Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/mem.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
d7d4d849 | 6 | * Added devfs support. |
1da177e4 | 7 | * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu> |
af901ca1 | 8 | * Shared /dev/zero mmapping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com> |
1da177e4 LT |
9 | */ |
10 | ||
1da177e4 LT |
11 | #include <linux/mm.h> |
12 | #include <linux/miscdevice.h> | |
13 | #include <linux/slab.h> | |
14 | #include <linux/vmalloc.h> | |
15 | #include <linux/mman.h> | |
16 | #include <linux/random.h> | |
17 | #include <linux/init.h> | |
18 | #include <linux/raw.h> | |
19 | #include <linux/tty.h> | |
20 | #include <linux/capability.h> | |
1da177e4 LT |
21 | #include <linux/ptrace.h> |
22 | #include <linux/device.h> | |
50b1fdbd | 23 | #include <linux/highmem.h> |
1da177e4 | 24 | #include <linux/backing-dev.h> |
d6b29d7c | 25 | #include <linux/splice.h> |
b8a3ad5b | 26 | #include <linux/pfn.h> |
66300e66 | 27 | #include <linux/export.h> |
e1612de9 | 28 | #include <linux/io.h> |
e2e40f2c | 29 | #include <linux/uio.h> |
1da177e4 | 30 | |
1cac41cb MB |
31 | #ifdef CONFIG_KNOX_KAP |
32 | #include <linux/knox_kap.h> | |
33 | #endif | |
34 | ||
35 | #ifdef CONFIG_MST_LDO | |
36 | #include <linux/mst_ctrl.h> | |
37 | #endif | |
38 | ||
35b6c7e4 | 39 | #include <linux/uaccess.h> |
1da177e4 LT |
40 | |
41 | #ifdef CONFIG_IA64 | |
42 | # include <linux/efi.h> | |
43 | #endif | |
44 | ||
e1612de9 HM |
45 | #define DEVPORT_MINOR 4 |
46 | ||
f222318e WF |
47 | static inline unsigned long size_inside_page(unsigned long start, |
48 | unsigned long size) | |
49 | { | |
50 | unsigned long sz; | |
51 | ||
7fabaddd | 52 | sz = PAGE_SIZE - (start & (PAGE_SIZE - 1)); |
f222318e | 53 | |
7fabaddd | 54 | return min(sz, size); |
f222318e WF |
55 | } |
56 | ||
1da177e4 | 57 | #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE |
7e6735c3 | 58 | static inline int valid_phys_addr_range(phys_addr_t addr, size_t count) |
1da177e4 | 59 | { |
cfaf346c | 60 | return addr + count <= __pa(high_memory); |
1da177e4 | 61 | } |
80851ef2 | 62 | |
06c67bef | 63 | static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) |
80851ef2 BH |
64 | { |
65 | return 1; | |
66 | } | |
1da177e4 LT |
67 | #endif |
68 | ||
d092633b | 69 | #ifdef CONFIG_STRICT_DEVMEM |
6739cc12 KC |
70 | static inline int page_is_allowed(unsigned long pfn) |
71 | { | |
72 | return devmem_is_allowed(pfn); | |
73 | } | |
e2beb3ea | 74 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 | 75 | { |
e2beb3ea VP |
76 | u64 from = ((u64)pfn) << PAGE_SHIFT; |
77 | u64 to = from + size; | |
78 | u64 cursor = from; | |
79 | ||
80 | while (cursor < to) { | |
81 | if (!devmem_is_allowed(pfn)) { | |
82 | printk(KERN_INFO | |
83 | "Program %s tried to access /dev/mem between %Lx->%Lx.\n", | |
ae531c26 AV |
84 | current->comm, from, to); |
85 | return 0; | |
86 | } | |
e2beb3ea VP |
87 | cursor += PAGE_SIZE; |
88 | pfn++; | |
ae531c26 AV |
89 | } |
90 | return 1; | |
91 | } | |
92 | #else | |
6739cc12 KC |
93 | static inline int page_is_allowed(unsigned long pfn) |
94 | { | |
95 | return 1; | |
96 | } | |
e2beb3ea | 97 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 AV |
98 | { |
99 | return 1; | |
100 | } | |
101 | #endif | |
102 | ||
4707a341 TR |
103 | #ifndef unxlate_dev_mem_ptr |
104 | #define unxlate_dev_mem_ptr unxlate_dev_mem_ptr | |
