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 VG |
23 | #include <linux/highmem.h> |
24 | #include <linux/crash_dump.h> | |
1da177e4 | 25 | #include <linux/backing-dev.h> |
315c215c | 26 | #include <linux/bootmem.h> |
d6b29d7c | 27 | #include <linux/splice.h> |
b8a3ad5b | 28 | #include <linux/pfn.h> |
66300e66 | 29 | #include <linux/export.h> |
e1612de9 | 30 | #include <linux/io.h> |
a27bb332 | 31 | #include <linux/aio.h> |
1da177e4 LT |
32 | |
33 | #include <asm/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 | ||
6fa3eb70 | 63 | #if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) |
d092633b | 64 | #ifdef CONFIG_STRICT_DEVMEM |
e2beb3ea | 65 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 | 66 | { |
e2beb3ea VP |
67 | u64 from = ((u64)pfn) << PAGE_SHIFT; |
68 | u64 to = from + size; | |
69 | u64 cursor = from; | |
70 | ||
71 | while (cursor < to) { | |
72 | if (!devmem_is_allowed(pfn)) { | |
73 | printk(KERN_INFO | |
74 | "Program %s tried to access /dev/mem between %Lx->%Lx.\n", | |
ae531c26 AV |
75 | current->comm, from, to); |
76 | return 0; | |
77 | } | |
e2beb3ea VP |
78 | cursor += PAGE_SIZE; |
79 | pfn++; | |
ae531c26 AV |
80 | } |
81 | return 1; | |
82 | } | |
83 | #else | |
e2beb3ea | 84 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 AV |
85 | { |
86 | return 1; | |
87 | } | |
88 | #endif | |
6fa3eb70 | 89 | #endif |
ae531c26 | 90 | |
6fa3eb70 | 91 | #ifdef CONFIG_DEVMEM |
d7d4d849 | 92 | void __weak unxlate_dev_mem_ptr(unsigned long phys, void *addr) |
e045fb2a | 93 | { |
94 | } | |
95 | ||
1da177e4 | 96 | /* |
d7d4d849 AM |
97 | * This funcion reads the *physical* memory. The f_pos points directly to the |
98 | * memory location. | |
1da177e4 | 99 | */ |
d7d4d849 | 100 | static ssize_t read_mem(struct file *file, char __user *buf, |
1da177e4 LT |
101 | size_t count, loff_t *ppos) |
102 | { | |
7e6735c3 | 103 | phys_addr_t p = *ppos; |
1da177e4 LT |
104 | ssize_t read, sz; |
105 | char *ptr; | |
106 | ||
136939a2 | 107 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
108 | return -EFAULT; |
109 | read = 0; | |
110 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
111 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
112 | if (p < PAGE_SIZE) { | |
7fabaddd | 113 | sz = size_inside_page(p, count); |
1da177e4 LT |
114 | if (sz > 0) { |
115 | if (clear_user(buf, sz)) | |
116 | return -EFAULT; | |
d7d4d849 AM |
117 | buf += sz; |
118 | p += sz; | |
119 | count -= sz; | |
120 | read += sz; | |
1da177e4 LT |
121 | } |
122 | } | |
123 | #endif | |
124 | ||
125 | while (count > 0) { | |
fa29e97b WF |
126 | unsigned long remaining; |
127 | ||
f222318e | 128 | sz = size_inside_page(p, count); |
1da177e4 | 129 | |
e045fb2a | 130 | if (!range_is_allowed(p >> PAGE_SHIFT, count)) |
131 | return -EPERM; | |
132 | ||
1da177e4 | 133 | /* |
d7d4d849 AM |
134 | * On ia64 if a page has been mapped somewhere as uncached, then |
135 | * it must also be accessed uncached by the kernel or data | |
136 | * corruption may occur. | |
1da177e4 LT |
137 | */ |
138 | ptr = xlate_dev_mem_ptr(p); | |
e045fb2a | 139 | if (!ptr) |
140 | return -EFAULT; | |
1da177e4 | 141 | |
fa29e97b | 142 | remaining = copy_to_user(buf, ptr, sz); |
e045fb2a | 143 | unxlate_dev_mem_ptr(p, ptr); |
fa29e97b WF |
144 | if (remaining) |
145 | return -EFAULT; | |
e045fb2a | 146 | |
1da177e4 LT |
147 | buf += sz; |
148 | p += sz; | |
149 | count -= sz; | |
150 | read += sz; | |
151 | } | |
152 | ||
153 | *ppos += read; | |
154 | return read; | |
155 | } | |
156 | ||
d7d4d849 | 157 | static ssize_t write_mem(struct file *file, const char __user *buf, |
1da177e4 LT |
158 | size_t count, loff_t *ppos) |
159 | { | |
7e6735c3 | 160 | phys_addr_t p = *ppos; |
1da177e4 LT |
161 | ssize_t written, sz; |
162 | unsigned long copied; | |
163 | void *ptr; | |
164 | ||
136939a2 | 165 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
166 | return -EFAULT; |
