]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/mem.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
d7d4d849 | 6 | * Added devfs support. |
1da177e4 | 7 | * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu> |
af901ca1 | 8 | * Shared /dev/zero mmapping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com> |
1da177e4 LT |
9 | */ |
10 | ||
1da177e4 LT |
11 | #include <linux/mm.h> |
12 | #include <linux/miscdevice.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/vmalloc.h> | |
15 | #include <linux/mman.h> | |
16 | #include <linux/random.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/raw.h> | |
19 | #include <linux/tty.h> | |
20 | #include <linux/capability.h> | |
1da177e4 LT |
21 | #include <linux/ptrace.h> |
22 | #include <linux/device.h> | |
50b1fdbd | 23 | #include <linux/highmem.h> |
1da177e4 | 24 | #include <linux/backing-dev.h> |
c01d5b30 | 25 | #include <linux/shmem_fs.h> |
d6b29d7c | 26 | #include <linux/splice.h> |
b8a3ad5b | 27 | #include <linux/pfn.h> |
66300e66 | 28 | #include <linux/export.h> |
e1612de9 | 29 | #include <linux/io.h> |
e2e40f2c | 30 | #include <linux/uio.h> |
1da177e4 | 31 | |
35b6c7e4 | 32 | #include <linux/uaccess.h> |
1da177e4 LT |
33 | |
34 | #ifdef CONFIG_IA64 | |
35 | # include <linux/efi.h> | |
36 | #endif | |
37 | ||
e1612de9 HM |
38 | #define DEVPORT_MINOR 4 |
39 | ||
f222318e WF |
40 | static inline unsigned long size_inside_page(unsigned long start, |
41 | unsigned long size) | |
42 | { | |
43 | unsigned long sz; | |
44 | ||
7fabaddd | 45 | sz = PAGE_SIZE - (start & (PAGE_SIZE - 1)); |
f222318e | 46 | |
7fabaddd | 47 | return min(sz, size); |
f222318e WF |
48 | } |
49 | ||
1da177e4 | 50 | #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE |
7e6735c3 | 51 | static inline int valid_phys_addr_range(phys_addr_t addr, size_t count) |
1da177e4 | 52 | { |
cfaf346c | 53 | return addr + count <= __pa(high_memory); |
1da177e4 | 54 | } |
80851ef2 | 55 | |
06c67bef | 56 | static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) |
80851ef2 BH |
57 | { |
58 | return 1; | |
59 | } | |
1da177e4 LT |
60 | #endif |
61 | ||
d092633b | 62 | #ifdef CONFIG_STRICT_DEVMEM |
a4866aa8 KC |
63 | static inline int page_is_allowed(unsigned long pfn) |
64 | { | |
65 | return devmem_is_allowed(pfn); | |
66 | } | |
e2beb3ea | 67 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 | 68 | { |
e2beb3ea VP |
69 | u64 from = ((u64)pfn) << PAGE_SHIFT; |
70 | u64 to = from + size; | |
71 | u64 cursor = from; | |
72 | ||
73 | while (cursor < to) { | |
39380b80 | 74 | if (!devmem_is_allowed(pfn)) |
ae531c26 | 75 | return 0; |
e2beb3ea VP |
76 | cursor += PAGE_SIZE; |
77 | pfn++; | |
ae531c26 AV |
78 | } |
79 | return 1; | |
80 | } | |
81 | #else | |
a4866aa8 KC |
82 | static inline int page_is_allowed(unsigned long pfn) |
83 | { | |
84 | return 1; | |
85 | } | |
e2beb3ea | 86 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 AV |
87 | { |
88 | return 1; | |
89 | } | |
90 | #endif | |
91 | ||
4707a341 TR |
92 | #ifndef unxlate_dev_mem_ptr |
93 | #define unxlate_dev_mem_ptr unxlate_dev_mem_ptr | |
94 | void __weak unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) | |
e045fb2a | 95 | { |
96 | } | |
4707a341 | 97 | #endif |
e045fb2a | 98 | |
1da177e4 | 99 | /* |
d7d4d849 AM |
100 | * This funcion reads the *physical* memory. The f_pos points directly to the |
101 | * memory location. | |
1da177e4 | 102 | */ |
d7d4d849 | 103 | static ssize_t read_mem(struct file *file, char __user *buf, |
1da177e4 LT |
104 | size_t count, loff_t *ppos) |
105 | { | |
7e6735c3 | 106 | phys_addr_t p = *ppos; |
1da177e4 | 107 | ssize_t read, sz; |
4707a341 | 108 | void *ptr; |
1da177e4 | 109 | |
08d2d00b PT |
110 | if (p != *ppos) |
111 | return 0; | |
112 | ||
136939a2 | 113 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
114 | return -EFAULT; |
115 | read = 0; | |
116 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
117 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
