Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/mem.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
d7d4d849 | 6 | * Added devfs support. |
1da177e4 | 7 | * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu> |
af901ca1 | 8 | * Shared /dev/zero mmapping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com> |
1da177e4 LT |
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 | 23 | #include <linux/highmem.h> |
1da177e4 | 24 | #include <linux/backing-dev.h> |
c01d5b30 | 25 | #include <linux/shmem_fs.h> |
d6b29d7c | 26 | #include <linux/splice.h> |
b8a3ad5b | 27 | #include <linux/pfn.h> |
66300e66 | 28 | #include <linux/export.h> |
e1612de9 | 29 | #include <linux/io.h> |
e2e40f2c | 30 | #include <linux/uio.h> |
1da177e4 | 31 | |
35b6c7e4 | 32 | #include <linux/uaccess.h> |
1da177e4 LT |
33 | |
34 | #ifdef CONFIG_IA64 | |
35 | # include <linux/efi.h> | |
36 | #endif | |
37 | ||
e1612de9 HM |
38 | #define DEVPORT_MINOR 4 |
39 | ||
f222318e WF |
40 | static inline unsigned long size_inside_page(unsigned long start, |
41 | unsigned long size) | |
42 | { | |
43 | unsigned long sz; | |
44 | ||
7fabaddd | 45 | sz = PAGE_SIZE - (start & (PAGE_SIZE - 1)); |
f222318e | 46 | |
7fabaddd | 47 | return min(sz, size); |
f222318e WF |
48 | } |
49 | ||
1da177e4 | 50 | #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE |
7e6735c3 | 51 | static inline int valid_phys_addr_range(phys_addr_t addr, size_t count) |
1da177e4 | 52 | { |
cfaf346c | 53 | return addr + count <= __pa(high_memory); |
1da177e4 | 54 | } |
80851ef2 | 55 | |
06c67bef | 56 | static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) |
80851ef2 BH |
57 | { |
58 | return 1; | |
59 | } | |
1da177e4 LT |
60 | #endif |
61 | ||
d092633b | 62 | #ifdef CONFIG_STRICT_DEVMEM |
a4866aa8 KC |
63 | static inline int page_is_allowed(unsigned long pfn) |
64 | { | |
65 | return devmem_is_allowed(pfn); | |
66 | } | |
e2beb3ea | 67 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 | 68 | { |
e2beb3ea VP |
69 | u64 from = ((u64)pfn) << PAGE_SHIFT; |
70 | u64 to = from + size; | |
71 | u64 cursor = from; | |
72 | ||
73 | while (cursor < to) { | |
39380b80 | 74 | if (!devmem_is_allowed(pfn)) |
ae531c26 | 75 | return 0; |
e2beb3ea VP |
76 | cursor += PAGE_SIZE; |
77 | pfn++; | |
ae531c26 AV |
78 | } |
79 | return 1; | |
80 | } | |
81 | #else | |
a4866aa8 KC |
82 | static inline int page_is_allowed(unsigned long pfn) |
83 | { | |
84 | return 1; | |
85 | } | |
e2beb3ea | 86 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 AV |
87 | { |
88 | return 1; | |
89 | } | |
90 | #endif | |
91 | ||
4707a341 TR |
92 | #ifndef unxlate_dev_mem_ptr |
93 | #define unxlate_dev_mem_ptr unxlate_dev_mem_ptr | |
94 | void __weak unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) | |
e045fb2a | 95 | { |
96 | } | |
4707a341 | 97 | #endif |
e045fb2a | 98 | |
1da177e4 | 99 | /* |
d7d4d849 AM |
100 | * This funcion reads the *physical* memory. The f_pos points directly to the |
101 | * memory location. | |
1da177e4 | 102 | */ |
d7d4d849 | 103 | static ssize_t read_mem(struct file *file, char __user *buf, |
1da177e4 LT |
104 | size_t count, loff_t *ppos) |
105 | { | |
7e6735c3 | 106 | phys_addr_t p = *ppos; |
1da177e4 | 107 | ssize_t read, sz; |
4707a341 | 108 | void *ptr; |
1da177e4 | 109 | |
08d2d00b PT |
110 | if (p != *ppos) |
111 | return 0; | |
112 | ||
136939a2 | 113 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
114 | return -EFAULT; |
115 | read = 0; | |
116 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
117 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
118 | if (p < PAGE_SIZE) { | |
7fabaddd | 119 | sz = size_inside_page(p, count); |
1da177e4 LT |
120 | if (sz > 0) { |
121 | if (clear_user(buf, sz)) | |
122 | return -EFAULT; | |
d7d4d849 AM |
123 | buf += sz; |
124 | p += sz; | |
125 | count -= sz; | |
126 | read += sz; | |
1da177e4 LT |