167 | ||
168 | written = 0; | |
169 | ||
170 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
171 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
172 | if (p < PAGE_SIZE) { | |
7fabaddd | 173 | sz = size_inside_page(p, count); |
1da177e4 LT |
174 | /* Hmm. Do something? */ |
175 | buf += sz; | |
176 | p += sz; | |
177 | count -= sz; | |
178 | written += sz; | |
179 | } | |
180 | #endif | |
181 | ||
182 | while (count > 0) { | |
f222318e | 183 | sz = size_inside_page(p, count); |
1da177e4 | 184 | |
e045fb2a | 185 | if (!range_is_allowed(p >> PAGE_SHIFT, sz)) |
186 | return -EPERM; | |
187 | ||
1da177e4 | 188 | /* |
d7d4d849 AM |
189 | * On ia64 if a page has been mapped somewhere as uncached, then |
190 | * it must also be accessed uncached by the kernel or data | |
191 | * corruption may occur. | |
1da177e4 LT |
192 | */ |
193 | ptr = xlate_dev_mem_ptr(p); | |
e045fb2a | 194 | if (!ptr) { |
195 | if (written) | |
196 | break; | |
197 | return -EFAULT; | |
198 | } | |
1da177e4 LT |
199 | |
200 | copied = copy_from_user(ptr, buf, sz); | |
fa29e97b | 201 | unxlate_dev_mem_ptr(p, ptr); |
1da177e4 | 202 | if (copied) { |
c654d60e JB |
203 | written += sz - copied; |
204 | if (written) | |
205 | break; | |
1da177e4 LT |
206 | return -EFAULT; |
207 | } | |
e045fb2a | 208 | |
1da177e4 LT |
209 | buf += sz; |
210 | p += sz; | |
211 | count -= sz; | |
212 | written += sz; | |
213 | } | |
214 | ||
215 | *ppos += written; | |
216 | return written; | |
217 | } | |
6fa3eb70 S |
218 | #endif /* CONFIG_DEVMEM */ |
219 | ||
220 | #if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) | |
1da177e4 | 221 | |
d7d4d849 | 222 | int __weak phys_mem_access_prot_allowed(struct file *file, |
f0970c13 | 223 | unsigned long pfn, unsigned long size, pgprot_t *vma_prot) |
224 | { | |
225 | return 1; | |
226 | } | |
227 | ||
44ac8413 | 228 | #ifndef __HAVE_PHYS_MEM_ACCESS_PROT |
d7d4d849 AM |
229 | |
230 | /* | |
231 | * Architectures vary in how they handle caching for addresses | |
232 | * outside of main memory. | |
233 | * | |
234 | */ | |
ea56f411 | 235 | #ifdef pgprot_noncached |
7e6735c3 | 236 | static int uncached_access(struct file *file, phys_addr_t addr) |
d7d4d849 AM |
237 | { |
238 | #if defined(CONFIG_IA64) | |
239 | /* | |
240 | * On ia64, we ignore O_DSYNC because we cannot tolerate memory | |
241 | * attribute aliases. | |
242 | */ | |
243 | return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); | |
244 | #elif defined(CONFIG_MIPS) | |
245 | { | |
246 | extern int __uncached_access(struct file *file, | |
247 | unsigned long addr); | |
248 | ||
249 | return __uncached_access(file, addr); | |
250 | } | |
251 | #else | |
252 | /* | |
253 | * Accessing memory above the top the kernel knows about or through a | |
254 | * file pointer | |
255 | * that was marked O_DSYNC will be done non-cached. | |
256 | */ | |
257 | if (file->f_flags & O_DSYNC) | |
258 | return 1; | |
259 | return addr >= __pa(high_memory); | |
260 | #endif | |
261 | } | |
ea56f411 | 262 | #endif |
d7d4d849 | 263 | |
44ac8413 BH |
264 | static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, |
265 | unsigned long size, pgprot_t vma_prot) | |
266 | { | |
267 | #ifdef pgprot_noncached | |
7e6735c3 | 268 | phys_addr_t offset = pfn << PAGE_SHIFT; |
44ac8413 BH |
269 | |
270 | if (uncached_access(file, offset)) | |
271 | return pgprot_noncached(vma_prot); | |
272 | #endif | |
273 | return vma_prot; | |
274 | } | |
275 | #endif | |
276 | ||
5da6185b DH |
277 | #ifndef CONFIG_MMU |
278 | static unsigned long get_unmapped_area_mem(struct file *file, | |
279 | unsigned long addr, | |
280 | unsigned long len, | |
281 | unsigned long pgoff, | |
282 | unsigned long flags) | |
283 | { | |
284 | if (!valid_mmap_phys_addr_range(pgoff, len)) | |
285 | return (unsigned long) -EINVAL; | |
8a93258c | 286 | return pgoff << PAGE_SHIFT; |
5da6185b DH |
287 | } |
288 | ||