118 | if (p < PAGE_SIZE) { | |
7fabaddd | 119 | sz = size_inside_page(p, count); |
1da177e4 LT |
120 | if (sz > 0) { |
121 | if (clear_user(buf, sz)) | |
122 | return -EFAULT; | |
d7d4d849 AM |
123 | buf += sz; |
124 | p += sz; | |
125 | count -= sz; | |
126 | read += sz; | |
1da177e4 LT |
127 | } |
128 | } | |
129 | #endif | |
130 | ||
131 | while (count > 0) { | |
fa29e97b | 132 | unsigned long remaining; |
a4866aa8 | 133 | int allowed; |
fa29e97b | 134 | |
f222318e | 135 | sz = size_inside_page(p, count); |
1da177e4 | 136 | |
a4866aa8 KC |
137 | allowed = page_is_allowed(p >> PAGE_SHIFT); |
138 | if (!allowed) | |
e045fb2a | 139 | return -EPERM; |
a4866aa8 KC |
140 | if (allowed == 2) { |
141 | /* Show zeros for restricted memory. */ | |
142 | remaining = clear_user(buf, sz); | |
143 | } else { | |
144 | /* | |
145 | * On ia64 if a page has been mapped somewhere as | |
146 | * uncached, then it must also be accessed uncached | |
147 | * by the kernel or data corruption may occur. | |
148 | */ | |
149 | ptr = xlate_dev_mem_ptr(p); | |
150 | if (!ptr) | |
151 | return -EFAULT; | |
e045fb2a | 152 | |
a4866aa8 KC |
153 | remaining = copy_to_user(buf, ptr, sz); |
154 | ||
155 | unxlate_dev_mem_ptr(p, ptr); | |
156 | } | |
1da177e4 | 157 | |
fa29e97b WF |
158 | if (remaining) |
159 | return -EFAULT; | |
e045fb2a | 160 | |
1da177e4 LT |
161 | buf += sz; |
162 | p += sz; | |
163 | count -= sz; | |
164 | read += sz; | |
165 | } | |
166 | ||
167 | *ppos += read; | |
168 | return read; | |
169 | } | |
170 | ||
d7d4d849 | 171 | static ssize_t write_mem(struct file *file, const char __user *buf, |
1da177e4 LT |
172 | size_t count, loff_t *ppos) |
173 | { | |
7e6735c3 | 174 | phys_addr_t p = *ppos; |
1da177e4 LT |
175 | ssize_t written, sz; |
176 | unsigned long copied; | |
177 | void *ptr; | |
178 | ||
08d2d00b PT |
179 | if (p != *ppos) |
180 | return -EFBIG; | |
181 | ||
5d1ffbd8 MG |
182 | if (kernel_is_locked_down()) |
183 | return -EPERM; | |
184 | ||
136939a2 | 185 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
186 | return -EFAULT; |
187 | ||
188 | written = 0; | |
189 | ||
190 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
191 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
192 | if (p < PAGE_SIZE) { | |
7fabaddd | 193 | sz = size_inside_page(p, count); |
1da177e4 LT |
194 | /* Hmm. Do something? */ |
195 | buf += sz; | |
196 | p += sz; | |
197 | count -= sz; | |
198 | written += sz; | |
199 | } | |
200 | #endif | |
201 | ||
202 | while (count > 0) { | |
a4866aa8 KC |
203 | int allowed; |
204 | ||
f222318e | 205 | sz = size_inside_page(p, count); |
1da177e4 | 206 | |
a4866aa8 KC |
207 | allowed = page_is_allowed(p >> PAGE_SHIFT); |
208 | if (!allowed) | |
e045fb2a | 209 | return -EPERM; |
210 | ||
a4866aa8 KC |
211 | /* Skip actual writing when a page is marked as restricted. */ |
212 | if (allowed == 1) { | |
213 | /* | |
214 | * On ia64 if a page has been mapped somewhere as | |
215 | * uncached, then it must also be accessed uncached | |
216 | * by the kernel or data corruption may occur. | |
217 | */ | |
218 | ptr = xlate_dev_mem_ptr(p); | |
219 | if (!ptr) { | |
220 | if (written) | |
221 | break; | |
222 | return -EFAULT; | |
223 | } | |
224 | ||
225 | copied = copy_from_user(ptr, buf, sz); | |
226 | unxlate_dev_mem_ptr(p, ptr); | |
227 | if (copied) { | |
228 | written += sz - copied; | |
229 | if (written) | |
230 | break; | |
231 | return -EFAULT; | |
232 | } | |
1da177e4 | 233 | } |
e045fb2a | 234 | |
1da177e4 LT |
235 | buf += sz; |
236 | p += sz; | |
237 | count -= sz; | |
238 | written += sz; | |
239 | } | |
240 | ||
241 | *ppos += written; | |
242 | return written; | |
243 | } | |
244 | ||
d7d4d849 | 245 | int __weak phys_mem_access_prot_allowed(struct file *file, |
f0970c13 | 246 | unsigned long pfn, unsigned long size, pgprot_t *vma_prot) |
247 | { | |
248 | return 1; | |
249 | } | |
250 | ||
44ac8413 | 251 | #ifndef __HAVE_PHYS_MEM_ACCESS_PROT |
d7d4d849 AM |
252 | |
253 | /* | |
