Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/mem.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * Added devfs support. | |
7 | * Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu> | |
8 | * Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com> | |
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> |
1da177e4 LT |
29 | |
30 | #include <asm/uaccess.h> | |
31 | #include <asm/io.h> | |
32 | ||
33 | #ifdef CONFIG_IA64 | |
34 | # include <linux/efi.h> | |
35 | #endif | |
36 | ||
1da177e4 LT |
37 | /* |
38 | * Architectures vary in how they handle caching for addresses | |
39 | * outside of main memory. | |
40 | * | |
41 | */ | |
42 | static inline int uncached_access(struct file *file, unsigned long addr) | |
43 | { | |
ca5cd877 | 44 | #if defined(__i386__) && !defined(__arch_um__) |
1da177e4 LT |
45 | /* |
46 | * On the PPro and successors, the MTRRs are used to set | |
47 | * memory types for physical addresses outside main memory, | |
48 | * so blindly setting PCD or PWT on those pages is wrong. | |
49 | * For Pentiums and earlier, the surround logic should disable | |
50 | * caching for the high addresses through the KEN pin, but | |
51 | * we maintain the tradition of paranoia in this code. | |
52 | */ | |
53 | if (file->f_flags & O_SYNC) | |
54 | return 1; | |
55 | return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) || | |
56 | test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) || | |
57 | test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) || | |
58 | test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) ) | |
59 | && addr >= __pa(high_memory); | |
ca5cd877 | 60 | #elif defined(__x86_64__) && !defined(__arch_um__) |
1da177e4 LT |
61 | /* |
62 | * This is broken because it can generate memory type aliases, | |
63 | * which can cause cache corruptions | |
64 | * But it is only available for root and we have to be bug-to-bug | |
65 | * compatible with i386. | |
66 | */ | |
67 | if (file->f_flags & O_SYNC) | |
68 | return 1; | |
69 | /* same behaviour as i386. PAT always set to cached and MTRRs control the | |
70 | caching behaviour. | |
71 | Hopefully a full PAT implementation will fix that soon. */ | |
72 | return 0; | |
73 | #elif defined(CONFIG_IA64) | |
74 | /* | |
75 | * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases. | |
76 | */ | |
77 | return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); | |
24e9d0b9 RB |
78 | #elif defined(CONFIG_MIPS) |
79 | { | |
80 | extern int __uncached_access(struct file *file, | |
81 | unsigned long addr); | |
82 | ||
83 | return __uncached_access(file, addr); | |
84 | } | |
1da177e4 LT |
85 | #else |
86 | /* | |
87 | * Accessing memory above the top the kernel knows about or through a file pointer | |
88 | * that was marked O_SYNC will be done non-cached. | |
89 | */ | |
90 | if (file->f_flags & O_SYNC) | |
91 | return 1; | |
92 | return addr >= __pa(high_memory); | |
93 | #endif | |
94 | } | |
95 | ||
96 | #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE | |
136939a2 | 97 | static inline int valid_phys_addr_range(unsigned long addr, size_t count) |
1da177e4 | 98 | { |
136939a2 | 99 | if (addr + count > __pa(high_memory)) |
1da177e4 LT |
100 | return 0; |
101 | ||
1da177e4 LT |
102 | return 1; |
103 | } | |
80851ef2 | 104 | |
06c67bef | 105 | static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) |
80851ef2 BH |
106 | { |
107 | return 1; | |
108 | } | |
1da177e4 LT |
109 | #endif |
110 | ||
ae531c26 | 111 | #ifdef CONFIG_NONPROMISC_DEVMEM |
e2beb3ea | 112 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 | 113 | { |
e2beb3ea VP |
114 | u64 from = ((u64)pfn) << PAGE_SHIFT; |
115 | u64 to = from + size; | |
