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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> |
e6540ba2 | 31 | #include <linux/module.h> |
1da177e4 | 32 | |
35b6c7e4 | 33 | #include <linux/uaccess.h> |
1da177e4 LT |
34 | |
35 | #ifdef CONFIG_IA64 | |
36 | # include <linux/efi.h> | |
37 | #endif | |
38 | ||
e1612de9 HM |
39 | #define DEVPORT_MINOR 4 |
40 | ||
f222318e WF |
41 | static inline unsigned long size_inside_page(unsigned long start, |
42 | unsigned long size) | |
43 | { | |
44 | unsigned long sz; | |
45 | ||
7fabaddd | 46 | sz = PAGE_SIZE - (start & (PAGE_SIZE - 1)); |
f222318e | 47 | |
7fabaddd | 48 | return min(sz, size); |
f222318e WF |
49 | } |
50 | ||
1da177e4 | 51 | #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE |
7e6735c3 | 52 | static inline int valid_phys_addr_range(phys_addr_t addr, size_t count) |
1da177e4 | 53 | { |
cfaf346c | 54 | return addr + count <= __pa(high_memory); |
1da177e4 | 55 | } |
80851ef2 | 56 | |
06c67bef | 57 | static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) |
80851ef2 BH |
58 | { |
59 | return 1; | |
60 | } | |
1da177e4 LT |
61 | #endif |
62 | ||
d092633b | 63 | #ifdef CONFIG_STRICT_DEVMEM |
e2beb3ea | 64 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 | 65 | { |
e2beb3ea VP |
66 | u64 from = ((u64)pfn) << PAGE_SHIFT; |
67 | u64 to = from + size; | |
68 | u64 cursor = from; | |
69 | ||
70 | while (cursor < to) { | |
39380b80 | 71 | if (!devmem_is_allowed(pfn)) |
ae531c26 | 72 | return 0; |
e2beb3ea VP |
73 | cursor += PAGE_SIZE; |
74 | pfn++; | |
ae531c26 AV |
75 | } |
76 | return 1; | |
77 | } | |
78 | #else | |
e2beb3ea | 79 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 AV |
80 | { |
81 | return 1; | |
82 | } | |
83 | #endif | |
84 | ||
4707a341 TR |
85 | #ifndef unxlate_dev_mem_ptr |
86 | #define unxlate_dev_mem_ptr unxlate_dev_mem_ptr | |
87 | void __weak unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) | |
e045fb2a | 88 | { |
89 | } | |
4707a341 | 90 | #endif |
e045fb2a | 91 | |
1da177e4 | 92 | /* |
d7d4d849 AM |
93 | * This funcion reads the *physical* memory. The f_pos points directly to the |
94 | * memory location. | |
1da177e4 | 95 | */ |
d7d4d849 | 96 | static ssize_t read_mem(struct file *file, char __user *buf, |
1da177e4 LT |
97 | size_t count, loff_t *ppos) |
98 | { | |
7e6735c3 | 99 | phys_addr_t p = *ppos; |
1da177e4 | 100 | ssize_t read, sz; |
4707a341 | 101 | void *ptr; |
1da177e4 | 102 | |
08d2d00b PT |
103 | if (p != *ppos) |
104 | return 0; | |
105 | ||
136939a2 | 106 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
107 | return -EFAULT; |
108 | read = 0; | |
109 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
110 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
111 | if (p < PAGE_SIZE) { | |
7fabaddd | 112 | sz = size_inside_page(p, count); |
1da177e4 LT |
113 | if (sz > 0) { |
114 | if (clear_user(buf, sz)) | |
115 | return -EFAULT; | |
d7d4d849 AM |
116 | buf += sz; |
117 | p += sz; | |
118 | count -= sz; | |
119 | read += sz; | |
1da177e4 LT |
120 | } |
121 | } | |
122 | #endif | |
123 | ||
124 | while (count > 0) { | |
fa29e97b WF |
125 | unsigned long remaining; |
126 | ||
f222318e | 127 | sz = size_inside_page(p, count); |
1da177e4 | 128 | |
e045fb2a | 129 | if (!range_is_allowed(p >> PAGE_SHIFT, count)) |
130 | return -EPERM; | |
131 | ||
1da177e4 | 132 | /* |
d7d4d849 AM |
133 | * On ia64 if a page has been mapped somewhere as uncached, then |
134 | * it must also be accessed uncached by the kernel or data | |
135 | * corruption may occur. | |
1da177e4 LT |
136 | */ |
137 | ptr = xlate_dev_mem_ptr(p); | |
e045fb2a | 138 | if (!ptr) |
139 | return -EFAULT; | |
1da177e4 | 140 | |
fa29e97b | 141 | remaining = copy_to_user(buf, ptr, sz); |