289 | /* can't do an in-place private mapping if there's no MMU */ | |
290 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
291 | { | |
292 | return vma->vm_flags & VM_MAYSHARE; | |
293 | } | |
294 | #else | |
295 | #define get_unmapped_area_mem NULL | |
296 | ||
297 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
298 | { | |
299 | return 1; | |
300 | } | |
301 | #endif | |
302 | ||
f0f37e2f | 303 | static const struct vm_operations_struct mmap_mem_ops = { |
7ae8ed50 RR |
304 | #ifdef CONFIG_HAVE_IOREMAP_PROT |
305 | .access = generic_access_phys | |
306 | #endif | |
e7f260a2 | 307 | }; |
308 | ||
d7d4d849 | 309 | static int mmap_mem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 310 | { |
80851ef2 BH |
311 | size_t size = vma->vm_end - vma->vm_start; |
312 | ||
06c67bef | 313 | if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) |
80851ef2 BH |
314 | return -EINVAL; |
315 | ||
5da6185b DH |
316 | if (!private_mapping_ok(vma)) |
317 | return -ENOSYS; | |
318 | ||
e2beb3ea VP |
319 | if (!range_is_allowed(vma->vm_pgoff, size)) |
320 | return -EPERM; | |
321 | ||
f0970c13 | 322 | if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size, |
323 | &vma->vm_page_prot)) | |
324 | return -EINVAL; | |
325 | ||
8b150478 | 326 | vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, |
80851ef2 | 327 | size, |
1da177e4 | 328 | vma->vm_page_prot); |
1da177e4 | 329 | |
e7f260a2 | 330 | vma->vm_ops = &mmap_mem_ops; |
331 | ||
314e51b9 | 332 | /* Remap-pfn-range will mark the range VM_IO */ |
1da177e4 LT |
333 | if (remap_pfn_range(vma, |
334 | vma->vm_start, | |
335 | vma->vm_pgoff, | |
80851ef2 | 336 | size, |
e7f260a2 | 337 | vma->vm_page_prot)) { |
1da177e4 | 338 | return -EAGAIN; |
e7f260a2 | 339 | } |
1da177e4 LT |
340 | return 0; |
341 | } | |
6fa3eb70 | 342 | #endif /* CONFIG_DEVMEM */ |
1da177e4 | 343 | |
b781ecb6 | 344 | #ifdef CONFIG_DEVKMEM |
d7d4d849 | 345 | static int mmap_kmem(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 346 | { |
4bb82551 LT |
347 | unsigned long pfn; |
348 | ||
6d3154cc LT |
349 | /* Turn a kernel-virtual address into a physical page frame */ |
350 | pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; | |
4bb82551 | 351 | |
1da177e4 | 352 | /* |
d7d4d849 AM |
353 | * RED-PEN: on some architectures there is more mapped memory than |
354 | * available in mem_map which pfn_valid checks for. Perhaps should add a | |
355 | * new macro here. | |
1da177e4 LT |
356 | * |
357 | * RED-PEN: vmalloc is not supported right now. | |
358 | */ | |
4bb82551 | 359 | if (!pfn_valid(pfn)) |
1da177e4 | 360 | return -EIO; |
4bb82551 LT |
361 | |
362 | vma->vm_pgoff = pfn; | |
1da177e4 LT |
363 | return mmap_mem(file, vma); |
364 | } | |
b781ecb6 | 365 | #endif |
1da177e4 | 366 | |
50b1fdbd VG |
367 | #ifdef CONFIG_CRASH_DUMP |
368 | /* | |
369 | * Read memory corresponding to the old kernel. | |
50b1fdbd | 370 | */ |
315c215c | 371 | static ssize_t read_oldmem(struct file *file, char __user *buf, |
50b1fdbd VG |
372 | size_t count, loff_t *ppos) |
373 | { | |
315c215c VG |
374 | unsigned long pfn, offset; |
375 | size_t read = 0, csize; | |
376 | int rc = 0; | |
50b1fdbd | 377 | |
72414d3f | 378 | while (count) { |
50b1fdbd | 379 | pfn = *ppos / PAGE_SIZE; |
315c215c VG |
380 | if (pfn > saved_max_pfn) |
381 | return read; | |
50b1fdbd | 382 | |
315c215c VG |
383 | offset = (unsigned long)(*ppos % PAGE_SIZE); |
384 | if (count > PAGE_SIZE - offset) | |
385 | csize = PAGE_SIZE - offset; | |
386 | else | |
387 | csize = count; | |
50b1fdbd | 388 | |
315c215c VG |
389 | rc = copy_oldmem_page(pfn, buf, csize, offset, 1); |
390 | if (rc < 0) | |
391 | return rc; | |
50b1fdbd VG |
392 | buf += csize; |
393 | *ppos += csize; | |
394 | read += csize; | |
395 | count -= csize; | |
396 | } | |
50b1fdbd VG |
397 | return read; |
398 | } | |
399 | #endif | |
1da177e4 | 400 | |
b781ecb6 | 401 | #ifdef CONFIG_DEVKMEM |
1da177e4 LT |
402 | /* |