105 | void __weak unxlate_dev_mem_ptr(phys_addr_t phys, void *addr) | |
e045fb2a | 106 | { |
107 | } | |
4707a341 | 108 | #endif |
e045fb2a | 109 | |
1da177e4 | 110 | /* |
d7d4d849 AM |
111 | * This funcion reads the *physical* memory. The f_pos points directly to the |
112 | * memory location. | |
1da177e4 | 113 | */ |
d7d4d849 | 114 | static ssize_t read_mem(struct file *file, char __user *buf, |
1da177e4 LT |
115 | size_t count, loff_t *ppos) |
116 | { | |
7e6735c3 | 117 | phys_addr_t p = *ppos; |
1da177e4 | 118 | ssize_t read, sz; |
4707a341 | 119 | void *ptr; |
1da177e4 | 120 | |
08d2d00b PT |
121 | if (p != *ppos) |
122 | return 0; | |
123 | ||
136939a2 | 124 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
125 | return -EFAULT; |
126 | read = 0; | |
127 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
128 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
129 | if (p < PAGE_SIZE) { | |
7fabaddd | 130 | sz = size_inside_page(p, count); |
1da177e4 LT |
131 | if (sz > 0) { |
132 | if (clear_user(buf, sz)) | |
133 | return -EFAULT; | |
d7d4d849 AM |
134 | buf += sz; |
135 | p += sz; | |
136 | count -= sz; | |
137 | read += sz; | |
1da177e4 LT |
138 | } |
139 | } | |
140 | #endif | |
141 | ||
142 | while (count > 0) { | |
fa29e97b | 143 | unsigned long remaining; |
6739cc12 | 144 | int allowed; |
fa29e97b | 145 | |
f222318e | 146 | sz = size_inside_page(p, count); |
1da177e4 | 147 | |
6739cc12 KC |
148 | allowed = page_is_allowed(p >> PAGE_SHIFT); |
149 | if (!allowed) | |
e045fb2a | 150 | return -EPERM; |
6739cc12 KC |
151 | if (allowed == 2) { |
152 | /* Show zeros for restricted memory. */ | |
153 | remaining = clear_user(buf, sz); | |
154 | } else { | |
155 | /* | |
156 | * On ia64 if a page has been mapped somewhere as | |
157 | * uncached, then it must also be accessed uncached | |
158 | * by the kernel or data corruption may occur. | |
159 | */ | |
160 | ptr = xlate_dev_mem_ptr(p); | |
161 | if (!ptr) | |
162 | return -EFAULT; | |
e045fb2a | 163 | |
6739cc12 KC |
164 | remaining = copy_to_user(buf, ptr, sz); |
165 | ||
166 | unxlate_dev_mem_ptr(p, ptr); | |
167 | } | |
1da177e4 | 168 | |
fa29e97b WF |
169 | if (remaining) |
170 | return -EFAULT; | |
e045fb2a | 171 | |
1da177e4 LT |
172 | buf += sz; |
173 | p += sz; | |
174 | count -= sz; | |
175 | read += sz; | |
176 | } | |
177 | ||
178 | *ppos += read; | |
179 | return read; | |
180 | } | |
181 | ||
d7d4d849 | 182 | static ssize_t write_mem(struct file *file, const char __user *buf, |
1da177e4 LT |
183 | size_t count, loff_t *ppos) |
184 | { | |
7e6735c3 | 185 | phys_addr_t p = *ppos; |
1da177e4 LT |
186 | ssize_t written, sz; |
187 | unsigned long copied; | |
188 | void *ptr; | |
189 | ||
08d2d00b PT |
190 | if (p != *ppos) |
191 | return -EFBIG; | |
192 | ||
136939a2 | 193 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
194 | return -EFAULT; |
195 | ||
196 | written = 0; | |
197 | ||
198 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
199 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
200 | if (p < PAGE_SIZE) { | |
7fabaddd | 201 | sz = size_inside_page(p, count); |
1da177e4 LT |
202 | /* Hmm. Do something? */ |
203 | buf += sz; | |
204 | p += sz; | |
205 | count -= sz; | |
206 | written += sz; | |
207 | } | |
208 | #endif | |
209 | ||
210 | while (count > 0) { | |
6739cc12 KC |
211 | int allowed; |
212 | ||
f222318e | 213 | sz = size_inside_page(p, count); |
1da177e4 | 214 | |
6739cc12 KC |
