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[PATCH] make valid_mmap_phys_addr_range() take a pfn
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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
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>
21 #include <linux/smp_lock.h>
22 #include <linux/ptrace.h>
23 #include <linux/device.h>
24 #include <linux/highmem.h>
25 #include <linux/crash_dump.h>
26 #include <linux/backing-dev.h>
27 #include <linux/bootmem.h>
28 #include <linux/pipe_fs_i.h>
29
30 #include <asm/uaccess.h>
31 #include <asm/io.h>
32
33 #ifdef CONFIG_IA64
34 # include <linux/efi.h>
35 #endif
36
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 {
44 #if defined(__i386__)
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);
60 #elif defined(__x86_64__)
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);
78 #else
79 /*
80 * Accessing memory above the top the kernel knows about or through a file pointer
81 * that was marked O_SYNC will be done non-cached.
82 */
83 if (file->f_flags & O_SYNC)
84 return 1;
85 return addr >= __pa(high_memory);
86 #endif
87 }
88
89 #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE
90 static inline int valid_phys_addr_range(unsigned long addr, size_t count)
91 {
92 if (addr + count > __pa(high_memory))
93 return 0;
94
95 return 1;
96 }
97
98 static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
99 {
100 return 1;
101 }
102 #endif
103
104 /*
105 * This funcion reads the *physical* memory. The f_pos points directly to the
106 * memory location.
107 */
108 static ssize_t read_mem(struct file * file, char __user * buf,
109 size_t count, loff_t *ppos)
110 {
111 unsigned long p = *ppos;
112 ssize_t read, sz;
113 char *ptr;
114
115 if (!valid_phys_addr_range(p, count))
116 return -EFAULT;
117 read = 0;
118 #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
119 /* we don't have page 0 mapped on sparc and m68k.. */
120 if (p < PAGE_SIZE) {
121 sz = PAGE_SIZE - p;
122 if (sz > count)
123 sz = count;
124 if (sz > 0) {
125 if (clear_user(buf, sz))
126 return -EFAULT;
127 buf += sz;
128 p += sz;
129 count -= sz;
130 read += sz;
131 }
132 }
133 #endif
134
135 while (count > 0) {
136 /*
137 * Handle first page in case it's not aligned
138 */
139 if (-p & (PAGE_SIZE - 1))
140 sz = -p & (PAGE_SIZE - 1);
141 else
142 sz = PAGE_SIZE;
143
144 sz = min_t(unsigned long, sz, count);
145
146 /*
147 * On ia64 if a page has been mapped somewhere as
148 * uncached, then it must also be accessed uncached
149 * by the kernel or data corruption may occur
150 */
151 ptr = xlate_dev_mem_ptr(p);
152
153 if (copy_to_user(buf, ptr, sz))
154 return -EFAULT;
155 buf += sz;
156 p += sz;
157 count -= sz;
158 read += sz;
159 }
160
161 *ppos += read;
162 return read;
163 }
164
165 static ssize_t write_mem(struct file * file, const char __user * buf,
166 size_t count, loff_t *ppos)
167 {
168 unsigned long p = *ppos;
169 ssize_t written, sz;
170 unsigned long copied;
171 void *ptr;
172
173 if (!valid_phys_addr_range(p, count))
174 return -EFAULT;
175
176 written = 0;
177
178 #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
179 /* we don't have page 0 mapped on sparc and m68k.. */
180 if (p < PAGE_SIZE) {
181 unsigned long sz = PAGE_SIZE - p;
