Commit | Line | Data |
---|---|---|
1c5de193 JF |
1 | /****************************************************************************** |
2 | * privcmd.c | |
3 | * | |
4 | * Interface to privileged domain-0 commands. | |
5 | * | |
6 | * Copyright (c) 2002-2004, K A Fraser, B Dragovic | |
7 | */ | |
8 | ||
283c0972 JP |
9 | #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt |
10 | ||
1c5de193 | 11 | #include <linux/kernel.h> |
d8414d3c | 12 | #include <linux/module.h> |
1c5de193 JF |
13 | #include <linux/sched.h> |
14 | #include <linux/slab.h> | |
15 | #include <linux/string.h> | |
16 | #include <linux/errno.h> | |
17 | #include <linux/mm.h> | |
18 | #include <linux/mman.h> | |
19 | #include <linux/uaccess.h> | |
20 | #include <linux/swap.h> | |
1c5de193 JF |
21 | #include <linux/highmem.h> |
22 | #include <linux/pagemap.h> | |
23 | #include <linux/seq_file.h> | |
d8414d3c | 24 | #include <linux/miscdevice.h> |
1c5de193 JF |
25 | |
26 | #include <asm/pgalloc.h> | |
27 | #include <asm/pgtable.h> | |
28 | #include <asm/tlb.h> | |
29 | #include <asm/xen/hypervisor.h> | |
30 | #include <asm/xen/hypercall.h> | |
31 | ||
32 | #include <xen/xen.h> | |
33 | #include <xen/privcmd.h> | |
34 | #include <xen/interface/xen.h> | |
35 | #include <xen/features.h> | |
36 | #include <xen/page.h> | |
de1ef206 | 37 | #include <xen/xen-ops.h> |
d71f5139 | 38 | #include <xen/balloon.h> |
f020e290 | 39 | |
d8414d3c BB |
40 | #include "privcmd.h" |
41 | ||
42 | MODULE_LICENSE("GPL"); | |
43 | ||
d71f5139 MR |
44 | #define PRIV_VMA_LOCKED ((void *)1) |
45 | ||
1c5de193 JF |
46 | #ifndef HAVE_ARCH_PRIVCMD_MMAP |
47 | static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma); | |
48 | #endif | |
49 | ||
1c5de193 JF |
50 | static long privcmd_ioctl_hypercall(void __user *udata) |
51 | { | |
52 | struct privcmd_hypercall hypercall; | |
53 | long ret; | |
54 | ||
55 | if (copy_from_user(&hypercall, udata, sizeof(hypercall))) | |
56 | return -EFAULT; | |
57 | ||
58 | ret = privcmd_call(hypercall.op, | |
59 | hypercall.arg[0], hypercall.arg[1], | |
60 | hypercall.arg[2], hypercall.arg[3], | |
61 | hypercall.arg[4]); | |
62 | ||
63 | return ret; | |
64 | } | |
65 | ||
66 | static void free_page_list(struct list_head *pages) | |
67 | { | |
68 | struct page *p, *n; | |
69 | ||
70 | list_for_each_entry_safe(p, n, pages, lru) | |
71 | __free_page(p); | |
72 | ||
73 | INIT_LIST_HEAD(pages); | |
74 | } | |
75 | ||
76 | /* | |
77 | * Given an array of items in userspace, return a list of pages | |
78 | * containing the data. If copying fails, either because of memory | |
79 | * allocation failure or a problem reading user memory, return an | |
80 | * error code; its up to the caller to dispose of any partial list. | |
81 | */ | |
82 | static int gather_array(struct list_head *pagelist, | |
83 | unsigned nelem, size_t size, | |
ceb90fa0 | 84 | const void __user *data) |
1c5de193 JF |
85 | { |
86 | unsigned pageidx; | |
87 | void *pagedata; | |
88 | int ret; | |
89 | ||
90 | if (size > PAGE_SIZE) | |
91 | return 0; | |
92 | ||
93 | pageidx = PAGE_SIZE; | |
94 | pagedata = NULL; /* quiet, gcc */ | |
95 | while (nelem--) { | |