215 | allowed = page_is_allowed(p >> PAGE_SHIFT); |
216 | if (!allowed) | |
e045fb2a | 217 | return -EPERM; |
218 | ||
6739cc12 KC |
219 | /* Skip actual writing when a page is marked as restricted. */ |
220 | if (allowed == 1) { | |
221 | /* | |
222 | * On ia64 if a page has been mapped somewhere as | |
223 | * uncached, then it must also be accessed uncached | |
224 | * by the kernel or data corruption may occur. | |
225 | */ | |
226 | ptr = xlate_dev_mem_ptr(p); | |
227 | if (!ptr) { | |
228 | if (written) | |
229 | break; | |
230 | return -EFAULT; | |
231 | } | |
232 | ||
233 | copied = copy_from_user(ptr, buf, sz); | |
234 | unxlate_dev_mem_ptr(p, ptr); | |
235 | if (copied) { | |
236 | written += sz - copied; | |
237 | if (written) | |
238 | break; | |
239 | return -EFAULT; | |
240 | } | |
1da177e4 | 241 | } |
e045fb2a | 242 | |
1da177e4 LT |
243 | buf += sz; |
244 | p += sz; | |
245 | count -= sz; | |
246 | written += sz; | |
247 | } | |
248 | ||
249 | *ppos += written; | |
250 | return written; | |
251 | } | |
252 | ||
d7d4d849 | 253 | int __weak phys_mem_access_prot_allowed(struct file *file, |
f0970c13 | 254 | unsigned long pfn, unsigned long size, pgprot_t *vma_prot) |
255 | { | |
256 | return 1; | |
257 | } | |
258 | ||
44ac8413 | 259 | #ifndef __HAVE_PHYS_MEM_ACCESS_PROT |
d7d4d849 AM |
260 | |
261 | /* | |
262 | * Architectures vary in how they handle caching for addresses | |
263 | * outside of main memory. | |
264 | * | |
265 | */ | |
ea56f411 | 266 | #ifdef pgprot_noncached |
7e6735c3 | 267 | static int uncached_access(struct file *file, phys_addr_t addr) |
d7d4d849 AM |
268 | { |
269 | #if defined(CONFIG_IA64) | |
270 | /* | |
271 | * On ia64, we ignore O_DSYNC because we cannot tolerate memory | |
272 | * attribute aliases. | |
273 | */ | |
274 | return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); | |
275 | #elif defined(CONFIG_MIPS) | |
276 | { | |
277 | extern int __uncached_access(struct file *file, | |
278 | unsigned long addr); | |
279 | ||
280 | return __uncached_access(file, addr); | |
281 | } | |
282 | #else | |
283 | /* | |
284 | * Accessing memory above the top the kernel knows about or through a | |
285 | * file pointer | |
286 | * that was marked O_DSYNC will be done non-cached. | |
287 | */ | |
288 | if (file->f_flags & O_DSYNC) | |
289 | return 1; | |
290 | return addr >= __pa(high_memory); | |
291 | #endif | |
292 | } | |
ea56f411 | 293 | #endif |
d7d4d849 | 294 | |
44ac8413 BH |
295 | static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
296 | unsigned long size, pgprot_t vma_prot) | |
297 | { | |
298 | #ifdef pgprot_noncached | |
7e6735c3 | 299 | phys_addr_t offset = pfn << PAGE_SHIFT; |
44ac8413 BH |
300 | |
301 | if (uncached_access(file, offset)) | |
302 | return pgprot_noncached(vma_prot); | |
303 | #endif | |
304 | return vma_prot; | |
305 | } | |
306 | #endif | |
307 | ||
5da6185b DH |
308 | #ifndef CONFIG_MMU |
309 | static unsigned long get_unmapped_area_mem(struct file *file, | |
310 | unsigned long addr, | |
311 | unsigned long len, | |
312 | unsigned long pgoff, | |
313 | unsigned long flags) | |
314 | { | |
315 | if (!valid_mmap_phys_addr_range(pgoff, len)) | |
316 | return (unsigned long) -EINVAL; | |
8a93258c | 317 | return pgoff << PAGE_SHIFT; |
5da6185b DH |
318 | } |
319 | ||
b4caecd4 CH |
320 | /* permit direct mmap, for read, write or exec */ |
321 | static unsigned memory_mmap_capabilities(struct file *file) | |