182 if (sz > count)
183 sz = count;
184 /* Hmm. Do something? */
185 buf += sz;
186 p += sz;
187 count -= sz;
188 written += sz;
189 }
190 #endif
191
192 while (count > 0) {
193 /*
194 * Handle first page in case it's not aligned
195 */
196 if (-p & (PAGE_SIZE - 1))
197 sz = -p & (PAGE_SIZE - 1);
198 else
199 sz = PAGE_SIZE;
200
201 sz = min_t(unsigned long, sz, count);
202
203 /*
204 * On ia64 if a page has been mapped somewhere as
205 * uncached, then it must also be accessed uncached
206 * by the kernel or data corruption may occur
207 */
208 ptr = xlate_dev_mem_ptr(p);
209
210 copied = copy_from_user(ptr, buf, sz);
211 if (copied) {
212 written += sz - copied;
213 if (written)
214 break;
215 return -EFAULT;
216 }
217 buf += sz;
218 p += sz;
219 count -= sz;
220 written += sz;
221 }
222
223 *ppos += written;
224 return written;
225 }
226
227 #ifndef __HAVE_PHYS_MEM_ACCESS_PROT
228 static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
229 unsigned long size, pgprot_t vma_prot)
230 {
231 #ifdef pgprot_noncached
232 unsigned long offset = pfn << PAGE_SHIFT;
233
234 if (uncached_access(file, offset))
235 return pgprot_noncached(vma_prot);
236 #endif
237 return vma_prot;
238 }
239 #endif
240
241 static int mmap_mem(struct file * file, struct vm_area_struct * vma)
242 {
243 size_t size = vma->vm_end - vma->vm_start;
244
245 if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size))
246 return -EINVAL;
247
248 vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
249 size,
250 vma->vm_page_prot);
251
252 /* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
253 if (remap_pfn_range(vma,
254 vma->vm_start,
255 vma->vm_pgoff,
256 size,
257 vma->vm_page_prot))
258 return -EAGAIN;
259 return 0;
260 }
261
262 static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
263 {
264 unsigned long pfn;
265
266 /* Turn a kernel-virtual address into a physical page frame */
267 pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT;
268
269 /*
270 * RED-PEN: on some architectures there is more mapped memory
271 * than available in mem_map which pfn_valid checks
272 * for. Perhaps should add a new macro here.
273 *
274 * RED-PEN: vmalloc is not supported right now.
275 */
276 if (!pfn_valid(pfn))
277 return -EIO;
278
279 vma->vm_pgoff = pfn;
280 return mmap_mem(file, vma);
281 }
282
283 #ifdef CONFIG_CRASH_DUMP
284 /*
285 * Read memory corresponding to the old kernel.
286 */
287 static ssize_t read_oldmem(struct file *file, char __user *buf,
288 size_t count, loff_t *ppos)
289 {
290 unsigned long pfn, offset;
291 size_t read = 0, csize;
292 int rc = 0;
293
294 while (count) {
295 pfn = *ppos / PAGE_SIZE;
296 if (pfn > saved_max_pfn)
297 return read;
298
299 offset = (unsigned long)(*ppos % PAGE_SIZE);
300 if (count > PAGE_SIZE - offset)
301 csize = PAGE_SIZE - offset;
302 else
303 csize = count;
304
305 rc = copy_oldmem_page(pfn, buf, csize, offset, 1);
306 if (rc < 0)
307 return rc;
308 buf += csize;
309 *ppos += csize;
310 read += csize;
311 count -= csize;
312 }
313 return read;
314 }
315 #endif
316
317 extern long vread(char *buf, char *addr, unsigned long count);
318 extern long vwrite(char *buf, char *addr, unsigned long count);
319
320 /*
321 * This function reads the *virtual* memory as seen by the kernel.