116 | u64 cursor = from; | |
117 | ||
118 | while (cursor < to) { | |
119 | if (!devmem_is_allowed(pfn)) { | |
120 | printk(KERN_INFO | |
121 | "Program %s tried to access /dev/mem between %Lx->%Lx.\n", | |
ae531c26 AV |
122 | current->comm, from, to); |
123 | return 0; | |
124 | } | |
e2beb3ea VP |
125 | cursor += PAGE_SIZE; |
126 | pfn++; | |
ae531c26 AV |
127 | } |
128 | return 1; | |
129 | } | |
130 | #else | |
e2beb3ea | 131 | static inline int range_is_allowed(unsigned long pfn, unsigned long size) |
ae531c26 AV |
132 | { |
133 | return 1; | |
134 | } | |
135 | #endif | |
136 | ||
e045fb2a | 137 | void __attribute__((weak)) unxlate_dev_mem_ptr(unsigned long phys, void *addr) |
138 | { | |
139 | } | |
140 | ||
1da177e4 LT |
141 | /* |
142 | * This funcion reads the *physical* memory. The f_pos points directly to the | |
143 | * memory location. | |
144 | */ | |
145 | static ssize_t read_mem(struct file * file, char __user * buf, | |
146 | size_t count, loff_t *ppos) | |
147 | { | |
148 | unsigned long p = *ppos; | |
149 | ssize_t read, sz; | |
150 | char *ptr; | |
151 | ||
136939a2 | 152 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
153 | return -EFAULT; |
154 | read = 0; | |
155 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
156 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
157 | if (p < PAGE_SIZE) { | |
158 | sz = PAGE_SIZE - p; | |
159 | if (sz > count) | |
160 | sz = count; | |
161 | if (sz > 0) { | |
162 | if (clear_user(buf, sz)) | |
163 | return -EFAULT; | |
164 | buf += sz; | |
165 | p += sz; | |
166 | count -= sz; | |
167 | read += sz; | |
168 | } | |
169 | } | |
170 | #endif | |
171 | ||
172 | while (count > 0) { | |
173 | /* | |
174 | * Handle first page in case it's not aligned | |
175 | */ | |
176 | if (-p & (PAGE_SIZE - 1)) | |
177 | sz = -p & (PAGE_SIZE - 1); | |
178 | else | |
179 | sz = PAGE_SIZE; | |
180 | ||
181 | sz = min_t(unsigned long, sz, count); | |
182 | ||
e045fb2a | 183 | if (!range_is_allowed(p >> PAGE_SHIFT, count)) |
184 | return -EPERM; | |
185 | ||
1da177e4 LT |
186 | /* |
187 | * On ia64 if a page has been mapped somewhere as | |
188 | * uncached, then it must also be accessed uncached | |
189 | * by the kernel or data corruption may occur | |
190 | */ | |
191 | ptr = xlate_dev_mem_ptr(p); | |
e045fb2a | 192 | if (!ptr) |
193 | return -EFAULT; | |
1da177e4 | 194 | |
e045fb2a | 195 | if (copy_to_user(buf, ptr, sz)) { |
196 | unxlate_dev_mem_ptr(p, ptr); | |
1da177e4 | 197 | return -EFAULT; |
e045fb2a | 198 | } |
199 | ||
200 | unxlate_dev_mem_ptr(p, ptr); | |
201 | ||
1da177e4 LT |
202 | buf += sz; |
203 | p += sz; | |
204 | count -= sz; | |
205 | read += sz; | |
206 | } | |
207 | ||
208 | *ppos += read; | |
209 | return read; | |
210 | } | |
211 | ||
212 | static ssize_t write_mem(struct file * file, const char __user * buf, | |
213 | size_t count, loff_t *ppos) | |
214 | { | |
215 | unsigned long p = *ppos; | |
216 | ssize_t written, sz; | |
217 | unsigned long copied; | |
218 | void *ptr; | |
219 | ||
136939a2 | 220 | if (!valid_phys_addr_range(p, count)) |
1da177e4 LT |
221 | return -EFAULT; |
222 | ||
223 | written = 0; | |
224 | ||
225 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
226 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
227 | if (p < PAGE_SIZE) { | |
228 | unsigned long sz = PAGE_SIZE - p; | |
229 | if (sz > count) | |
230 | sz = count; | |
231 | /* Hmm. Do something? */ | |
232 | buf += sz; | |
233 | p += sz; | |
234 | count -= sz; | |
235 | written += sz; | |
236 | } | |
237 | #endif | |
238 | ||
239 | while (count > 0) { | |
240 | /* | |
241 | * Handle first page in case it's not aligned | |
242 | */ | |
243 | if (-p & (PAGE_SIZE - 1)) | |