254 | * Architectures vary in how they handle caching for addresses | |
255 | * outside of main memory. | |
256 | * | |
257 | */ | |
ea56f411 | 258 | #ifdef pgprot_noncached |
7e6735c3 | 259 | static int uncached_access(struct file *file, phys_addr_t addr) |
d7d4d849 AM |
260 | { |
261 | #if defined(CONFIG_IA64) | |
262 | /* | |
263 | * On ia64, we ignore O_DSYNC because we cannot tolerate memory | |
264 | * attribute aliases. | |
265 | */ | |
266 | return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); | |
267 | #elif defined(CONFIG_MIPS) | |
268 | { | |
269 | extern int __uncached_access(struct file *file, | |
270 | unsigned long addr); | |
271 | ||
272 | return __uncached_access(file, addr); | |
273 | } | |
274 | #else | |
275 | /* | |
276 | * Accessing memory above the top the kernel knows about or through a | |
277 | * file pointer | |
278 | * that was marked O_DSYNC will be done non-cached. | |
279 | */ | |
280 | if (file->f_flags & O_DSYNC) | |
281 | return 1; | |
282 | return addr >= __pa(high_memory); | |
283 | #endif | |
284 | } | |
ea56f411 | 285 | #endif |
d7d4d849 | 286 | |
44ac8413 BH |
287 | static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
288 | unsigned long size, pgprot_t vma_prot) | |
289 | { | |
290 | #ifdef pgprot_noncached | |
7e6735c3 | 291 | phys_addr_t offset = pfn << PAGE_SHIFT; |
44ac8413 BH |
292 | |
293 | if (uncached_access(file, offset)) | |
294 | return pgprot_noncached(vma_prot); | |
295 | #endif | |
296 | return vma_prot; | |
297 | } | |
298 | #endif | |
299 | ||
5da6185b DH |
300 | #ifndef CONFIG_MMU |
301 | static unsigned long get_unmapped_area_mem(struct file *file, | |
302 | unsigned long addr, | |
303 | unsigned long len, | |
304 | unsigned long pgoff, | |
305 | unsigned long flags) | |
306 | { | |
307 | if (!valid_mmap_phys_addr_range(pgoff, len)) | |
308 | return (unsigned long) -EINVAL; | |
8a93258c | 309 | return pgoff << PAGE_SHIFT; |
5da6185b DH |
310 | } |
311 | ||
b4caecd4 CH |
312 | /* permit direct mmap, for read, write or exec */ |
313 | static unsigned memory_mmap_capabilities(struct file *file) | |
314 | { | |
315 | return NOMMU_MAP_DIRECT | | |
316 | NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC; | |
317 | } | |
318 | ||
319 | static unsigned zero_mmap_capabilities(struct file *file) | |
320 | { | |
321 | return NOMMU_MAP_COPY; | |
322 | } | |
323 | ||
5da6185b DH |
324 | /* can't do an in-place private mapping if there's no MMU */ |
325 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
326 | { | |
327 | return vma->vm_flags & VM_MAYSHARE; | |
328 | } | |
329 | #else | |
5da6185b DH |
330 | |
331 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
332 | { | |
333 | return 1; | |
334 | } | |
335 | #endif | |
336 | ||
f0f37e2f | 337 | static const struct vm_operations_struct mmap_mem_ops = { |
7ae8ed50 RR |
338 | #ifdef CONFIG_HAVE_IOREMAP_PROT |
339 | .access = generic_access_phys | |
340 | #endif | |
e7f260a2 | 341 | }; |
342 | ||
d7d4d849 | 343 | static int mmap_mem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 344 | { |
80851ef2 | 345 | size_t size = vma->vm_end - vma->vm_start; |
b299cde2 JW |
346 | phys_addr_t offset = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; |
347 | ||
348 | /* It's illegal to wrap around the end of the physical address space. */ | |
32829da5 | 349 | if (offset + (phys_addr_t)size - 1 < offset) |
b299cde2 | 350 | return -EINVAL; |
80851ef2 | 351 | |
06c67bef | 352 | if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) |
80851ef2 BH |
353 | return -EINVAL; |
354 | ||
5da6185b DH |
355 | if (!private_mapping_ok(vma)) |
356 | return -ENOSYS; | |
357 | ||
e2beb3ea VP |
358 | if (!range_is_allowed(vma->vm_pgoff, size)) |
359 | return -EPERM; | |
360 | ||
f0970c13 | 361 | if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, |
362 | &vma->vm_page_prot)) | |
363 | return -EINVAL; | |
364 | ||
8b150478 | 365 | vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, |
80851ef2 | 366 | size, |