322 | { | |
323 | return NOMMU_MAP_DIRECT | | |
324 | NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC; | |
325 | } | |
326 | ||
327 | static unsigned zero_mmap_capabilities(struct file *file) | |
328 | { | |
329 | return NOMMU_MAP_COPY; | |
330 | } | |
331 | ||
5da6185b DH |
332 | /* can't do an in-place private mapping if there's no MMU */ |
333 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
334 | { | |
335 | return vma->vm_flags & VM_MAYSHARE; | |
336 | } | |
337 | #else | |
5da6185b DH |
338 | |
339 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
340 | { | |
341 | return 1; | |
342 | } | |
343 | #endif | |
344 | ||
f0f37e2f | 345 | static const struct vm_operations_struct mmap_mem_ops = { |
7ae8ed50 RR |
346 | #ifdef CONFIG_HAVE_IOREMAP_PROT |
347 | .access = generic_access_phys | |
348 | #endif | |
e7f260a2 | 349 | }; |
350 | ||
d7d4d849 | 351 | static int mmap_mem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 352 | { |
80851ef2 | 353 | size_t size = vma->vm_end - vma->vm_start; |
837bfdb4 JW |
354 | phys_addr_t offset = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; |
355 | ||
356 | /* It's illegal to wrap around the end of the physical address space. */ | |
983c09eb | 357 | if (offset + (phys_addr_t)size - 1 < offset) |
837bfdb4 | 358 | return -EINVAL; |
80851ef2 | 359 | |
06c67bef | 360 | if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) |
80851ef2 BH |
361 | return -EINVAL; |
362 | ||
5da6185b DH |
363 | if (!private_mapping_ok(vma)) |
364 | return -ENOSYS; | |
365 | ||
e2beb3ea VP |
366 | if (!range_is_allowed(vma->vm_pgoff, size)) |
367 | return -EPERM; | |
368 | ||
f0970c13 | 369 | if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, |
370 | &vma->vm_page_prot)) | |
371 | return -EINVAL; | |
372 | ||
8b150478 | 373 | vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, |
80851ef2 | 374 | size, |
1da177e4 | 375 | vma->vm_page_prot); |
1da177e4 | 376 | |
e7f260a2 | 377 | vma->vm_ops = &mmap_mem_ops; |
378 | ||
314e51b9 | 379 | /* Remap-pfn-range will mark the range VM_IO */ |
1da177e4 LT |
380 | if (remap_pfn_range(vma, |
381 | vma->vm_start, | |
382 | vma->vm_pgoff, | |
80851ef2 | 383 | size, |
e7f260a2 | 384 | vma->vm_page_prot)) { |
1da177e4 | 385 | return -EAGAIN; |
e7f260a2 | 386 | } |
1da177e4 LT |
387 | return 0; |
388 | } | |
389 | ||
d7d4d849 | 390 | static int mmap_kmem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 391 | { |
4bb82551 LT |
392 | unsigned long pfn; |
393 | ||
6d3154cc LT |
394 | /* Turn a kernel-virtual address into a physical page frame */ |
395 | pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; | |
4bb82551 | 396 | |
1da177e4 | 397 | /* |
d7d4d849 AM |
398 | * RED-PEN: on some architectures there is more mapped memory than |
399 | * available in mem_map which pfn_valid checks for. Perhaps should add a | |
400 | * new macro here. | |
1da177e4 LT |
401 | * |
402 | * RED-PEN: vmalloc is not supported right now. | |
403 | */ | |
4bb82551 | 404 | if (!pfn_valid(pfn)) |
1da177e4 | 405 | return -EIO; |
4bb82551 LT |
406 | |
407 | vma->vm_pgoff = pfn; | |
1da177e4 LT |
408 | return mmap_mem(file, vma); |
409 | } | |
410 | ||
1da177e4 LT |
411 | /* |
412 | * This function reads the *virtual* memory as seen by the kernel. | |
413 | */ | |
d7d4d849 | 414 | static ssize_t read_kmem(struct file *file, char __user *buf, |
1da177e4 LT |
415 | size_t count, loff_t *ppos) |
416 | { | |
