd VG |
23 | #include <linux/highmem.h> |
24 | #include <linux/crash_dump.h> | |
1da177e4 | 25 | #include <linux/backing-dev.h> |
315c215c | 26 | #include <linux/bootmem.h> |
d6b29d7c | 27 | #include <linux/splice.h> |
b8a3ad5b | 28 | #include <linux/pfn.h> |
1da177e4 LT |
29 | |
30 | #include <asm/uaccess.h> | |
31 | #include <asm/io.h> | |
32 | ||
33 | #ifdef CONFIG_IA64 | |
34 | # include <linux/efi.h> | |
35 | #endif | |
36 | ||
1da177e4 LT |
37 | /* |
38 | * Architectures vary in how they handle caching for addresses | |
39 | * outside of main memory. | |
40 | * | |
41 | */ | |
42 | static inline int uncached_access(struct file *file, unsigned long addr) | |
43 | { | |
f0970c13 | 44 | #if defined(CONFIG_IA64) |
1da177e4 LT |
45 | /* |
46 | * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases. | |
47 | */ | |
48 | return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); | |
24e9d0b9 RB |
49 | #elif defined(CONFIG_MIPS) |
50 | { | |
51 | extern int __uncached_access(struct file *file, | |
52 | unsigned long addr); | |
53 | ||
54 | return __uncached_access(file, addr); | |
55 | } | |
1da177e4 LT |
56 | #else |
57 | /* | |
58 | * Accessing memory above the top the kernel knows about or through a file pointer | |
59 | * that was marked O_SYNC will be done non-cached. | |
60 | */ | |
61 | if (file->f_flags & O_SYNC) | |
62 | return 1; | |
63 | return addr >= __pa(high_memory); | |
64 | #endif | |
65 | } | |
66 | ||
67 | #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE | |
136939a2 | 68 | static inline int valid_phys_addr_range(unsigned long addr, size_t count) |
1da177e4 | 69 | { |
136939a2 | 70 | if (addr + count > __pa(high_memory)) |
1da177e4 LT |
71 | return 0; |
72 | ||
1da177e4 LT |
73 | return 1; |
74 | } | |
80851ef2 | 75 | |
06c67bef | 76 | static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) |
80851ef2 BH |
77 | { |
78 | return 1; | |
79 | } | |
1da177e4 LT |
80 | #endif |
81 | ||
ae531c26 | 82 | #ifdef CONFIG_NONPROMISC_DEVMEM |
e2beb3ea | 83 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 | 84 | { |
e2beb3ea VP |
85 | u64 from = ((u64)pfn) << PAGE_SHIFT; |
86 | u64 to = from + size; | |
87 | u64 cursor = from; | |
88 | ||
89 | while (cursor < to) { | |
90 | if (!devmem_is_allowed(pfn)) { | |
91 | printk(KERN_INFO | |
92 | "Program %s tried to access /dev/mem between %Lx->%Lx.\n", | |
ae531c26 AV |
93 | current->comm, from, to); |
94 | return 0; | |
95 | } | |
e2beb3ea VP |
96 | cursor += PAGE_SIZE; |
97 | pfn++; | |
ae531c26 AV |
98 | } |
99 | return 1; | |
100 | } | |
101 | #else | |
e2beb3ea | 102 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 AV |
103 | { |
104 | return 1; | |
105 | } | |
106 | #endif | |
107 | ||
e045fb2a | 108 | void __attribute__((weak)) unxlate_dev_mem_ptr(unsigned long phys, void *addr) |
109 | { | |
110 | } | |
111 | ||
1da177e4 LT |
112 | /* |
113 | * This funcion reads the *physical* memory. The f_pos points directly to the | |
114 | * memory location. | |
115 | */ | |
116 | static ssize_t read_mem(struct file * file, char __user * buf, | |
117 | size_t count, loff_t *ppos) | |
118 | { | |
119 | unsigned long p = *ppos; | |
120 | ssize_t read, sz; | |
121 | char *ptr; | |
122 | ||
136939a2 | 123 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
124 | return -EFAULT; |
125 | read = 0; | |
126 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
127 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
128 | if (p < PAGE_SIZE) { | |
129 | sz = PAGE_SIZE - p; | |
130 | if (sz > count) | |
131 | sz = count; | |
132 | if (sz > 0) { | |
133 | if (clear_user(buf, sz)) | |
134 | return -EFAULT; | |
135 | buf += sz; | |
136 | p += sz; | |
137 | count -= sz; | |
138 | read += sz; | |
139 | } | |
140 | } | |
141 | #endif | |
142 | ||
143 | while (count > 0) { | |