322 */
323 static ssize_t read_kmem(struct file *file, char __user *buf,
324 size_t count, loff_t *ppos)
325 {
326 unsigned long p = *ppos;
327 ssize_t low_count, read, sz;
328 char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */
329
330 read = 0;
331 if (p < (unsigned long) high_memory) {
332 low_count = count;
333 if (count > (unsigned long) high_memory - p)
334 low_count = (unsigned long) high_memory - p;
335
336 #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
337 /* we don't have page 0 mapped on sparc and m68k.. */
338 if (p < PAGE_SIZE && low_count > 0) {
339 size_t tmp = PAGE_SIZE - p;
340 if (tmp > low_count) tmp = low_count;
341 if (clear_user(buf, tmp))
342 return -EFAULT;
343 buf += tmp;
344 p += tmp;
345 read += tmp;
346 low_count -= tmp;
347 count -= tmp;
348 }
349 #endif
350 while (low_count > 0) {
351 /*
352 * Handle first page in case it's not aligned
353 */
354 if (-p & (PAGE_SIZE - 1))
355 sz = -p & (PAGE_SIZE - 1);
356 else
357 sz = PAGE_SIZE;
358
359 sz = min_t(unsigned long, sz, low_count);
360
361 /*
362 * On ia64 if a page has been mapped somewhere as
363 * uncached, then it must also be accessed uncached
364 * by the kernel or data corruption may occur
365 */
366 kbuf = xlate_dev_kmem_ptr((char *)p);
367
368 if (copy_to_user(buf, kbuf, sz))
369 return -EFAULT;
370 buf += sz;
371 p += sz;
372 read += sz;
373 low_count -= sz;
374 count -= sz;
375 }
376 }
377
378 if (count > 0) {
379 kbuf = (char *)__get_free_page(GFP_KERNEL);
380 if (!kbuf)
381 return -ENOMEM;
382 while (count > 0) {
383 int len = count;
384
385 if (len > PAGE_SIZE)
386 len = PAGE_SIZE;
387 len = vread(kbuf, (char *)p, len);
388 if (!len)
389 break;
390 if (copy_to_user(buf, kbuf, len)) {
391 free_page((unsigned long)kbuf);
392 return -EFAULT;
393 }
394 count -= len;
395 buf += len;
396 read += len;
397 p += len;
398 }
399 free_page((unsigned long)kbuf);
400 }
401 *ppos = p;
402 return read;
403 }
404
405
406 static inline ssize_t
407 do_write_kmem(void *p, unsigned long realp, const char __user * buf,
408 size_t count, loff_t *ppos)
409 {
410 ssize_t written, sz;
411 unsigned long copied;
412
413 written = 0;
414 #ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
415 /* we don't have page 0 mapped on sparc and m68k.. */
416 if (realp < PAGE_SIZE) {
417 unsigned long sz = PAGE_SIZE - realp;
418 if (sz > count)
419 sz = count;
420 /* Hmm. Do something? */
421 buf += sz;
422 p += sz;
423 realp += sz;
424 count -= sz;
425 written += sz;
426 }
427 #endif
428
429 while (count > 0) {
430 char *ptr;
431 /*
432 * Handle first page in case it's not aligned
433 */
434 if (-realp & (PAGE_SIZE - 1))
435 sz = -realp & (PAGE_SIZE - 1);
436 else
437 sz = PAGE_SIZE;
438
439 sz = min_t(unsigned long, sz, count);
440
441 /*
442 * On ia64 if a page has been mapped somewhere as
443 * uncached, then it must also be accessed uncached
444 * by the kernel or data corruption may occur
445 */
446 ptr = xlate_dev_kmem_ptr(p);
447
448 copied = copy_from_user(ptr, buf, sz);
449 if (copied) {
450 written += sz - copied;
451 if (written)
452 break;
453 return -EFAULT;
454 }
455 buf += sz;
456 p += sz;
457 realp += sz;
458 count -= sz;
459 written += sz;
460 }
461
462 *ppos += written;
463 return written;
464 }
465
466
467 /*
468 * This function writes to the *virtual* memory as seen by the kernel.
469 */
470 static ssize_t write_kmem(struct file * file, const char __user * buf,
471 size_t count, loff_t *ppos)
472 {
473 unsigned long p = *ppos;
474 ssize_t wrote = 0;
475 ssize_t virtr = 0;
476 ssize_t written;
477 char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
478
479 if (p < (unsigned long) high_memory) {
480
481 wrote = count;
482 if (count > (unsigned long) high_memory - p)
483 wrote = (unsigned long) high_memory - p;
484
485 written = do_write_kmem((void*)p, p, buf, wrote, ppos);