417 | unsigned long p = *ppos; | |
418 | ssize_t low_count, read, sz; | |
890537b3 | 419 | char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ |
325fda71 | 420 | int err = 0; |
1da177e4 LT |
421 | |
422 | read = 0; | |
423 | if (p < (unsigned long) high_memory) { | |
424 | low_count = count; | |
d7d4d849 AM |
425 | if (count > (unsigned long)high_memory - p) |
426 | low_count = (unsigned long)high_memory - p; | |
1da177e4 LT |
427 | |
428 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
429 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
430 | if (p < PAGE_SIZE && low_count > 0) { | |
7fabaddd WF |
431 | sz = size_inside_page(p, low_count); |
432 | if (clear_user(buf, sz)) | |
1da177e4 | 433 | return -EFAULT; |
7fabaddd WF |
434 | buf += sz; |
435 | p += sz; | |
436 | read += sz; | |
437 | low_count -= sz; | |
438 | count -= sz; | |
1da177e4 LT |
439 | } |
440 | #endif | |
441 | while (low_count > 0) { | |
f222318e | 442 | sz = size_inside_page(p, low_count); |
1da177e4 LT |
443 | |
444 | /* | |
445 | * On ia64 if a page has been mapped somewhere as | |
446 | * uncached, then it must also be accessed uncached | |
447 | * by the kernel or data corruption may occur | |
448 | */ | |
4707a341 | 449 | kbuf = xlate_dev_kmem_ptr((void *)p); |
1da177e4 LT |
450 | |
451 | if (copy_to_user(buf, kbuf, sz)) | |
452 | return -EFAULT; | |
453 | buf += sz; | |
454 | p += sz; | |
455 | read += sz; | |
456 | low_count -= sz; | |
457 | count -= sz; | |
458 | } | |
459 | } | |
460 | ||
461 | if (count > 0) { | |
462 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
463 | if (!kbuf) | |
464 | return -ENOMEM; | |
465 | while (count > 0) { | |
80ad89a0 | 466 | sz = size_inside_page(p, count); |
325fda71 KH |
467 | if (!is_vmalloc_or_module_addr((void *)p)) { |
468 | err = -ENXIO; | |
469 | break; | |
470 | } | |
80ad89a0 WF |
471 | sz = vread(kbuf, (char *)p, sz); |
472 | if (!sz) | |
1da177e4 | 473 | break; |
80ad89a0 | 474 | if (copy_to_user(buf, kbuf, sz)) { |
325fda71 KH |
475 | err = -EFAULT; |
476 | break; | |
1da177e4 | 477 | } |
80ad89a0 WF |
478 | count -= sz; |
479 | buf += sz; | |
480 | read += sz; | |
481 | p += sz; | |
1da177e4 LT |
482 | } |
483 | free_page((unsigned long)kbuf); | |
484 | } | |
325fda71 KH |
485 | *ppos = p; |
486 | return read ? read : err; | |
1da177e4 LT |
487 | } |
488 | ||
489 | ||
d7d4d849 AM |
490 | static ssize_t do_write_kmem(unsigned long p, const char __user *buf, |
491 | size_t count, loff_t *ppos) | |
1da177e4 LT |
492 | { |
493 | ssize_t written, sz; | |
494 | unsigned long copied; | |
495 | ||
496 | written = 0; | |
497 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
498 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
ee32398f WF |
499 | if (p < PAGE_SIZE) { |
500 | sz = size_inside_page(p, count); | |
1da177e4 LT |
501 | /* Hmm. Do something? */ |
502 | buf += sz; | |
503 | p += sz; | |
1da177e4 LT |
504 | count -= sz; |
505 | written += sz; | |
506 | } | |
507 | #endif | |
508 | ||
509 | while (count > 0) { | |
4707a341 | 510 | void *ptr; |
1da177e4 | 511 | |
ee32398f | 512 | sz = size_inside_page(p, count); |
1da177e4 LT |
513 | |
514 | /* | |
d7d4d849 AM |
515 | * On ia64 if a page has been mapped somewhere as uncached, then |
516 | * it must also be accessed uncached by the kernel or data | |
517 | * corruption may occur. | |
1da177e4 | 518 | */ |
4707a341 | 519 | ptr = xlate_dev_kmem_ptr((void *)p); |