403 | * This function reads the *virtual* memory as seen by the kernel. | |
404 | */ | |
d7d4d849 | 405 | static ssize_t read_kmem(struct file *file, char __user *buf, |
1da177e4 LT |
406 | size_t count, loff_t *ppos) |
407 | { | |
408 | unsigned long p = *ppos; | |
409 | ssize_t low_count, read, sz; | |
890537b3 | 410 | char *kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ |
325fda71 | 411 | int err = 0; |
1da177e4 LT |
412 | |
413 | read = 0; | |
414 | if (p < (unsigned long) high_memory) { | |
415 | low_count = count; | |
d7d4d849 AM |
416 | if (count > (unsigned long)high_memory - p) |
417 | low_count = (unsigned long)high_memory - p; | |
1da177e4 LT |
418 | |
419 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
420 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
421 | if (p < PAGE_SIZE && low_count > 0) { | |
7fabaddd WF |
422 | sz = size_inside_page(p, low_count); |
423 | if (clear_user(buf, sz)) | |
1da177e4 | 424 | return -EFAULT; |
7fabaddd WF |
425 | buf += sz; |
426 | p += sz; | |
427 | read += sz; | |
428 | low_count -= sz; | |
429 | count -= sz; | |
1da177e4 LT |
430 | } |
431 | #endif | |
432 | while (low_count > 0) { | |
f222318e | 433 | sz = size_inside_page(p, low_count); |
1da177e4 LT |
434 | |
435 | /* | |
436 | * On ia64 if a page has been mapped somewhere as | |
437 | * uncached, then it must also be accessed uncached | |
438 | * by the kernel or data corruption may occur | |
439 | */ | |
440 | kbuf = xlate_dev_kmem_ptr((char *)p); | |
441 | ||
442 | if (copy_to_user(buf, kbuf, sz)) | |
443 | return -EFAULT; | |
444 | buf += sz; | |
445 | p += sz; | |
446 | read += sz; | |
447 | low_count -= sz; | |
448 | count -= sz; | |
449 | } | |
450 | } | |
451 | ||
452 | if (count > 0) { | |
453 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
454 | if (!kbuf) | |
455 | return -ENOMEM; | |
456 | while (count > 0) { | |
80ad89a0 | 457 | sz = size_inside_page(p, count); |
325fda71 KH |
458 | if (!is_vmalloc_or_module_addr((void *)p)) { |
459 | err = -ENXIO; | |
460 | break; | |
461 | } | |
80ad89a0 WF |
462 | sz = vread(kbuf, (char *)p, sz); |
463 | if (!sz) | |
1da177e4 | 464 | break; |
80ad89a0 | 465 | if (copy_to_user(buf, kbuf, sz)) { |
325fda71 KH |
466 | err = -EFAULT; |
467 | break; | |
1da177e4 | 468 | } |
80ad89a0 WF |
469 | count -= sz; |
470 | buf += sz; | |
471 | read += sz; | |
472 | p += sz; | |
1da177e4 LT |
473 | } |
474 | free_page((unsigned long)kbuf); | |
475 | } | |
325fda71 KH |
476 | *ppos = p; |
477 | return read ? read : err; | |
1da177e4 LT |
478 | } |
479 | ||
480 | ||
d7d4d849 AM |
481 | static ssize_t do_write_kmem(unsigned long p, const char __user *buf, |
482 | size_t count, loff_t *ppos) | |
1da177e4 LT |
483 | { |
484 | ssize_t written, sz; | |
485 | unsigned long copied; | |
486 | ||
487 | written = 0; | |
488 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
489 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
ee32398f WF |
490 | if (p < PAGE_SIZE) { |
491 | sz = size_inside_page(p, count); | |
1da177e4 LT |
492 | /* Hmm. Do something? */ |
493 | buf += sz; | |
494 | p += sz; | |
1da177e4 LT |
495 | count -= sz; |
496 | written += sz; | |
497 | } | |
498 | #endif | |
499 | ||
500 | while (count > 0) { | |
501 | char *ptr; | |
1da177e4 | 502 | |
ee32398f | 503 | sz = size_inside_page(p, count); |
1da177e4 LT |
504 | |
505 | /* | |
d7d4d849 AM |
506 | * On ia64 if a page has been mapped somewhere as uncached, then |
507 | * it must also be accessed uncached by the kernel or data | |
508 | * corruption may occur. | |
1da177e4 | 509 | */ |
ee32398f | 510 | ptr = xlate_dev_kmem_ptr((char *)p); |
1da177e4 LT |
511 | |
512 | copied = copy_from_user(ptr, buf, sz); | |
513 | if (copied) { | |
c654d60e JB |
514 | written += sz - copied; |
515 | if (written) | |
516 | break; | |
1da177e4 LT |
517 | return -EFAULT; |
518 | } | |
519 | buf += sz; | |
520 | p += sz; | |
1da177e4 LT |
521 | count -= sz; |