1da177e4 | 367 | vma->vm_page_prot); |
1da177e4 | 368 | |
e7f260a2 | 369 | vma->vm_ops = &mmap_mem_ops; |
370 | ||
314e51b9 | 371 | /* Remap-pfn-range will mark the range VM_IO */ |
1da177e4 LT |
372 | if (remap_pfn_range(vma, |
373 | vma->vm_start, | |
374 | vma->vm_pgoff, | |
80851ef2 | 375 | size, |
e7f260a2 | 376 | vma->vm_page_prot)) { |
1da177e4 | 377 | return -EAGAIN; |
e7f260a2 | 378 | } |
1da177e4 LT |
379 | return 0; |
380 | } | |
381 | ||
d7d4d849 | 382 | static int mmap_kmem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 383 | { |
4bb82551 LT |
384 | unsigned long pfn; |
385 | ||
6d3154cc LT |
386 | /* Turn a kernel-virtual address into a physical page frame */ |
387 | pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; | |
4bb82551 | 388 | |
1da177e4 | 389 | /* |
d7d4d849 AM |
390 | * RED-PEN: on some architectures there is more mapped memory than |
391 | * available in mem_map which pfn_valid checks for. Perhaps should add a | |
392 | * new macro here. | |
1da177e4 LT |
393 | * |
394 | * RED-PEN: vmalloc is not supported right now. | |
395 | */ | |
4bb82551 | 396 | if (!pfn_valid(pfn)) |
1da177e4 | 397 | return -EIO; |
4bb82551 LT |
398 | |
399 | vma->vm_pgoff = pfn; | |
1da177e4 LT |
400 | return mmap_mem(file, vma); |
401 | } | |
402 | ||
1da177e4 LT |
403 | /* |
404 | * This function reads the *virtual* memory as seen by the kernel. | |
405 | */ | |
d7d4d849 | 406 | static ssize_t read_kmem(struct file *file, char __user *buf, |
1da177e4 LT |
407 | size_t count, loff_t *ppos) |
408 | { | |
409 | unsigned long p = *ppos; | |
410 | ssize_t low_count, read, sz; | |
890537b3 | 411 | char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ |
325fda71 | 412 | int err = 0; |
1da177e4 LT |
413 | |
414 | read = 0; | |
415 | if (p < (unsigned long) high_memory) { | |
416 | low_count = count; | |
d7d4d849 AM |
417 | if (count > (unsigned long)high_memory - p) |
418 | low_count = (unsigned long)high_memory - p; | |
1da177e4 LT |
419 | |
420 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
421 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
422 | if (p < PAGE_SIZE && low_count > 0) { | |
7fabaddd WF |
423 | sz = size_inside_page(p, low_count); |
424 | if (clear_user(buf, sz)) | |
1da177e4 | 425 | return -EFAULT; |
7fabaddd WF |
426 | buf += sz; |
427 | p += sz; | |
428 | read += sz; | |
429 | low_count -= sz; | |
430 | count -= sz; | |
1da177e4 LT |
431 | } |
432 | #endif | |
433 | while (low_count > 0) { | |
f222318e | 434 | sz = size_inside_page(p, low_count); |
1da177e4 LT |
435 | |
436 | /* | |
437 | * On ia64 if a page has been mapped somewhere as | |
438 | * uncached, then it must also be accessed uncached | |
439 | * by the kernel or data corruption may occur | |
440 | */ | |
4707a341 | 441 | kbuf = xlate_dev_kmem_ptr((void *)p); |
488debb9 RM |
442 | if (!virt_addr_valid(kbuf)) |
443 | return -ENXIO; | |
1da177e4 LT |
444 | |
445 | if (copy_to_user(buf, kbuf, sz)) | |
446 | return -EFAULT; | |
447 | buf += sz; | |
448 | p += sz; | |
449 | read += sz; | |
450 | low_count -= sz; | |
451 | count -= sz; | |
452 | } | |
453 | } | |
454 | ||
455 | if (count > 0) { | |
456 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
457 | if (!kbuf) | |
458 | return -ENOMEM; | |
459 | while (count > 0) { | |
80ad89a0 | 460 | sz = size_inside_page(p, count); |
325fda71 KH |
461 | if (!is_vmalloc_or_module_addr((void *)p)) { |
462 | err = -ENXIO; | |
463 | break; | |
464 | } | |
80ad89a0 WF |
465 | sz = vread(kbuf, (char *)p, sz); |
466 | if (!sz) | |
1da177e4 | 467 | break; |
80ad89a0 | 468 | if (copy_to_user(buf, kbuf, sz)) { |
325fda71 KH |
469 | err = -EFAULT; |
470 | break; | |
1da177e4 | 471 | } |
80ad89a0 WF |
472 | count -= sz; |
473 | buf += sz; | |
474 | read += sz; | |
475 | p += sz; | |
1da177e4 LT |
476 | } |
477 | free_page((unsigned long)kbuf); | |
478 | } | |
325fda71 KH |
479 | *ppos = p; |
480 | return read ? read : err; | |
1da177e4 LT |
481 | } |
482 | ||
483 | ||
d7d4d849 AM |