127 | } |
128 | } | |
129 | #endif | |
130 | ||
131 | while (count > 0) { | |
fa29e97b | 132 | unsigned long remaining; |
a4866aa8 | 133 | int allowed; |
fa29e97b | 134 | |
f222318e | 135 | sz = size_inside_page(p, count); |
1da177e4 | 136 | |
a4866aa8 KC |
137 | allowed = page_is_allowed(p >> PAGE_SHIFT); |
138 | if (!allowed) | |
e045fb2a | 139 | return -EPERM; |
a4866aa8 KC |
140 | if (allowed == 2) { |
141 | /* Show zeros for restricted memory. */ | |
142 | remaining = clear_user(buf, sz); | |
143 | } else { | |
144 | /* | |
145 | * On ia64 if a page has been mapped somewhere as | |
146 | * uncached, then it must also be accessed uncached | |
147 | * by the kernel or data corruption may occur. | |
148 | */ | |
149 | ptr = xlate_dev_mem_ptr(p); | |
150 | if (!ptr) | |
151 | return -EFAULT; | |
e045fb2a | 152 | |
a4866aa8 KC |
153 | remaining = copy_to_user(buf, ptr, sz); |
154 | ||
155 | unxlate_dev_mem_ptr(p, ptr); | |
156 | } | |
1da177e4 | 157 | |
fa29e97b WF |
158 | if (remaining) |
159 | return -EFAULT; | |
e045fb2a | 160 | |
1da177e4 LT |
161 | buf += sz; |
162 | p += sz; | |
163 | count -= sz; | |
164 | read += sz; | |
165 | } | |
166 | ||
167 | *ppos += read; | |
168 | return read; | |
169 | } | |
170 | ||
d7d4d849 | 171 | static ssize_t write_mem(struct file *file, const char __user *buf, |
1da177e4 LT |
172 | size_t count, loff_t *ppos) |
173 | { | |
7e6735c3 | 174 | phys_addr_t p = *ppos; |
1da177e4 LT |
175 | ssize_t written, sz; |
176 | unsigned long copied; | |
177 | void *ptr; | |
178 | ||
08d2d00b PT |
179 | if (p != *ppos) |
180 | return -EFBIG; | |
181 | ||
136939a2 | 182 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
183 | return -EFAULT; |
184 | ||
185 | written = 0; | |
186 | ||
187 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
188 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
189 | if (p < PAGE_SIZE) { | |
7fabaddd | 190 | sz = size_inside_page(p, count); |
1da177e4 LT |
191 | /* Hmm. Do something? */ |
192 | buf += sz; | |
193 | p += sz; | |
194 | count -= sz; | |
195 | written += sz; | |
196 | } | |
197 | #endif | |
198 | ||
199 | while (count > 0) { | |
a4866aa8 KC |
200 | int allowed; |
201 | ||
f222318e | 202 | sz = size_inside_page(p, count); |
1da177e4 | 203 | |
a4866aa8 KC |
204 | allowed = page_is_allowed(p >> PAGE_SHIFT); |
205 | if (!allowed) | |
e045fb2a | 206 | return -EPERM; |
207 | ||
a4866aa8 KC |
208 | /* Skip actual writing when a page is marked as restricted. */ |
209 | if (allowed == 1) { | |
210 | /* | |
211 | * On ia64 if a page has been mapped somewhere as | |
212 | * uncached, then it must also be accessed uncached | |
213 | * by the kernel or data corruption may occur. | |
214 | */ | |
215 | ptr = xlate_dev_mem_ptr(p); | |
216 | if (!ptr) { | |
217 | if (written) | |
218 | break; | |
219 | return -EFAULT; | |
220 | } | |
221 | ||
222 | copied = copy_from_user(ptr, buf, sz); | |
223 | unxlate_dev_mem_ptr(p, ptr); | |
224 | if (copied) { | |
225 | written += sz - copied; | |
226 | if (written) | |
227 | break; | |
228 | return -EFAULT; | |
229 | } | |
1da177e4 | 230 | } |
e045fb2a | 231 | |
1da177e4 LT |
232 | buf += sz; |
233 | p += sz; | |
234 | count -= sz; | |
235 | written += sz; | |
236 | } | |
237 | ||
238 | *ppos += written; | |
239 | return written; | |
240 | } | |
241 | ||
d7d4d849 | 242 | int __weak phys_mem_access_prot_allowed(struct file *file, |
f0970c13 | 243 | unsigned long pfn, unsigned long size, pgprot_t *vma_prot) |
244 | { | |
245 | return 1; | |
246 | } | |
247 | ||
44ac8413 | 248 | #ifndef __HAVE_PHYS_MEM_ACCESS_PROT |
d7d4d849 AM |
249 | |
250 | /* | |
251 | * Architectures vary in how they handle caching for addresses | |
252 | * outside of main memory. | |
253 | * | |
254 | */ | |
ea56f411 | 255 | #ifdef pgprot_noncached |
7e6735c3 | 256 | static int uncached_access(struct file *file, phys_addr_t addr) |