96 | if (pageidx > PAGE_SIZE-size) { | |
97 | struct page *page = alloc_page(GFP_KERNEL); | |
98 | ||
99 | ret = -ENOMEM; | |
100 | if (page == NULL) | |
101 | goto fail; | |
102 | ||
103 | pagedata = page_address(page); | |
104 | ||
105 | list_add_tail(&page->lru, pagelist); | |
106 | pageidx = 0; | |
107 | } | |
108 | ||
109 | ret = -EFAULT; | |
110 | if (copy_from_user(pagedata + pageidx, data, size)) | |
111 | goto fail; | |
112 | ||
113 | data += size; | |
114 | pageidx += size; | |
115 | } | |
116 | ||
117 | ret = 0; | |
118 | ||
119 | fail: | |
120 | return ret; | |
121 | } | |
122 | ||
123 | /* | |
124 | * Call function "fn" on each element of the array fragmented | |
125 | * over a list of pages. | |
126 | */ | |
127 | static int traverse_pages(unsigned nelem, size_t size, | |
128 | struct list_head *pos, | |
129 | int (*fn)(void *data, void *state), | |
130 | void *state) | |
131 | { | |
132 | void *pagedata; | |
133 | unsigned pageidx; | |
f020e290 | 134 | int ret = 0; |
1c5de193 JF |
135 | |
136 | BUG_ON(size > PAGE_SIZE); | |
137 | ||
138 | pageidx = PAGE_SIZE; | |
139 | pagedata = NULL; /* hush, gcc */ | |
140 | ||
141 | while (nelem--) { | |
142 | if (pageidx > PAGE_SIZE-size) { | |
143 | struct page *page; | |
144 | pos = pos->next; | |
145 | page = list_entry(pos, struct page, lru); | |
146 | pagedata = page_address(page); | |
147 | pageidx = 0; | |
148 | } | |
149 | ||
150 | ret = (*fn)(pagedata + pageidx, state); | |
151 | if (ret) | |
152 | break; | |
153 | pageidx += size; | |
154 | } | |
155 | ||
156 | return ret; | |
157 | } | |
158 | ||
159 | struct mmap_mfn_state { | |
160 | unsigned long va; | |
161 | struct vm_area_struct *vma; | |
162 | domid_t domain; | |
163 | }; | |
164 | ||
165 | static int mmap_mfn_range(void *data, void *state) | |
166 | { | |
167 | struct privcmd_mmap_entry *msg = data; | |
168 | struct mmap_mfn_state *st = state; | |
169 | struct vm_area_struct *vma = st->vma; | |
170 | int rc; | |
171 | ||
172 | /* Do not allow range to wrap the address space. */ | |
173 | if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) || | |
174 | ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va)) | |
175 | return -EINVAL; | |
176 | ||
177 | /* Range chunks must be contiguous in va space. */ | |
178 | if ((msg->va != st->va) || | |
179 | ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end)) | |
180 | return -EINVAL; | |
181 | ||
de1ef206 IC |
182 | rc = xen_remap_domain_mfn_range(vma, |
183 | msg->va & PAGE_MASK, | |
184 | msg->mfn, msg->npages, | |
185 | vma->vm_page_prot, | |
9a032e39 | 186 | st->domain, NULL); |
1c5de193 JF |
187 | if (rc < 0) |
188 | return rc; | |
189 | ||
190 | st->va += msg->npages << PAGE_SHIFT; | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | static long privcmd_ioctl_mmap(void __user *udata) | |
196 | { | |
197 | struct privcmd_mmap mmapcmd; | |
198 | struct mm_struct *mm = current->mm; | |
199 | struct vm_area_struct *vma; | |
200 | int rc; | |
201 | LIST_HEAD(pagelist); | |
202 | struct mmap_mfn_state state; | |
203 | ||
d71f5139 MR |
204 | /* We only support privcmd_ioctl_mmap_batch for auto translated. */ |
205 | if (xen_feature(XENFEAT_auto_translated_physmap)) | |