244 | sz = -p & (PAGE_SIZE - 1); | |
245 | else | |
246 | sz = PAGE_SIZE; | |
247 | ||
248 | sz = min_t(unsigned long, sz, count); | |
249 | ||
e045fb2a | 250 | if (!range_is_allowed(p >> PAGE_SHIFT, sz)) |
251 | return -EPERM; | |
252 | ||
1da177e4 LT |
253 | /* |
254 | * On ia64 if a page has been mapped somewhere as | |
255 | * uncached, then it must also be accessed uncached | |
256 | * by the kernel or data corruption may occur | |
257 | */ | |
258 | ptr = xlate_dev_mem_ptr(p); | |
e045fb2a | 259 | if (!ptr) { |
260 | if (written) | |
261 | break; | |
262 | return -EFAULT; | |
263 | } | |
1da177e4 LT |
264 | |
265 | copied = copy_from_user(ptr, buf, sz); | |
266 | if (copied) { | |
c654d60e | 267 | written += sz - copied; |
e045fb2a | 268 | unxlate_dev_mem_ptr(p, ptr); |
c654d60e JB |
269 | if (written) |
270 | break; | |
1da177e4 LT |
271 | return -EFAULT; |
272 | } | |
e045fb2a | 273 | |
274 | unxlate_dev_mem_ptr(p, ptr); | |
275 | ||
1da177e4 LT |
276 | buf += sz; |
277 | p += sz; | |
278 | count -= sz; | |
279 | written += sz; | |
280 | } | |
281 | ||
282 | *ppos += written; | |
283 | return written; | |
284 | } | |
285 | ||
44ac8413 BH |
286 | #ifndef __HAVE_PHYS_MEM_ACCESS_PROT |
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 | |
291 | unsigned long offset = pfn << PAGE_SHIFT; | |
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 | ||
312 | /* can't do an in-place private mapping if there's no MMU */ | |
313 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
314 | { | |
315 | return vma->vm_flags & VM_MAYSHARE; | |
316 | } | |
317 | #else | |
318 | #define get_unmapped_area_mem NULL | |
319 | ||
320 | static inline int private_mapping_ok(struct vm_area_struct *vma) | |
321 | { | |
322 | return 1; | |
323 | } | |
324 | #endif | |
325 | ||
1da177e4 LT |
326 | static int mmap_mem(struct file * file, struct vm_area_struct * vma) |
327 | { | |
80851ef2 BH |
328 | size_t size = vma->vm_end - vma->vm_start; |
329 | ||
06c67bef | 330 | if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) |
80851ef2 BH |
331 | return -EINVAL; |
332 | ||
5da6185b DH |
333 | if (!private_mapping_ok(vma)) |
334 | return -ENOSYS; | |
335 | ||
e2beb3ea VP |
336 | if (!range_is_allowed(vma->vm_pgoff, size)) |
337 | return -EPERM; | |
338 | ||
8b150478 | 339 | vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, |
80851ef2 | 340 | size, |
1da177e4 | 341 | vma->vm_page_prot); |
1da177e4 LT |
342 | |
343 | /* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */ | |
344 | if (remap_pfn_range(vma, | |
345 | vma->vm_start, | |
346 | vma->vm_pgoff, | |
80851ef2 | 347 | size, |
1da177e4 LT |
348 | vma->vm_page_prot)) |
349 | return -EAGAIN; | |
350 | return 0; | |
351 | } | |
352 | ||
353 | static int mmap_kmem(struct file * file, struct vm_area_struct * vma) | |
354 | { | |
4bb82551 LT |
355 | unsigned long pfn; |
356 | ||
6d3154cc LT |
357 | /* Turn a kernel-virtual address into a physical page frame */ |
358 | pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; | |
4bb82551 | 359 | |
1da177e4 LT |
360 | /* |
361 | * RED-PEN: on some architectures there is more mapped memory | |
362 | * than available in mem_map which pfn_valid checks | |
363 | * for. Perhaps should add a new macro here. | |
364 | * | |
365 | * RED-PEN: vmalloc is not supported right now. | |
366 | */ | |
4bb82551 | 367 | if (!pfn_valid(pfn)) |
1da177e4 | 368 | return -EIO; |
4bb82551 LT |
369 | |
370 | vma->vm_pgoff = pfn; | |
1da177e4 LT |
371 | return mmap_mem(file, vma); |
372 | } | |
373 | ||
50b1fdbd VG |
374 | #ifdef CONFIG_CRASH_DUMP |
375 | /* | |
376 | * Read memory corresponding to the old kernel. | |
50b1fdbd | 377 | */ |