d7d4d849 AM |
257 | { |
258 | #if defined(CONFIG_IA64) | |
259 | /* | |
260 | * On ia64, we ignore O_DSYNC because we cannot tolerate memory | |
261 | * attribute aliases. | |
262 | */ | |
263 | return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); | |
264 | #elif defined(CONFIG_MIPS) | |
265 | { | |
266 | extern int __uncached_access(struct file *file, | |
267 | unsigned long addr); | |
268 | ||
269 | return __uncached_access(file, addr); | |
270 | } | |
271 | #else | |
272 | /* | |
273 | * Accessing memory above the top the kernel knows about or through a | |
274 | * file pointer | |
275 | * that was marked O_DSYNC will be done non-cached. | |
276 | */ | |
277 | if (file->f_flags & O_DSYNC) | |
278 | return 1; | |
279 | return addr >= __pa(high_memory); | |
280 | #endif | |
281 | } | |
ea56f411 | 282 | #endif |
d7d4d849 | 283 | |
44ac8413 BH |
284 | static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
285 | unsigned long size, pgprot_t vma_prot) | |
286 | { | |
287 | #ifdef pgprot_noncached | |
7e6735c3 | 288 | phys_addr_t offset = pfn << PAGE_SHIFT; |
44ac8413 BH |
289 | |
290 | if (uncached_access(file, offset)) | |
291 | return pgprot_noncached(vma_prot); | |
292 | #endif | |
293 | return vma_prot; | |
294 | } | |
295 | #endif | |
296 | ||
5da6185b DH |
297 | #ifndef CONFIG_MMU |
298 | static unsigned long get_unmapped_area_mem(struct file *file, | |
299 | unsigned long addr, | |
300 | unsigned long len, | |
301 | unsigned long pgoff, | |
302 | unsigned long flags) | |
303 | { | |
304 | if (!valid_mmap_phys_addr_range(pgoff, len)) | |
305 | return (unsigned long) -EINVAL; | |
8a93258c | 306 | return pgoff << PAGE_SHIFT; |
5da6185b DH |
307 | } |
308 | ||
b4caecd4 CH |
309 | /* permit direct mmap, for read, write or exec */ |
310 | static unsigned memory_mmap_capabilities(struct file *file) | |
311 | { | |
312 | return NOMMU_MAP_DIRECT | | |
313 | NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC; | |
314 | } | |
315 | ||
316 | static unsigned zero_mmap_capabilities(struct file *file) | |
317 | { | |
318 | return NOMMU_MAP_COPY; | |
319 | } | |
320 | ||
5da6185b DH |
321 | /* can't do an in-place private mapping if there's no MMU */ |
322 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
323 | { | |
324 | return vma->vm_flags & VM_MAYSHARE; | |
325 | } | |
326 | #else | |
5da6185b DH |
327 | |
328 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
329 | { | |
330 | return 1; | |
331 | } | |
332 | #endif | |
333 | ||
f0f37e2f | 334 | static const struct vm_operations_struct mmap_mem_ops = { |
7ae8ed50 RR |
335 | #ifdef CONFIG_HAVE_IOREMAP_PROT |
336 | .access = generic_access_phys | |
337 | #endif | |
e7f260a2 | 338 | }; |
339 | ||
d7d4d849 | 340 | static int mmap_mem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 341 | { |
80851ef2 BH |
342 | size_t size = vma->vm_end - vma->vm_start; |
343 | ||
06c67bef | 344 | if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) |
80851ef2 BH |
345 | return -EINVAL; |
346 | ||
5da6185b DH |
347 | if (!private_mapping_ok(vma)) |
348 | return -ENOSYS; | |
349 | ||
e2beb3ea VP |
350 | if (!range_is_allowed(vma->vm_pgoff, size)) |
351 | return -EPERM; | |
352 | ||
f0970c13 | 353 | if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, |
354 | &vma->vm_page_prot)) | |
355 | return -EINVAL; | |
356 | ||
8b150478 | 357 | vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, |
80851ef2 | 358 | size, |
1da177e4 | 359 | vma->vm_page_prot); |
1da177e4 | 360 | |
e7f260a2 | 361 | vma->vm_ops = &mmap_mem_ops; |
362 | ||
314e51b9 | 363 | /* Remap-pfn-range will mark the range VM_IO */ |
1da177e4 LT |
364 | if (remap_pfn_range(vma, |
365 | vma->vm_start, | |
366 | vma->vm_pgoff, | |
80851ef2 | 367 | size, |
e7f260a2 | 368 | vma->vm_page_prot)) { |
1da177e4 | 369 | return -EAGAIN; |
e7f260a2 | 370 | } |
1da177e4 LT |
371 | return 0; |
