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Commit | Line | Data |
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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 | 342 | size_t size = vma->vm_end - vma->vm_start; |
b299cde2 JW |
343 | phys_addr_t offset = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; |
344 | ||
345 | /* It's illegal to wrap around the end of the physical address space. */ | |
32829da5 | 346 | if (offset + (phys_addr_t)size - 1 < offset) |
b299cde2 | 347 | return -EINVAL; |
80851ef2 | 348 | |
06c67bef | 349 | if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) |
80851ef2 BH |
350 | return -EINVAL; |
351 | ||
5da6185b DH |
352 | if (!private_mapping_ok(vma)) |
353 | return -ENOSYS; | |
354 | ||
e2beb3ea VP |
355 | if (!range_is_allowed(vma->vm_pgoff, size)) |
356 | return -EPERM; | |
357 | ||
f0970c13 | 358 | if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, |
359 | &vma->vm_page_prot)) | |
360 | return -EINVAL; | |
361 | ||
8b150478 | 362 | vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, |
80851ef2 | 363 | size, |
1da177e4 | 364 | vma->vm_page_prot); |
1da177e4 | 365 | |
e7f260a2 | 366 | vma->vm_ops = &mmap_mem_ops; |
367 | ||
314e51b9 | 368 | /* Remap-pfn-range will mark the range VM_IO */ |
1da177e4 LT |
369 | if (remap_pfn_range(vma, |
370 | vma->vm_start, | |
371 | vma->vm_pgoff, | |
80851ef2 | 372 | size, |
e7f260a2 | 373 | vma->vm_page_prot)) { |
1da177e4 | 374 | return -EAGAIN; |
e7f260a2 | 375 | } |
1da177e4 LT |
376 | return 0; |
377 | } | |
378 | ||
d7d4d849 | 379 | static int mmap_kmem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 380 | { |
4bb82551 LT |
381 | unsigned long pfn; |
382 | ||
6d3154cc LT |
383 | /* Turn a kernel-virtual address into a physical page frame */ |
384 | pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; | |
4bb82551 | 385 | |
1da177e4 | 386 | /* |
d7d4d849 AM |
387 | * RED-PEN: on some architectures there is more mapped memory than |
388 | * available in mem_map which pfn_valid checks for. Perhaps should add a | |
389 | * new macro here. | |
1da177e4 LT |
390 | * |
391 | * RED-PEN: vmalloc is not supported right now. | |
392 | */ | |
4bb82551 | 393 | if (!pfn_valid(pfn)) |
1da177e4 | 394 | return -EIO; |
4bb82551 LT |
395 | |
396 | vma->vm_pgoff = pfn; | |
1da177e4 LT |
397 | return mmap_mem(file, vma); |
398 | } | |
399 | ||
1da177e4 LT |
400 | /* |
401 | * This function reads the *virtual* memory as seen by the kernel. | |
402 | */ | |
d7d4d849 | 403 | static ssize_t read_kmem(struct file *file, char __user *buf, |
1da177e4 LT |
404 | size_t count, loff_t *ppos) |
405 | { | |
406 | unsigned long p = *ppos; | |
407 | ssize_t low_count, read, sz; | |
890537b3 | 408 | char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ |
325fda71 | 409 | int err = 0; |
1da177e4 LT |
410 | |
411 | read = 0; | |
412 | if (p < (unsigned long) high_memory) { | |
413 | low_count = count; | |
d7d4d849 AM |
414 | if (count > (unsigned long)high_memory - p) |
415 | low_count = (unsigned long)high_memory - p; | |
1da177e4 LT |
416 | |
417 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
418 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
419 | if (p < PAGE_SIZE && low_count > 0) { | |
7fabaddd WF |
420 | sz = size_inside_page(p, low_count); |
421 | if (clear_user(buf, sz)) | |
1da177e4 | 422 | return -EFAULT; |
7fabaddd WF |
423 | buf += sz; |
424 | p += sz; | |
425 | read += sz; | |
426 | low_count -= sz; | |