144 | /* | |
145 | * Handle first page in case it's not aligned | |
146 | */ | |
147 | if (-p & (PAGE_SIZE - 1)) | |
148 | sz = -p & (PAGE_SIZE - 1); | |
149 | else | |
150 | sz = PAGE_SIZE; | |
151 | ||
152 | sz = min_t(unsigned long, sz, count); | |
153 | ||
e045fb2a | 154 | if (!range_is_allowed(p >> PAGE_SHIFT, count)) |
155 | return -EPERM; | |
156 | ||
1da177e4 LT |
157 | /* |
158 | * On ia64 if a page has been mapped somewhere as | |
159 | * uncached, then it must also be accessed uncached | |
160 | * by the kernel or data corruption may occur | |
161 | */ | |
162 | ptr = xlate_dev_mem_ptr(p); | |
e045fb2a | 163 | if (!ptr) |
164 | return -EFAULT; | |
1da177e4 | 165 | |
e045fb2a | 166 | if (copy_to_user(buf, ptr, sz)) { |
167 | unxlate_dev_mem_ptr(p, ptr); | |
1da177e4 | 168 | return -EFAULT; |
e045fb2a | 169 | } |
170 | ||
171 | unxlate_dev_mem_ptr(p, ptr); | |
172 | ||
1da177e4 LT |
173 | buf += sz; |
174 | p += sz; | |
175 | count -= sz; | |
176 | read += sz; | |
177 | } | |
178 | ||
179 | *ppos += read; | |
180 | return read; | |
181 | } | |
182 | ||
183 | static ssize_t write_mem(struct file * file, const char __user * buf, | |
184 | size_t count, loff_t *ppos) | |
185 | { | |
186 | unsigned long p = *ppos; | |
187 | ssize_t written, sz; | |
188 | unsigned long copied; | |
189 | void *ptr; | |
190 | ||
136939a2 | 191 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
192 | return -EFAULT; |
193 | ||
194 | written = 0; | |
195 | ||
196 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
197 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
198 | if (p < PAGE_SIZE) { | |
199 | unsigned long sz = PAGE_SIZE - p; | |
200 | if (sz > count) | |
201 | sz = count; | |
202 | /* Hmm. Do something? */ | |
203 | buf += sz; | |
204 | p += sz; | |
205 | count -= sz; | |
206 | written += sz; | |
207 | } | |
208 | #endif | |
209 | ||
210 | while (count > 0) { | |
211 | /* | |
212 | * Handle first page in case it's not aligned | |
213 | */ | |
214 | if (-p & (PAGE_SIZE - 1)) | |
215 | sz = -p & (PAGE_SIZE - 1); | |
216 | else | |
217 | sz = PAGE_SIZE; | |
218 | ||
219 | sz = min_t(unsigned long, sz, count); | |
220 | ||
e045fb2a | 221 | if (!range_is_allowed(p >> PAGE_SHIFT, sz)) |
222 | return -EPERM; | |
223 | ||
1da177e4 LT |
224 | /* |
225 | * On ia64 if a page has been mapped somewhere as | |
226 | * uncached, then it must also be accessed uncached | |
227 | * by the kernel or data corruption may occur | |
228 | */ | |
229 | ptr = xlate_dev_mem_ptr(p); | |
e045fb2a | 230 | if (!ptr) { |
231 | if (written) | |
232 | break; | |
233 | return -EFAULT; | |
234 | } | |
1da177e4 LT |
235 | |
236 | copied = copy_from_user(ptr, buf, sz); | |
237 | if (copied) { | |
c654d60e | 238 | written += sz - copied; |
e045fb2a | 239 | unxlate_dev_mem_ptr(p, ptr); |
c654d60e JB |
240 | if (written) |
241 | break; | |
1da177e4 LT |
242 | return -EFAULT; |
243 | } | |
e045fb2a | 244 | |
245 | unxlate_dev_mem_ptr(p, ptr); | |
246 | ||
1da177e4 LT |
247 | buf += sz; |
248 | p += sz; | |
249 | count -= sz; | |
250 | written += sz; | |
251 | } | |
252 | ||
253 | *ppos += written; | |
254 | return written; | |
255 | } | |
256 | ||
f0970c13 | 257 | int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file, |
258 | unsigned long pfn, unsigned long size, pgprot_t *vma_prot) | |
259 | { | |
260 | return 1; | |
261 | } | |
262 | ||
44ac8413 BH |
263 | #ifndef __HAVE_PHYS_MEM_ACCESS_PROT |
264 | static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, | |
265 | unsigned long size, pgprot_t vma_prot) | |
266 | { | |
267 | #ifdef pgprot_noncached | |
268 | unsigned long offset = pfn << PAGE_SHIFT; | |
269 | ||
270 | if (uncached_access(file, offset)) | |
271 | return pgprot_noncached(vma_prot); | |
272 | #endif | |
273 | return vma_prot; | |