e045fb2a | 142 | unxlate_dev_mem_ptr(p, ptr); |
fa29e97b WF |
143 | if (remaining) |
144 | return -EFAULT; | |
e045fb2a | 145 | |
1da177e4 LT |
146 | buf += sz; |
147 | p += sz; | |
148 | count -= sz; | |
149 | read += sz; | |
150 | } | |
151 | ||
152 | *ppos += read; | |
153 | return read; | |
154 | } | |
155 | ||
d7d4d849 | 156 | static ssize_t write_mem(struct file *file, const char __user *buf, |
1da177e4 LT |
157 | size_t count, loff_t *ppos) |
158 | { | |
7e6735c3 | 159 | phys_addr_t p = *ppos; |
1da177e4 LT |
160 | ssize_t written, sz; |
161 | unsigned long copied; | |
162 | void *ptr; | |
163 | ||
08d2d00b PT |
164 | if (p != *ppos) |
165 | return -EFBIG; | |
166 | ||
99f0760c MG |
167 | if (secure_modules()) |
168 | return -EPERM; | |
169 | ||
136939a2 | 170 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
171 | return -EFAULT; |
172 | ||
173 | written = 0; | |
174 | ||
175 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
176 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
177 | if (p < PAGE_SIZE) { | |
7fabaddd | 178 | sz = size_inside_page(p, count); |
1da177e4 LT |
179 | /* Hmm. Do something? */ |
180 | buf += sz; | |
181 | p += sz; | |
182 | count -= sz; | |
183 | written += sz; | |
184 | } | |
185 | #endif | |
186 | ||
187 | while (count > 0) { | |
f222318e | 188 | sz = size_inside_page(p, count); |
1da177e4 | 189 | |
e045fb2a | 190 | if (!range_is_allowed(p >> PAGE_SHIFT, sz)) |
191 | return -EPERM; | |
192 | ||
1da177e4 | 193 | /* |
d7d4d849 AM |
194 | * On ia64 if a page has been mapped somewhere as uncached, then |
195 | * it must also be accessed uncached by the kernel or data | |
196 | * corruption may occur. | |
1da177e4 LT |
197 | */ |
198 | ptr = xlate_dev_mem_ptr(p); | |
e045fb2a | 199 | if (!ptr) { |
200 | if (written) | |
201 | break; | |
202 | return -EFAULT; | |
203 | } | |
1da177e4 LT |
204 | |
205 | copied = copy_from_user(ptr, buf, sz); | |
fa29e97b | 206 | unxlate_dev_mem_ptr(p, ptr); |
1da177e4 | 207 | if (copied) { |
c654d60e JB |
208 | written += sz - copied; |
209 | if (written) | |
210 | break; | |
1da177e4 LT |
211 | return -EFAULT; |
212 | } | |
e045fb2a | 213 | |
1da177e4 LT |
214 | buf += sz; |
215 | p += sz; | |
216 | count -= sz; | |
217 | written += sz; | |
218 | } | |
219 | ||
220 | *ppos += written; | |
221 | return written; | |
222 | } | |
223 | ||
d7d4d849 | 224 | int __weak phys_mem_access_prot_allowed(struct file *file, |
f0970c13 | 225 | unsigned long pfn, unsigned long size, pgprot_t *vma_prot) |
226 | { | |
227 | return 1; | |
228 | } | |
229 | ||
44ac8413 | 230 | #ifndef __HAVE_PHYS_MEM_ACCESS_PROT |
d7d4d849 AM |
231 | |
232 | /* | |
233 | * Architectures vary in how they handle caching for addresses | |
234 | * outside of main memory. | |
235 | * | |
236 | */ | |
ea56f411 | 237 | #ifdef pgprot_noncached |
7e6735c3 | 238 | static int uncached_access(struct file *file, phys_addr_t addr) |
d7d4d849 AM |
239 | { |
240 | #if defined(CONFIG_IA64) | |
241 | /* | |
242 | * On ia64, we ignore O_DSYNC because we cannot tolerate memory | |
243 | * attribute aliases. | |
244 | */ | |
245 | return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); | |
246 | #elif defined(CONFIG_MIPS) | |
247 | { | |
248 | extern int __uncached_access(struct file *file, | |
249 | unsigned long addr); | |
250 | ||
251 | return __uncached_access(file, addr); | |
252 | } | |
253 | #else | |
254 | /* | |
255 | * Accessing memory above the top the kernel knows about or through a | |
256 | * file pointer | |
257 | * that was marked O_DSYNC will be done non-cached. | |
258 | */ | |
259 | if (file->f_flags & O_DSYNC) | |
260 | return 1; | |
261 | return addr >= __pa(high_memory); | |
262 | #endif | |
263 | } | |
ea56f411 | 264 | #endif |
d7d4d849 | 265 | |
44ac8413 BH |
