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