274 | } | |
275 | #endif | |
276 | ||
5da6185b DH |
277 | #ifndef CONFIG_MMU |
278 | static unsigned long get_unmapped_area_mem(struct file *file, | |
279 | unsigned long addr, | |
280 | unsigned long len, | |
281 | unsigned long pgoff, | |
282 | unsigned long flags) | |
283 | { | |
284 | if (!valid_mmap_phys_addr_range(pgoff, len)) | |
285 | return (unsigned long) -EINVAL; | |
8a93258c | 286 | return pgoff << PAGE_SHIFT; |
5da6185b DH |
287 | } |
288 | ||
289 | /* can't do an in-place private mapping if there's no MMU */ | |
290 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
291 | { | |
292 | return vma->vm_flags & VM_MAYSHARE; | |
293 | } | |
294 | #else | |
295 | #define get_unmapped_area_mem NULL | |
296 | ||
297 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
298 | { | |
299 | return 1; | |
300 | } | |
301 | #endif | |
302 | ||
e7f260a2 | 303 | void __attribute__((weak)) |
304 | map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot) | |
305 | { | |
306 | /* nothing. architectures can override. */ | |
307 | } | |
308 | ||
309 | void __attribute__((weak)) | |
310 | unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot) | |
311 | { | |
312 | /* nothing. architectures can override. */ | |
313 | } | |
314 | ||
315 | static void mmap_mem_open(struct vm_area_struct *vma) | |
316 | { | |
317 | map_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start, | |
318 | vma->vm_page_prot); | |
319 | } | |
320 | ||
321 | static void mmap_mem_close(struct vm_area_struct *vma) | |
322 | { | |
323 | unmap_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start, | |
324 | vma->vm_page_prot); | |
325 | } | |
326 | ||
327 | static struct vm_operations_struct mmap_mem_ops = { | |
328 | .open = mmap_mem_open, | |
329 | .close = mmap_mem_close | |
330 | }; | |
331 | ||
1da177e4 LT |
332 | static int mmap_mem(struct file * file, struct vm_area_struct * vma) |
333 | { | |
80851ef2 BH |
334 | size_t size = vma->vm_end - vma->vm_start; |
335 | ||
06c67bef | 336 | if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) |
80851ef2 BH |
337 | return -EINVAL; |
338 | ||
5da6185b DH |
339 | if (!private_mapping_ok(vma)) |
340 | return -ENOSYS; | |
341 | ||
e2beb3ea VP |
342 | if (!range_is_allowed(vma->vm_pgoff, size)) |
343 | return -EPERM; | |
344 | ||
f0970c13 | 345 | if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, |
346 | &vma->vm_page_prot)) | |
347 | return -EINVAL; | |
348 | ||
8b150478 | 349 | vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, |
80851ef2 | 350 | size, |
1da177e4 | 351 | vma->vm_page_prot); |
1da177e4 | 352 | |
e7f260a2 | 353 | vma->vm_ops = &mmap_mem_ops; |
354 | ||
1da177e4 LT |
355 | /* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */ |
356 | if (remap_pfn_range(vma, | |
357 | vma->vm_start, | |
358 | vma->vm_pgoff, | |
80851ef2 | 359 | size, |
e7f260a2 | 360 | vma->vm_page_prot)) { |
361 | unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot); | |
1da177e4 | 362 | return -EAGAIN; |
e7f260a2 | 363 | } |
1da177e4 LT |
364 | return 0; |
365 | } | |
366 | ||
367 | static int mmap_kmem(struct file * file, struct vm_area_struct * vma) | |
368 | { | |
4bb82551 LT |
369 | unsigned long pfn; |
370 | ||
6d3154cc LT |
371 | /* Turn a kernel-virtual address into a physical page frame */ |
372 | pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; | |
4bb82551 | 373 | |
1da177e4 LT |
374 | /* |
375 | * RED-PEN: on some architectures there is more mapped memory | |
376 | * than available in mem_map which pfn_valid checks | |
377 | * for. Perhaps should add a new macro here. | |
378 | * | |
379 | * RED-PEN: vmalloc is not supported right now. | |
380 | */ | |
4bb82551 | 381 | if (!pfn_valid(pfn)) |
1da177e4 | 382 | return -EIO; |
4bb82551 LT |
383 | |
384 | vma->vm_pgoff = pfn; | |