266 | static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
267 | unsigned long size, pgprot_t vma_prot) | |
268 | { | |
269 | #ifdef pgprot_noncached | |
7e6735c3 | 270 | phys_addr_t offset = pfn << PAGE_SHIFT; |
44ac8413 BH |
271 | |
272 | if (uncached_access(file, offset)) | |
273 | return pgprot_noncached(vma_prot); | |
274 | #endif | |
275 | return vma_prot; | |
276 | } | |
277 | #endif | |
278 | ||
5da6185b DH |
279 | #ifndef CONFIG_MMU |
280 | static unsigned long get_unmapped_area_mem(struct file *file, | |
281 | unsigned long addr, | |
282 | unsigned long len, | |
283 | unsigned long pgoff, | |
284 | unsigned long flags) | |
285 | { | |
286 | if (!valid_mmap_phys_addr_range(pgoff, len)) | |
287 | return (unsigned long) -EINVAL; | |
8a93258c | 288 | return pgoff << PAGE_SHIFT; |
5da6185b DH |
289 | } |
290 | ||
b4caecd4 CH |
291 | /* permit direct mmap, for read, write or exec */ |
292 | static unsigned memory_mmap_capabilities(struct file *file) | |
293 | { | |
294 | return NOMMU_MAP_DIRECT | | |
295 | NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC; | |
296 | } | |
297 | ||
298 | static unsigned zero_mmap_capabilities(struct file *file) | |
299 | { | |
300 | return NOMMU_MAP_COPY; | |
301 | } | |
302 | ||
5da6185b DH |
303 | /* can't do an in-place private mapping if there's no MMU */ |
304 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
305 | { | |
306 | return vma->vm_flags & VM_MAYSHARE; | |
307 | } | |
308 | #else | |
5da6185b DH |
309 | |
310 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
311 | { | |
312 | return 1; | |
313 | } | |
314 | #endif | |
315 | ||
f0f37e2f | 316 | static const struct vm_operations_struct mmap_mem_ops = { |
7ae8ed50 RR |
317 | #ifdef CONFIG_HAVE_IOREMAP_PROT |
318 | .access = generic_access_phys | |
319 | #endif | |
e7f260a2 | 320 | }; |
321 | ||
d7d4d849 | 322 | static int mmap_mem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 323 | { |
80851ef2 BH |
324 | size_t size = vma->vm_end - vma->vm_start; |
325 | ||
06c67bef | 326 | if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) |
80851ef2 BH |
327 | return -EINVAL; |
328 | ||
5da6185b DH |
329 | if (!private_mapping_ok(vma)) |
330 | return -ENOSYS; | |
331 | ||
e2beb3ea VP |
332 | if (!range_is_allowed(vma->vm_pgoff, size)) |
333 | return -EPERM; | |
334 | ||
f0970c13 | 335 | if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, |
336 | &vma->vm_page_prot)) | |
337 | return -EINVAL; | |
338 | ||
8b150478 | 339 | vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, |
80851ef2 | 340 | size, |
1da177e4 | 341 | vma->vm_page_prot); |
1da177e4 | 342 | |
e7f260a2 | 343 | vma->vm_ops = &mmap_mem_ops; |
344 | ||
314e51b9 | 345 | /* Remap-pfn-range will mark the range VM_IO */ |
1da177e4 LT |
346 | if (remap_pfn_range(vma, |
347 | vma->vm_start, | |
348 | vma->vm_pgoff, | |
80851ef2 | 349 | size, |
e7f260a2 | 350 | vma->vm_page_prot)) { |
1da177e4 | 351 | return -EAGAIN; |
e7f260a2 | 352 | } |
1da177e4 LT |
353 | return 0; |
354 | } | |
355 | ||
d7d4d849 | 356 | static int mmap_kmem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 357 | { |
4bb82551 LT |
358 | unsigned long pfn; |
359 | ||
6d3154cc LT |
360 | /* Turn a kernel-virtual address into a physical page frame */ |
361 | pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; | |
4bb82551 | 362 | |
1da177e4 | 363 | /* |
d7d4d849 AM |
364 | * RED-PEN: on some architectures there is more mapped memory than |
365 | * available in mem_map which pfn_valid checks for. Perhaps should add a | |
366 | * new macro here. | |
1da177e4 LT |
367 | * |
368 | * RED-PEN: vmalloc is not supported right now. | |
369 | */ | |
4bb82551 | 370 | if (!pfn_valid(pfn)) |
1da177e4 | 371 | return -EIO; |
4bb82551 LT |
372 | |