1da177e4 LT |
520 | |
521 | copied = copy_from_user(ptr, buf, sz); | |
522 | if (copied) { | |
c654d60e JB |
523 | written += sz - copied; |
524 | if (written) | |
525 | break; | |
1da177e4 LT |
526 | return -EFAULT; |
527 | } | |
528 | buf += sz; | |
529 | p += sz; | |
1da177e4 LT |
530 | count -= sz; |
531 | written += sz; | |
532 | } | |
533 | ||
534 | *ppos += written; | |
535 | return written; | |
536 | } | |
537 | ||
1da177e4 LT |
538 | /* |
539 | * This function writes to the *virtual* memory as seen by the kernel. | |
540 | */ | |
d7d4d849 | 541 | static ssize_t write_kmem(struct file *file, const char __user *buf, |
1da177e4 LT |
542 | size_t count, loff_t *ppos) |
543 | { | |
544 | unsigned long p = *ppos; | |
545 | ssize_t wrote = 0; | |
546 | ssize_t virtr = 0; | |
890537b3 | 547 | char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ |
325fda71 | 548 | int err = 0; |
1da177e4 LT |
549 | |
550 | if (p < (unsigned long) high_memory) { | |
80ad89a0 WF |
551 | unsigned long to_write = min_t(unsigned long, count, |
552 | (unsigned long)high_memory - p); | |
ee32398f | 553 | wrote = do_write_kmem(p, buf, to_write, ppos); |
80ad89a0 WF |
554 | if (wrote != to_write) |
555 | return wrote; | |
1da177e4 LT |
556 | p += wrote; |
557 | buf += wrote; | |
558 | count -= wrote; | |
559 | } | |
560 | ||
561 | if (count > 0) { | |
562 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
563 | if (!kbuf) | |
564 | return wrote ? wrote : -ENOMEM; | |
565 | while (count > 0) { | |
80ad89a0 WF |
566 | unsigned long sz = size_inside_page(p, count); |
567 | unsigned long n; | |
1da177e4 | 568 | |
325fda71 KH |
569 | if (!is_vmalloc_or_module_addr((void *)p)) { |
570 | err = -ENXIO; | |
571 | break; | |
572 | } | |
80ad89a0 WF |
573 | n = copy_from_user(kbuf, buf, sz); |
574 | if (n) { | |
325fda71 KH |
575 | err = -EFAULT; |
576 | break; | |
1da177e4 | 577 | } |
c85e9a97 | 578 | vwrite(kbuf, (char *)p, sz); |
80ad89a0 WF |
579 | count -= sz; |
580 | buf += sz; | |
581 | virtr += sz; | |
582 | p += sz; | |
1da177e4 LT |
583 | } |
584 | free_page((unsigned long)kbuf); | |
585 | } | |
586 | ||
325fda71 KH |
587 | *ppos = p; |
588 | return virtr + wrote ? : err; | |
1da177e4 LT |
589 | } |
590 | ||
d7d4d849 | 591 | static ssize_t read_port(struct file *file, char __user *buf, |
1da177e4 LT |
592 | size_t count, loff_t *ppos) |
593 | { | |
594 | unsigned long i = *ppos; | |
595 | char __user *tmp = buf; | |
596 | ||
597 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
d7d4d849 | 598 | return -EFAULT; |
1da177e4 | 599 | while (count-- > 0 && i < 65536) { |
d7d4d849 AM |
600 | if (__put_user(inb(i), tmp) < 0) |
601 | return -EFAULT; | |
1da177e4 LT |
602 | i++; |
603 | tmp++; | |
604 | } | |
605 | *ppos = i; | |
606 | return tmp-buf; | |
607 | } | |
608 | ||
d7d4d849 | 609 | static ssize_t write_port(struct file *file, const char __user *buf, |
1da177e4 LT |
610 | size_t count, loff_t *ppos) |
611 | { | |
612 | unsigned long i = *ppos; | |
890537b3 | 613 | const char __user *tmp = buf; |
1da177e4 | 614 | |
d7d4d849 | 615 | if (!access_ok(VERIFY_READ, buf, count)) |
1da177e4 LT |
616 | return -EFAULT; |
617 | while (count-- > 0 && i < 65536) { | |
618 | char c; | |
6a0061ba | 619 | |
c654d60e JB |
620 | if (__get_user(c, tmp)) { |
621 | if (tmp > buf) | |
622 | break; | |
d7d4d849 | 623 | return -EFAULT; |
c654d60e | 624 | } |
d7d4d849 | 625 | outb(c, i); |
1da177e4 LT |