427 | count -= sz; | |
1da177e4 LT |
428 | } |
429 | #endif | |
430 | while (low_count > 0) { | |
f222318e | 431 | sz = size_inside_page(p, low_count); |
1da177e4 LT |
432 | |
433 | /* | |
434 | * On ia64 if a page has been mapped somewhere as | |
435 | * uncached, then it must also be accessed uncached | |
436 | * by the kernel or data corruption may occur | |
437 | */ | |
4707a341 | 438 | kbuf = xlate_dev_kmem_ptr((void *)p); |
488debb9 RM |
439 | if (!virt_addr_valid(kbuf)) |
440 | return -ENXIO; | |
1da177e4 LT |
441 | |
442 | if (copy_to_user(buf, kbuf, sz)) | |
443 | return -EFAULT; | |
444 | buf += sz; | |
445 | p += sz; | |
446 | read += sz; | |
447 | low_count -= sz; | |
448 | count -= sz; | |
449 | } | |
450 | } | |
451 | ||
452 | if (count > 0) { | |
453 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
454 | if (!kbuf) | |
455 | return -ENOMEM; | |
456 | while (count > 0) { | |
80ad89a0 | 457 | sz = size_inside_page(p, count); |
325fda71 KH |
458 | if (!is_vmalloc_or_module_addr((void *)p)) { |
459 | err = -ENXIO; | |
460 | break; | |
461 | } | |
80ad89a0 WF |
462 | sz = vread(kbuf, (char *)p, sz); |
463 | if (!sz) | |
1da177e4 | 464 | break; |
80ad89a0 | 465 | if (copy_to_user(buf, kbuf, sz)) { |
325fda71 KH |
466 | err = -EFAULT; |
467 | break; | |
1da177e4 | 468 | } |
80ad89a0 WF |
469 | count -= sz; |
470 | buf += sz; | |
471 | read += sz; | |
472 | p += sz; | |
1da177e4 LT |
473 | } |
474 | free_page((unsigned long)kbuf); | |
475 | } | |
325fda71 KH |
476 | *ppos = p; |
477 | return read ? read : err; | |
1da177e4 LT |
478 | } |
479 | ||
480 | ||
d7d4d849 AM |
481 | static ssize_t do_write_kmem(unsigned long p, const char __user *buf, |
482 | size_t count, loff_t *ppos) | |
1da177e4 LT |
483 | { |
484 | ssize_t written, sz; | |
485 | unsigned long copied; | |
486 | ||
487 | written = 0; | |
488 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
489 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
ee32398f WF |
490 | if (p < PAGE_SIZE) { |
491 | sz = size_inside_page(p, count); | |
1da177e4 LT |
492 | /* Hmm. Do something? */ |
493 | buf += sz; | |
494 | p += sz; | |
1da177e4 LT |
495 | count -= sz; |
496 | written += sz; | |
497 | } | |
498 | #endif | |
499 | ||
500 | while (count > 0) { | |
4707a341 | 501 | void *ptr; |
1da177e4 | 502 | |
ee32398f | 503 | sz = size_inside_page(p, count); |
1da177e4 LT |
504 | |
505 | /* | |
d7d4d849 AM |
506 | * On ia64 if a page has been mapped somewhere as uncached, then |
507 | * it must also be accessed uncached by the kernel or data | |
508 | * corruption may occur. | |
1da177e4 | 509 | */ |
4707a341 | 510 | ptr = xlate_dev_kmem_ptr((void *)p); |
488debb9 RM |
511 | if (!virt_addr_valid(ptr)) |
512 | return -ENXIO; | |
1da177e4 LT |
513 | |
514 | copied = copy_from_user(ptr, buf, sz); | |
515 | if (copied) { | |
c654d60e JB |
516 | written += sz - copied; |
517 | if (written) | |
518 | break; | |
1da177e4 LT |
519 | return -EFAULT; |
520 | } | |
521 | buf += sz; | |
522 | p += sz; | |
1da177e4 LT |
523 | count -= sz; |
524 | written += sz; | |
525 | } | |
526 | ||
527 | *ppos += written; | |
528 | return written; | |
529 | } | |
530 | ||
1da177e4 LT |
531 | /* |
532 | * This function writes to the *virtual* memory as seen by the kernel. | |
533 | */ | |
d7d4d849 | 534 | static ssize_t write_kmem(struct file *file, const char __user *buf, |
1da177e4 LT |
535 | size_t count, loff_t *ppos) |
536 | { | |
537 | unsigned long p = *ppos; | |
538 | ssize_t wrote = 0; | |