373 | vma->vm_pgoff = pfn; | |
1da177e4 LT |
374 | return mmap_mem(file, vma); |
375 | } | |
376 | ||
1da177e4 LT |
377 | /* |
378 | * This function reads the *virtual* memory as seen by the kernel. | |
379 | */ | |
d7d4d849 | 380 | static ssize_t read_kmem(struct file *file, char __user *buf, |
1da177e4 LT |
381 | size_t count, loff_t *ppos) |
382 | { | |
383 | unsigned long p = *ppos; | |
384 | ssize_t low_count, read, sz; | |
890537b3 | 385 | char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ |
325fda71 | 386 | int err = 0; |
1da177e4 LT |
387 | |
388 | read = 0; | |
389 | if (p < (unsigned long) high_memory) { | |
390 | low_count = count; | |
d7d4d849 AM |
391 | if (count > (unsigned long)high_memory - p) |
392 | low_count = (unsigned long)high_memory - p; | |
1da177e4 LT |
393 | |
394 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
395 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
396 | if (p < PAGE_SIZE && low_count > 0) { | |
7fabaddd WF |
397 | sz = size_inside_page(p, low_count); |
398 | if (clear_user(buf, sz)) | |
1da177e4 | 399 | return -EFAULT; |
7fabaddd WF |
400 | buf += sz; |
401 | p += sz; | |
402 | read += sz; | |
403 | low_count -= sz; | |
404 | count -= sz; | |
1da177e4 LT |
405 | } |
406 | #endif | |
407 | while (low_count > 0) { | |
f222318e | 408 | sz = size_inside_page(p, low_count); |
1da177e4 LT |
409 | |
410 | /* | |
411 | * On ia64 if a page has been mapped somewhere as | |
412 | * uncached, then it must also be accessed uncached | |
413 | * by the kernel or data corruption may occur | |
414 | */ | |
4707a341 | 415 | kbuf = xlate_dev_kmem_ptr((void *)p); |
488debb9 RM |
416 | if (!virt_addr_valid(kbuf)) |
417 | return -ENXIO; | |
1da177e4 LT |
418 | |
419 | if (copy_to_user(buf, kbuf, sz)) | |
420 | return -EFAULT; | |
421 | buf += sz; | |
422 | p += sz; | |
423 | read += sz; | |
424 | low_count -= sz; | |
425 | count -= sz; | |
426 | } | |
427 | } | |
428 | ||
429 | if (count > 0) { | |
430 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
431 | if (!kbuf) | |
432 | return -ENOMEM; | |
433 | while (count > 0) { | |
80ad89a0 | 434 | sz = size_inside_page(p, count); |
325fda71 KH |
435 | if (!is_vmalloc_or_module_addr((void *)p)) { |
436 | err = -ENXIO; | |
437 | break; | |
438 | } | |
80ad89a0 WF |
439 | sz = vread(kbuf, (char *)p, sz); |
440 | if (!sz) | |
1da177e4 | 441 | break; |
80ad89a0 | 442 | if (copy_to_user(buf, kbuf, sz)) { |
325fda71 KH |
443 | err = -EFAULT; |
444 | break; | |
1da177e4 | 445 | } |
80ad89a0 WF |
446 | count -= sz; |
447 | buf += sz; | |
448 | read += sz; | |
449 | p += sz; | |
1da177e4 LT |
450 | } |
451 | free_page((unsigned long)kbuf); | |
452 | } | |
325fda71 KH |
453 | *ppos = p; |
454 | return read ? read : err; | |
1da177e4 LT |
455 | } |
456 | ||
457 | ||
d7d4d849 AM |
458 | static ssize_t do_write_kmem(unsigned long p, const char __user *buf, |
459 | size_t count, loff_t *ppos) | |
1da177e4 LT |
460 | { |
461 | ssize_t written, sz; | |
462 | unsigned long copied; | |
463 | ||
464 | written = 0; | |
465 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
466 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
ee32398f WF |
467 | if (p < PAGE_SIZE) { |
468 | sz = size_inside_page(p, count); | |
1da177e4 LT |
469 | /* Hmm. Do something? */ |
470 | buf += sz; | |
471 | p += sz; | |
1da177e4 LT |
472 | count -= sz; |
473 | written += sz; | |
474 | } | |
475 | #endif | |
476 | ||
477 | while (count > 0) { | |
4707a341 | 478 | void *ptr; |
1da177e4 | 479 | |
ee32398f | 480 | sz = size_inside_page(p, count); |
1da177e4 LT |
481 | |
482 | /* | |
d7d4d849 AM |
483 | * On ia64 if a page has been mapped somewhere as uncached, then |
484 | * it must also be accessed uncached by the kernel or data | |
485 | * corruption may occur. | |