486 if (written != wrote)
487 return written;
488 wrote = written;
489 p += wrote;
490 buf += wrote;
491 count -= wrote;
492 }
493
494 if (count > 0) {
495 kbuf = (char *)__get_free_page(GFP_KERNEL);
496 if (!kbuf)
497 return wrote ? wrote : -ENOMEM;
498 while (count > 0) {
499 int len = count;
500
501 if (len > PAGE_SIZE)
502 len = PAGE_SIZE;
503 if (len) {
504 written = copy_from_user(kbuf, buf, len);
505 if (written) {
506 if (wrote + virtr)
507 break;
508 free_page((unsigned long)kbuf);
509 return -EFAULT;
510 }
511 }
512 len = vwrite(kbuf, (char *)p, len);
513 count -= len;
514 buf += len;
515 virtr += len;
516 p += len;
517 }
518 free_page((unsigned long)kbuf);
519 }
520
521 *ppos = p;
522 return virtr + wrote;
523 }
524
525 #if defined(CONFIG_ISA) || !defined(__mc68000__)
526 static ssize_t read_port(struct file * file, char __user * buf,
527 size_t count, loff_t *ppos)
528 {
529 unsigned long i = *ppos;
530 char __user *tmp = buf;
531
532 if (!access_ok(VERIFY_WRITE, buf, count))
533 return -EFAULT;
534 while (count-- > 0 && i < 65536) {
535 if (__put_user(inb(i),tmp) < 0)
536 return -EFAULT;
537 i++;
538 tmp++;
539 }
540 *ppos = i;
541 return tmp-buf;
542 }
543
544 static ssize_t write_port(struct file * file, const char __user * buf,
545 size_t count, loff_t *ppos)
546 {
547 unsigned long i = *ppos;
548 const char __user * tmp = buf;
549
550 if (!access_ok(VERIFY_READ,buf,count))
551 return -EFAULT;
552 while (count-- > 0 && i < 65536) {
553 char c;
554 if (__get_user(c, tmp)) {
555 if (tmp > buf)
556 break;
557 return -EFAULT;
558 }
559 outb(c,i);
560 i++;
561 tmp++;
562 }
563 *ppos = i;
564 return tmp-buf;
565 }
566 #endif
567
568 static ssize_t read_null(struct file * file, char __user * buf,
569 size_t count, loff_t *ppos)
570 {
571 return 0;
572 }
573
574 static ssize_t write_null(struct file * file, const char __user * buf,
575 size_t count, loff_t *ppos)
576 {
577 return count;
578 }
579
580 static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf,
581 struct splice_desc *sd)
582 {
583 return sd->len;
584 }
585
586 static ssize_t splice_write_null(struct pipe_inode_info *pipe,struct file *out,
587 loff_t *ppos, size_t len, unsigned int flags)
588 {
589 return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null);
590 }
591
592 #ifdef CONFIG_MMU
593 /*
594 * For fun, we are using the MMU for this.
595 */
596 static inline size_t read_zero_pagealigned(char __user * buf, size_t size)
597 {
598 struct mm_struct *mm;
599 struct vm_area_struct * vma;
600 unsigned long addr=(unsigned long)buf;
601
602 mm = current->mm;
603 /* Oops, this was forgotten before. -ben */
604 down_read(&mm->mmap_sem);
605
606 /* For private mappings, just map in zero pages. */
607 for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) {
608 unsigned long count;
609
610 if (vma->vm_start > addr || (vma->vm_flags & VM_WRITE) == 0)
611 goto out_up;
612 if (vma->vm_flags & (VM_SHARED | VM_HUGETLB))
613 break;
614 count = vma->vm_end - addr;
615 if (count > size)
616 count = size;
617
618 zap_page_range(vma, addr, count, NULL);
619 zeromap_page_range(vma, addr, count, PAGE_COPY);
620
621 size -= count;
622 buf += count;
623 addr += count;
624 if (size == 0)
625 goto out_up;
626 }
627
628 up_read(&mm->mmap_sem);
629
630 /* The shared case is hard. Let's do the conventional zeroing. */
631 do {
632 unsigned long unwritten = clear_user(buf, PAGE_SIZE);
633 if (unwritten)
634 return size + unwritten - PAGE_SIZE;
635 cond_resched();
636 buf += PAGE_SIZE;
637 size -= PAGE_SIZE;
638 } while (size);
639
640 return size;
641 out_up:
642 up_read(&mm->mmap_sem);
643 return size;
644 }
645
646 static ssize_t read_zero(struct file * file, char __user * buf,
647 size_t count, loff_t *ppos)
648 {
649 unsigned long left, unwritten, written = 0;
