Commit | Line | Data |
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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 | ||
9 | #include <linux/kernel.h> | |
10 | #include <linux/sched.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/string.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/mman.h> | |
16 | #include <linux/uaccess.h> | |
17 | #include <linux/swap.h> | |
18 | #include <linux/smp_lock.h> | |
19 | #include <linux/highmem.h> | |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/seq_file.h> | |
22 | ||
23 | #include <asm/pgalloc.h> | |
24 | #include <asm/pgtable.h> | |
25 | #include <asm/tlb.h> | |
26 | #include <asm/xen/hypervisor.h> | |
27 | #include <asm/xen/hypercall.h> | |
28 | ||
29 | #include <xen/xen.h> | |
30 | #include <xen/privcmd.h> | |
31 | #include <xen/interface/xen.h> | |
32 | #include <xen/features.h> | |
33 | #include <xen/page.h> | |
34 | ||
35 | #ifndef HAVE_ARCH_PRIVCMD_MMAP | |
36 | static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma); | |
37 | #endif | |
38 | ||
39 | struct remap_data { | |
40 | unsigned long mfn; | |
41 | unsigned domid; | |
42 | pgprot_t prot; | |
43 | }; | |
44 | ||
45 | static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token, | |
46 | unsigned long addr, void *data) | |
47 | { | |
48 | struct remap_data *rmd = data; | |
49 | pte_t pte = pte_mkspecial(pfn_pte(rmd->mfn++, rmd->prot)); | |
50 | ||
51 | xen_set_domain_pte(ptep, pte, rmd->domid); | |
52 | ||
53 | return 0; | |
54 | } | |
55 | ||
56 | int remap_domain_mfn_range(struct vm_area_struct *vma, unsigned long addr, | |
57 | unsigned long mfn, unsigned long size, | |
58 | pgprot_t prot, unsigned domid) | |
59 | { | |
60 | struct remap_data rmd; | |
61 | int err; | |
62 | ||
63 | prot = __pgprot(pgprot_val(prot) | _PAGE_IOMAP); | |
64 | ||
65 | vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; | |
66 | ||
67 | rmd.mfn = mfn; | |
68 | rmd.prot = prot; | |
69 | rmd.domid = domid; | |
70 | ||
71 | err = apply_to_page_range(vma->vm_mm, addr, size, | |
72 | remap_area_mfn_pte_fn, &rmd); | |
73 | ||
74 | return err; | |
75 | } | |
76 | ||
77 | static long privcmd_ioctl_hypercall(void __user *udata) | |
78 | { | |
79 | struct privcmd_hypercall hypercall; | |
80 | long ret; | |
81 | ||
82 | if (copy_from_user(&hypercall, udata, sizeof(hypercall))) | |
83 | return -EFAULT; | |
84 | ||
85 | ret = privcmd_call(hypercall.op, | |
86 | hypercall.arg[0], hypercall.arg[1], | |
87 | hypercall.arg[2], hypercall.arg[3], | |
88 | hypercall.arg[4]); | |
89 | ||
90 | return ret; | |
91 | } | |
92 | ||
93 | static void free_page_list(struct list_head *pages) | |
94 | { | |
95 | struct page *p, *n; | |
96 | ||
97 | list_for_each_entry_safe(p, n, pages, lru) | |
98 | __free_page(p); | |
99 | ||
100 | INIT_LIST_HEAD(pages); | |
101 | } | |
102 | ||
103 | /* | |
104 | * Given an array of items in userspace, return a list of pages | |
105 | * containing the data. If copying fails, either because of memory | |
106 | * allocation failure or a problem reading user memory, return an | |
107 | * error code; its up to the caller to dispose of any partial list. | |