315c215c | 378 | static ssize_t read_oldmem(struct file *file, char __user *buf, |
50b1fdbd VG |
379 | size_t count, loff_t *ppos) |
380 | { | |
315c215c VG |
381 | unsigned long pfn, offset; |
382 | size_t read = 0, csize; | |
383 | int rc = 0; | |
50b1fdbd | 384 | |
72414d3f | 385 | while (count) { |
50b1fdbd | 386 | pfn = *ppos / PAGE_SIZE; |
315c215c VG |
387 | if (pfn > saved_max_pfn) |
388 | return read; | |
50b1fdbd | 389 | |
315c215c VG |
390 | offset = (unsigned long)(*ppos % PAGE_SIZE); |
391 | if (count > PAGE_SIZE - offset) | |
392 | csize = PAGE_SIZE - offset; | |
393 | else | |
394 | csize = count; | |
50b1fdbd | 395 | |
315c215c VG |
396 | rc = copy_oldmem_page(pfn, buf, csize, offset, 1); |
397 | if (rc < 0) | |
398 | return rc; | |
50b1fdbd VG |
399 | buf += csize; |
400 | *ppos += csize; | |
401 | read += csize; | |
402 | count -= csize; | |
403 | } | |
50b1fdbd VG |
404 | return read; |
405 | } | |
406 | #endif | |
407 | ||
1da177e4 LT |
408 | extern long vread(char *buf, char *addr, unsigned long count); |
409 | extern long vwrite(char *buf, char *addr, unsigned long count); | |
410 | ||
411 | /* | |
412 | * This function reads the *virtual* memory as seen by the kernel. | |
413 | */ | |
414 | static ssize_t read_kmem(struct file *file, char __user *buf, | |
415 | size_t count, loff_t *ppos) | |
416 | { | |
417 | unsigned long p = *ppos; | |
418 | ssize_t low_count, read, sz; | |
419 | char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ | |
420 | ||
421 | read = 0; | |
422 | if (p < (unsigned long) high_memory) { | |
423 | low_count = count; | |
424 | if (count > (unsigned long) high_memory - p) | |
425 | low_count = (unsigned long) high_memory - p; | |
426 | ||
427 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
428 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
429 | if (p < PAGE_SIZE && low_count > 0) { | |
430 | size_t tmp = PAGE_SIZE - p; | |
431 | if (tmp > low_count) tmp = low_count; | |
432 | if (clear_user(buf, tmp)) | |
433 | return -EFAULT; | |
434 | buf += tmp; | |
435 | p += tmp; | |
436 | read += tmp; | |
437 | low_count -= tmp; | |
438 | count -= tmp; | |
439 | } | |
440 | #endif | |
441 | while (low_count > 0) { | |
442 | /* | |
443 | * Handle first page in case it's not aligned | |
444 | */ | |
445 | if (-p & (PAGE_SIZE - 1)) | |
446 | sz = -p & (PAGE_SIZE - 1); | |
447 | else | |
448 | sz = PAGE_SIZE; | |
449 | ||
450 | sz = min_t(unsigned long, sz, low_count); | |
451 | ||
452 | /* | |
453 | * On ia64 if a page has been mapped somewhere as | |
454 | * uncached, then it must also be accessed uncached | |
455 | * by the kernel or data corruption may occur | |
456 | */ | |
457 | kbuf = xlate_dev_kmem_ptr((char *)p); | |
458 | ||
459 | if (copy_to_user(buf, kbuf, sz)) | |
460 | return -EFAULT; | |
461 | buf += sz; | |
462 | p += sz; | |
463 | read += sz; | |
464 | low_count -= sz; | |
465 | count -= sz; | |
466 | } | |
467 | } | |
468 | ||
469 | if (count > 0) { | |
470 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
471 | if (!kbuf) | |
472 | return -ENOMEM; | |
473 | while (count > 0) { | |
474 | int len = count; | |
475 | ||
476 | if (len > PAGE_SIZE) | |
477 | len = PAGE_SIZE; | |
478 | len = vread(kbuf, (char *)p, len); | |
479 | if (!len) | |
480 | break; | |
481 | if (copy_to_user(buf, kbuf, len)) { | |
482 | free_page((unsigned long)kbuf); | |
483 | return -EFAULT; | |
484 | } | |
485 | count -= len; | |
486 | buf += len; | |
487 | read += len; | |
488 | p += len; | |
489 | } | |
490 | free_page((unsigned long)kbuf); | |
491 | } | |
492 | *ppos = p; | |
493 | return read; | |
494 | } | |
495 | ||
496 | ||
497 | static inline ssize_t | |