484 | static ssize_t do_write_kmem(unsigned long p, const char __user *buf, |
485 | size_t count, loff_t *ppos) | |
1da177e4 LT |
486 | { |
487 | ssize_t written, sz; | |
488 | unsigned long copied; | |
489 | ||
490 | written = 0; | |
491 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
492 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
ee32398f WF |
493 | if (p < PAGE_SIZE) { |
494 | sz = size_inside_page(p, count); | |
1da177e4 LT |
495 | /* Hmm. Do something? */ |
496 | buf += sz; | |
497 | p += sz; | |
1da177e4 LT |
498 | count -= sz; |
499 | written += sz; | |
500 | } | |
501 | #endif | |
502 | ||
503 | while (count > 0) { | |
4707a341 | 504 | void *ptr; |
1da177e4 | 505 | |
ee32398f | 506 | sz = size_inside_page(p, count); |
1da177e4 LT |
507 | |
508 | /* | |
d7d4d849 AM |
509 | * On ia64 if a page has been mapped somewhere as uncached, then |
510 | * it must also be accessed uncached by the kernel or data | |
511 | * corruption may occur. | |
1da177e4 | 512 | */ |
4707a341 | 513 | ptr = xlate_dev_kmem_ptr((void *)p); |
488debb9 RM |
514 | if (!virt_addr_valid(ptr)) |
515 | return -ENXIO; | |
1da177e4 LT |
516 | |
517 | copied = copy_from_user(ptr, buf, sz); | |
518 | if (copied) { | |
c654d60e JB |
519 | written += sz - copied; |
520 | if (written) | |
521 | break; | |
1da177e4 LT |
522 | return -EFAULT; |
523 | } | |
524 | buf += sz; | |
525 | p += sz; | |
1da177e4 LT |
526 | count -= sz; |
527 | written += sz; | |
528 | } | |
529 | ||
530 | *ppos += written; | |
531 | return written; | |
532 | } | |
533 | ||
1da177e4 LT |
534 | /* |
535 | * This function writes to the *virtual* memory as seen by the kernel. | |
536 | */ | |
d7d4d849 | 537 | static ssize_t write_kmem(struct file *file, const char __user *buf, |
1da177e4 LT |
538 | size_t count, loff_t *ppos) |
539 | { | |
540 | unsigned long p = *ppos; | |
541 | ssize_t wrote = 0; | |
542 | ssize_t virtr = 0; | |
890537b3 | 543 | char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ |
325fda71 | 544 | int err = 0; |
1da177e4 | 545 | |
5d1ffbd8 MG |
546 | if (kernel_is_locked_down()) |
547 | return -EPERM; | |
548 | ||
1da177e4 | 549 | if (p < (unsigned long) high_memory) { |
80ad89a0 WF |
550 | unsigned long to_write = min_t(unsigned long, count, |
551 | (unsigned long)high_memory - p); | |
ee32398f | 552 | wrote = do_write_kmem(p, buf, to_write, ppos); |
80ad89a0 WF |
553 | if (wrote != to_write) |
554 | return wrote; | |
1da177e4 LT |
555 | p += wrote; |
556 | buf += wrote; | |
557 | count -= wrote; | |
558 | } | |
559 | ||
560 | if (count > 0) { | |
561 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
562 | if (!kbuf) | |
563 | return wrote ? wrote : -ENOMEM; | |
564 | while (count > 0) { | |
80ad89a0 WF |
565 | unsigned long sz = size_inside_page(p, count); |
566 | unsigned long n; | |
1da177e4 | 567 | |
325fda71 KH |
568 | if (!is_vmalloc_or_module_addr((void *)p)) { |
569 | err = -ENXIO; | |
570 | break; | |
571 | } | |
80ad89a0 WF |
572 | n = copy_from_user(kbuf, buf, sz); |
573 | if (n) { | |
325fda71 KH |
574 | err = -EFAULT; |
575 | break; | |
1da177e4 | 576 | } |
c85e9a97 | 577 | vwrite(kbuf, (char *)p, sz); |
80ad89a0 WF |
578 | count -= sz; |
579 | buf += sz; | |
580 | virtr += sz; | |
581 | p += sz; | |
1da177e4 LT |
582 | } |
583 | free_page((unsigned long)kbuf); | |
584 | } | |
585 | ||
325fda71 KH |
586 | *ppos = p; |
587 | return virtr + wrote ? : err; | |
1da177e4 LT |
588 | } |
589 | ||
d7d4d849 | 590 | static ssize_t read_port(struct file *file, char __user *buf, |
1da177e4 LT |
591 | size_t count, loff_t *ppos) |
592 | { | |
593 | unsigned long i = *ppos; | |
594 | char __user *tmp = buf; | |
595 | ||
596 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
d7d4d849 | 597 | return -EFAULT; |
1da177e4 | 598 | while (count-- > 0 && i < 65536) { |
d7d4d849 AM |
599 | if (__put_user(inb(i), tmp) < 0) |
600 | return -EFAULT; | |
1da177e4 LT |
601 | i++; |
602 | tmp++; | |
603 | } | |
604 | *ppos = i; | |
605 | return tmp-buf; | |