108 | */ | |
109 | static int gather_array(struct list_head *pagelist, | |
110 | unsigned nelem, size_t size, | |
111 | void __user *data) | |
112 | { | |
113 | unsigned pageidx; | |
114 | void *pagedata; | |
115 | int ret; | |
116 | ||
117 | if (size > PAGE_SIZE) | |
118 | return 0; | |
119 | ||
120 | pageidx = PAGE_SIZE; | |
121 | pagedata = NULL; /* quiet, gcc */ | |
122 | while (nelem--) { | |
123 | if (pageidx > PAGE_SIZE-size) { | |
124 | struct page *page = alloc_page(GFP_KERNEL); | |
125 | ||
126 | ret = -ENOMEM; | |
127 | if (page == NULL) | |
128 | goto fail; | |
129 | ||
130 | pagedata = page_address(page); | |
131 | ||
132 | list_add_tail(&page->lru, pagelist); | |
133 | pageidx = 0; | |
134 | } | |
135 | ||
136 | ret = -EFAULT; | |
137 | if (copy_from_user(pagedata + pageidx, data, size)) | |
138 | goto fail; | |
139 | ||
140 | data += size; | |
141 | pageidx += size; | |
142 | } | |
143 | ||
144 | ret = 0; | |
145 | ||
146 | fail: | |
147 | return ret; | |
148 | } | |
149 | ||
150 | /* | |
151 | * Call function "fn" on each element of the array fragmented | |
152 | * over a list of pages. | |
153 | */ | |
154 | static int traverse_pages(unsigned nelem, size_t size, | |
155 | struct list_head *pos, | |
156 | int (*fn)(void *data, void *state), | |
157 | void *state) | |
158 | { | |
159 | void *pagedata; | |
160 | unsigned pageidx; | |
161 | int ret; | |
162 | ||
163 | BUG_ON(size > PAGE_SIZE); | |
164 | ||
165 | pageidx = PAGE_SIZE; | |
166 | pagedata = NULL; /* hush, gcc */ | |
167 | ||
168 | while (nelem--) { | |
169 | if (pageidx > PAGE_SIZE-size) { | |
170 | struct page *page; | |
171 | pos = pos->next; | |
172 | page = list_entry(pos, struct page, lru); | |
173 | pagedata = page_address(page); | |
174 | pageidx = 0; | |
175 | } | |
176 | ||
177 | ret = (*fn)(pagedata + pageidx, state); | |
178 | if (ret) | |
179 | break; | |
180 | pageidx += size; | |
181 | } | |
182 | ||
183 | return ret; | |
184 | } | |
185 | ||
186 | struct mmap_mfn_state { | |
187 | unsigned long va; | |
188 | struct vm_area_struct *vma; | |
189 | domid_t domain; | |
190 | }; | |
191 | ||
192 | static int mmap_mfn_range(void *data, void *state) | |
193 | { | |
194 | struct privcmd_mmap_entry *msg = data; | |
195 | struct mmap_mfn_state *st = state; | |
196 | struct vm_area_struct *vma = st->vma; | |
197 | int rc; | |
198 | ||
199 | /* Do not allow range to wrap the address space. */ | |
200 | if ((msg->npages > (LONG_MAX >> PAGE_SHIFT)) || | |
201 | ((unsigned long)(msg->npages << PAGE_SHIFT) >= -st->va)) | |
202 | return -EINVAL; | |
203 | ||
204 | /* Range chunks must be contiguous in va space. */ | |
205 | if ((msg->va != st->va) || | |
206 | ((msg->va+(msg->npages<<PAGE_SHIFT)) > vma->vm_end)) | |
207 | return -EINVAL; | |
208 | ||
209 | rc = remap_domain_mfn_range(vma, | |
210 | msg->va & PAGE_MASK, | |
211 | msg->mfn, | |
212 | msg->npages << PAGE_SHIFT, | |
213 | vma->vm_page_prot, | |
214 | st->domain); | |
215 | if (rc < 0) | |
216 | return rc; | |
217 | ||
218 | st->va += msg->npages << PAGE_SHIFT; | |
219 | ||
220 | return 0; | |
221 | } | |
222 | ||