206 | return -ENOSYS; | |
207 | ||
1c5de193 JF |
208 | if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) |
209 | return -EFAULT; | |
210 | ||
211 | rc = gather_array(&pagelist, | |
212 | mmapcmd.num, sizeof(struct privcmd_mmap_entry), | |
213 | mmapcmd.entry); | |
214 | ||
215 | if (rc || list_empty(&pagelist)) | |
216 | goto out; | |
217 | ||
218 | down_write(&mm->mmap_sem); | |
219 | ||
220 | { | |
221 | struct page *page = list_first_entry(&pagelist, | |
222 | struct page, lru); | |
223 | struct privcmd_mmap_entry *msg = page_address(page); | |
224 | ||
225 | vma = find_vma(mm, msg->va); | |
226 | rc = -EINVAL; | |
227 | ||
228 | if (!vma || (msg->va != vma->vm_start) || | |
229 | !privcmd_enforce_singleshot_mapping(vma)) | |
230 | goto out_up; | |
231 | } | |
232 | ||
233 | state.va = vma->vm_start; | |
234 | state.vma = vma; | |
235 | state.domain = mmapcmd.dom; | |
236 | ||
237 | rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry), | |
238 | &pagelist, | |
239 | mmap_mfn_range, &state); | |
240 | ||
241 | ||
242 | out_up: | |
243 | up_write(&mm->mmap_sem); | |
244 | ||
245 | out: | |
246 | free_page_list(&pagelist); | |
247 | ||
248 | return rc; | |
249 | } | |
250 | ||
251 | struct mmap_batch_state { | |
252 | domid_t domain; | |
253 | unsigned long va; | |
254 | struct vm_area_struct *vma; | |
d71f5139 | 255 | int index; |
ceb90fa0 ALC |
256 | /* A tristate: |
257 | * 0 for no errors | |
258 | * 1 if at least one error has happened (and no | |
259 | * -ENOENT errors have happened) | |
260 | * -ENOENT if at least 1 -ENOENT has happened. | |
261 | */ | |
262 | int global_error; | |
99beae6c | 263 | int version; |
ceb90fa0 ALC |
264 | |
265 | /* User-space mfn array to store errors in the second pass for V1. */ | |
266 | xen_pfn_t __user *user_mfn; | |
99beae6c ALC |
267 | /* User-space int array to store errors in the second pass for V2. */ |
268 | int __user *user_err; | |
1c5de193 JF |
269 | }; |
270 | ||
d71f5139 MR |
271 | /* auto translated dom0 note: if domU being created is PV, then mfn is |
272 | * mfn(addr on bus). If it's auto xlated, then mfn is pfn (input to HAP). | |
273 | */ | |
1c5de193 JF |
274 | static int mmap_batch_fn(void *data, void *state) |
275 | { | |
276 | xen_pfn_t *mfnp = data; | |
277 | struct mmap_batch_state *st = state; | |
d71f5139 MR |
278 | struct vm_area_struct *vma = st->vma; |
279 | struct page **pages = vma->vm_private_data; | |
280 | struct page *cur_page = NULL; | |
ceb90fa0 ALC |
281 | int ret; |
282 | ||
d71f5139 MR |
283 | if (xen_feature(XENFEAT_auto_translated_physmap)) |
284 | cur_page = pages[st->index++]; | |
285 | ||
ceb90fa0 | 286 | ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1, |
9a032e39 | 287 | st->vma->vm_page_prot, st->domain, |
d71f5139 | 288 | &cur_page); |
1c5de193 | 289 | |
ceb90fa0 | 290 | /* Store error code for second pass. */ |
99beae6c ALC |
291 | if (st->version == 1) { |
292 | if (ret < 0) { | |
293 | /* | |
294 | * V1 encodes the error codes in the 32bit top nibble of the | |
295 | * mfn (with its known limitations vis-a-vis 64 bit callers). | |
296 | */ | |
297 | *mfnp |= (ret == -ENOENT) ? | |