606 | } | |
607 | ||
d7d4d849 | 608 | static ssize_t write_port(struct file *file, const char __user *buf, |
1da177e4 LT |
609 | size_t count, loff_t *ppos) |
610 | { | |
611 | unsigned long i = *ppos; | |
890537b3 | 612 | const char __user *tmp = buf; |
1da177e4 | 613 | |
d7d4d849 | 614 | if (!access_ok(VERIFY_READ, buf, count)) |
1da177e4 LT |
615 | return -EFAULT; |
616 | while (count-- > 0 && i < 65536) { | |
617 | char c; | |
6a0061ba | 618 | |
c654d60e JB |
619 | if (__get_user(c, tmp)) { |
620 | if (tmp > buf) | |
621 | break; | |
d7d4d849 | 622 | return -EFAULT; |
c654d60e | 623 | } |
d7d4d849 | 624 | outb(c, i); |
1da177e4 LT |
625 | i++; |
626 | tmp++; | |
627 | } | |
628 | *ppos = i; | |
629 | return tmp-buf; | |
630 | } | |
1da177e4 | 631 | |
d7d4d849 | 632 | static ssize_t read_null(struct file *file, char __user *buf, |
1da177e4 LT |
633 | size_t count, loff_t *ppos) |
634 | { | |
635 | return 0; | |
636 | } | |
637 | ||
d7d4d849 | 638 | static ssize_t write_null(struct file *file, const char __user *buf, |
1da177e4 LT |
639 | size_t count, loff_t *ppos) |
640 | { | |
641 | return count; | |
642 | } | |
643 | ||
cd28e28d | 644 | static ssize_t read_iter_null(struct kiocb *iocb, struct iov_iter *to) |
162934de ZB |
645 | { |
646 | return 0; | |
647 | } | |
648 | ||
cd28e28d | 649 | static ssize_t write_iter_null(struct kiocb *iocb, struct iov_iter *from) |
162934de | 650 | { |
cd28e28d AV |
651 | size_t count = iov_iter_count(from); |
652 | iov_iter_advance(from, count); | |
653 | return count; | |
162934de ZB |
654 | } |
655 | ||
1ebd32fc JA |
656 | static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, |
657 | struct splice_desc *sd) | |
658 | { | |
659 | return sd->len; | |
660 | } | |
661 | ||
d7d4d849 | 662 | static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out, |
1ebd32fc JA |
663 | loff_t *ppos, size_t len, unsigned int flags) |
664 | { | |
665 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); | |
666 | } | |
667 | ||
13ba33e8 | 668 | static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 | 669 | { |
13ba33e8 | 670 | size_t written = 0; |
1da177e4 | 671 | |
13ba33e8 AV |
672 | while (iov_iter_count(iter)) { |
673 | size_t chunk = iov_iter_count(iter), n; | |
6a0061ba | 674 | |
557ed1fa NP |
675 | if (chunk > PAGE_SIZE) |
676 | chunk = PAGE_SIZE; /* Just for latency reasons */ | |
13ba33e8 AV |
677 | n = iov_iter_zero(chunk, iter); |
678 | if (!n && iov_iter_count(iter)) | |
679 | return written ? written : -EFAULT; | |
680 | written += n; | |
2b838687 LT |
681 | if (signal_pending(current)) |
682 | return written ? written : -ERESTARTSYS; | |
1da177e4 LT |
683 | cond_resched(); |
684 | } | |
13ba33e8 | 685 | return written; |
162934de ZB |
686 | } |
687 | ||
d7d4d849 | 688 | static int mmap_zero(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 689 | { |
557ed1fa | 690 | #ifndef CONFIG_MMU |
1da177e4 | 691 | return -ENOSYS; |
557ed1fa NP |
692 | #endif |
693 | if (vma->vm_flags & VM_SHARED) | |
694 | return shmem_zero_setup(vma); | |
695 | return 0; | |
1da177e4 | 696 | } |
1da177e4 | 697 | |
c01d5b30 HD |
698 | static unsigned long get_unmapped_area_zero(struct file *file, |
699 | unsigned long addr, unsigned long len, | |
700 | unsigned long pgoff, unsigned long flags) | |
701 | { | |
702 | #ifdef CONFIG_MMU | |
703 | if (flags & MAP_SHARED) { | |
704 | /* | |
705 | * mmap_zero() will call shmem_zero_setup() to create a file, | |
706 | * so use shmem's get_unmapped_area in case it can be huge; | |
707 | * and pass NULL for file as in mmap.c's get_unmapped_area(), | |
708 | * so as not to confuse shmem with our handle on "/dev/zero". | |
709 | */ | |
710 | return shmem_get_unmapped_area(NULL, addr, len, pgoff, flags); | |
711 | } | |
712 | ||
713 | /* Otherwise flags & MAP_PRIVATE: with no shmem object beneath it */ | |
714 | return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); | |
715 | #else | |
716 | return -ENOSYS; | |
717 | #endif | |
718 | } | |