223 | static long privcmd_ioctl_mmap(void __user *udata) | |
224 | { | |
225 | struct privcmd_mmap mmapcmd; | |
226 | struct mm_struct *mm = current->mm; | |
227 | struct vm_area_struct *vma; | |
228 | int rc; | |
229 | LIST_HEAD(pagelist); | |
230 | struct mmap_mfn_state state; | |
231 | ||
232 | if (!xen_initial_domain()) | |
233 | return -EPERM; | |
234 | ||
235 | if (copy_from_user(&mmapcmd, udata, sizeof(mmapcmd))) | |
236 | return -EFAULT; | |
237 | ||
238 | rc = gather_array(&pagelist, | |
239 | mmapcmd.num, sizeof(struct privcmd_mmap_entry), | |
240 | mmapcmd.entry); | |
241 | ||
242 | if (rc || list_empty(&pagelist)) | |
243 | goto out; | |
244 | ||
245 | down_write(&mm->mmap_sem); | |
246 | ||
247 | { | |
248 | struct page *page = list_first_entry(&pagelist, | |
249 | struct page, lru); | |
250 | struct privcmd_mmap_entry *msg = page_address(page); | |
251 | ||
252 | vma = find_vma(mm, msg->va); | |
253 | rc = -EINVAL; | |
254 | ||
255 | if (!vma || (msg->va != vma->vm_start) || | |
256 | !privcmd_enforce_singleshot_mapping(vma)) | |
257 | goto out_up; | |
258 | } | |
259 | ||
260 | state.va = vma->vm_start; | |
261 | state.vma = vma; | |
262 | state.domain = mmapcmd.dom; | |
263 | ||
264 | rc = traverse_pages(mmapcmd.num, sizeof(struct privcmd_mmap_entry), | |
265 | &pagelist, | |
266 | mmap_mfn_range, &state); | |
267 | ||
268 | ||
269 | out_up: | |
270 | up_write(&mm->mmap_sem); | |
271 | ||
272 | out: | |
273 | free_page_list(&pagelist); | |
274 | ||
275 | return rc; | |
276 | } | |
277 | ||
278 | struct mmap_batch_state { | |
279 | domid_t domain; | |
280 | unsigned long va; | |
281 | struct vm_area_struct *vma; | |
282 | int err; | |
283 | ||
284 | xen_pfn_t __user *user; | |
285 | }; | |
286 | ||
287 | static int mmap_batch_fn(void *data, void *state) | |
288 | { | |
289 | xen_pfn_t *mfnp = data; | |
290 | struct mmap_batch_state *st = state; | |
291 | ||
292 | if (remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, | |
293 | *mfnp, PAGE_SIZE, | |
294 | st->vma->vm_page_prot, st->domain) < 0) { | |
295 | *mfnp |= 0xf0000000U; | |
296 | st->err++; | |
297 | } | |
298 | st->va += PAGE_SIZE; | |
299 | ||
300 | return 0; | |
301 | } | |
302 | ||
303 | static int mmap_return_errors(void *data, void *state) | |
304 | { | |
305 | xen_pfn_t *mfnp = data; | |
306 | struct mmap_batch_state *st = state; | |
307 | ||
308 | put_user(*mfnp, st->user++); | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
313 | static long privcmd_ioctl_mmap_batch(void __user *udata) | |
314 | { | |
315 | int ret; | |
316 | struct privcmd_mmapbatch m; | |
317 | struct mm_struct *mm = current->mm; | |
318 | struct vm_area_struct *vma; | |
319 | unsigned long nr_pages; | |
320 | LIST_HEAD(pagelist); | |
321 | struct mmap_batch_state state; | |
322 | ||
323 | if (!xen_initial_domain()) | |
324 | return -EPERM; | |
325 | ||
326 | if (copy_from_user(&m, udata, sizeof(m))) | |
327 | return -EFAULT; | |
328 | ||
329 | nr_pages = m.num; | |
330 | if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT))) | |
331 | return -EINVAL; | |
332 | ||
333 | ret = gather_array(&pagelist, m.num, sizeof(xen_pfn_t), | |