522 | written += sz; | |
523 | } | |
524 | ||
525 | *ppos += written; | |
526 | return written; | |
527 | } | |
528 | ||
1da177e4 LT |
529 | /* |
530 | * This function writes to the *virtual* memory as seen by the kernel. | |
531 | */ | |
d7d4d849 | 532 | static ssize_t write_kmem(struct file *file, const char __user *buf, |
1da177e4 LT |
533 | size_t count, loff_t *ppos) |
534 | { | |
535 | unsigned long p = *ppos; | |
536 | ssize_t wrote = 0; | |
537 | ssize_t virtr = 0; | |
890537b3 | 538 | char *kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ |
325fda71 | 539 | int err = 0; |
1da177e4 LT |
540 | |
541 | if (p < (unsigned long) high_memory) { | |
80ad89a0 WF |
542 | unsigned long to_write = min_t(unsigned long, count, |
543 | (unsigned long)high_memory - p); | |
ee32398f | 544 | wrote = do_write_kmem(p, buf, to_write, ppos); |
80ad89a0 WF |
545 | if (wrote != to_write) |
546 | return wrote; | |
1da177e4 LT |
547 | p += wrote; |
548 | buf += wrote; | |
549 | count -= wrote; | |
550 | } | |
551 | ||
552 | if (count > 0) { | |
553 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
554 | if (!kbuf) | |
555 | return wrote ? wrote : -ENOMEM; | |
556 | while (count > 0) { | |
80ad89a0 WF |
557 | unsigned long sz = size_inside_page(p, count); |
558 | unsigned long n; | |
1da177e4 | 559 | |
325fda71 KH |
560 | if (!is_vmalloc_or_module_addr((void *)p)) { |
561 | err = -ENXIO; | |
562 | break; | |
563 | } | |
80ad89a0 WF |
564 | n = copy_from_user(kbuf, buf, sz); |
565 | if (n) { | |
325fda71 KH |
566 | err = -EFAULT; |
567 | break; | |
1da177e4 | 568 | } |
c85e9a97 | 569 | vwrite(kbuf, (char *)p, sz); |
80ad89a0 WF |
570 | count -= sz; |
571 | buf += sz; | |
572 | virtr += sz; | |
573 | p += sz; | |
1da177e4 LT |
574 | } |
575 | free_page((unsigned long)kbuf); | |
576 | } | |
577 | ||
325fda71 KH |
578 | *ppos = p; |
579 | return virtr + wrote ? : err; | |
1da177e4 | 580 | } |
b781ecb6 | 581 | #endif |
1da177e4 | 582 | |
4f911d64 | 583 | #ifdef CONFIG_DEVPORT |
d7d4d849 | 584 | static ssize_t read_port(struct file *file, char __user *buf, |
1da177e4 LT |
585 | size_t count, loff_t *ppos) |
586 | { | |
587 | unsigned long i = *ppos; | |
588 | char __user *tmp = buf; | |
589 | ||
590 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
d7d4d849 | 591 | return -EFAULT; |
1da177e4 | 592 | while (count-- > 0 && i < 65536) { |
d7d4d849 AM |
593 | if (__put_user(inb(i), tmp) < 0) |
594 | return -EFAULT; | |
1da177e4 LT |
595 | i++; |
596 | tmp++; | |
597 | } | |
598 | *ppos = i; | |
599 | return tmp-buf; | |
600 | } | |
601 | ||
d7d4d849 | 602 | static ssize_t write_port(struct file *file, const char __user *buf, |
1da177e4 LT |
603 | size_t count, loff_t *ppos) |
604 | { | |
605 | unsigned long i = *ppos; | |
890537b3 | 606 | const char __user *tmp = buf; |
1da177e4 | 607 | |
d7d4d849 | 608 | if (!access_ok(VERIFY_READ, buf, count)) |
1da177e4 LT |
609 | return -EFAULT; |
610 | while (count-- > 0 && i < 65536) { | |
611 | char c; | |
c654d60e JB |
612 | if (__get_user(c, tmp)) { |
613 | if (tmp > buf) | |
614 | break; | |
d7d4d849 | 615 | return -EFAULT; |
c654d60e | 616 | } |
d7d4d849 | 617 | outb(c, i); |
1da177e4 LT |
618 | i++; |
619 | tmp++; | |
620 | } | |
621 | *ppos = i; | |
622 | return tmp-buf; | |
623 | } | |
624 | #endif | |
625 | ||
d7d4d849 | 626 | static ssize_t read_null(struct file *file, char __user *buf, |
1da177e4 LT |
627 | size_t count, loff_t *ppos) |
628 | { | |
629 | return 0; | |
630 | } | |
631 | ||
d7d4d849 | 632 | static ssize_t write_null(struct file *file, const char __user *buf, |
1da177e4 LT |
633 | size_t count, loff_t *ppos) |
634 | { | |
635 | return count; | |
636 | } | |
637 | ||
162934de ZB |
638 | static ssize_t aio_read_null(struct kiocb *iocb, const struct iovec *iov, |
639 | unsigned long nr_segs, loff_t pos) | |
640 | { | |
641 | return 0; | |
642 | } | |
643 | ||