539 | ssize_t virtr = 0; | |
890537b3 | 540 | char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ |
325fda71 | 541 | int err = 0; |
1da177e4 LT |
542 | |
543 | if (p < (unsigned long) high_memory) { | |
80ad89a0 WF |
544 | unsigned long to_write = min_t(unsigned long, count, |
545 | (unsigned long)high_memory - p); | |
ee32398f | 546 | wrote = do_write_kmem(p, buf, to_write, ppos); |
80ad89a0 WF |
547 | if (wrote != to_write) |
548 | return wrote; | |
1da177e4 LT |
549 | p += wrote; |
550 | buf += wrote; | |
551 | count -= wrote; | |
552 | } | |
553 | ||
554 | if (count > 0) { | |
555 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
556 | if (!kbuf) | |
557 | return wrote ? wrote : -ENOMEM; | |
558 | while (count > 0) { | |
80ad89a0 WF |
559 | unsigned long sz = size_inside_page(p, count); |
560 | unsigned long n; | |
1da177e4 | 561 | |
325fda71 KH |
562 | if (!is_vmalloc_or_module_addr((void *)p)) { |
563 | err = -ENXIO; | |
564 | break; | |
565 | } | |
80ad89a0 WF |
566 | n = copy_from_user(kbuf, buf, sz); |
567 | if (n) { | |
325fda71 KH |
568 | err = -EFAULT; |
569 | break; | |
1da177e4 | 570 | } |
c85e9a97 | 571 | vwrite(kbuf, (char *)p, sz); |
80ad89a0 WF |
572 | count -= sz; |
573 | buf += sz; | |
574 | virtr += sz; | |
575 | p += sz; | |
1da177e4 LT |
576 | } |
577 | free_page((unsigned long)kbuf); | |
578 | } | |
579 | ||
325fda71 KH |
580 | *ppos = p; |
581 | return virtr + wrote ? : err; | |
1da177e4 LT |
582 | } |
583 | ||
d7d4d849 | 584 | static ssize_t read_port(struct file *file, char __user *buf, |
1da177e4 LT |
585 | size_t count, loff_t *ppos) |
586 | { | |
587 | unsigned long i = *ppos; | |
588 | char __user *tmp = buf; | |
589 | ||
590 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
d7d4d849 | 591 | return -EFAULT; |
1da177e4 | 592 | while (count-- > 0 && i < 65536) { |
d7d4d849 AM |
593 | if (__put_user(inb(i), tmp) < 0) |
594 | return -EFAULT; | |
1da177e4 LT |
595 | i++; |
596 | tmp++; | |
597 | } | |
598 | *ppos = i; | |
599 | return tmp-buf; | |
600 | } | |
601 | ||
d7d4d849 | 602 | static ssize_t write_port(struct file *file, const char __user *buf, |
1da177e4 LT |
603 | size_t count, loff_t *ppos) |
604 | { | |
605 | unsigned long i = *ppos; | |
890537b3 | 606 | const char __user *tmp = buf; |
1da177e4 | 607 | |
d7d4d849 | 608 | if (!access_ok(VERIFY_READ, buf, count)) |
1da177e4 LT |
609 | return -EFAULT; |
610 | while (count-- > 0 && i < 65536) { | |
611 | char c; | |
6a0061ba | 612 | |
c654d60e JB |
613 | if (__get_user(c, tmp)) { |
614 | if (tmp > buf) | |
615 | break; | |
d7d4d849 | 616 | return -EFAULT; |
c654d60e | 617 | } |
d7d4d849 | 618 | outb(c, i); |
1da177e4 LT |
619 | i++; |
620 | tmp++; | |
621 | } | |
622 | *ppos = i; | |
623 | return tmp-buf; | |
624 | } | |
1da177e4 | 625 | |
d7d4d849 | 626 | static ssize_t read_null(struct file *file, char __user *buf, |
1da177e4 LT |
627 | size_t count, loff_t *ppos) |
628 | { | |
629 | return 0; | |
630 | } | |
631 | ||
d7d4d849 | 632 | static ssize_t write_null(struct file *file, const char __user *buf, |
1da177e4 LT |
633 | size_t count, loff_t *ppos) |
634 | { | |
635 | return count; | |
636 | } | |
637 | ||
cd28e28d | 638 | static ssize_t read_iter_null(struct kiocb *iocb, struct iov_iter *to) |
162934de ZB |
639 | { |
640 | return 0; | |
641 | } | |
642 | ||
cd28e28d | 643 | static ssize_t write_iter_null(struct kiocb *iocb, struct iov_iter *from) |
162934de | 644 | { |
cd28e28d AV |