334 | m.arr); | |
335 | ||
336 | if (ret || list_empty(&pagelist)) | |
337 | goto out; | |
338 | ||
339 | down_write(&mm->mmap_sem); | |
340 | ||
341 | vma = find_vma(mm, m.addr); | |
342 | ret = -EINVAL; | |
343 | if (!vma || | |
344 | (m.addr != vma->vm_start) || | |
345 | ((m.addr + (nr_pages << PAGE_SHIFT)) != vma->vm_end) || | |
346 | !privcmd_enforce_singleshot_mapping(vma)) { | |
347 | up_write(&mm->mmap_sem); | |
348 | goto out; | |
349 | } | |
350 | ||
351 | state.domain = m.dom; | |
352 | state.vma = vma; | |
353 | state.va = m.addr; | |
354 | state.err = 0; | |
355 | ||
356 | ret = traverse_pages(m.num, sizeof(xen_pfn_t), | |
357 | &pagelist, mmap_batch_fn, &state); | |
358 | ||
359 | up_write(&mm->mmap_sem); | |
360 | ||
361 | if (state.err > 0) { | |
362 | ret = state.err; | |
363 | ||
364 | state.user = udata; | |
365 | traverse_pages(m.num, sizeof(xen_pfn_t), | |
366 | &pagelist, | |
367 | mmap_return_errors, &state); | |
368 | } | |
369 | ||
370 | out: | |
371 | free_page_list(&pagelist); | |
372 | ||
373 | return ret; | |
374 | } | |
375 | ||
376 | static long privcmd_ioctl(struct file *file, | |
377 | unsigned int cmd, unsigned long data) | |
378 | { | |
379 | int ret = -ENOSYS; | |
380 | void __user *udata = (void __user *) data; | |
381 | ||
382 | switch (cmd) { | |
383 | case IOCTL_PRIVCMD_HYPERCALL: | |
384 | ret = privcmd_ioctl_hypercall(udata); | |
385 | break; | |
386 | ||
387 | case IOCTL_PRIVCMD_MMAP: | |
388 | ret = privcmd_ioctl_mmap(udata); | |
389 | break; | |
390 | ||
391 | case IOCTL_PRIVCMD_MMAPBATCH: | |
392 | ret = privcmd_ioctl_mmap_batch(udata); | |
393 | break; | |
394 | ||
395 | default: | |
396 | ret = -EINVAL; | |
397 | break; | |
398 | } | |
399 | ||
400 | return ret; | |
401 | } | |
402 | ||
403 | #ifndef HAVE_ARCH_PRIVCMD_MMAP | |
404 | static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf) | |
405 | { | |
441c7416 JF |
406 | printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n", |
407 | vma, vma->vm_start, vma->vm_end, | |
408 | vmf->pgoff, vmf->virtual_address); | |
409 | ||
1c5de193 JF |
410 | return VM_FAULT_SIGBUS; |
411 | } | |
412 | ||
413 | static struct vm_operations_struct privcmd_vm_ops = { | |
414 | .fault = privcmd_fault | |
415 | }; | |
416 | ||
417 | static int privcmd_mmap(struct file *file, struct vm_area_struct *vma) | |
418 | { | |
419 | /* Unsupported for auto-translate guests. */ | |
420 | if (xen_feature(XENFEAT_auto_translated_physmap)) | |
421 | return -ENOSYS; | |
422 | ||
423 | /* DONTCOPY is essential for Xen as copy_page_range is broken. */ | |
424 | vma->vm_flags |= VM_RESERVED | VM_IO | VM_DONTCOPY; | |
425 | vma->vm_ops = &privcmd_vm_ops; | |
426 | vma->vm_private_data = NULL; | |
427 | ||
428 | return 0; | |
429 | } | |
430 | ||
431 | static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma) | |
432 | { | |
433 | return (xchg(&vma->vm_private_data, (void *)1) == NULL); | |
434 | } | |
435 | #endif | |
436 | ||
437 | const struct file_operations privcmd_file_ops = { | |
438 | .unlocked_ioctl = privcmd_ioctl, | |
439 | .mmap = privcmd_mmap, | |
440 | }; |