644 | static ssize_t aio_write_null(struct kiocb *iocb, const struct iovec *iov, | |
645 | unsigned long nr_segs, loff_t pos) | |
646 | { | |
647 | return iov_length(iov, nr_segs); | |
648 | } | |
649 | ||
1ebd32fc JA |
650 | static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, |
651 | struct splice_desc *sd) | |
652 | { | |
653 | return sd->len; | |
654 | } | |
655 | ||
d7d4d849 | 656 | static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out, |
1ebd32fc JA |
657 | loff_t *ppos, size_t len, unsigned int flags) |
658 | { | |
659 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); | |
660 | } | |
661 | ||
d7d4d849 | 662 | static ssize_t read_zero(struct file *file, char __user *buf, |
1da177e4 LT |
663 | size_t count, loff_t *ppos) |
664 | { | |
557ed1fa | 665 | size_t written; |
1da177e4 LT |
666 | |
667 | if (!count) | |
668 | return 0; | |
669 | ||
670 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
671 | return -EFAULT; | |
672 | ||
557ed1fa NP |
673 | written = 0; |
674 | while (count) { | |
675 | unsigned long unwritten; | |
676 | size_t chunk = count; | |
1da177e4 | 677 | |
557ed1fa NP |
678 | if (chunk > PAGE_SIZE) |
679 | chunk = PAGE_SIZE; /* Just for latency reasons */ | |
bb521c5d | 680 | unwritten = __clear_user(buf, chunk); |
557ed1fa | 681 | written += chunk - unwritten; |
1da177e4 | 682 | if (unwritten) |
557ed1fa | 683 | break; |
2b838687 LT |
684 | if (signal_pending(current)) |
685 | return written ? written : -ERESTARTSYS; | |
1da177e4 | 686 | buf += chunk; |
557ed1fa | 687 | count -= chunk; |
1da177e4 LT |
688 | cond_resched(); |
689 | } | |
557ed1fa | 690 | return written ? written : -EFAULT; |
1da177e4 LT |
691 | } |
692 | ||
162934de ZB |
693 | static ssize_t aio_read_zero(struct kiocb *iocb, const struct iovec *iov, |
694 | unsigned long nr_segs, loff_t pos) | |
695 | { | |
696 | size_t written = 0; | |
697 | unsigned long i; | |
698 | ssize_t ret; | |
699 | ||
700 | for (i = 0; i < nr_segs; i++) { | |
701 | ret = read_zero(iocb->ki_filp, iov[i].iov_base, iov[i].iov_len, | |
702 | &pos); | |
703 | if (ret < 0) | |
704 | break; | |
705 | written += ret; | |
706 | } | |
707 | ||
708 | return written ? written : -EFAULT; | |
709 | } | |
710 | ||
d7d4d849 | 711 | static int mmap_zero(struct file *file, struct vm_area_struct *vma) |
1da177e4 | 712 | { |
557ed1fa | 713 | #ifndef CONFIG_MMU |
1da177e4 | 714 | return -ENOSYS; |
557ed1fa NP |
715 | #endif |
716 | if (vma->vm_flags & VM_SHARED) | |
717 | return shmem_zero_setup(vma); | |
718 | return 0; | |
1da177e4 | 719 | } |
1da177e4 | 720 | |
d7d4d849 | 721 | static ssize_t write_full(struct file *file, const char __user *buf, |
1da177e4 LT |
722 | size_t count, loff_t *ppos) |
723 | { | |
724 | return -ENOSPC; | |
725 | } | |
726 | ||
727 | /* | |
728 | * Special lseek() function for /dev/null and /dev/zero. Most notably, you | |
729 | * can fopen() both devices with "a" now. This was previously impossible. | |
730 | * -- SRB. | |
731 | */ | |
d7d4d849 | 732 | static loff_t null_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
733 | { |
734 | return file->f_pos = 0; | |
735 | } | |
736 | ||
6fa3eb70 S |
737 | #if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || defined(CONFIG_DEVPORT) |
738 | ||
1da177e4 LT |
739 | /* |
740 | * The memory devices use the full 32/64 bits of the offset, and so we cannot | |
741 | * check against negative addresses: they are ok. The return value is weird, | |
742 | * though, in that case (0). | |
743 | * | |
744 | * also note that seeking relative to the "end of file" isn't supported: | |
745 | * it has no meaning, so it returns -EINVAL. | |
746 | */ | |
d7d4d849 | 747 | static loff_t memory_lseek(struct file *file, loff_t offset, int orig) |
1da177e4 LT |
748 | { |
749 | loff_t ret; | |
750 | ||
496ad9aa | 751 | mutex_lock(&file_inode(file)->i_mutex); |
1da177e4 | 752 | switch (orig) { |
d7d4d849 AM |
753 | case SEEK_CUR: |
754 | offset += file->f_pos; | |