645 | size_t count = iov_iter_count(from); |
646 | iov_iter_advance(from, count); | |
647 | return count; | |
162934de ZB |
648 | } |
649 | ||
1ebd32fc JA |
650 | static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, |
651 | struct splice_desc *sd) | |
652 | { | |
653 | return sd->len; | |
654 | } | |
655 | ||
d7d4d849 | 656 | static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out, |
1ebd32fc JA |
657 | loff_t *ppos, size_t len, unsigned int flags) |
658 | { | |
659 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); | |
660 | } | |
661 | ||
13ba33e8 | 662 | static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 | 663 | { |
13ba33e8 | 664 | size_t written = 0; |
1da177e4 | 665 | |
13ba33e8 AV |
666 | while (iov_iter_count(iter)) { |
667 | size_t chunk = iov_iter_count(iter), n; | |
6a0061ba | 668 | |
557ed1fa NP |
669 | if (chunk > PAGE_SIZE) |
670 | chunk = PAGE_SIZE; /* Just for latency reasons */ | |
13ba33e8 AV |
671 | n = iov_iter_zero(chunk, iter); |
672 | if (!n && iov_iter_count(iter)) | |
673 | return written ? written : -EFAULT; | |
674 | written += n; | |
2b838687 LT |
675 | if (signal_pending(current)) |
676 | return written ? written : -ERESTARTSYS; | |
1da177e4 LT |
677 | cond_resched(); |
678 | } | |
13ba33e8 | 679 | return written; |
162934de ZB |
680 | } |
681 | ||
d7d4d849 | 682 | static int mmap_zero(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 683 | { |
557ed1fa | 684 | #ifndef CONFIG_MMU |
1da177e4 | 685 | return -ENOSYS; |
557ed1fa NP |
686 | #endif |
687 | if (vma->vm_flags & VM_SHARED) | |
688 | return shmem_zero_setup(vma); | |
689 | return 0; | |
1da177e4 | 690 | } |
1da177e4 | 691 | |
c01d5b30 HD |
692 | static unsigned long get_unmapped_area_zero(struct file *file, |
693 | unsigned long addr, unsigned long len, | |
694 | unsigned long pgoff, unsigned long flags) | |
695 | { | |
696 | #ifdef CONFIG_MMU | |
697 | if (flags & MAP_SHARED) { | |
698 | /* | |
699 | * mmap_zero() will call shmem_zero_setup() to create a file, | |
700 | * so use shmem's get_unmapped_area in case it can be huge; | |
701 | * and pass NULL for file as in mmap.c's get_unmapped_area(), | |
702 | * so as not to confuse shmem with our handle on "/dev/zero". | |
703 | */ | |
704 | return shmem_get_unmapped_area(NULL, addr, len, pgoff, flags); | |
705 | } | |
706 | ||
707 | /* Otherwise flags & MAP_PRIVATE: with no shmem object beneath it */ | |
708 | return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); | |
709 | #else | |
710 | return -ENOSYS; | |
711 | #endif | |
712 | } | |
713 | ||
d7d4d849 | 714 | static ssize_t write_full(struct file *file, const char __user *buf, |
1da177e4 LT |
715 | size_t count, loff_t *ppos) |
716 | { | |
717 | return -ENOSPC; | |
718 | } | |
719 | ||
720 | /* | |
721 | * Special lseek() function for /dev/null and /dev/zero. Most notably, you | |
722 | * can fopen() both devices with "a" now. This was previously impossible. | |
723 | * -- SRB. | |
724 | */ | |
d7d4d849 | 725 | static loff_t null_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
726 | { |
727 | return file->f_pos = 0; | |
728 | } | |
729 | ||
730 | /* | |
731 | * The memory devices use the full 32/64 bits of the offset, and so we cannot | |
732 | * check against negative addresses: they are ok. The return value is weird, | |
733 | * though, in that case (0). | |
734 | * | |
735 | * also note that seeking relative to the "end of file" isn't supported: | |
736 | * it has no meaning, so it returns -EINVAL. | |