298 | PRIVCMD_MMAPBATCH_PAGED_ERROR : | |
299 | PRIVCMD_MMAPBATCH_MFN_ERROR; | |
300 | } | |
301 | } else { /* st->version == 2 */ | |
302 | *((int *) mfnp) = ret; | |
303 | } | |
ceb90fa0 ALC |
304 | |
305 | /* And see if it affects the global_error. */ | |
306 | if (ret < 0) { | |
307 | if (ret == -ENOENT) | |
308 | st->global_error = -ENOENT; | |
309 | else { | |
310 | /* Record that at least one error has happened. */ | |
311 | if (st->global_error == 0) | |
312 | st->global_error = 1; | |
313 | } | |
1c5de193 JF |
314 | } |
315 | st->va += PAGE_SIZE; | |
316 | ||
317 | return 0; | |
318 | } | |
319 | ||
99beae6c | 320 | static int mmap_return_errors(void *data, void *state) |
1c5de193 | 321 | { |
1c5de193 | 322 | struct mmap_batch_state *st = state; |
ceb90fa0 | 323 | |
99beae6c ALC |
324 | if (st->version == 1) { |
325 | xen_pfn_t mfnp = *((xen_pfn_t *) data); | |
326 | if (mfnp & PRIVCMD_MMAPBATCH_MFN_ERROR) | |
327 | return __put_user(mfnp, st->user_mfn++); | |
328 | else | |
329 | st->user_mfn++; | |
330 | } else { /* st->version == 2 */ | |
331 | int err = *((int *) data); | |
332 | if (err) | |
333 | return __put_user(err, st->user_err++); | |
334 | else | |
335 | st->user_err++; | |
336 | } | |
337 | ||
338 | return 0; | |
1c5de193 JF |
339 | } |
340 | ||
d71f5139 MR |
341 | /* Allocate pfns that are then mapped with gmfns from foreign domid. Update |
342 | * the vma with the page info to use later. | |
343 | * Returns: 0 if success, otherwise -errno | |
344 | */ | |
345 | static int alloc_empty_pages(struct vm_area_struct *vma, int numpgs) | |
346 | { | |
347 | int rc; | |
348 | struct page **pages; | |
349 | ||
350 | pages = kcalloc(numpgs, sizeof(pages[0]), GFP_KERNEL); | |
351 | if (pages == NULL) | |
352 | return -ENOMEM; | |
353 | ||
354 | rc = alloc_xenballooned_pages(numpgs, pages, 0); | |
355 | if (rc != 0) { | |
356 | pr_warn("%s Could not alloc %d pfns rc:%d\n", __func__, | |
357 | numpgs, rc); | |
358 | kfree(pages); | |
359 | return -ENOMEM; | |
360 | } | |
361 | BUG_ON(vma->vm_private_data != PRIV_VMA_LOCKED); | |
362 | vma->vm_private_data = pages; | |
363 | ||
364 | return 0; | |
365 | } | |
366 | ||
f31fdf51 JF |
367 | static struct vm_operations_struct privcmd_vm_ops; |
368 | ||
ceb90fa0 | 369 | static long privcmd_ioctl_mmap_batch(void __user *udata, int version) |
1c5de193 JF |
370 | { |
371 | int ret; | |
ceb90fa0 | 372 | struct privcmd_mmapbatch_v2 m; |
1c5de193 JF |
373 | struct mm_struct *mm = current->mm; |
374 | struct vm_area_struct *vma; | |
375 | unsigned long nr_pages; | |
376 | LIST_HEAD(pagelist); | |
377 | struct mmap_batch_state state; | |
378 | ||
ceb90fa0 ALC |
379 | switch (version) { |
380 | case 1: | |
381 | if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch))) | |
382 | return -EFAULT; | |
383 | /* Returns per-frame error in m.arr. */ | |
384 | m.err = NULL; | |
385 | if (!access_ok(VERIFY_WRITE, m.arr, m.num * sizeof(*m.arr))) | |
386 | return -EFAULT; | |
387 | break; | |
388 | case 2: | |
389 | if (copy_from_user(&m, udata, sizeof(struct privcmd_mmapbatch_v2))) | |
390 | return -EFAULT; | |
391 | /* Returns per-frame error code in m.err. */ | |