372 | } | |
373 | ||
d7d4d849 | 374 | static int mmap_kmem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 375 | { |
4bb82551 LT |
376 | unsigned long pfn; |
377 | ||
6d3154cc LT |
378 | /* Turn a kernel-virtual address into a physical page frame */ |
379 | pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; | |
4bb82551 | 380 | |
1da177e4 | 381 | /* |
d7d4d849 AM |
382 | * RED-PEN: on some architectures there is more mapped memory than |
383 | * available in mem_map which pfn_valid checks for. Perhaps should add a | |
384 | * new macro here. | |
1da177e4 LT |
385 | * |
386 | * RED-PEN: vmalloc is not supported right now. | |
387 | */ | |
4bb82551 | 388 | if (!pfn_valid(pfn)) |
1da177e4 | 389 | return -EIO; |
4bb82551 LT |
390 | |
391 | vma->vm_pgoff = pfn; | |
1da177e4 LT |
392 | return mmap_mem(file, vma); |
393 | } | |
394 | ||
1da177e4 LT |
395 | /* |
396 | * This function reads the *virtual* memory as seen by the kernel. | |
397 | */ | |
d7d4d849 | 398 | static ssize_t read_kmem(struct file *file, char __user *buf, |
1da177e4 LT |
399 | size_t count, loff_t *ppos) |
400 | { | |
401 | unsigned long p = *ppos; | |
402 | ssize_t low_count, read, sz; | |
890537b3 | 403 | char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ |
325fda71 | 404 | int err = 0; |
1da177e4 LT |
405 | |
406 | read = 0; | |
407 | if (p < (unsigned long) high_memory) { | |
408 | low_count = count; | |
d7d4d849 AM |
409 | if (count > (unsigned long)high_memory - p) |
410 | low_count = (unsigned long)high_memory - p; | |
1da177e4 LT |
411 | |
412 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
413 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
414 | if (p < PAGE_SIZE && low_count > 0) { | |
7fabaddd WF |
415 | sz = size_inside_page(p, low_count); |
416 | if (clear_user(buf, sz)) | |
1da177e4 | 417 | return -EFAULT; |
7fabaddd WF |
418 | buf += sz; |
419 | p += sz; | |
420 | read += sz; | |
421 | low_count -= sz; | |
422 | count -= sz; | |
1da177e4 LT |
423 | } |
424 | #endif | |
425 | while (low_count > 0) { | |
f222318e | 426 | sz = size_inside_page(p, low_count); |
1da177e4 LT |
427 | |
428 | /* | |
429 | * On ia64 if a page has been mapped somewhere as | |
430 | * uncached, then it must also be accessed uncached | |
431 | * by the kernel or data corruption may occur | |
432 | */ | |
4707a341 | 433 | kbuf = xlate_dev_kmem_ptr((void *)p); |
488debb9 RM |
434 | if (!virt_addr_valid(kbuf)) |
435 | return -ENXIO; | |
1da177e4 LT |
436 | |
437 | if (copy_to_user(buf, kbuf, sz)) | |
438 | return -EFAULT; | |
439 | buf += sz; | |
440 | p += sz; | |
441 | read += sz; | |
442 | low_count -= sz; | |
443 | count -= sz; | |
444 | } | |
445 | } | |
446 | ||
447 | if (count > 0) { | |
448 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
449 | if (!kbuf) | |
450 | return -ENOMEM; | |
451 | while (count > 0) { | |
80ad89a0 | 452 | sz = size_inside_page(p, count); |
325fda71 KH |
453 | if (!is_vmalloc_or_module_addr((void *)p)) { |
454 | err = -ENXIO; | |
455 | break; | |
456 | } | |
80ad89a0 WF |
457 | sz = vread(kbuf, (char *)p, sz); |
458 | if (!sz) | |
1da177e4 | 459 | break; |
80ad89a0 | 460 | if (copy_to_user(buf, kbuf, sz)) { |
325fda71 KH |
461 | err = -EFAULT; |
462 | break; | |
1da177e4 | 463 | } |
80ad89a0 WF |
464 | count -= sz; |
465 | buf += sz; | |
466 | read += sz; | |
467 | p += sz; | |
1da177e4 LT |
468 | } |
469 | free_page((unsigned long)kbuf); | |
470 | } | |
325fda71 KH |
471 | *ppos = p; |
472 | return read ? read : err; | |
1da177e4 LT |
473 | } |
474 | ||
475 | ||
d7d4d849 AM |
476 | static ssize_t do_write_kmem(unsigned long p, const char __user *buf, |
477 | size_t count, loff_t *ppos) | |
1da177e4 LT |
478 | { |
479 | ssize_t written, sz; | |
480 | unsigned long copied; | |
481 | ||
482 | written = 0; | |
483 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