d7d4d849 AM |
755 | case SEEK_SET: |
756 | /* to avoid userland mistaking f_pos=-9 as -EBADF=-9 */ | |
757 | if ((unsigned long long)offset >= ~0xFFFULL) { | |
758 | ret = -EOVERFLOW; | |
1da177e4 | 759 | break; |
d7d4d849 AM |
760 | } |
761 | file->f_pos = offset; | |
762 | ret = file->f_pos; | |
763 | force_successful_syscall_return(); | |
764 | break; | |
765 | default: | |
766 | ret = -EINVAL; | |
1da177e4 | 767 | } |
496ad9aa | 768 | mutex_unlock(&file_inode(file)->i_mutex); |
1da177e4 LT |
769 | return ret; |
770 | } | |
771 | ||
6fa3eb70 S |
772 | #endif |
773 | ||
774 | #if defined(CONFIG_DEVMEM) || defined(CONFIG_DEVKMEM) || defined(CONFIG_DEVPORT) | |
890537b3 | 775 | static int open_port(struct inode *inode, struct file *filp) |
1da177e4 LT |
776 | { |
777 | return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; | |
778 | } | |
6fa3eb70 | 779 | #endif |
1da177e4 LT |
780 | |
781 | #define zero_lseek null_lseek | |
782 | #define full_lseek null_lseek | |
783 | #define write_zero write_null | |
784 | #define read_full read_zero | |
162934de | 785 | #define aio_write_zero aio_write_null |
1da177e4 LT |
786 | #define open_mem open_port |
787 | #define open_kmem open_mem | |
50b1fdbd | 788 | #define open_oldmem open_mem |
1da177e4 | 789 | |
6fa3eb70 | 790 | #ifdef CONFIG_DEVMEM |
62322d25 | 791 | static const struct file_operations mem_fops = { |
1da177e4 LT |
792 | .llseek = memory_lseek, |
793 | .read = read_mem, | |
794 | .write = write_mem, | |
795 | .mmap = mmap_mem, | |
796 | .open = open_mem, | |
5da6185b | 797 | .get_unmapped_area = get_unmapped_area_mem, |
1da177e4 | 798 | }; |
6fa3eb70 | 799 | #endif |
1da177e4 | 800 | |
b781ecb6 | 801 | #ifdef CONFIG_DEVKMEM |
62322d25 | 802 | static const struct file_operations kmem_fops = { |
1da177e4 LT |
803 | .llseek = memory_lseek, |
804 | .read = read_kmem, | |
805 | .write = write_kmem, | |
806 | .mmap = mmap_kmem, | |
807 | .open = open_kmem, | |
5da6185b | 808 | .get_unmapped_area = get_unmapped_area_mem, |
1da177e4 | 809 | }; |
b781ecb6 | 810 | #endif |
1da177e4 | 811 | |
62322d25 | 812 | static const struct file_operations null_fops = { |
1da177e4 LT |
813 | .llseek = null_lseek, |
814 | .read = read_null, | |
815 | .write = write_null, | |
162934de ZB |
816 | .aio_read = aio_read_null, |
817 | .aio_write = aio_write_null, | |
1ebd32fc | 818 | .splice_write = splice_write_null, |
1da177e4 LT |
819 | }; |
820 | ||
4f911d64 | 821 | #ifdef CONFIG_DEVPORT |
62322d25 | 822 | static const struct file_operations port_fops = { |
1da177e4 LT |
823 | .llseek = memory_lseek, |
824 | .read = read_port, | |
825 | .write = write_port, | |
826 | .open = open_port, | |
827 | }; | |
828 | #endif | |
829 | ||
62322d25 | 830 | static const struct file_operations zero_fops = { |
1da177e4 LT |
831 | .llseek = zero_lseek, |
832 | .read = read_zero, | |
833 | .write = write_zero, | |
162934de ZB |
834 | .aio_read = aio_read_zero, |
835 | .aio_write = aio_write_zero, | |
1da177e4 LT |
836 | .mmap = mmap_zero, |
837 | }; | |
838 | ||
5da6185b DH |
839 | /* |
840 | * capabilities for /dev/zero | |
841 | * - permits private mappings, "copies" are taken of the source of zeros | |
371d217e | 842 | * - no writeback happens |
5da6185b | 843 | */ |
1da177e4 | 844 | static struct backing_dev_info zero_bdi = { |
d993831f | 845 | .name = "char/mem", |
371d217e | 846 | .capabilities = BDI_CAP_MAP_COPY | BDI_CAP_NO_ACCT_AND_WRITEBACK, |
1da177e4 LT |
847 | }; |
848 | ||
62322d25 | 849 | static const struct file_operations full_fops = { |
1da177e4 LT |
850 | .llseek = full_lseek, |
851 | .read = read_full, | |
852 | .write = write_full, | |
853 | }; | |
854 | ||
50b1fdbd | 855 | #ifdef CONFIG_CRASH_DUMP |
62322d25 | 856 | static const struct file_operations oldmem_fops = { |
50b1fdbd VG |
857 | .read = read_oldmem, |
858 | .open = open_oldmem, | |
6038f373 | 859 | .llseek = default_llseek, |
50b1fdbd VG |
