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