737 | */ | |
d7d4d849 | 738 | static loff_t memory_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
739 | { |
740 | loff_t ret; | |
741 | ||
5955102c | 742 | inode_lock(file_inode(file)); |
1da177e4 | 743 | switch (orig) { |
d7d4d849 AM |
744 | case SEEK_CUR: |
745 | offset += file->f_pos; | |
d7d4d849 AM |
746 | case SEEK_SET: |
747 | /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */ | |
ecb63a1b | 748 | if ((unsigned long long)offset >= -MAX_ERRNO) { |
d7d4d849 | 749 | ret = -EOVERFLOW; |
1da177e4 | 750 | break; |
d7d4d849 AM |
751 | } |
752 | file->f_pos = offset; | |
753 | ret = file->f_pos; | |
754 | force_successful_syscall_return(); | |
755 | break; | |
756 | default: | |
757 | ret = -EINVAL; | |
1da177e4 | 758 | } |
5955102c | 759 | inode_unlock(file_inode(file)); |
1da177e4 LT |
760 | return ret; |
761 | } | |
762 | ||
890537b3 | 763 | static int open_port(struct inode *inode, struct file *filp) |
1da177e4 LT |
764 | { |
765 | return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; | |
766 | } | |
767 | ||
768 | #define zero_lseek null_lseek | |
769 | #define full_lseek null_lseek | |
770 | #define write_zero write_null | |
cd28e28d | 771 | #define write_iter_zero write_iter_null |
1da177e4 LT |
772 | #define open_mem open_port |
773 | #define open_kmem open_mem | |
774 | ||
73f0718e | 775 | static const struct file_operations __maybe_unused mem_fops = { |
1da177e4 LT |
776 | .llseek = memory_lseek, |
777 | .read = read_mem, | |
778 | .write = write_mem, | |
779 | .mmap = mmap_mem, | |
780 | .open = open_mem, | |
b4caecd4 | 781 | #ifndef CONFIG_MMU |
5da6185b | 782 | .get_unmapped_area = get_unmapped_area_mem, |
b4caecd4 CH |
783 | .mmap_capabilities = memory_mmap_capabilities, |
784 | #endif | |
1da177e4 LT |
785 | }; |
786 | ||
a8c91252 | 787 | static const struct file_operations __maybe_unused kmem_fops = { |
1da177e4 LT |
788 | .llseek = memory_lseek, |
789 | .read = read_kmem, | |
790 | .write = write_kmem, | |
791 | .mmap = mmap_kmem, | |
792 | .open = open_kmem, | |
b4caecd4 | 793 | #ifndef CONFIG_MMU |
5da6185b | 794 | .get_unmapped_area = get_unmapped_area_mem, |
b4caecd4 CH |
795 | .mmap_capabilities = memory_mmap_capabilities, |
796 | #endif | |
1da177e4 LT |
797 | }; |
798 | ||
62322d25 | 799 | static const struct file_operations null_fops = { |
1da177e4 LT |
800 | .llseek = null_lseek, |
801 | .read = read_null, | |
802 | .write = write_null, | |
cd28e28d AV |
803 | .read_iter = read_iter_null, |
804 | .write_iter = write_iter_null, | |
1ebd32fc | 805 | .splice_write = splice_write_null, |
1da177e4 LT |
806 | }; |
807 | ||
3a4bc2fb | 808 | static const struct file_operations __maybe_unused port_fops = { |
1da177e4 LT |
809 | .llseek = memory_lseek, |
810 | .read = read_port, | |
811 | .write = write_port, | |
812 | .open = open_port, | |
813 | }; | |
1da177e4 | 814 | |
62322d25 | 815 | static const struct file_operations zero_fops = { |
1da177e4 | 816 | .llseek = zero_lseek, |
1da177e4 | 817 | .write = write_zero, |
13ba33e8 | 818 | .read_iter = read_iter_zero, |
cd28e28d | 819 | .write_iter = write_iter_zero, |
1da177e4 | 820 | .mmap = mmap_zero, |
c01d5b30 | 821 | .get_unmapped_area = get_unmapped_area_zero, |
b4caecd4 CH |
822 | #ifndef CONFIG_MMU |
823 | .mmap_capabilities = zero_mmap_capabilities, | |
824 | #endif | |
1da177e4 LT |
825 | }; |
826 | ||
62322d25 | 827 | static const struct file_operations full_fops = { |
1da177e4 | 828 | .llseek = full_lseek, |