1da177e4 | 486 | */ |
4707a341 | 487 | ptr = xlate_dev_kmem_ptr((void *)p); |
488debb9 RM |
488 | if (!virt_addr_valid(ptr)) |
489 | return -ENXIO; | |
1da177e4 LT |
490 | |
491 | copied = copy_from_user(ptr, buf, sz); | |
492 | if (copied) { | |
c654d60e JB |
493 | written += sz - copied; |
494 | if (written) | |
495 | break; | |
1da177e4 LT |
496 | return -EFAULT; |
497 | } | |
498 | buf += sz; | |
499 | p += sz; | |
1da177e4 LT |
500 | count -= sz; |
501 | written += sz; | |
502 | } | |
503 | ||
504 | *ppos += written; | |
505 | return written; | |
506 | } | |
507 | ||
1da177e4 LT |
508 | /* |
509 | * This function writes to the *virtual* memory as seen by the kernel. | |
510 | */ | |
d7d4d849 | 511 | static ssize_t write_kmem(struct file *file, const char __user *buf, |
1da177e4 LT |
512 | size_t count, loff_t *ppos) |
513 | { | |
514 | unsigned long p = *ppos; | |
515 | ssize_t wrote = 0; | |
516 | ssize_t virtr = 0; | |
890537b3 | 517 | char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ |
325fda71 | 518 | int err = 0; |
1da177e4 | 519 | |
99f0760c MG |
520 | if (!pfn_valid(PFN_DOWN(p))) |
521 | return -EIO; | |
522 | if (secure_modules()) | |
523 | return -EPERM; | |
524 | ||
1da177e4 | 525 | if (p < (unsigned long) high_memory) { |
80ad89a0 WF |
526 | unsigned long to_write = min_t(unsigned long, count, |
527 | (unsigned long)high_memory - p); | |
ee32398f | 528 | wrote = do_write_kmem(p, buf, to_write, ppos); |
80ad89a0 WF |
529 | if (wrote != to_write) |
530 | return wrote; | |
1da177e4 LT |
531 | p += wrote; |
532 | buf += wrote; | |
533 | count -= wrote; | |
534 | } | |
535 | ||
536 | if (count > 0) { | |
537 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
538 | if (!kbuf) | |
539 | return wrote ? wrote : -ENOMEM; | |
540 | while (count > 0) { | |
80ad89a0 WF |
541 | unsigned long sz = size_inside_page(p, count); |
542 | unsigned long n; | |
1da177e4 | 543 | |
325fda71 KH |
544 | if (!is_vmalloc_or_module_addr((void *)p)) { |
545 | err = -ENXIO; | |
546 | break; | |
547 | } | |
80ad89a0 WF |
548 | n = copy_from_user(kbuf, buf, sz); |
549 | if (n) { | |
325fda71 KH |
550 | err = -EFAULT; |
551 | break; | |
1da177e4 | 552 | } |
c85e9a97 | 553 | vwrite(kbuf, (char *)p, sz); |
80ad89a0 WF |
554 | count -= sz; |
555 | buf += sz; | |
556 | virtr += sz; | |
557 | p += sz; | |
1da177e4 LT |
558 | } |
559 | free_page((unsigned long)kbuf); | |
560 | } | |
561 | ||
325fda71 KH |
562 | *ppos = p; |
563 | return virtr + wrote ? : err; | |
1da177e4 LT |
564 | } |
565 | ||
d7d4d849 | 566 | static ssize_t read_port(struct file *file, char __user *buf, |
1da177e4 LT |
567 | size_t count, loff_t *ppos) |
568 | { | |
569 | unsigned long i = *ppos; | |
570 | char __user *tmp = buf; | |
571 | ||
572 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
d7d4d849 | 573 | return -EFAULT; |
1da177e4 | 574 | while (count-- > 0 && i < 65536) { |
d7d4d849 AM |
575 | if (__put_user(inb(i), tmp) < 0) |
576 | return -EFAULT; | |
1da177e4 LT |
577 | i++; |
578 | tmp++; | |
579 | } | |
580 | *ppos = i; | |
581 | return tmp-buf; | |
582 | } | |
583 | ||
d7d4d849 | 584 | static ssize_t write_port(struct file *file, const char __user *buf, |
1da177e4 LT |
585 | size_t count, loff_t *ppos) |
586 | { | |
587 | unsigned long i = *ppos; | |
890537b3 | 588 | const char __user *tmp = buf; |
1da177e4 | 589 | |
e6540ba2 MG |
590 | if (secure_modules()) |
591 | return -EPERM; | |
592 | ||
d7d4d849 | 593 | if (!access_ok(VERIFY_READ, buf, count)) |
1da177e4 LT |
594 | return -EFAULT; |
595 | while (count-- > 0 && i < 65536) { | |
596 | char c; | |
6a0061ba | 597 | |
c654d60e JB |
598 | if (__get_user(c, tmp)) { |
599 | if (tmp > buf) | |
600 | break; | |
d7d4d849 | 601 | return -EFAULT; |
c654d60e | 602 | } |