650
651 if (!count)
652 return 0;
653
654 if (!access_ok(VERIFY_WRITE, buf, count))
655 return -EFAULT;
656
657 left = count;
658
659 /* do we want to be clever? Arbitrary cut-off */
660 if (count >= PAGE_SIZE*4) {
661 unsigned long partial;
662
663 /* How much left of the page? */
664 partial = (PAGE_SIZE-1) & -(unsigned long) buf;
665 unwritten = clear_user(buf, partial);
666 written = partial - unwritten;
667 if (unwritten)
668 goto out;
669 left -= partial;
670 buf += partial;
671 unwritten = read_zero_pagealigned(buf, left & PAGE_MASK);
672 written += (left & PAGE_MASK) - unwritten;
673 if (unwritten)
674 goto out;
675 buf += left & PAGE_MASK;
676 left &= ~PAGE_MASK;
677 }
678 unwritten = clear_user(buf, left);
679 written += left - unwritten;
680 out:
681 return written ? written : -EFAULT;
682 }
683
684 static int mmap_zero(struct file * file, struct vm_area_struct * vma)
685 {
686 if (vma->vm_flags & VM_SHARED)
687 return shmem_zero_setup(vma);
688 if (zeromap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot))
689 return -EAGAIN;
690 return 0;
691 }
692 #else /* CONFIG_MMU */
693 static ssize_t read_zero(struct file * file, char * buf,
694 size_t count, loff_t *ppos)
695 {
696 size_t todo = count;
697
698 while (todo) {
699 size_t chunk = todo;
700
701 if (chunk > 4096)
702 chunk = 4096; /* Just for latency reasons */
703 if (clear_user(buf, chunk))
704 return -EFAULT;
705 buf += chunk;
706 todo -= chunk;
707 cond_resched();
708 }
709 return count;
710 }
711
712 static int mmap_zero(struct file * file, struct vm_area_struct * vma)
713 {
714 return -ENOSYS;
715 }
716 #endif /* CONFIG_MMU */
717
718 static ssize_t write_full(struct file * file, const char __user * buf,
719 size_t count, loff_t *ppos)
720 {
721 return -ENOSPC;
722 }
723
724 /*
725 * Special lseek() function for /dev/null and /dev/zero. Most notably, you
726 * can fopen() both devices with "a" now. This was previously impossible.
727 * -- SRB.
728 */
729
730 static loff_t null_lseek(struct file * file, loff_t offset, int orig)
731 {
732 return file->f_pos = 0;
733 }
734
735 /*
736 * The memory devices use the full 32/64 bits of the offset, and so we cannot
737 * check against negative addresses: they are ok. The return value is weird,
738 * though, in that case (0).
739 *
740 * also note that seeking relative to the "end of file" isn't supported:
741 * it has no meaning, so it returns -EINVAL.
742 */
743 static loff_t memory_lseek(struct file * file, loff_t offset, int orig)
744 {
745 loff_t ret;
746
747 mutex_lock(&file->f_dentry->d_inode->i_mutex);
748 switch (orig) {
749 case 0:
750 file->f_pos = offset;
751 ret = file->f_pos;
752 force_successful_syscall_return();
753 break;
754 case 1:
755 file->f_pos += offset;
756 ret = file->f_pos;
757 force_successful_syscall_return();
758 break;
759 default:
760 ret = -EINVAL;
761 }
762 mutex_unlock(&file->f_dentry->d_inode->i_mutex);
763 return ret;
764 }
765
766 static int open_port(struct inode * inode, struct file * filp)
767 {
768 return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
769 }
770
771 #define zero_lseek null_lseek
772 #define full_lseek null_lseek
773 #define write_zero write_null
774 #define read_full read_zero
775 #define open_mem open_port
776 #define open_kmem open_mem
777 #define open_oldmem open_mem
778
779 static const struct file_operations mem_fops = {
780 .llseek = memory_lseek,
781 .read = read_mem,
782 .write = write_mem,
783 .mmap = mmap_mem,
784 .open = open_mem,
785 };
786
787 static const struct file_operations kmem_fops = {
788 .llseek = memory_lseek,
789 .read = read_kmem,
790 .write = write_kmem,
791 .mmap = mmap_kmem,
792 .open = open_kmem,
793 };
794
795 static const struct file_operations null_fops = {
796 .llseek = null_lseek,
797 .read = read_null,
798 .write = write_null,