626 | i++; |
627 | tmp++; | |
628 | } | |
629 | *ppos = i; | |
630 | return tmp-buf; | |
631 | } | |
1da177e4 | 632 | |
d7d4d849 | 633 | static ssize_t read_null(struct file *file, char __user *buf, |
1da177e4 LT |
634 | size_t count, loff_t *ppos) |
635 | { | |
636 | return 0; | |
637 | } | |
638 | ||
d7d4d849 | 639 | static ssize_t write_null(struct file *file, const char __user *buf, |
1da177e4 LT |
640 | size_t count, loff_t *ppos) |
641 | { | |
642 | return count; | |
643 | } | |
644 | ||
cd28e28d | 645 | static ssize_t read_iter_null(struct kiocb *iocb, struct iov_iter *to) |
162934de ZB |
646 | { |
647 | return 0; | |
648 | } | |
649 | ||
cd28e28d | 650 | static ssize_t write_iter_null(struct kiocb *iocb, struct iov_iter *from) |
162934de | 651 | { |
cd28e28d AV |
652 | size_t count = iov_iter_count(from); |
653 | iov_iter_advance(from, count); | |
654 | return count; | |
162934de ZB |
655 | } |
656 | ||
1ebd32fc JA |
657 | static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, |
658 | struct splice_desc *sd) | |
659 | { | |
660 | return sd->len; | |
661 | } | |
662 | ||
d7d4d849 | 663 | static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out, |
1ebd32fc JA |
664 | loff_t *ppos, size_t len, unsigned int flags) |
665 | { | |
666 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); | |
667 | } | |
668 | ||
13ba33e8 | 669 | static ssize_t read_iter_zero(struct kiocb *iocb, struct iov_iter *iter) |
1da177e4 | 670 | { |
13ba33e8 | 671 | size_t written = 0; |
1da177e4 | 672 | |
13ba33e8 AV |
673 | while (iov_iter_count(iter)) { |
674 | size_t chunk = iov_iter_count(iter), n; | |
6a0061ba | 675 | |
557ed1fa NP |
676 | if (chunk > PAGE_SIZE) |
677 | chunk = PAGE_SIZE; /* Just for latency reasons */ | |
13ba33e8 AV |
678 | n = iov_iter_zero(chunk, iter); |
679 | if (!n && iov_iter_count(iter)) | |
680 | return written ? written : -EFAULT; | |
681 | written += n; | |
2b838687 LT |
682 | if (signal_pending(current)) |
683 | return written ? written : -ERESTARTSYS; | |
1da177e4 LT |
684 | cond_resched(); |
685 | } | |
13ba33e8 | 686 | return written; |
162934de ZB |
687 | } |
688 | ||
d7d4d849 | 689 | static int mmap_zero(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 690 | { |
557ed1fa | 691 | #ifndef CONFIG_MMU |
1da177e4 | 692 | return -ENOSYS; |
557ed1fa NP |
693 | #endif |
694 | if (vma->vm_flags & VM_SHARED) | |
695 | return shmem_zero_setup(vma); | |
696 | return 0; | |
1da177e4 | 697 | } |
1da177e4 | 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 | ||
496ad9aa | 727 | mutex_lock(&file_inode(file)->i_mutex); |
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 */ | |
71811f32 | 733 | if (IS_ERR_VALUE((unsigned long long)offset)) { |
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 | } |
496ad9aa | 744 | mutex_unlock(&file_inode(file)->i_mutex); |
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, |
b4caecd4 CH |
806 | #ifndef CONFIG_MMU |
807 | .mmap_capabilities = zero_mmap_capabilities, | |
808 | #endif | |
1da177e4 LT |
809 | }; |
810 | ||
62322d25 | 811 | static const struct file_operations full_fops = { |
1da177e4 | 812 | .llseek = full_lseek, |
13ba33e8 | 813 | .read_iter = read_iter_zero, |
1da177e4 LT |
814 | .write = write_full, |
815 | }; | |
816 | ||
389e0cb9 KS |
817 | static const struct memdev { |
818 | const char *name; | |
2c9ede55 | 819 | umode_t mode; |
389e0cb9 | 820 | const struct file_operations *fops; |