d7d4d849 | 603 | outb(c, i); |
1da177e4 LT |
604 | i++; |
605 | tmp++; | |
606 | } | |
607 | *ppos = i; | |
608 | return tmp-buf; | |
609 | } | |
1da177e4 | 610 | |
d7d4d849 | 611 | static ssize_t read_null(struct file *file, char __user *buf, |
1da177e4 LT |
612 | size_t count, loff_t *ppos) |
613 | { | |
614 | return 0; | |
615 | } | |
616 | ||
d7d4d849 | 617 | static ssize_t write_null(struct file *file, const char __user *buf, |
1da177e4 LT |
618 | size_t count, loff_t *ppos) |
619 | { | |
620 | return count; | |
621 | } | |
622 | ||
cd28e28d | 623 | static ssize_t read_iter_null(struct kiocb *iocb, struct iov_iter *to) |
162934de ZB |
624 | { |
625 | return 0; | |
626 | } | |
627 | ||
cd28e28d | 628 | static ssize_t write_iter_null(struct kiocb *iocb, struct iov_iter *from) |
162934de | 629 | { |
cd28e28d AV |
630 | size_t count = iov_iter_count(from); |
631 | iov_iter_advance(from, count); | |
632 | return count; | |
162934de ZB |
633 | } |
634 | ||
1ebd32fc JA |
635 | static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, |
636 | struct splice_desc *sd) | |
637 | { | |
638 | return sd->len; | |
639 | } | |
640 | ||
d7d4d849 | 641 | static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out, |
1ebd32fc JA |
642 | loff_t *ppos, size_t len, unsigned int flags) |
643 | { | |
644 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); | |
645 | } | |
646 | ||
13ba33e8 | 647 | static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 | 648 | { |
13ba33e8 | 649 | size_t written = 0; |
1da177e4 | 650 | |
13ba33e8 AV |
651 | while (iov_iter_count(iter)) { |
652 | size_t chunk = iov_iter_count(iter), n; | |
6a0061ba | 653 | |
557ed1fa NP |
654 | if (chunk > PAGE_SIZE) |
655 | chunk = PAGE_SIZE; /* Just for latency reasons */ | |
13ba33e8 AV |
656 | n = iov_iter_zero(chunk, iter); |
657 | if (!n && iov_iter_count(iter)) | |
658 | return written ? written : -EFAULT; | |
659 | written += n; | |
2b838687 LT |
660 | if (signal_pending(current)) |
661 | return written ? written : -ERESTARTSYS; | |
1da177e4 LT |
662 | cond_resched(); |
663 | } | |
13ba33e8 | 664 | return written; |
162934de ZB |
665 | } |
666 | ||
d7d4d849 | 667 | static int mmap_zero(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 668 | { |
557ed1fa | 669 | #ifndef CONFIG_MMU |
1da177e4 | 670 | return -ENOSYS; |
557ed1fa NP |
671 | #endif |
672 | if (vma->vm_flags & VM_SHARED) | |
673 | return shmem_zero_setup(vma); | |
674 | return 0; | |
1da177e4 | 675 | } |
1da177e4 | 676 | |
c01d5b30 HD |
677 | static unsigned long get_unmapped_area_zero(struct file *file, |
678 | unsigned long addr, unsigned long len, | |
679 | unsigned long pgoff, unsigned long flags) | |
680 | { | |
681 | #ifdef CONFIG_MMU | |
682 | if (flags & MAP_SHARED) { | |
683 | /* | |
684 | * mmap_zero() will call shmem_zero_setup() to create a file, | |
685 | * so use shmem's get_unmapped_area in case it can be huge; | |
686 | * and pass NULL for file as in mmap.c's get_unmapped_area(), | |
687 | * so as not to confuse shmem with our handle on "/dev/zero". | |
688 | */ | |
689 | return shmem_get_unmapped_area(NULL, addr, len, pgoff, flags); | |
690 | } | |
691 | ||
692 | /* Otherwise flags & MAP_PRIVATE: with no shmem object beneath it */ | |
693 | return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); | |
694 | #else | |
695 | return -ENOSYS; | |
696 | #endif | |
697 | } | |
698 | ||
d7d4d849 | 699 | static ssize_t write_full(struct file *file, const char __user *buf, |
1da177e4 LT |
700 | size_t count, loff_t *ppos) |
701 | { | |
702 | return -ENOSPC; | |
703 | } | |
704 | ||
705 | /* | |
706 | * Special lseek() function for /dev/null and /dev/zero. Most notably, you | |
707 | * can fopen() both devices with "a" now. This was previously impossible. | |