799 .splice_write = splice_write_null,
800 };
801
802 #if defined(CONFIG_ISA) || !defined(__mc68000__)
803 static const struct file_operations port_fops = {
804 .llseek = memory_lseek,
805 .read = read_port,
806 .write = write_port,
807 .open = open_port,
808 };
809 #endif
810
811 static const struct file_operations zero_fops = {
812 .llseek = zero_lseek,
813 .read = read_zero,
814 .write = write_zero,
815 .mmap = mmap_zero,
816 };
817
818 static struct backing_dev_info zero_bdi = {
819 .capabilities = BDI_CAP_MAP_COPY,
820 };
821
822 static const struct file_operations full_fops = {
823 .llseek = full_lseek,
824 .read = read_full,
825 .write = write_full,
826 };
827
828 #ifdef CONFIG_CRASH_DUMP
829 static const struct file_operations oldmem_fops = {
830 .read = read_oldmem,
831 .open = open_oldmem,
832 };
833 #endif
834
835 static ssize_t kmsg_write(struct file * file, const char __user * buf,
836 size_t count, loff_t *ppos)
837 {
838 char *tmp;
839 ssize_t ret;
840
841 tmp = kmalloc(count + 1, GFP_KERNEL);
842 if (tmp == NULL)
843 return -ENOMEM;
844 ret = -EFAULT;
845 if (!copy_from_user(tmp, buf, count)) {
846 tmp[count] = 0;
847 ret = printk("%s", tmp);
848 if (ret > count)
849 /* printk can add a prefix */
850 ret = count;
851 }
852 kfree(tmp);
853 return ret;
854 }
855
856 static const struct file_operations kmsg_fops = {
857 .write = kmsg_write,
858 };
859
860 static int memory_open(struct inode * inode, struct file * filp)
861 {
862 switch (iminor(inode)) {
863 case 1:
864 filp->f_op = &mem_fops;
865 break;
866 case 2:
867 filp->f_op = &kmem_fops;
868 break;
869 case 3:
870 filp->f_op = &null_fops;
871 break;
872 #if defined(CONFIG_ISA) || !defined(__mc68000__)
873 case 4:
874 filp->f_op = &port_fops;
875 break;
876 #endif
877 case 5:
878 filp->f_mapping->backing_dev_info = &zero_bdi;
879 filp->f_op = &zero_fops;
880 break;
881 case 7:
882 filp->f_op = &full_fops;
883 break;
884 case 8:
885 filp->f_op = &random_fops;
886 break;
887 case 9:
888 filp->f_op = &urandom_fops;
889 break;
890 case 11:
891 filp->f_op = &kmsg_fops;
892 break;
893 #ifdef CONFIG_CRASH_DUMP
894 case 12:
895 filp->f_op = &oldmem_fops;
896 break;
897 #endif
898 default:
899 return -ENXIO;
900 }
901 if (filp->f_op && filp->f_op->open)
902 return filp->f_op->open(inode,filp);
903 return 0;
904 }
905
906 static const struct file_operations memory_fops = {
907 .open = memory_open, /* just a selector for the real open */
908 };
909
910 static const struct {
911 unsigned int minor;
912 char *name;
913 umode_t mode;
914 const struct file_operations *fops;
915 } devlist[] = { /* list of minor devices */
916 {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
917 {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
918 {3, "null", S_IRUGO | S_IWUGO, &null_fops},
919 #if defined(CONFIG_ISA) || !defined(__mc68000__)
920 {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
921 #endif
922 {5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
923 {7, "full", S_IRUGO | S_IWUGO, &full_fops},
924 {8, "random", S_IRUGO | S_IWUSR, &random_fops},
925 {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops},
926 {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
927 #ifdef CONFIG_CRASH_DUMP
928 {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
929 #endif
930 };
931
932 static struct class *mem_class;
933
934 static int __init chr_dev_init(void)
935 {
936 int i;
937
938 if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))
939 printk("unable to get major %d for memory devs\n", MEM_MAJOR);
940
941 mem_class = class_create(THIS_MODULE, "mem");
942 for (i = 0; i < ARRAY_SIZE(devlist); i++)
943 class_device_create(mem_class, NULL,
944 MKDEV(MEM_MAJOR, devlist[i].minor),
945 NULL, devlist[i].name);
946
947 return 0;
948 }
949
950 fs_initcall(chr_dev_init);