b4caecd4 | 821 | fmode_t fmode; |
389e0cb9 | 822 | } devlist[] = { |
73f0718e | 823 | #ifdef CONFIG_DEVMEM |
b4caecd4 | 824 | [1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET }, |
73f0718e | 825 | #endif |
b781ecb6 | 826 | #ifdef CONFIG_DEVKMEM |
b4caecd4 | 827 | [2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET }, |
b781ecb6 | 828 | #endif |
b4caecd4 | 829 | [3] = { "null", 0666, &null_fops, 0 }, |
4f911d64 | 830 | #ifdef CONFIG_DEVPORT |
b4caecd4 | 831 | [4] = { "port", 0, &port_fops, 0 }, |
1da177e4 | 832 | #endif |
b4caecd4 CH |
833 | [5] = { "zero", 0666, &zero_fops, 0 }, |
834 | [7] = { "full", 0666, &full_fops, 0 }, | |
835 | [8] = { "random", 0666, &random_fops, 0 }, | |
836 | [9] = { "urandom", 0666, &urandom_fops, 0 }, | |
7f3a781d | 837 | #ifdef CONFIG_PRINTK |
b4caecd4 | 838 | [11] = { "kmsg", 0644, &kmsg_fops, 0 }, |
7f3a781d | 839 | #endif |
1cac41cb MB |
840 | #ifdef CONFIG_KNOX_KAP |
841 | [13] = { "knox_kap", 0664, &knox_kap_fops, 0 }, | |
842 | #endif | |
843 | #ifdef CONFIG_MST_LDO | |
844 | [14] = { "mst_ctrl", 0666, &mst_ctrl_fops, 0 }, | |
845 | #endif | |
d6f47bef ASF |
846 | }; |
847 | ||
848 | static int memory_open(struct inode *inode, struct file *filp) | |
849 | { | |
389e0cb9 KS |
850 | int minor; |
851 | const struct memdev *dev; | |
d6f47bef | 852 | |
389e0cb9 KS |
853 | minor = iminor(inode); |
854 | if (minor >= ARRAY_SIZE(devlist)) | |
205153aa | 855 | return -ENXIO; |
d6f47bef | 856 | |
389e0cb9 KS |
857 | dev = &devlist[minor]; |
858 | if (!dev->fops) | |
205153aa | 859 | return -ENXIO; |
d6f47bef | 860 | |
389e0cb9 | 861 | filp->f_op = dev->fops; |
b4caecd4 | 862 | filp->f_mode |= dev->fmode; |
4a3956c7 | 863 | |
389e0cb9 | 864 | if (dev->fops->open) |
205153aa FW |
865 | return dev->fops->open(inode, filp); |
866 | ||
867 | return 0; | |
1da177e4 LT |
868 | } |
869 | ||
62322d25 | 870 | static const struct file_operations memory_fops = { |
d7d4d849 | 871 | .open = memory_open, |
6038f373 | 872 | .llseek = noop_llseek, |
1da177e4 LT |
873 | }; |
874 | ||
2c9ede55 | 875 | static char *mem_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
876 | { |
877 | if (mode && devlist[MINOR(dev->devt)].mode) | |
878 | *mode = devlist[MINOR(dev->devt)].mode; | |
879 | return NULL; | |
880 | } | |
881 | ||
ca8eca68 | 882 | static struct class *mem_class; |
1da177e4 LT |
883 | |
884 | static int __init chr_dev_init(void) | |
885 | { | |
389e0cb9 | 886 | int minor; |
1da177e4 | 887 | |
d7d4d849 | 888 | if (register_chrdev(MEM_MAJOR, "mem", &memory_fops)) |
1da177e4 LT |
889 | printk("unable to get major %d for memory devs\n", MEM_MAJOR); |
890 | ||
ca8eca68 | 891 | mem_class = class_create(THIS_MODULE, "mem"); |
6e191f7b AB |
892 | if (IS_ERR(mem_class)) |
893 | return PTR_ERR(mem_class); | |
894 | ||
e454cea2 | 895 | mem_class->devnode = mem_devnode; |
389e0cb9 KS |
896 | for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) { |
897 | if (!devlist[minor].name) | |
898 | continue; | |
e1612de9 HM |
899 | |
900 | /* | |
890537b3 | 901 | * Create /dev/port? |
e1612de9 HM |
902 | */ |
903 | if ((minor == DEVPORT_MINOR) && !arch_has_dev_port()) | |
904 | continue; | |
905 | ||
389e0cb9 KS |
906 | device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor), |
907 | NULL, devlist[minor].name); | |
908 | } | |
ebf644c4 | 909 | |
31d1d48e | 910 | return tty_init(); |
1da177e4 LT |
911 | } |
912 | ||
913 | fs_initcall(chr_dev_init); |