1da177e4 LT |
385 | return mmap_mem(file, vma); |
386 | } | |
387 | ||
50b1fdbd VG |
388 | #ifdef CONFIG_CRASH_DUMP |
389 | /* | |
390 | * Read memory corresponding to the old kernel. | |
50b1fdbd | 391 | */ |
315c215c | 392 | static ssize_t read_oldmem(struct file *file, char __user *buf, |
50b1fdbd VG |
393 | size_t count, loff_t *ppos) |
394 | { | |
315c215c VG |
395 | unsigned long pfn, offset; |
396 | size_t read = 0, csize; | |
397 | int rc = 0; | |
50b1fdbd | 398 | |
72414d3f | 399 | while (count) { |
50b1fdbd | 400 | pfn = *ppos / PAGE_SIZE; |
315c215c VG |
401 | if (pfn > saved_max_pfn) |
402 | return read; | |
50b1fdbd | 403 | |
315c215c VG |
404 | offset = (unsigned long)(*ppos % PAGE_SIZE); |
405 | if (count > PAGE_SIZE - offset) | |
406 | csize = PAGE_SIZE - offset; | |
407 | else | |
408 | csize = count; | |
50b1fdbd | 409 | |
315c215c VG |
410 | rc = copy_oldmem_page(pfn, buf, csize, offset, 1); |
411 | if (rc < 0) | |
412 | return rc; | |
50b1fdbd VG |
413 | buf += csize; |
414 | *ppos += csize; | |
415 | read += csize; | |
416 | count -= csize; | |
417 | } | |
50b1fdbd VG |
418 | return read; |
419 | } | |
420 | #endif | |
421 | ||
1da177e4 LT |
422 | extern long vread(char *buf, char *addr, unsigned long count); |
423 | extern long vwrite(char *buf, char *addr, unsigned long count); | |
424 | ||
425 | /* | |
426 | * This function reads the *virtual* memory as seen by the kernel. | |
427 | */ | |
428 | static ssize_t read_kmem(struct file *file, char __user *buf, | |
429 | size_t count, loff_t *ppos) | |
430 | { | |
431 | unsigned long p = *ppos; | |
432 | ssize_t low_count, read, sz; | |
433 | char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ | |
434 | ||
435 | read = 0; | |
436 | if (p < (unsigned long) high_memory) { | |
437 | low_count = count; | |
438 | if (count > (unsigned long) high_memory - p) | |
439 | low_count = (unsigned long) high_memory - p; | |
440 | ||
441 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
442 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
443 | if (p < PAGE_SIZE && low_count > 0) { | |
444 | size_t tmp = PAGE_SIZE - p; | |
445 | if (tmp > low_count) tmp = low_count; | |
446 | if (clear_user(buf, tmp)) | |
447 | return -EFAULT; | |
448 | buf += tmp; | |
449 | p += tmp; | |
450 | read += tmp; | |
451 | low_count -= tmp; | |
452 | count -= tmp; | |
453 | } | |
454 | #endif | |
455 | while (low_count > 0) { | |
456 | /* | |
457 | * Handle first page in case it's not aligned | |
458 | */ | |
459 | if (-p & (PAGE_SIZE - 1)) | |
460 | sz = -p & (PAGE_SIZE - 1); | |
461 | else | |
462 | sz = PAGE_SIZE; | |
463 | ||
464 | sz = min_t(unsigned long, sz, low_count); | |
465 | ||
466 | /* | |
467 | * On ia64 if a page has been mapped somewhere as | |
468 | * uncached, then it must also be accessed uncached | |
469 | * by the kernel or data corruption may occur | |
470 | */ | |
471 | kbuf = xlate_dev_kmem_ptr((char *)p); | |
472 | ||
473 | if (copy_to_user(buf, kbuf, sz)) | |
474 | return -EFAULT; | |
475 | buf += sz; | |
476 | p += sz; | |
477 | read += sz; | |
478 | low_count -= sz; | |
479 | count -= sz; | |
480 | } | |
481 | } | |
482 | ||
483 | if (count > 0) { | |
484 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
485 | if (!kbuf) | |
486 | return -ENOMEM; | |
487 | while (count > 0) { | |
488 | int len = count; | |
489 | ||
490 | if (len > PAGE_SIZE) | |
491 | len = PAGE_SIZE; | |
492 | len = vread(kbuf, (char *)p, len); | |
493 | if (!len) | |
494 | break; | |
495 | if (copy_to_user(buf, kbuf, len)) { | |
496 | free_page((unsigned long)kbuf); | |
497 | return -EFAULT; | |
498 | } | |
499 | count -= len; | |
500 | buf += len; | |
501 | read += len; | |
502 | p += len; | |
503 | } | |
504 | free_page((unsigned long)kbuf); | |
505 | } | |
506 | *ppos = p; | |