498 | do_write_kmem(void *p, unsigned long realp, const char __user * buf, | |
499 | size_t count, loff_t *ppos) | |
500 | { | |
501 | ssize_t written, sz; | |
502 | unsigned long copied; | |
503 | ||
504 | written = 0; | |
505 | #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED | |
506 | /* we don't have page 0 mapped on sparc and m68k.. */ | |
507 | if (realp < PAGE_SIZE) { | |
508 | unsigned long sz = PAGE_SIZE - realp; | |
509 | if (sz > count) | |
510 | sz = count; | |
511 | /* Hmm. Do something? */ | |
512 | buf += sz; | |
513 | p += sz; | |
514 | realp += sz; | |
515 | count -= sz; | |
516 | written += sz; | |
517 | } | |
518 | #endif | |
519 | ||
520 | while (count > 0) { | |
521 | char *ptr; | |
522 | /* | |
523 | * Handle first page in case it's not aligned | |
524 | */ | |
525 | if (-realp & (PAGE_SIZE - 1)) | |
526 | sz = -realp & (PAGE_SIZE - 1); | |
527 | else | |
528 | sz = PAGE_SIZE; | |
529 | ||
530 | sz = min_t(unsigned long, sz, count); | |
531 | ||
532 | /* | |
533 | * On ia64 if a page has been mapped somewhere as | |
534 | * uncached, then it must also be accessed uncached | |
535 | * by the kernel or data corruption may occur | |
536 | */ | |
537 | ptr = xlate_dev_kmem_ptr(p); | |
538 | ||
539 | copied = copy_from_user(ptr, buf, sz); | |
540 | if (copied) { | |
c654d60e JB |
541 | written += sz - copied; |
542 | if (written) | |
543 | break; | |
1da177e4 LT |
544 | return -EFAULT; |
545 | } | |
546 | buf += sz; | |
547 | p += sz; | |
548 | realp += sz; | |
549 | count -= sz; | |
550 | written += sz; | |
551 | } | |
552 | ||
553 | *ppos += written; | |
554 | return written; | |
555 | } | |
556 | ||
557 | ||
558 | /* | |
559 | * This function writes to the *virtual* memory as seen by the kernel. | |
560 | */ | |
561 | static ssize_t write_kmem(struct file * file, const char __user * buf, | |
562 | size_t count, loff_t *ppos) | |
563 | { | |
564 | unsigned long p = *ppos; | |
565 | ssize_t wrote = 0; | |
566 | ssize_t virtr = 0; | |
567 | ssize_t written; | |
568 | char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ | |
569 | ||
570 | if (p < (unsigned long) high_memory) { | |
571 | ||
572 | wrote = count; | |
573 | if (count > (unsigned long) high_memory - p) | |
574 | wrote = (unsigned long) high_memory - p; | |
575 | ||
576 | written = do_write_kmem((void*)p, p, buf, wrote, ppos); | |
577 | if (written != wrote) | |
578 | return written; | |
579 | wrote = written; | |
580 | p += wrote; | |
581 | buf += wrote; | |
582 | count -= wrote; | |
583 | } | |
584 | ||
585 | if (count > 0) { | |
586 | kbuf = (char *)__get_free_page(GFP_KERNEL); | |
587 | if (!kbuf) | |
588 | return wrote ? wrote : -ENOMEM; | |
589 | while (count > 0) { | |
590 | int len = count; | |
591 | ||
592 | if (len > PAGE_SIZE) | |
593 | len = PAGE_SIZE; | |
594 | if (len) { | |
595 | written = copy_from_user(kbuf, buf, len); | |
596 | if (written) { | |
c654d60e JB |
597 | if (wrote + virtr) |
598 | break; | |
1da177e4 | 599 | free_page((unsigned long)kbuf); |
c654d60e | 600 | return -EFAULT; |
1da177e4 LT |
601 | } |
602 | } | |
603 | len = vwrite(kbuf, (char *)p, len); | |
604 | count -= len; | |
605 | buf += len; | |
606 | virtr += len; | |
607 | p += len; | |
608 | } | |
609 | free_page((unsigned long)kbuf); | |
610 | } | |
611 | ||
612 | *ppos = p; | |
613 | return virtr + wrote; | |
614 | } | |
615 | ||
4f911d64 | 616 | #ifdef CONFIG_DEVPORT |
1da177e4 LT |
617 | static ssize_t read_port(struct file * file, char __user * buf, |
618 | size_t count, loff_t *ppos) | |
619 | { | |
620 | unsigned long i = *ppos; | |
621 | char __user *tmp = buf; | |
622 | ||
623 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
624 | return -EFAULT; | |