13ba33e8 | 829 | .read_iter = read_iter_zero, |
1da177e4 LT |
830 | .write = write_full, |
831 | }; | |
832 | ||
389e0cb9 KS |
833 | static const struct memdev { |
834 | const char *name; | |
2c9ede55 | 835 | umode_t mode; |
389e0cb9 | 836 | const struct file_operations *fops; |
b4caecd4 | 837 | fmode_t fmode; |
389e0cb9 | 838 | } devlist[] = { |
73f0718e | 839 | #ifdef CONFIG_DEVMEM |
b4caecd4 | 840 | [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET }, |
73f0718e | 841 | #endif |
b781ecb6 | 842 | #ifdef CONFIG_DEVKMEM |
b4caecd4 | 843 | [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET }, |
b781ecb6 | 844 | #endif |
b4caecd4 | 845 | [3] = { "null", 0666, &null_fops, 0 }, |
4f911d64 | 846 | #ifdef CONFIG_DEVPORT |
b4caecd4 | 847 | [4] = { "port", 0, &port_fops, 0 }, |
1da177e4 | 848 | #endif |
b4caecd4 CH |
849 | [5] = { "zero", 0666, &zero_fops, 0 }, |
850 | [7] = { "full", 0666, &full_fops, 0 }, | |
851 | [8] = { "random", 0666, &random_fops, 0 }, | |
852 | [9] = { "urandom", 0666, &urandom_fops, 0 }, | |
7f3a781d | 853 | #ifdef CONFIG_PRINTK |
b4caecd4 | 854 | [11] = { "kmsg", 0644, &kmsg_fops, 0 }, |
7f3a781d | 855 | #endif |
d6f47bef ASF |
856 | }; |
857 | ||
858 | static int memory_open(struct inode *inode, struct file *filp) | |
859 | { | |
389e0cb9 KS |
860 | int minor; |
861 | const struct memdev *dev; | |
d6f47bef | 862 | |
389e0cb9 KS |
863 | minor = iminor(inode); |
864 | if (minor >= ARRAY_SIZE(devlist)) | |
205153aa | 865 | return -ENXIO; |
d6f47bef | 866 | |
389e0cb9 KS |
867 | dev = &devlist[minor]; |
868 | if (!dev->fops) | |
205153aa | 869 | return -ENXIO; |
d6f47bef | 870 | |
389e0cb9 | 871 | filp->f_op = dev->fops; |
b4caecd4 | 872 | filp->f_mode |= dev->fmode; |
4a3956c7 | 873 | |
389e0cb9 | 874 | if (dev->fops->open) |
205153aa FW |
875 | return dev->fops->open(inode, filp); |
876 | ||
877 | return 0; | |
1da177e4 LT |
878 | } |
879 | ||
62322d25 | 880 | static const struct file_operations memory_fops = { |
d7d4d849 | 881 | .open = memory_open, |
6038f373 | 882 | .llseek = noop_llseek, |
1da177e4 LT |
883 | }; |
884 | ||
2c9ede55 | 885 | static char *mem_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
886 | { |
887 | if (mode && devlist[MINOR(dev->devt)].mode) | |
888 | *mode = devlist[MINOR(dev->devt)].mode; | |
889 | return NULL; | |
890 | } | |
891 | ||
ca8eca68 | 892 | static struct class *mem_class; |
1da177e4 LT |
893 | |
894 | static int __init chr_dev_init(void) | |
895 | { | |
389e0cb9 | 896 | int minor; |
1da177e4 | 897 | |
d7d4d849 | 898 | if (register_chrdev(MEM_MAJOR, "mem", &memory_fops)) |
1da177e4 LT |
899 | printk("unable to get major %d for memory devs\n", MEM_MAJOR); |
900 | ||
ca8eca68 | 901 | mem_class = class_create(THIS_MODULE, "mem"); |
6e191f7b AB |
902 | if (IS_ERR(mem_class)) |
903 | return PTR_ERR(mem_class); | |
904 | ||
e454cea2 | 905 | mem_class->devnode = mem_devnode; |
389e0cb9 KS |
906 | for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) { |
907 | if (!devlist[minor].name) | |
908 | continue; | |
e1612de9 HM |
909 | |
910 | /* | |
890537b3 | 911 | * Create /dev/port? |
e1612de9 HM |
912 | */ |
913 | if ((minor == DEVPORT_MINOR) && !arch_has_dev_port()) | |
914 | continue; | |
915 | ||
389e0cb9 KS |
916 | device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor), |
917 | NULL, devlist[minor].name); | |
918 | } | |
ebf644c4 | 919 | |
31d1d48e | 920 | return tty_init(); |
1da177e4 LT |
921 | } |
922 | ||
923 | fs_initcall(chr_dev_init); |