507 | return read; | |
508 | } | |
509 | ||
510 | ||
511 | static inline ssize_t | |
512 | do_write_kmem(void *p, unsigned long realp, const char __user * buf, | |
513 | size_t count, loff_t *ppos) | |
514 | { | |
515 | ssize_t written, sz; | |
516 | unsigned long copied; | |
517 | ||
518 | written = 0; | |
519 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
520 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
521 | if (realp < PAGE_SIZE) { | |
522 | unsigned long sz = PAGE_SIZE - realp; | |
523 | if (sz > count) | |
524 | sz = count; | |
525 | /* Hmm. Do something? */ | |
526 | buf += sz; | |
527 | p += sz; | |
528 | realp += sz; | |
529 | count -= sz; | |
530 | written += sz; | |
531 | } | |
532 | #endif | |
533 | ||
534 | while (count > 0) { | |
535 | char *ptr; | |
536 | /* | |
537 | * Handle first page in case it's not aligned | |
538 | */ | |
539 | if (-realp & (PAGE_SIZE - 1)) | |
540 | sz = -realp & (PAGE_SIZE - 1); | |
541 | else | |
542 | sz = PAGE_SIZE; | |
543 | ||
544 | sz = min_t(unsigned long, sz, count); | |
545 | ||
546 | /* | |
547 | * On ia64 if a page has been mapped somewhere as | |
548 | * uncached, then it must also be accessed uncached | |
549 | * by the kernel or data corruption may occur | |
550 | */ | |
551 | ptr = xlate_dev_kmem_ptr(p); | |
552 | ||
553 | copied = copy_from_user(ptr, buf, sz); | |
554 | if (copied) { | |
c654d60e JB |
555 | written += sz - copied; |
556 | if (written) | |
557 | break; | |
1da177e4 LT |
558 | return -EFAULT; |
559 | } | |
560 | buf += sz; | |
561 | p += sz; | |
562 | realp += sz; | |
563 | count -= sz; | |
564 | written += sz; | |
565 | } | |
566 | ||
567 | *ppos += written; | |
568 | return written; | |
569 | } | |
570 | ||
571 | ||
572 | /* | |
573 | * This function writes to the *virtual* memory as seen by the kernel. | |
574 | */ | |
575 | static ssize_t write_kmem(struct file * file, const char __user * buf, | |
576 | size_t count, loff_t *ppos) | |
577 | { | |
578 | unsigned long p = *ppos; | |
579 | ssize_t wrote = 0; | |
580 | ssize_t virtr = 0; | |
581 | ssize_t written; | |
582 | char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ | |
583 | ||
584 | if (p < (unsigned long) high_memory) { | |
585 | ||
586 | wrote = count; | |
587 | if (count > (unsigned long) high_memory - p) | |
588 | wrote = (unsigned long) high_memory - p; | |
589 | ||
590 | written = do_write_kmem((void*)p, p, buf, wrote, ppos); | |
591 | if (written != wrote) | |
592 | return written; | |
593 | wrote = written; | |
594 | p += wrote; | |
595 | buf += wrote; | |
596 | count -= wrote; | |
597 | } | |
598 | ||
599 | if (count > 0) { | |
600 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
601 | if (!kbuf) | |
602 | return wrote ? wrote : -ENOMEM; | |
603 | while (count > 0) { | |
604 | int len = count; | |
605 | ||
606 | if (len > PAGE_SIZE) | |
607 | len = PAGE_SIZE; | |
608 | if (len) { | |
609 | written = copy_from_user(kbuf, buf, len); | |
610 | if (written) { | |
c654d60e JB |
611 | if (wrote + virtr) |
612 | break; | |
1da177e4 | 613 | free_page((unsigned long)kbuf); |
c654d60e | 614 | return -EFAULT; |
1da177e4 LT |
615 | } |
616 | } | |
617 | len = vwrite(kbuf, (char *)p, len); | |
618 | count -= len; | |
619 | buf += len; | |
620 | virtr += len; | |
621 | p += len; | |
622 | } | |
623 | free_page((unsigned long)kbuf); | |
624 | } | |
625 | ||
626 | *ppos = p; | |
627 | return virtr + wrote; | |
628 | } | |
629 | ||
4f911d64 | 630 | #ifdef CONFIG_DEVPORT |
1da177e4 LT |
631 | static ssize_t read_port(struct file * file, char __user * buf, |
632 | size_t count, loff_t *ppos) | |
633 | { | |
634 | unsigned long i = *ppos; | |
635 | char __user *tmp = buf; | |
636 | ||
637 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
638 | return -EFAULT; | |