625 | while (count-- > 0 && i < 65536) { | |
626 | if (__put_user(inb(i),tmp) < 0) | |
627 | return -EFAULT; | |
628 | i++; | |
629 | tmp++; | |
630 | } | |
631 | *ppos = i; | |
632 | return tmp-buf; | |
633 | } | |
634 | ||
635 | static ssize_t write_port(struct file * file, const char __user * buf, | |
636 | size_t count, loff_t *ppos) | |
637 | { | |
638 | unsigned long i = *ppos; | |
639 | const char __user * tmp = buf; | |
640 | ||
641 | if (!access_ok(VERIFY_READ,buf,count)) | |
642 | return -EFAULT; | |
643 | while (count-- > 0 && i < 65536) { | |
644 | char c; | |
c654d60e JB |
645 | if (__get_user(c, tmp)) { |
646 | if (tmp > buf) | |
647 | break; | |
1da177e4 | 648 | return -EFAULT; |
c654d60e | 649 | } |
1da177e4 LT |
650 | outb(c,i); |
651 | i++; | |
652 | tmp++; | |
653 | } | |
654 | *ppos = i; | |
655 | return tmp-buf; | |
656 | } | |
657 | #endif | |
658 | ||
659 | static ssize_t read_null(struct file * file, char __user * buf, | |
660 | size_t count, loff_t *ppos) | |
661 | { | |
662 | return 0; | |
663 | } | |
664 | ||
665 | static ssize_t write_null(struct file * file, const char __user * buf, | |
666 | size_t count, loff_t *ppos) | |
667 | { | |
668 | return count; | |
669 | } | |
670 | ||
1ebd32fc JA |
671 | static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, |
672 | struct splice_desc *sd) | |
673 | { | |
674 | return sd->len; | |
675 | } | |
676 | ||
677 | static ssize_t splice_write_null(struct pipe_inode_info *pipe,struct file *out, | |
678 | loff_t *ppos, size_t len, unsigned int flags) | |
679 | { | |
680 | return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); | |
681 | } | |
682 | ||
1da177e4 LT |
683 | static ssize_t read_zero(struct file * file, char __user * buf, |
684 | size_t count, loff_t *ppos) | |
685 | { | |
557ed1fa | 686 | size_t written; |
1da177e4 LT |
687 | |
688 | if (!count) | |
689 | return 0; | |
690 | ||
691 | if (!access_ok(VERIFY_WRITE, buf, count)) | |
692 | return -EFAULT; | |
693 | ||
557ed1fa NP |
694 | written = 0; |
695 | while (count) { | |
696 | unsigned long unwritten; | |
697 | size_t chunk = count; | |
1da177e4 | 698 | |
557ed1fa NP |
699 | if (chunk > PAGE_SIZE) |
700 | chunk = PAGE_SIZE; /* Just for latency reasons */ | |
701 | unwritten = clear_user(buf, chunk); | |
702 | written += chunk - unwritten; | |
1da177e4 | 703 | if (unwritten) |
557ed1fa | 704 | break; |
1da177e4 | 705 | buf += chunk; |
557ed1fa | 706 | count -= chunk; |
1da177e4 LT |
707 | cond_resched(); |
708 | } | |
557ed1fa | 709 | return written ? written : -EFAULT; |
1da177e4 LT |
710 | } |
711 | ||
712 | static int mmap_zero(struct file * file, struct vm_area_struct * vma) | |
713 | { | |
557ed1fa | 714 | #ifndef CONFIG_MMU |
1da177e4 | 715 | return -ENOSYS; |
557ed1fa NP |
716 | #endif |
717 | if (vma->vm_flags & VM_SHARED) | |
718 | return shmem_zero_setup(vma); | |
719 | return 0; | |
1da177e4 | 720 | } |
1da177e4 LT |
721 | |
722 | static ssize_t write_full(struct file * file, const char __user * buf, | |
723 | size_t count, loff_t *ppos) | |
724 | { | |
725 | return -ENOSPC; | |
726 | } | |
727 | ||
728 | /* | |
729 | * Special lseek() function for /dev/null and /dev/zero. Most notably, you | |
730 | * can fopen() both devices with "a" now. This was previously impossible. | |
731 | * -- SRB. | |
732 | */ | |
733 | ||
734 | static loff_t null_lseek(struct file * file, loff_t offset, int orig) | |
735 | { | |
736 | return file->f_pos = 0; | |
737 | } | |
738 | ||
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 | */ | |
747 | static loff_t memory_lseek(struct file * file, loff_t offset, int orig) | |
748 | { | |
749 | loff_t ret; | |
750 | ||