484 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
ee32398f WF |
485 | if (p < PAGE_SIZE) { |
486 | sz = size_inside_page(p, count); | |
1da177e4 LT |
487 | /* Hmm. Do something? */ |
488 | buf += sz; | |
489 | p += sz; | |
1da177e4 LT |
490 | count -= sz; |
491 | written += sz; | |
492 | } | |
493 | #endif | |
494 | ||
495 | while (count > 0) { | |
4707a341 | 496 | void *ptr; |
1da177e4 | 497 | |
ee32398f | 498 | sz = size_inside_page(p, count); |
1da177e4 LT |
499 | |
500 | /* | |
d7d4d849 AM |
501 | * On ia64 if a page has been mapped somewhere as uncached, then |
502 | * it must also be accessed uncached by the kernel or data | |
503 | * corruption may occur. | |
1da177e4 | 504 | */ |
4707a341 | 505 | ptr = xlate_dev_kmem_ptr((void *)p); |
488debb9 RM |
506 | if (!virt_addr_valid(ptr)) |
507 | return -ENXIO; | |
1da177e4 LT |
508 | |
509 | copied = copy_from_user(ptr, buf, sz); | |
510 | if (copied) { | |
c654d60e JB |
511 | written += sz - copied; |
512 | if (written) | |
513 | break; | |
1da177e4 LT |
514 | return -EFAULT; |
515 | } | |
516 | buf += sz; | |
517 | p += sz; | |
1da177e4 LT |
518 | count -= sz; |
519 | written += sz; | |
520 | } | |
521 | ||
522 | *ppos += written; | |
523 | return written; | |
524 | } | |
525 | ||
1da177e4 LT |
526 | /* |
527 | * This function writes to the *virtual* memory as seen by the kernel. | |
528 | */ | |
d7d4d849 | 529 | static ssize_t write_kmem(struct file *file, const char __user *buf, |
1da177e4 LT |
530 | size_t count, loff_t *ppos) |
531 | { | |
532 | unsigned long p = *ppos; | |
533 | ssize_t wrote = 0; | |
534 | ssize_t virtr = 0; | |
890537b3 | 535 | char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ |
325fda71 | 536 | int err = 0; |
1da177e4 LT |
537 | |
538 | if (p < (unsigned long) high_memory) { | |
80ad89a0 WF |
539 | unsigned long to_write = min_t(unsigned long, count, |
540 | (unsigned long)high_memory - p); | |
ee32398f | 541 | wrote = do_write_kmem(p, buf, to_write, ppos); |
80ad89a0 WF |
542 | if (wrote != to_write) |
543 | return wrote; | |
1da177e4 LT |
544 | p += wrote; |
545 | buf += wrote; | |
546 | count -= wrote; | |
547 | } | |
548 | ||
549 | if (count > 0) { | |
550 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
551 | if (!kbuf) | |
552 | return wrote ? wrote : -ENOMEM; | |
553 | while (count > 0) { | |
80ad89a0 WF |
554 | unsigned long sz = size_inside_page(p, count); |
555 | unsigned long n; | |
1da177e4 | 556 | |
325fda71 KH |
557 | if (!is_vmalloc_or_module_addr((void *)p)) { |
558 | err = -ENXIO; | |
559 | break; | |
560 | } | |
80ad89a0 WF |
561 | n = copy_from_user(kbuf, buf, sz); |
562 | if (n) { | |
325fda71 KH |
563 | err = -EFAULT; |
564 | break; | |
1da177e4 | 565 | } |
c85e9a97 | 566 | vwrite(kbuf, (char *)p, sz); |
80ad89a0 WF |
567 | count -= sz; |
568 | buf += sz; | |
569 | virtr += sz; | |
570 | p += sz; | |
1da177e4 LT |
571 | } |
572 | free_page((unsigned long)kbuf); | |
573 | } | |
574 | ||
325fda71 KH |
575 | *ppos = p; |
576 | return virtr + wrote ? : err; | |
1da177e4 LT |
577 | } |
578 | ||
d7d4d849 | 579 | static ssize_t read_port(struct file *file, char __user *buf, |
1da177e4 LT |
580 | size_t count, loff_t *ppos) |
581 | { | |
582 | unsigned long i = *ppos; | |
583 | char __user *tmp = buf; | |
584 | ||
585 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
d7d4d849 | 586 | return -EFAULT; |
1da177e4 | 587 | while (count-- > 0 && i < 65536) { |
d7d4d849 AM |
588 | if (__put_user(inb(i), tmp) < 0) |
589 | return -EFAULT; | |
1da177e4 LT |
590 | i++; |
591 | tmp++; | |
592 | } | |
593 | *ppos = i; | |
594 | return tmp-buf; | |
595 | } | |
596 | ||
d7d4d849 | 597 | static ssize_t write_port(struct file *file, const char __user *buf, |
1da177e4 LT |
598 | size_t count, loff_t *ppos) |
599 | { | |
600 | unsigned long i = *ppos; | |
890537b3 | 601 | const char __user *tmp = buf; |
1da177e4 | 602 | |