639 | while (count-- > 0 && i < 65536) { | |
640 | if (__put_user(inb(i),tmp) < 0) | |
641 | return -EFAULT; | |
642 | i++; | |
643 | tmp++; | |
644 | } | |
645 | *ppos = i; | |
646 | return tmp-buf; | |
647 | } | |
648 | ||
649 | static ssize_t write_port(struct file * file, const char __user * buf, | |
650 | size_t count, loff_t *ppos) | |
651 | { | |
652 | unsigned long i = *ppos; | |
653 | const char __user * tmp = buf; | |
654 | ||
655 | if (!access_ok(VERIFY_READ,buf,count)) | |
656 | return -EFAULT; | |
657 | while (count-- > 0 && i < 65536) { | |
658 | char c; | |
c654d60e JB |
659 | if (__get_user(c, tmp)) { |
660 | if (tmp > buf) | |
661 | break; | |
1da177e4 | 662 | return -EFAULT; |
c654d60e | 663 | } |
1da177e4 LT |
664 | outb(c,i); |
665 | i++; | |
666 | tmp++; | |
667 | } | |
668 | *ppos = i; | |
669 | return tmp-buf; | |
670 | } | |
671 | #endif | |
672 | ||
673 | static ssize_t read_null(struct file * file, char __user * buf, | |
674 | size_t count, loff_t *ppos) | |
675 | { | |
676 | return 0; | |
677 | } | |
678 | ||
679 | static ssize_t write_null(struct file * file, const char __user * buf, | |
680 | size_t count, loff_t *ppos) | |
681 | { | |
682 | return count; | |
683 | } | |
684 | ||
1ebd32fc JA |
685 | static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, |
686 | struct splice_desc *sd) | |
687 | { | |
688 | return sd->len; | |
689 | } | |
690 | ||
691 | static ssize_t splice_write_null(struct pipe_inode_info *pipe,struct file *out, | |
692 | loff_t *ppos, size_t len, unsigned int flags) | |
693 | { | |
694 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); | |
695 | } | |
696 | ||
1da177e4 LT |
697 | static ssize_t read_zero(struct file * file, char __user * buf, |
698 | size_t count, loff_t *ppos) | |
699 | { | |
557ed1fa | 700 | size_t written; |
1da177e4 LT |
701 | |
702 | if (!count) | |
703 | return 0; | |
704 | ||
705 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
706 | return -EFAULT; | |
707 | ||
557ed1fa NP |
708 | written = 0; |
709 | while (count) { | |
710 | unsigned long unwritten; | |
711 | size_t chunk = count; | |
1da177e4 | 712 | |
557ed1fa NP |
713 | if (chunk > PAGE_SIZE) |
714 | chunk = PAGE_SIZE; /* Just for latency reasons */ | |
715 | unwritten = clear_user(buf, chunk); | |
716 | written += chunk - unwritten; | |
1da177e4 | 717 | if (unwritten) |
557ed1fa | 718 | break; |
1da177e4 | 719 | buf += chunk; |
557ed1fa | 720 | count -= chunk; |
1da177e4 LT |
721 | cond_resched(); |
722 | } | |
557ed1fa | 723 | return written ? written : -EFAULT; |
1da177e4 LT |
724 | } |
725 | ||
726 | static int mmap_zero(struct file * file, struct vm_area_struct * vma) | |
727 | { | |
557ed1fa | 728 | #ifndef CONFIG_MMU |
1da177e4 | 729 | return -ENOSYS; |
557ed1fa NP |
730 | #endif |
731 | if (vma->vm_flags & VM_SHARED) | |
732 | return shmem_zero_setup(vma); | |
733 | return 0; | |
1da177e4 | 734 | } |
1da177e4 LT |
735 | |
736 | static ssize_t write_full(struct file * file, const char __user * buf, | |
737 | size_t count, loff_t *ppos) | |
738 | { | |
739 | return -ENOSPC; | |
740 | } | |
741 | ||
742 | /* | |
743 | * Special lseek() function for /dev/null and /dev/zero. Most notably, you | |
744 | * can fopen() both devices with "a" now. This was previously impossible. | |
745 | * -- SRB. | |
746 | */ | |
747 | ||
748 | static loff_t null_lseek(struct file * file, loff_t offset, int orig) | |
749 | { | |
750 | return file->f_pos = 0; | |
751 | } | |
752 | ||
753 | /* | |
754 | * The memory devices use the full 32/64 bits of the offset, and so we cannot | |
755 | * check against negative addresses: they are ok. The return value is weird, | |
756 | * though, in that case (0). | |
757 | * | |
758 | * also note that seeking relative to the "end of file" isn't supported: | |