719 | ||
d7d4d849 | 720 | static ssize_t write_full(struct file *file, const char __user *buf, |
1da177e4 LT |
721 | size_t count, loff_t *ppos) |
722 | { | |
723 | return -ENOSPC; | |
724 | } | |
725 | ||
726 | /* | |
727 | * Special lseek() function for /dev/null and /dev/zero. Most notably, you | |
728 | * can fopen() both devices with "a" now. This was previously impossible. | |
729 | * -- SRB. | |
730 | */ | |
d7d4d849 | 731 | static loff_t null_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
732 | { |
733 | return file->f_pos = 0; | |
734 | } | |
735 | ||
736 | /* | |
737 | * The memory devices use the full 32/64 bits of the offset, and so we cannot | |
738 | * check against negative addresses: they are ok. The return value is weird, | |
739 | * though, in that case (0). | |
740 | * | |
741 | * also note that seeking relative to the "end of file" isn't supported: | |
742 | * it has no meaning, so it returns -EINVAL. | |
743 | */ | |
d7d4d849 | 744 | static loff_t memory_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
745 | { |
746 | loff_t ret; | |
747 | ||
5955102c | 748 | inode_lock(file_inode(file)); |
1da177e4 | 749 | switch (orig) { |
d7d4d849 AM |
750 | case SEEK_CUR: |
751 | offset += file->f_pos; | |
d7d4d849 AM |
752 | case SEEK_SET: |
753 | /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */ | |
ecb63a1b | 754 | if ((unsigned long long)offset >= -MAX_ERRNO) { |
d7d4d849 | 755 | ret = -EOVERFLOW; |
1da177e4 | 756 | break; |
d7d4d849 AM |
757 | } |
758 | file->f_pos = offset; | |
759 | ret = file->f_pos; | |
760 | force_successful_syscall_return(); | |
761 | break; | |
762 | default: | |
763 | ret = -EINVAL; | |
1da177e4 | 764 | } |
5955102c | 765 | inode_unlock(file_inode(file)); |
1da177e4 LT |
766 | return ret; |
767 | } | |
768 | ||
890537b3 | 769 | static int open_port(struct inode *inode, struct file *filp) |
1da177e4 | 770 | { |
1ebb9cde MG |
771 | if (kernel_is_locked_down()) |
772 | return -EPERM; | |
1da177e4 LT |
773 | return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; |
774 | } | |
775 | ||
776 | #define zero_lseek null_lseek | |
777 | #define full_lseek null_lseek | |
778 | #define write_zero write_null | |
cd28e28d | 779 | #define write_iter_zero write_iter_null |
1da177e4 LT |
780 | #define open_mem open_port |
781 | #define open_kmem open_mem | |
782 | ||
73f0718e | 783 | static const struct file_operations __maybe_unused mem_fops = { |
1da177e4 LT |
784 | .llseek = memory_lseek, |
785 | .read = read_mem, | |
786 | .write = write_mem, | |
787 | .mmap = mmap_mem, | |
788 | .open = open_mem, | |
b4caecd4 | 789 | #ifndef CONFIG_MMU |
5da6185b | 790 | .get_unmapped_area = get_unmapped_area_mem, |
b4caecd4 CH |
791 | .mmap_capabilities = memory_mmap_capabilities, |
792 | #endif | |
1da177e4 LT |
793 | }; |
794 | ||
a8c91252 | 795 | static const struct file_operations __maybe_unused kmem_fops = { |
1da177e4 LT |
796 | .llseek = memory_lseek, |
797 | .read = read_kmem, | |
798 | .write = write_kmem, | |
799 | .mmap = mmap_kmem, | |
800 | .open = open_kmem, | |
b4caecd4 | 801 | #ifndef CONFIG_MMU |
5da6185b | 802 | .get_unmapped_area = get_unmapped_area_mem, |
b4caecd4 CH |
803 | .mmap_capabilities = memory_mmap_capabilities, |
804 | #endif | |
1da177e4 LT |
805 | }; |
806 | ||
62322d25 | 807 | static const struct file_operations null_fops = { |
1da177e4 LT |
808 | .llseek = null_lseek, |
809 | .read = read_null, | |
810 | .write = write_null, | |
cd28e28d AV |
811 | .read_iter = read_iter_null, |
812 | .write_iter = write_iter_null, | |
1ebd32fc | 813 | .splice_write = splice_write_null, |
1da177e4 LT |
814 | }; |
815 | ||
3a4bc2fb | 816 | static const struct file_operations __maybe_unused port_fops = { |
1da177e4 LT |
817 | .llseek = memory_lseek, |
818 | .read = read_port, | |
819 | .write = write_port, | |
820 | .open = open_port, | |
821 | }; | |
1da177e4 | 822 | |
62322d25 | 823 | static const struct file_operations zero_fops = { |
1da177e4 | 824 | .llseek = zero_lseek, |