392 | if (!access_ok(VERIFY_WRITE, m.err, m.num * (sizeof(*m.err)))) | |
393 | return -EFAULT; | |
394 | break; | |
395 | default: | |
396 | return -EINVAL; | |
397 | } | |
1c5de193 JF |
398 | |
399 | nr_pages = m.num; | |
400 | if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT))) | |
401 | return -EINVAL; | |
402 | ||
ceb90fa0 | 403 | ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), m.arr); |
1c5de193 | 404 | |
ceb90fa0 | 405 | if (ret) |
1c5de193 | 406 | goto out; |
ceb90fa0 ALC |
407 | if (list_empty(&pagelist)) { |
408 | ret = -EINVAL; | |
409 | goto out; | |
410 | } | |
411 | ||
99beae6c ALC |
412 | if (version == 2) { |
413 | /* Zero error array now to only copy back actual errors. */ | |
414 | if (clear_user(m.err, sizeof(int) * m.num)) { | |
415 | ret = -EFAULT; | |
416 | goto out; | |
417 | } | |
ceb90fa0 | 418 | } |
1c5de193 JF |
419 | |
420 | down_write(&mm->mmap_sem); | |
421 | ||
422 | vma = find_vma(mm, m.addr); | |
1c5de193 | 423 | if (!vma || |
f31fdf51 | 424 | vma->vm_ops != &privcmd_vm_ops || |
1c5de193 JF |
425 | (m.addr != vma->vm_start) || |
426 | ((m.addr + (nr_pages << PAGE_SHIFT)) != vma->vm_end) || | |
427 | !privcmd_enforce_singleshot_mapping(vma)) { | |
428 | up_write(&mm->mmap_sem); | |
68fa965d | 429 | ret = -EINVAL; |
1c5de193 JF |
430 | goto out; |
431 | } | |
d71f5139 MR |
432 | if (xen_feature(XENFEAT_auto_translated_physmap)) { |
433 | ret = alloc_empty_pages(vma, m.num); | |
434 | if (ret < 0) { | |
435 | up_write(&mm->mmap_sem); | |
436 | goto out; | |
437 | } | |
438 | } | |
1c5de193 | 439 | |
ceb90fa0 ALC |
440 | state.domain = m.dom; |
441 | state.vma = vma; | |
442 | state.va = m.addr; | |
d71f5139 | 443 | state.index = 0; |
ceb90fa0 | 444 | state.global_error = 0; |
99beae6c | 445 | state.version = version; |
1c5de193 | 446 | |
ceb90fa0 ALC |
447 | /* mmap_batch_fn guarantees ret == 0 */ |
448 | BUG_ON(traverse_pages(m.num, sizeof(xen_pfn_t), | |
449 | &pagelist, mmap_batch_fn, &state)); | |
1c5de193 JF |
450 | |
451 | up_write(&mm->mmap_sem); | |
452 | ||
99beae6c ALC |
453 | if (state.global_error) { |
454 | /* Write back errors in second pass. */ | |
455 | state.user_mfn = (xen_pfn_t *)m.arr; | |
456 | state.user_err = m.err; | |
457 | ret = traverse_pages(m.num, sizeof(xen_pfn_t), | |
458 | &pagelist, mmap_return_errors, &state); | |
459 | } else | |
460 | ret = 0; | |
ceb90fa0 ALC |
461 | |
462 | /* If we have not had any EFAULT-like global errors then set the global | |
463 | * error to -ENOENT if necessary. */ | |
464 | if ((ret == 0) && (state.global_error == -ENOENT)) | |
465 | ret = -ENOENT; | |
1c5de193 JF |
466 | |
467 | out: | |
468 | free_page_list(&pagelist); | |
469 | ||
470 | return ret; | |
471 | } | |
472 | ||
473 | static long privcmd_ioctl(struct file *file, | |
474 | unsigned int cmd, unsigned long data) | |
475 | { | |
476 | int ret = -ENOSYS; | |
477 | void __user *udata = (void __user *) data; | |
478 | ||
479 | switch (cmd) { | |
480 | case IOCTL_PRIVCMD_HYPERCALL: | |
481 | ret = privcmd_ioctl_hypercall(udata); | |
482 | break; | |
483 | ||
484 | case IOCTL_PRIVCMD_MMAP: | |
485 | ret = privcmd_ioctl_mmap(udata); | |