d7d4d849 | 603 | if (!access_ok(VERIFY_READ, buf, count)) |
1da177e4 LT |
604 | return -EFAULT; |
605 | while (count-- > 0 && i < 65536) { | |
606 | char c; | |
6a0061ba | 607 | |
c654d60e JB |
608 | if (__get_user(c, tmp)) { |
609 | if (tmp > buf) | |
610 | break; | |
d7d4d849 | 611 | return -EFAULT; |
c654d60e | 612 | } |
d7d4d849 | 613 | outb(c, i); |
1da177e4 LT |
614 | i++; |
615 | tmp++; | |
616 | } | |
617 | *ppos = i; | |
618 | return tmp-buf; | |
619 | } | |
1da177e4 | 620 | |
d7d4d849 | 621 | static ssize_t read_null(struct file *file, char __user *buf, |
1da177e4 LT |
622 | size_t count, loff_t *ppos) |
623 | { | |
624 | return 0; | |
625 | } | |
626 | ||
d7d4d849 | 627 | static ssize_t write_null(struct file *file, const char __user *buf, |
1da177e4 LT |
628 | size_t count, loff_t *ppos) |
629 | { | |
630 | return count; | |
631 | } | |
632 | ||
cd28e28d | 633 | static ssize_t read_iter_null(struct kiocb *iocb, struct iov_iter *to) |
162934de ZB |
634 | { |
635 | return 0; | |
636 | } | |
637 | ||
cd28e28d | 638 | static ssize_t write_iter_null(struct kiocb *iocb, struct iov_iter *from) |
162934de | 639 | { |
cd28e28d AV |
640 | size_t count = iov_iter_count(from); |
641 | iov_iter_advance(from, count); | |
642 | return count; | |
162934de ZB |
643 | } |
644 | ||
1ebd32fc JA |
645 | static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, |
646 | struct splice_desc *sd) | |
647 | { | |
648 | return sd->len; | |
649 | } | |
650 | ||
d7d4d849 | 651 | static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out, |
1ebd32fc JA |
652 | loff_t *ppos, size_t len, unsigned int flags) |
653 | { | |
654 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); | |
655 | } | |
656 | ||
13ba33e8 | 657 | static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 | 658 | { |
13ba33e8 | 659 | size_t written = 0; |
1da177e4 | 660 | |
13ba33e8 AV |
661 | while (iov_iter_count(iter)) { |
662 | size_t chunk = iov_iter_count(iter), n; | |
6a0061ba | 663 | |
557ed1fa NP |
664 | if (chunk > PAGE_SIZE) |
665 | chunk = PAGE_SIZE; /* Just for latency reasons */ | |
13ba33e8 AV |
666 | n = iov_iter_zero(chunk, iter); |
667 | if (!n && iov_iter_count(iter)) | |
668 | return written ? written : -EFAULT; | |
669 | written += n; | |
2b838687 LT |
670 | if (signal_pending(current)) |
671 | return written ? written : -ERESTARTSYS; | |
1da177e4 LT |
672 | cond_resched(); |
673 | } | |
13ba33e8 | 674 | return written; |
162934de ZB |
675 | } |
676 | ||
d7d4d849 | 677 | static int mmap_zero(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 678 | { |
557ed1fa | 679 | #ifndef CONFIG_MMU |
1da177e4 | 680 | return -ENOSYS; |
557ed1fa NP |
681 | #endif |
682 | if (vma->vm_flags & VM_SHARED) | |
683 | return shmem_zero_setup(vma); | |
684 | return 0; | |
1da177e4 | 685 | } |
1da177e4 | 686 | |
c01d5b30 HD |
687 | static unsigned long get_unmapped_area_zero(struct file *file, |
688 | unsigned long addr, unsigned long len, | |
689 | unsigned long pgoff, unsigned long flags) | |
690 | { | |
691 | #ifdef CONFIG_MMU | |
692 | if (flags & MAP_SHARED) { | |
693 | /* | |
694 | * mmap_zero() will call shmem_zero_setup() to create a file, | |
695 | * so use shmem's get_unmapped_area in case it can be huge; | |
696 | * and pass NULL for file as in mmap.c's get_unmapped_area(), | |
697 | * so as not to confuse shmem with our handle on "/dev/zero". | |
698 | */ | |
699 | return shmem_get_unmapped_area(NULL, addr, len, pgoff, flags); | |
700 | } | |
701 | ||
702 | /* Otherwise flags & MAP_PRIVATE: with no shmem object beneath it */ | |
703 | return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); | |
704 | #else | |
705 | return -ENOSYS; | |
706 | #endif | |
707 | } | |
708 | ||
d7d4d849 | 709 | static ssize_t write_full(struct file *file, const char __user *buf, |
1da177e4 LT |
710 | size_t count, loff_t *ppos) |
711 | { | |