1da177e4 | 825 | .write = write_zero, |
13ba33e8 | 826 | .read_iter = read_iter_zero, |
cd28e28d | 827 | .write_iter = write_iter_zero, |
1da177e4 | 828 | .mmap = mmap_zero, |
c01d5b30 | 829 | .get_unmapped_area = get_unmapped_area_zero, |
b4caecd4 CH |
830 | #ifndef CONFIG_MMU |
831 | .mmap_capabilities = zero_mmap_capabilities, | |
832 | #endif | |
1da177e4 LT |
833 | }; |
834 | ||
62322d25 | 835 | static const struct file_operations full_fops = { |
1da177e4 | 836 | .llseek = full_lseek, |
13ba33e8 | 837 | .read_iter = read_iter_zero, |
1da177e4 LT |
838 | .write = write_full, |
839 | }; | |
840 | ||
389e0cb9 KS |
841 | static const struct memdev { |
842 | const char *name; | |
2c9ede55 | 843 | umode_t mode; |
389e0cb9 | 844 | const struct file_operations *fops; |
b4caecd4 | 845 | fmode_t fmode; |
389e0cb9 | 846 | } devlist[] = { |
73f0718e | 847 | #ifdef CONFIG_DEVMEM |
b4caecd4 | 848 | [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET }, |
73f0718e | 849 | #endif |
b781ecb6 | 850 | #ifdef CONFIG_DEVKMEM |
b4caecd4 | 851 | [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET }, |
b781ecb6 | 852 | #endif |
b4caecd4 | 853 | [3] = { "null", 0666, &null_fops, 0 }, |
4f911d64 | 854 | #ifdef CONFIG_DEVPORT |
b4caecd4 | 855 | [4] = { "port", 0, &port_fops, 0 }, |
1da177e4 | 856 | #endif |
b4caecd4 CH |
857 | [5] = { "zero", 0666, &zero_fops, 0 }, |
858 | [7] = { "full", 0666, &full_fops, 0 }, | |
859 | [8] = { "random", 0666, &random_fops, 0 }, | |
860 | [9] = { "urandom", 0666, &urandom_fops, 0 }, | |
7f3a781d | 861 | #ifdef CONFIG_PRINTK |
b4caecd4 | 862 | [11] = { "kmsg", 0644, &kmsg_fops, 0 }, |
7f3a781d | 863 | #endif |
d6f47bef ASF |
864 | }; |
865 | ||
866 | static int memory_open(struct inode *inode, struct file *filp) | |
867 | { | |
389e0cb9 KS |
868 | int minor; |
869 | const struct memdev *dev; | |
d6f47bef | 870 | |
389e0cb9 KS |
871 | minor = iminor(inode); |
872 | if (minor >= ARRAY_SIZE(devlist)) | |
205153aa | 873 | return -ENXIO; |
d6f47bef | 874 | |
389e0cb9 KS |
875 | dev = &devlist[minor]; |
876 | if (!dev->fops) | |
205153aa | 877 | return -ENXIO; |
d6f47bef | 878 | |
389e0cb9 | 879 | filp->f_op = dev->fops; |
b4caecd4 | 880 | filp->f_mode |= dev->fmode; |
4a3956c7 | 881 | |
389e0cb9 | 882 | if (dev->fops->open) |
205153aa FW |
883 | return dev->fops->open(inode, filp); |
884 | ||
885 | return 0; | |
1da177e4 LT |
886 | } |
887 | ||
62322d25 | 888 | static const struct file_operations memory_fops = { |
d7d4d849 | 889 | .open = memory_open, |
6038f373 | 890 | .llseek = noop_llseek, |
1da177e4 LT |
891 | }; |
892 | ||
2c9ede55 | 893 | static char *mem_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
894 | { |
895 | if (mode && devlist[MINOR(dev->devt)].mode) | |
896 | *mode = devlist[MINOR(dev->devt)].mode; | |
897 | return NULL; | |
898 | } | |
899 | ||
ca8eca68 | 900 | static struct class *mem_class; |
1da177e4 LT |
901 | |
902 | static int __init chr_dev_init(void) | |
903 | { | |
389e0cb9 | 904 | int minor; |
1da177e4 | 905 | |
d7d4d849 | 906 | if (register_chrdev(MEM_MAJOR, "mem", &memory_fops)) |
1da177e4 LT |
907 | printk("unable to get major %d for memory devs\n", MEM_MAJOR); |
908 | ||
ca8eca68 | 909 | mem_class = class_create(THIS_MODULE, "mem"); |
6e191f7b AB |
910 | if (IS_ERR(mem_class)) |
911 | return PTR_ERR(mem_class); | |
912 | ||
e454cea2 | 913 | mem_class->devnode = mem_devnode; |
389e0cb9 KS |
914 | for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) { |
915 | if (!devlist[minor].name) | |
916 | continue; | |
e1612de9 HM |
917 | |
918 | /* | |
890537b3 | 919 | * Create /dev/port? |
e1612de9 HM |
920 | */ |
921 | if ((minor == DEVPORT_MINOR) && !arch_has_dev_port()) | |
922 | continue; | |
923 | ||
389e0cb9 KS |
924 | device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor), |
925 | NULL, devlist[minor].name); | |
926 | } | |
ebf644c4 | 927 | |
31d1d48e | 928 | return tty_init(); |
1da177e4 LT |
929 | } |
930 | ||
931 | fs_initcall(chr_dev_init); |