759 | * it has no meaning, so it returns -EINVAL. | |
760 | */ | |
761 | static loff_t memory_lseek(struct file * file, loff_t offset, int orig) | |
762 | { | |
763 | loff_t ret; | |
764 | ||
a7113a96 | 765 | mutex_lock(&file->f_path.dentry->d_inode->i_mutex); |
1da177e4 LT |
766 | switch (orig) { |
767 | case 0: | |
768 | file->f_pos = offset; | |
769 | ret = file->f_pos; | |
770 | force_successful_syscall_return(); | |
771 | break; | |
772 | case 1: | |
773 | file->f_pos += offset; | |
774 | ret = file->f_pos; | |
775 | force_successful_syscall_return(); | |
776 | break; | |
777 | default: | |
778 | ret = -EINVAL; | |
779 | } | |
a7113a96 | 780 | mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); |
1da177e4 LT |
781 | return ret; |
782 | } | |
783 | ||
784 | static int open_port(struct inode * inode, struct file * filp) | |
785 | { | |
786 | return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; | |
787 | } | |
788 | ||
789 | #define zero_lseek null_lseek | |
790 | #define full_lseek null_lseek | |
791 | #define write_zero write_null | |
792 | #define read_full read_zero | |
793 | #define open_mem open_port | |
794 | #define open_kmem open_mem | |
50b1fdbd | 795 | #define open_oldmem open_mem |
1da177e4 | 796 | |
62322d25 | 797 | static const struct file_operations mem_fops = { |
1da177e4 LT |
798 | .llseek = memory_lseek, |
799 | .read = read_mem, | |
800 | .write = write_mem, | |
801 | .mmap = mmap_mem, | |
802 | .open = open_mem, | |
5da6185b | 803 | .get_unmapped_area = get_unmapped_area_mem, |
1da177e4 LT |
804 | }; |
805 | ||
62322d25 | 806 | static const struct file_operations kmem_fops = { |
1da177e4 LT |
807 | .llseek = memory_lseek, |
808 | .read = read_kmem, | |
809 | .write = write_kmem, | |
810 | .mmap = mmap_kmem, | |
811 | .open = open_kmem, | |
5da6185b | 812 | .get_unmapped_area = get_unmapped_area_mem, |
1da177e4 LT |
813 | }; |
814 | ||
62322d25 | 815 | static const struct file_operations null_fops = { |
1da177e4 LT |
816 | .llseek = null_lseek, |
817 | .read = read_null, | |
818 | .write = write_null, | |
1ebd32fc | 819 | .splice_write = splice_write_null, |
1da177e4 LT |
820 | }; |
821 | ||
4f911d64 | 822 | #ifdef CONFIG_DEVPORT |
62322d25 | 823 | static const struct file_operations port_fops = { |
1da177e4 LT |
824 | .llseek = memory_lseek, |
825 | .read = read_port, | |
826 | .write = write_port, | |
827 | .open = open_port, | |
828 | }; | |
829 | #endif | |
830 | ||
62322d25 | 831 | static const struct file_operations zero_fops = { |
1da177e4 LT |
832 | .llseek = zero_lseek, |
833 | .read = read_zero, | |
834 | .write = write_zero, | |
835 | .mmap = mmap_zero, | |
836 | }; | |
837 | ||
5da6185b DH |
838 | /* |
839 | * capabilities for /dev/zero | |
840 | * - permits private mappings, "copies" are taken of the source of zeros | |
841 | */ | |
1da177e4 LT |
842 | static struct backing_dev_info zero_bdi = { |
843 | .capabilities = BDI_CAP_MAP_COPY, | |
844 | }; | |
845 | ||
62322d25 | 846 | static const struct file_operations full_fops = { |
1da177e4 LT |
847 | .llseek = full_lseek, |
848 | .read = read_full, | |
849 | .write = write_full, | |
850 | }; | |
851 | ||
50b1fdbd | 852 | #ifdef CONFIG_CRASH_DUMP |
62322d25 | 853 | static const struct file_operations oldmem_fops = { |
50b1fdbd VG |
854 | .read = read_oldmem, |
855 | .open = open_oldmem, | |
856 | }; | |
857 | #endif | |
858 | ||
1da177e4 LT |
859 | static ssize_t kmsg_write(struct file * file, const char __user * buf, |
860 | size_t count, loff_t *ppos) | |
861 | { | |
862 | char *tmp; | |
cd140a5c | 863 | ssize_t ret; |
1da177e4 LT |
864 | |
865 | tmp = kmalloc(count + 1, GFP_KERNEL); | |
866 | if (tmp == NULL) | |
867 | return -ENOMEM; | |
868 | ret = -EFAULT; | |
869 | if (!copy_from_user(tmp, buf, count)) { | |
870 | tmp[count] = 0; | |