a7113a96 | 751 | mutex_lock(&file->f_path.dentry->d_inode->i_mutex); |
1da177e4 LT |
752 | switch (orig) { |
753 | case 0: | |
754 | file->f_pos = offset; | |
755 | ret = file->f_pos; | |
756 | force_successful_syscall_return(); | |
757 | break; | |
758 | case 1: | |
759 | file->f_pos += offset; | |
760 | ret = file->f_pos; | |
761 | force_successful_syscall_return(); | |
762 | break; | |
763 | default: | |
764 | ret = -EINVAL; | |
765 | } | |
a7113a96 | 766 | mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); |
1da177e4 LT |
767 | return ret; |
768 | } | |
769 | ||
770 | static int open_port(struct inode * inode, struct file * filp) | |
771 | { | |
772 | return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; | |
773 | } | |
774 | ||
775 | #define zero_lseek null_lseek | |
776 | #define full_lseek null_lseek | |
777 | #define write_zero write_null | |
778 | #define read_full read_zero | |
779 | #define open_mem open_port | |
780 | #define open_kmem open_mem | |
50b1fdbd | 781 | #define open_oldmem open_mem |
1da177e4 | 782 | |
62322d25 | 783 | static const struct file_operations mem_fops = { |
1da177e4 LT |
784 | .llseek = memory_lseek, |
785 | .read = read_mem, | |
786 | .write = write_mem, | |
787 | .mmap = mmap_mem, | |
788 | .open = open_mem, | |
5da6185b | 789 | .get_unmapped_area = get_unmapped_area_mem, |
1da177e4 LT |
790 | }; |
791 | ||
62322d25 | 792 | static const struct file_operations kmem_fops = { |
1da177e4 LT |
793 | .llseek = memory_lseek, |
794 | .read = read_kmem, | |
795 | .write = write_kmem, | |
796 | .mmap = mmap_kmem, | |
797 | .open = open_kmem, | |
5da6185b | 798 | .get_unmapped_area = get_unmapped_area_mem, |
1da177e4 LT |
799 | }; |
800 | ||
62322d25 | 801 | static const struct file_operations null_fops = { |
1da177e4 LT |
802 | .llseek = null_lseek, |
803 | .read = read_null, | |
804 | .write = write_null, | |
1ebd32fc | 805 | .splice_write = splice_write_null, |
1da177e4 LT |
806 | }; |
807 | ||
4f911d64 | 808 | #ifdef CONFIG_DEVPORT |
62322d25 | 809 | static const struct file_operations port_fops = { |
1da177e4 LT |
810 | .llseek = memory_lseek, |
811 | .read = read_port, | |
812 | .write = write_port, | |
813 | .open = open_port, | |
814 | }; | |
815 | #endif | |
816 | ||
62322d25 | 817 | static const struct file_operations zero_fops = { |
1da177e4 LT |
818 | .llseek = zero_lseek, |
819 | .read = read_zero, | |
820 | .write = write_zero, | |
821 | .mmap = mmap_zero, | |
822 | }; | |
823 | ||
5da6185b DH |
824 | /* |
825 | * capabilities for /dev/zero | |
826 | * - permits private mappings, "copies" are taken of the source of zeros | |
827 | */ | |
1da177e4 LT |
828 | static struct backing_dev_info zero_bdi = { |
829 | .capabilities = BDI_CAP_MAP_COPY, | |
830 | }; | |
831 | ||
62322d25 | 832 | static const struct file_operations full_fops = { |
1da177e4 LT |
833 | .llseek = full_lseek, |
834 | .read = read_full, | |
835 | .write = write_full, | |
836 | }; | |
837 | ||
50b1fdbd | 838 | #ifdef CONFIG_CRASH_DUMP |
62322d25 | 839 | static const struct file_operations oldmem_fops = { |
50b1fdbd VG |
840 | .read = read_oldmem, |
841 | .open = open_oldmem, | |
842 | }; | |
843 | #endif | |
844 | ||
1da177e4 LT |
845 | static ssize_t kmsg_write(struct file * file, const char __user * buf, |
846 | size_t count, loff_t *ppos) | |
847 | { | |
848 | char *tmp; | |
cd140a5c | 849 | ssize_t ret; |
1da177e4 LT |
850 | |
851 | tmp = kmalloc(count + 1, GFP_KERNEL); | |
852 | if (tmp == NULL) | |
853 | return -ENOMEM; | |
854 | ret = -EFAULT; | |
855 | if (!copy_from_user(tmp, buf, count)) { | |
856 | tmp[count] = 0; | |
857 | ret = printk("%s", tmp); | |
cd140a5c GC |
858 | if (ret > count) |
859 | /* printk can add a prefix */ | |