860 | }; |
861 | #endif | |
862 | ||
389e0cb9 KS |
863 | static const struct memdev { |
864 | const char *name; | |
2c9ede55 | 865 | umode_t mode; |
389e0cb9 KS |
866 | const struct file_operations *fops; |
867 | struct backing_dev_info *dev_info; | |
868 | } devlist[] = { | |
6fa3eb70 | 869 | #ifdef CONFIG_DEVMEM |
e454cea2 | 870 | [1] = { "mem", 0, &mem_fops, &directly_mappable_cdev_bdi }, |
6fa3eb70 | 871 | #endif |
b781ecb6 | 872 | #ifdef CONFIG_DEVKMEM |
e454cea2 | 873 | [2] = { "kmem", 0, &kmem_fops, &directly_mappable_cdev_bdi }, |
b781ecb6 | 874 | #endif |
e454cea2 | 875 | [3] = { "null", 0666, &null_fops, NULL }, |
4f911d64 | 876 | #ifdef CONFIG_DEVPORT |
e454cea2 | 877 | [4] = { "port", 0, &port_fops, NULL }, |
1da177e4 | 878 | #endif |
e454cea2 KS |
879 | [5] = { "zero", 0666, &zero_fops, &zero_bdi }, |
880 | [7] = { "full", 0666, &full_fops, NULL }, | |
881 | [8] = { "random", 0666, &random_fops, NULL }, | |
882 | [9] = { "urandom", 0666, &urandom_fops, NULL }, | |
7f3a781d | 883 | #ifdef CONFIG_PRINTK |
e11fea92 | 884 | [11] = { "kmsg", 0644, &kmsg_fops, NULL }, |
7f3a781d | 885 | #endif |
50b1fdbd | 886 | #ifdef CONFIG_CRASH_DUMP |
e454cea2 | 887 | [12] = { "oldmem", 0, &oldmem_fops, NULL }, |
50b1fdbd | 888 | #endif |
d6f47bef ASF |
889 | }; |
890 | ||
891 | static int memory_open(struct inode *inode, struct file *filp) | |
892 | { | |
389e0cb9 KS |
893 | int minor; |
894 | const struct memdev *dev; | |
d6f47bef | 895 | |
389e0cb9 KS |
896 | minor = iminor(inode); |
897 | if (minor >= ARRAY_SIZE(devlist)) | |
205153aa | 898 | return -ENXIO; |
d6f47bef | 899 | |
389e0cb9 KS |
900 | dev = &devlist[minor]; |
901 | if (!dev->fops) | |
205153aa | 902 | return -ENXIO; |
d6f47bef | 903 | |
389e0cb9 KS |
904 | filp->f_op = dev->fops; |
905 | if (dev->dev_info) | |
906 | filp->f_mapping->backing_dev_info = dev->dev_info; | |
d6f47bef | 907 | |
4a3956c7 KH |
908 | /* Is /dev/mem or /dev/kmem ? */ |
909 | if (dev->dev_info == &directly_mappable_cdev_bdi) | |
910 | filp->f_mode |= FMODE_UNSIGNED_OFFSET; | |
911 | ||
389e0cb9 | 912 | if (dev->fops->open) |
205153aa FW |
913 | return dev->fops->open(inode, filp); |
914 | ||
915 | return 0; | |
1da177e4 LT |
916 | } |
917 | ||
62322d25 | 918 | static const struct file_operations memory_fops = { |
d7d4d849 | 919 | .open = memory_open, |
6038f373 | 920 | .llseek = noop_llseek, |
1da177e4 LT |
921 | }; |
922 | ||
2c9ede55 | 923 | static char *mem_devnode(struct device *dev, umode_t *mode) |
e454cea2 KS |
924 | { |
925 | if (mode && devlist[MINOR(dev->devt)].mode) | |
926 | *mode = devlist[MINOR(dev->devt)].mode; | |
927 | return NULL; | |
928 | } | |
929 | ||
ca8eca68 | 930 | static struct class *mem_class; |
1da177e4 LT |
931 | |
932 | static int __init chr_dev_init(void) | |
933 | { | |
389e0cb9 | 934 | int minor; |
e0bf68dd PZ |
935 | int err; |
936 | ||
937 | err = bdi_init(&zero_bdi); | |
938 | if (err) | |
939 | return err; | |
1da177e4 | 940 | |
d7d4d849 | 941 | if (register_chrdev(MEM_MAJOR, "mem", &memory_fops)) |
1da177e4 LT |
942 | printk("unable to get major %d for memory devs\n", MEM_MAJOR); |
943 | ||
ca8eca68 | 944 | mem_class = class_create(THIS_MODULE, "mem"); |
6e191f7b AB |
945 | if (IS_ERR(mem_class)) |
946 | return PTR_ERR(mem_class); | |
947 | ||
e454cea2 | 948 | mem_class->devnode = mem_devnode; |
389e0cb9 KS |
949 | for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) { |
950 | if (!devlist[minor].name) | |
951 | continue; | |
e1612de9 HM |
952 | |
953 | /* | |
890537b3 | 954 | * Create /dev/port? |
e1612de9 HM |
955 | */ |
956 | if ((minor == DEVPORT_MINOR) && !arch_has_dev_port()) | |
957 | continue; | |
958 | ||
389e0cb9 KS |
959 | device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor), |
960 | NULL, devlist[minor].name); | |
961 | } | |
ebf644c4 | 962 | |
31d1d48e | 963 | return tty_init(); |
1da177e4 LT |
964 | } |
965 | ||
966 | fs_initcall(chr_dev_init); |