871 | ret = printk("%s", tmp); | |
cd140a5c GC |
872 | if (ret > count) |
873 | /* printk can add a prefix */ | |
874 | ret = count; | |
1da177e4 LT |
875 | } |
876 | kfree(tmp); | |
877 | return ret; | |
878 | } | |
879 | ||
62322d25 | 880 | static const struct file_operations kmsg_fops = { |
1da177e4 LT |
881 | .write = kmsg_write, |
882 | }; | |
883 | ||
884 | static int memory_open(struct inode * inode, struct file * filp) | |
885 | { | |
886 | switch (iminor(inode)) { | |
887 | case 1: | |
888 | filp->f_op = &mem_fops; | |
5da6185b DH |
889 | filp->f_mapping->backing_dev_info = |
890 | &directly_mappable_cdev_bdi; | |
1da177e4 LT |
891 | break; |
892 | case 2: | |
893 | filp->f_op = &kmem_fops; | |
5da6185b DH |
894 | filp->f_mapping->backing_dev_info = |
895 | &directly_mappable_cdev_bdi; | |
1da177e4 LT |
896 | break; |
897 | case 3: | |
898 | filp->f_op = &null_fops; | |
899 | break; | |
4f911d64 | 900 | #ifdef CONFIG_DEVPORT |
1da177e4 LT |
901 | case 4: |
902 | filp->f_op = &port_fops; | |
903 | break; | |
904 | #endif | |
905 | case 5: | |
906 | filp->f_mapping->backing_dev_info = &zero_bdi; | |
907 | filp->f_op = &zero_fops; | |
908 | break; | |
909 | case 7: | |
910 | filp->f_op = &full_fops; | |
911 | break; | |
912 | case 8: | |
913 | filp->f_op = &random_fops; | |
914 | break; | |
915 | case 9: | |
916 | filp->f_op = &urandom_fops; | |
917 | break; | |
918 | case 11: | |
919 | filp->f_op = &kmsg_fops; | |
920 | break; | |
50b1fdbd VG |
921 | #ifdef CONFIG_CRASH_DUMP |
922 | case 12: | |
923 | filp->f_op = &oldmem_fops; | |
924 | break; | |
925 | #endif | |
1da177e4 LT |
926 | default: |
927 | return -ENXIO; | |
928 | } | |
929 | if (filp->f_op && filp->f_op->open) | |
930 | return filp->f_op->open(inode,filp); | |
931 | return 0; | |
932 | } | |
933 | ||
62322d25 | 934 | static const struct file_operations memory_fops = { |
1da177e4 LT |
935 | .open = memory_open, /* just a selector for the real open */ |
936 | }; | |
937 | ||
938 | static const struct { | |
939 | unsigned int minor; | |
940 | char *name; | |
941 | umode_t mode; | |
99ac48f5 | 942 | const struct file_operations *fops; |
1da177e4 LT |
943 | } devlist[] = { /* list of minor devices */ |
944 | {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops}, | |
945 | {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops}, | |
946 | {3, "null", S_IRUGO | S_IWUGO, &null_fops}, | |
4f911d64 | 947 | #ifdef CONFIG_DEVPORT |
1da177e4 LT |
948 | {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops}, |
949 | #endif | |
950 | {5, "zero", S_IRUGO | S_IWUGO, &zero_fops}, | |
951 | {7, "full", S_IRUGO | S_IWUGO, &full_fops}, | |
952 | {8, "random", S_IRUGO | S_IWUSR, &random_fops}, | |
953 | {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops}, | |
954 | {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops}, | |
50b1fdbd VG |
955 | #ifdef CONFIG_CRASH_DUMP |
956 | {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops}, | |
957 | #endif | |
1da177e4 LT |
958 | }; |
959 | ||
ca8eca68 | 960 | static struct class *mem_class; |
1da177e4 LT |
961 | |
962 | static int __init chr_dev_init(void) | |
963 | { | |
964 | int i; | |
e0bf68dd PZ |
965 | int err; |
966 | ||
967 | err = bdi_init(&zero_bdi); | |
968 | if (err) | |
969 | return err; | |
1da177e4 LT |
970 | |
971 | if (register_chrdev(MEM_MAJOR,"mem",&memory_fops)) | |
972 | printk("unable to get major %d for memory devs\n", MEM_MAJOR); | |
973 | ||
ca8eca68 | 974 | mem_class = class_create(THIS_MODULE, "mem"); |
7c69ef79 | 975 | for (i = 0; i < ARRAY_SIZE(devlist); i++) |
ebf644c4 GKH |
976 | device_create(mem_class, NULL, |
977 | MKDEV(MEM_MAJOR, devlist[i].minor), | |
978 | devlist[i].name); | |
979 | ||
1da177e4 LT |
980 | return 0; |
981 | } | |
982 | ||
983 | fs_initcall(chr_dev_init); |