712 | return -ENOSPC; | |
713 | } | |
714 | ||
715 | /* | |
716 | * Special lseek() function for /dev/null and /dev/zero. Most notably, you | |
717 | * can fopen() both devices with "a" now. This was previously impossible. | |
718 | * -- SRB. | |
719 | */ | |
d7d4d849 | 720 | static loff_t null_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
721 | { |
722 | return file->f_pos = 0; | |
723 | } | |
724 | ||
725 | /* | |
726 | * The memory devices use the full 32/64 bits of the offset, and so we cannot | |
727 | * check against negative addresses: they are ok. The return value is weird, | |
728 | * though, in that case (0). | |
729 | * | |
730 | * also note that seeking relative to the "end of file" isn't supported: | |
731 | * it has no meaning, so it returns -EINVAL. | |
732 | */ | |
d7d4d849 | 733 | static loff_t memory_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
734 | { |
735 | loff_t ret; | |
736 | ||
5955102c | 737 | inode_lock(file_inode(file)); |
1da177e4 | 738 | switch (orig) { |
d7d4d849 AM |
739 | case SEEK_CUR: |
740 | offset += file->f_pos; | |
d7d4d849 AM |
741 | case SEEK_SET: |
742 | /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */ | |
ecb63a1b | 743 | if ((unsigned long long)offset >= -MAX_ERRNO) { |
d7d4d849 | 744 | ret = -EOVERFLOW; |
1da177e4 | 745 | break; |
d7d4d849 AM |
746 | } |
747 | file->f_pos = offset; | |
748 | ret = file->f_pos; | |
749 | force_successful_syscall_return(); | |
750 | break; | |
751 | default: | |
752 | ret = -EINVAL; | |
1da177e4 | 753 | } |
5955102c | 754 | inode_unlock(file_inode(file)); |
1da177e4 LT |
755 | return ret; |
756 | } | |
757 | ||
890537b3 | 758 | static int open_port(struct inode *inode, struct file *filp) |
1da177e4 LT |
759 | { |
760 | return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; | |
761 | } | |
762 | ||
763 | #define zero_lseek null_lseek | |
764 | #define full_lseek null_lseek | |
765 | #define write_zero write_null | |
cd28e28d | 766 | #define write_iter_zero write_iter_null |
1da177e4 LT |
767 | #define open_mem open_port |
768 | #define open_kmem open_mem | |
769 | ||
73f0718e | 770 | static const struct file_operations __maybe_unused mem_fops = { |
1da177e4 LT |
771 | .llseek = memory_lseek, |
772 | .read = read_mem, | |
773 | .write = write_mem, | |
774 | .mmap = mmap_mem, | |
775 | .open = open_mem, | |
b4caecd4 | 776 | #ifndef CONFIG_MMU |
5da6185b | 777 | .get_unmapped_area = get_unmapped_area_mem, |
b4caecd4 CH |
778 | .mmap_capabilities = memory_mmap_capabilities, |
779 | #endif | |
1da177e4 LT |
780 | }; |
781 | ||
a8c91252 | 782 | static const struct file_operations __maybe_unused kmem_fops = { |
1da177e4 LT |
783 | .llseek = memory_lseek, |
784 | .read = read_kmem, | |
785 | .write = write_kmem, | |
786 | .mmap = mmap_kmem, | |
787 | .open = open_kmem, | |
b4caecd4 | 788 | #ifndef CONFIG_MMU |
5da6185b | 789 | .get_unmapped_area = get_unmapped_area_mem, |
b4caecd4 CH |
790 | .mmap_capabilities = memory_mmap_capabilities, |
791 | #endif | |
1da177e4 LT |
792 | }; |
793 | ||
62322d25 | 794 | static const struct file_operations null_fops = { |
1da177e4 LT |
795 | .llseek = null_lseek, |
796 | .read = read_null, | |
797 | .write = write_null, | |
cd28e28d AV |
798 | .read_iter = read_iter_null, |
799 | .write_iter = write_iter_null, | |
1ebd32fc | 800 | .splice_write = splice_write_null, |
1da177e4 LT |
801 | }; |
802 | ||
3a4bc2fb | 803 | static const struct file_operations __maybe_unused port_fops = { |
1da177e4 LT |
804 | .llseek = memory_lseek, |
805 | .read = read_port, | |
806 | .write = write_port, | |
807 | .open = open_port, | |
808 | }; | |
1da177e4 | 809 | |
62322d25 | 810 | static const struct file_operations zero_fops = { |
1da177e4 | 811 | .llseek = zero_lseek, |
1da177e4 | 812 | .write = write_zero, |
13ba33e8 | 813 | .read_iter = read_iter_zero, |