708 | * -- SRB. | |
709 | */ | |
d7d4d849 | 710 | static loff_t null_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
711 | { |
712 | return file->f_pos = 0; | |
713 | } | |
714 | ||
715 | /* | |
716 | * The memory devices use the full 32/64 bits of the offset, and so we cannot | |
717 | * check against negative addresses: they are ok. The return value is weird, | |
718 | * though, in that case (0). | |
719 | * | |
720 | * also note that seeking relative to the "end of file" isn't supported: | |
721 | * it has no meaning, so it returns -EINVAL. | |
722 | */ | |
d7d4d849 | 723 | static loff_t memory_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
724 | { |
725 | loff_t ret; | |
726 | ||
5955102c | 727 | inode_lock(file_inode(file)); |
1da177e4 | 728 | switch (orig) { |
d7d4d849 AM |
729 | case SEEK_CUR: |
730 | offset += file->f_pos; | |
d7d4d849 AM |
731 | case SEEK_SET: |
732 | /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */ | |
ecb63a1b | 733 | if ((unsigned long long)offset >= -MAX_ERRNO) { |
d7d4d849 | 734 | ret = -EOVERFLOW; |
1da177e4 | 735 | break; |
d7d4d849 AM |
736 | } |
737 | file->f_pos = offset; | |
738 | ret = file->f_pos; | |
739 | force_successful_syscall_return(); | |
740 | break; | |
741 | default: | |
742 | ret = -EINVAL; | |
1da177e4 | 743 | } |
5955102c | 744 | inode_unlock(file_inode(file)); |
1da177e4 LT |
745 | return ret; |
746 | } | |
747 | ||
890537b3 | 748 | static int open_port(struct inode *inode, struct file *filp) |
1da177e4 LT |
749 | { |
750 | return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; | |
751 | } | |
752 | ||
753 | #define zero_lseek null_lseek | |
754 | #define full_lseek null_lseek | |
755 | #define write_zero write_null | |
cd28e28d | 756 | #define write_iter_zero write_iter_null |
1da177e4 LT |
757 | #define open_mem open_port |
758 | #define open_kmem open_mem | |
759 | ||
73f0718e | 760 | static const struct file_operations __maybe_unused mem_fops = { |
1da177e4 LT |
761 | .llseek = memory_lseek, |
762 | .read = read_mem, | |
763 | .write = write_mem, | |
764 | .mmap = mmap_mem, | |
765 | .open = open_mem, | |
b4caecd4 | 766 | #ifndef CONFIG_MMU |
5da6185b | 767 | .get_unmapped_area = get_unmapped_area_mem, |
b4caecd4 CH |
768 | .mmap_capabilities = memory_mmap_capabilities, |
769 | #endif | |
1da177e4 LT |
770 | }; |
771 | ||
a8c91252 | 772 | static const struct file_operations __maybe_unused kmem_fops = { |
1da177e4 LT |
773 | .llseek = memory_lseek, |
774 | .read = read_kmem, | |
775 | .write = write_kmem, | |
776 | .mmap = mmap_kmem, | |
777 | .open = open_kmem, | |
b4caecd4 | 778 | #ifndef CONFIG_MMU |
5da6185b | 779 | .get_unmapped_area = get_unmapped_area_mem, |
b4caecd4 CH |
780 | .mmap_capabilities = memory_mmap_capabilities, |
781 | #endif | |
1da177e4 LT |
782 | }; |
783 | ||
62322d25 | 784 | static const struct file_operations null_fops = { |
1da177e4 LT |
785 | .llseek = null_lseek, |
786 | .read = read_null, | |
787 | .write = write_null, | |
cd28e28d AV |
788 | .read_iter = read_iter_null, |
789 | .write_iter = write_iter_null, | |
1ebd32fc | 790 | .splice_write = splice_write_null, |
1da177e4 LT |
791 | }; |
792 | ||
3a4bc2fb | 793 | static const struct file_operations __maybe_unused port_fops = { |
1da177e4 LT |
794 | .llseek = memory_lseek, |
795 | .read = read_port, | |
796 | .write = write_port, | |
797 | .open = open_port, | |
798 | }; | |
1da177e4 | 799 | |
62322d25 | 800 | static const struct file_operations zero_fops = { |
1da177e4 | 801 | .llseek = zero_lseek, |
1da177e4 | 802 | .write = write_zero, |
13ba33e8 | 803 | .read_iter = read_iter_zero, |
cd28e28d | 804 | .write_iter = write_iter_zero, |
1da177e4 | 805 | .mmap = mmap_zero, |
c01d5b30 | 806 | .get_unmapped_area = get_unmapped_area_zero, |