486 | break; | |
487 | ||
488 | case IOCTL_PRIVCMD_MMAPBATCH: | |
ceb90fa0 ALC |
489 | ret = privcmd_ioctl_mmap_batch(udata, 1); |
490 | break; | |
491 | ||
492 | case IOCTL_PRIVCMD_MMAPBATCH_V2: | |
493 | ret = privcmd_ioctl_mmap_batch(udata, 2); | |
1c5de193 JF |
494 | break; |
495 | ||
496 | default: | |
497 | ret = -EINVAL; | |
498 | break; | |
499 | } | |
500 | ||
501 | return ret; | |
502 | } | |
503 | ||
d71f5139 MR |
504 | static void privcmd_close(struct vm_area_struct *vma) |
505 | { | |
506 | struct page **pages = vma->vm_private_data; | |
507 | int numpgs = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; | |
508 | ||
9eff37a8 | 509 | if (!xen_feature(XENFEAT_auto_translated_physmap) || !numpgs || !pages) |
d71f5139 MR |
510 | return; |
511 | ||
512 | xen_unmap_domain_mfn_range(vma, numpgs, pages); | |
513 | free_xenballooned_pages(numpgs, pages); | |
514 | kfree(pages); | |
515 | } | |
516 | ||
1c5de193 JF |
517 | static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf) |
518 | { | |
441c7416 JF |
519 | printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", |
520 | vma, vma->vm_start, vma->vm_end, | |
521 | vmf->pgoff, vmf->virtual_address); | |
522 | ||
1c5de193 JF |
523 | return VM_FAULT_SIGBUS; |
524 | } | |
525 | ||
526 | static struct vm_operations_struct privcmd_vm_ops = { | |
d71f5139 | 527 | .close = privcmd_close, |
1c5de193 JF |
528 | .fault = privcmd_fault |
529 | }; | |
530 | ||
531 | static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) | |
532 | { | |
e060e7af SS |
533 | /* DONTCOPY is essential for Xen because copy_page_range doesn't know |
534 | * how to recreate these mappings */ | |
314e51b9 KK |
535 | vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTCOPY | |
536 | VM_DONTEXPAND | VM_DONTDUMP; | |
1c5de193 JF |
537 | vma->vm_ops = &privcmd_vm_ops; |
538 | vma->vm_private_data = NULL; | |
539 | ||
540 | return 0; | |
541 | } | |
542 | ||
543 | static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma) | |
544 | { | |
d71f5139 | 545 | return !cmpxchg(&vma->vm_private_data, NULL, PRIV_VMA_LOCKED); |
1c5de193 | 546 | } |
1c5de193 | 547 | |
d8414d3c BB |
548 | const struct file_operations xen_privcmd_fops = { |
549 | .owner = THIS_MODULE, | |
1c5de193 JF |
550 | .unlocked_ioctl = privcmd_ioctl, |
551 | .mmap = privcmd_mmap, | |
552 | }; | |
d8414d3c BB |
553 | EXPORT_SYMBOL_GPL(xen_privcmd_fops); |
554 | ||
555 | static struct miscdevice privcmd_dev = { | |
556 | .minor = MISC_DYNAMIC_MINOR, | |
557 | .name = "xen/privcmd", | |
558 | .fops = &xen_privcmd_fops, | |
559 | }; | |
560 | ||
561 | static int __init privcmd_init(void) | |
562 | { | |
563 | int err; | |
564 | ||
565 | if (!xen_domain()) | |
566 | return -ENODEV; | |
567 | ||
568 | err = misc_register(&privcmd_dev); | |
569 | if (err != 0) { | |
283c0972 | 570 | pr_err("Could not register Xen privcmd device\n"); |
d8414d3c BB |
571 | return err; |
572 | } | |
573 | return 0; | |
574 | } | |
575 | ||
576 | static void __exit privcmd_exit(void) | |
577 | { | |
578 | misc_deregister(&privcmd_dev); | |
579 | } | |
580 | ||
581 | module_init(privcmd_init); | |
582 | module_exit(privcmd_exit); |