860 | ret = count; | |
1da177e4 LT |
861 | } |
862 | kfree(tmp); | |
863 | return ret; | |
864 | } | |
865 | ||
62322d25 | 866 | static const struct file_operations kmsg_fops = { |
1da177e4 LT |
867 | .write = kmsg_write, |
868 | }; | |
869 | ||
870 | static int memory_open(struct inode * inode, struct file * filp) | |
871 | { | |
872 | switch (iminor(inode)) { | |
873 | case 1: | |
874 | filp->f_op = &mem_fops; | |
5da6185b DH |
875 | filp->f_mapping->backing_dev_info = |
876 | &directly_mappable_cdev_bdi; | |
1da177e4 LT |
877 | break; |
878 | case 2: | |
879 | filp->f_op = &kmem_fops; | |
5da6185b DH |
880 | filp->f_mapping->backing_dev_info = |
881 | &directly_mappable_cdev_bdi; | |
1da177e4 LT |
882 | break; |
883 | case 3: | |
884 | filp->f_op = &null_fops; | |
885 | break; | |
4f911d64 | 886 | #ifdef CONFIG_DEVPORT |
1da177e4 LT |
887 | case 4: |
888 | filp->f_op = &port_fops; | |
889 | break; | |
890 | #endif | |
891 | case 5: | |
892 | filp->f_mapping->backing_dev_info = &zero_bdi; | |
893 | filp->f_op = &zero_fops; | |
894 | break; | |
895 | case 7: | |
896 | filp->f_op = &full_fops; | |
897 | break; | |
898 | case 8: | |
899 | filp->f_op = &random_fops; | |
900 | break; | |
901 | case 9: | |
902 | filp->f_op = &urandom_fops; | |
903 | break; | |
904 | case 11: | |
905 | filp->f_op = &kmsg_fops; | |
906 | break; | |
50b1fdbd VG |
907 | #ifdef CONFIG_CRASH_DUMP |
908 | case 12: | |
909 | filp->f_op = &oldmem_fops; | |
910 | break; | |
911 | #endif | |
1da177e4 LT |
912 | default: |
913 | return -ENXIO; | |
914 | } | |
915 | if (filp->f_op && filp->f_op->open) | |
916 | return filp->f_op->open(inode,filp); | |
917 | return 0; | |
918 | } | |
919 | ||
62322d25 | 920 | static const struct file_operations memory_fops = { |
1da177e4 LT |
921 | .open = memory_open, /* just a selector for the real open */ |
922 | }; | |
923 | ||
924 | static const struct { | |
925 | unsigned int minor; | |
926 | char *name; | |
927 | umode_t mode; | |
99ac48f5 | 928 | const struct file_operations *fops; |
1da177e4 LT |
929 | } devlist[] = { /* list of minor devices */ |
930 | {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops}, | |
931 | {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops}, | |
932 | {3, "null", S_IRUGO | S_IWUGO, &null_fops}, | |
4f911d64 | 933 | #ifdef CONFIG_DEVPORT |
1da177e4 LT |
934 | {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops}, |
935 | #endif | |
936 | {5, "zero", S_IRUGO | S_IWUGO, &zero_fops}, | |
937 | {7, "full", S_IRUGO | S_IWUGO, &full_fops}, | |
938 | {8, "random", S_IRUGO | S_IWUSR, &random_fops}, | |
939 | {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops}, | |
940 | {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops}, | |
50b1fdbd VG |
941 | #ifdef CONFIG_CRASH_DUMP |
942 | {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops}, | |
943 | #endif | |
1da177e4 LT |
944 | }; |
945 | ||
ca8eca68 | 946 | static struct class *mem_class; |
1da177e4 LT |
947 | |
948 | static int __init chr_dev_init(void) | |
949 | { | |
950 | int i; | |
e0bf68dd PZ |
951 | int err; |
952 | ||
953 | err = bdi_init(&zero_bdi); | |
954 | if (err) | |
955 | return err; | |
1da177e4 LT |
956 | |
957 | if (register_chrdev(MEM_MAJOR,"mem",&memory_fops)) | |
958 | printk("unable to get major %d for memory devs\n", MEM_MAJOR); | |
959 | ||
ca8eca68 | 960 | mem_class = class_create(THIS_MODULE, "mem"); |
7c69ef79 | 961 | for (i = 0; i < ARRAY_SIZE(devlist); i++) |
ebf644c4 GKH |
962 | device_create(mem_class, NULL, |
963 | MKDEV(MEM_MAJOR, devlist[i].minor), | |
964 | devlist[i].name); | |
965 | ||
1da177e4 LT |
966 | return 0; |
967 | } | |
968 | ||
969 | fs_initcall(chr_dev_init); |