b4caecd4 CH |
807 | #ifndef CONFIG_MMU |
808 | .mmap_capabilities = zero_mmap_capabilities, | |
809 | #endif | |
1da177e4 LT |
810 | }; |
811 | ||
62322d25 | 812 | static const struct file_operations full_fops = { |
1da177e4 | 813 | .llseek = full_lseek, |
13ba33e8 | 814 | .read_iter = read_iter_zero, |
1da177e4 LT |
815 | .write = write_full, |
816 | }; | |
817 | ||
389e0cb9 KS |
818 | static const struct memdev { |
819 | const char *name; | |
2c9ede55 | 820 | umode_t mode; |
389e0cb9 | 821 | const struct file_operations *fops; |
b4caecd4 | 822 | fmode_t fmode; |
389e0cb9 | 823 | } devlist[] = { |
73f0718e | 824 | #ifdef CONFIG_DEVMEM |
b4caecd4 | 825 | [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET }, |
73f0718e | 826 | #endif |
b781ecb6 | 827 | #ifdef CONFIG_DEVKMEM |
b4caecd4 | 828 | [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET }, |
b781ecb6 | 829 | #endif |
b4caecd4 | 830 | [3] = { "null", 0666, &null_fops, 0 }, |
4f911d64 | 831 | #ifdef CONFIG_DEVPORT |
b4caecd4 | 832 | [4] = { "port", 0, &port_fops, 0 }, |
1da177e4 | 833 | #endif |
b4caecd4 CH |
834 | [5] = { "zero", 0666, &zero_fops, 0 }, |
835 | [7] = { "full", 0666, &full_fops, 0 }, | |
836 | [8] = { "random", 0666, &random_fops, 0 }, | |
837 | [9] = { "urandom", 0666, &urandom_fops, 0 }, | |
7f3a781d | 838 | #ifdef CONFIG_PRINTK |
b4caecd4 | 839 | [11] = { "kmsg", 0644, &kmsg_fops, 0 }, |
7f3a781d | 840 | #endif |
d6f47bef ASF |
841 | }; |
842 | ||
843 | static int memory_open(struct inode *inode, struct file *filp) | |
844 | { | |
389e0cb9 KS |
845 | int minor; |
846 | const struct memdev *dev; | |
d6f47bef | 847 | |
389e0cb9 KS |
848 | minor = iminor(inode); |
849 | if (minor >= ARRAY_SIZE(devlist)) | |
205153aa | 850 | return -ENXIO; |
d6f47bef | 851 | |
389e0cb9 KS |
852 | dev = &devlist[minor]; |
853 | if (!dev->fops) | |
205153aa | 854 | return -ENXIO; |
d6f47bef | 855 | |
389e0cb9 | 856 | filp->f_op = dev->fops; |
b4caecd4 | 857 | filp->f_mode |= dev->fmode; |
4a3956c7 | 858 | |
389e0cb9 | 859 | if (dev->fops->open) |
205153aa FW |
860 | return dev->fops->open(inode, filp); |
861 | ||
862 | return 0; | |
1da177e4 LT |
863 | } |
864 | ||
62322d25 | 865 | static const struct file_operations memory_fops = { |
d7d4d849 | 866 | .open = memory_open, |
6038f373 | 867 | .llseek = noop_llseek, |
1da177e4 LT |
868 | }; |
869 | ||
2c9ede55 | 870 | static char *mem_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
871 | { |
872 | if (mode && devlist[MINOR(dev->devt)].mode) | |
873 | *mode = devlist[MINOR(dev->devt)].mode; | |
874 | return NULL; | |
875 | } | |
876 | ||
ca8eca68 | 877 | static struct class *mem_class; |
1da177e4 LT |
878 | |
879 | static int __init chr_dev_init(void) | |
880 | { | |
389e0cb9 | 881 | int minor; |
1da177e4 | 882 | |
d7d4d849 | 883 | if (register_chrdev(MEM_MAJOR, "mem", &memory_fops)) |
1da177e4 LT |
884 | printk("unable to get major %d for memory devs\n", MEM_MAJOR); |
885 | ||
ca8eca68 | 886 | mem_class = class_create(THIS_MODULE, "mem"); |
6e191f7b AB |
887 | if (IS_ERR(mem_class)) |
888 | return PTR_ERR(mem_class); | |
889 | ||
e454cea2 | 890 | mem_class->devnode = mem_devnode; |
389e0cb9 KS |
891 | for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) { |
892 | if (!devlist[minor].name) | |
893 | continue; | |
e1612de9 HM |
894 | |
895 | /* | |
890537b3 | 896 | * Create /dev/port? |
e1612de9 HM |
897 | */ |
898 | if ((minor == DEVPORT_MINOR) && !arch_has_dev_port()) | |
899 | continue; | |
900 | ||
389e0cb9 KS |
901 | device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor), |
902 | NULL, devlist[minor].name); | |
903 | } | |
ebf644c4 | 904 | |
31d1d48e | 905 | return tty_init(); |
1da177e4 LT |
906 | } |
907 | ||
908 | fs_initcall(chr_dev_init); |