cd28e28d | 814 | .write_iter = write_iter_zero, |
1da177e4 | 815 | .mmap = mmap_zero, |
c01d5b30 | 816 | .get_unmapped_area = get_unmapped_area_zero, |
b4caecd4 CH |
817 | #ifndef CONFIG_MMU |
818 | .mmap_capabilities = zero_mmap_capabilities, | |
819 | #endif | |
1da177e4 LT |
820 | }; |
821 | ||
62322d25 | 822 | static const struct file_operations full_fops = { |
1da177e4 | 823 | .llseek = full_lseek, |
13ba33e8 | 824 | .read_iter = read_iter_zero, |
1da177e4 LT |
825 | .write = write_full, |
826 | }; | |
827 | ||
389e0cb9 KS |
828 | static const struct memdev { |
829 | const char *name; | |
2c9ede55 | 830 | umode_t mode; |
389e0cb9 | 831 | const struct file_operations *fops; |
b4caecd4 | 832 | fmode_t fmode; |
389e0cb9 | 833 | } devlist[] = { |
73f0718e | 834 | #ifdef CONFIG_DEVMEM |
b4caecd4 | 835 | [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET }, |
73f0718e | 836 | #endif |
b781ecb6 | 837 | #ifdef CONFIG_DEVKMEM |
b4caecd4 | 838 | [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET }, |
b781ecb6 | 839 | #endif |
b4caecd4 | 840 | [3] = { "null", 0666, &null_fops, 0 }, |
4f911d64 | 841 | #ifdef CONFIG_DEVPORT |
b4caecd4 | 842 | [4] = { "port", 0, &port_fops, 0 }, |
1da177e4 | 843 | #endif |
b4caecd4 CH |
844 | [5] = { "zero", 0666, &zero_fops, 0 }, |
845 | [7] = { "full", 0666, &full_fops, 0 }, | |
846 | [8] = { "random", 0666, &random_fops, 0 }, | |
847 | [9] = { "urandom", 0666, &urandom_fops, 0 }, | |
7f3a781d | 848 | #ifdef CONFIG_PRINTK |
b4caecd4 | 849 | [11] = { "kmsg", 0644, &kmsg_fops, 0 }, |
7f3a781d | 850 | #endif |
d6f47bef ASF |
851 | }; |
852 | ||
853 | static int memory_open(struct inode *inode, struct file *filp) | |
854 | { | |
389e0cb9 KS |
855 | int minor; |
856 | const struct memdev *dev; | |
d6f47bef | 857 | |
389e0cb9 KS |
858 | minor = iminor(inode); |
859 | if (minor >= ARRAY_SIZE(devlist)) | |
205153aa | 860 | return -ENXIO; |
d6f47bef | 861 | |
389e0cb9 KS |
862 | dev = &devlist[minor]; |
863 | if (!dev->fops) | |
205153aa | 864 | return -ENXIO; |
d6f47bef | 865 | |
389e0cb9 | 866 | filp->f_op = dev->fops; |
b4caecd4 | 867 | filp->f_mode |= dev->fmode; |
4a3956c7 | 868 | |
389e0cb9 | 869 | if (dev->fops->open) |
205153aa FW |
870 | return dev->fops->open(inode, filp); |
871 | ||
872 | return 0; | |
1da177e4 LT |
873 | } |
874 | ||
62322d25 | 875 | static const struct file_operations memory_fops = { |
d7d4d849 | 876 | .open = memory_open, |
6038f373 | 877 | .llseek = noop_llseek, |
1da177e4 LT |
878 | }; |
879 | ||
2c9ede55 | 880 | static char *mem_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
881 | { |
882 | if (mode && devlist[MINOR(dev->devt)].mode) | |
883 | *mode = devlist[MINOR(dev->devt)].mode; | |
884 | return NULL; | |
885 | } | |
886 | ||
ca8eca68 | 887 | static struct class *mem_class; |
1da177e4 LT |
888 | |
889 | static int __init chr_dev_init(void) | |
890 | { | |
389e0cb9 | 891 | int minor; |
1da177e4 | 892 | |
d7d4d849 | 893 | if (register_chrdev(MEM_MAJOR, "mem", &memory_fops)) |
1da177e4 LT |
894 | printk("unable to get major %d for memory devs\n", MEM_MAJOR); |
895 | ||
ca8eca68 | 896 | mem_class = class_create(THIS_MODULE, "mem"); |
6e191f7b AB |
897 | if (IS_ERR(mem_class)) |
898 | return PTR_ERR(mem_class); | |
899 | ||
e454cea2 | 900 | mem_class->devnode = mem_devnode; |
389e0cb9 KS |
901 | for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) { |
902 | if (!devlist[minor].name) | |
903 | continue; | |
e1612de9 HM |
904 | |
905 | /* | |
890537b3 | 906 | * Create /dev/port? |
e1612de9 HM |
907 | */ |
908 | if ((minor == DEVPORT_MINOR) && !arch_has_dev_port()) | |
909 | continue; | |
910 | ||
389e0cb9 KS |
911 | device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor), |
912 | NULL, devlist[minor].name); | |
913 | } | |
ebf644c4 | 914 | |
31d1d48e | 915 | return tty_init(); |
1da177e4 LT |
916 | } |
917 | ||
918 | fs_initcall(chr_dev_init); |