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1/*
2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <linux/mm.h>
7#include <linux/sched.h>
8#include <linux/slab.h>
9#include <linux/uaccess.h>
10#include <asm/unistd.h>
11#include <os.h>
12#include <skas.h>
13#include <sysdep/tls.h>
14
15static inline int modify_ldt (int func, void *ptr, unsigned long bytecount)
16{
17 return syscall(__NR_modify_ldt, func, ptr, bytecount);
18}
19
20static long write_ldt_entry(struct mm_id *mm_idp, int func,
21 struct user_desc *desc, void **addr, int done)
22{
23 long res;
24 void *stub_addr;
25 res = syscall_stub_data(mm_idp, (unsigned long *)desc,
26 (sizeof(*desc) + sizeof(long) - 1) &
27 ~(sizeof(long) - 1),
28 addr, &stub_addr);
29 if (!res) {
30 unsigned long args[] = { func,
31 (unsigned long)stub_addr,
32 sizeof(*desc),
33 0, 0, 0 };
34 res = run_syscall_stub(mm_idp, __NR_modify_ldt, args,
35 0, addr, done);
36 }
37
38 return res;
39}
40
41/*
42 * In skas mode, we hold our own ldt data in UML.
43 * Thus, the code implementing sys_modify_ldt_skas
44 * is very similar to (and mostly stolen from) sys_modify_ldt
45 * for arch/i386/kernel/ldt.c
46 * The routines copied and modified in part are:
47 * - read_ldt
48 * - read_default_ldt
49 * - write_ldt
50 * - sys_modify_ldt_skas
51 */
52
53static int read_ldt(void __user * ptr, unsigned long bytecount)
54{
55 int i, err = 0;
56 unsigned long size;
57 uml_ldt_t *ldt = ¤t->mm->context.arch.ldt;
58
59 if (!ldt->entry_count)
60 goto out;
61 if (bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES)
62 bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES;
63 err = bytecount;
64
65 mutex_lock(&ldt->lock);
66 if (ldt->entry_count <= LDT_DIRECT_ENTRIES) {
67 size = LDT_ENTRY_SIZE*LDT_DIRECT_ENTRIES;
68 if (size > bytecount)
69 size = bytecount;
70 if (copy_to_user(ptr, ldt->u.entries, size))
71 err = -EFAULT;
72 bytecount -= size;
73 ptr += size;
74 }
75 else {
76 for (i=0; i<ldt->entry_count/LDT_ENTRIES_PER_PAGE && bytecount;
77 i++) {
78 size = PAGE_SIZE;
79 if (size > bytecount)
80 size = bytecount;
81 if (copy_to_user(ptr, ldt->u.pages[i], size)) {
82 err = -EFAULT;
83 break;
84 }
85 bytecount -= size;
86 ptr += size;
87 }
88 }
89 mutex_unlock(&ldt->lock);
90
91 if (bytecount == 0 || err == -EFAULT)
92 goto out;
93
94 if (clear_user(ptr, bytecount))
95 err = -EFAULT;
96
97out:
98 return err;
99}
100
101static int read_default_ldt(void __user * ptr, unsigned long bytecount)
102{
103 int err;
104
105 if (bytecount > 5*LDT_ENTRY_SIZE)
106 bytecount = 5*LDT_ENTRY_SIZE;
107
108 err = bytecount;
109 /*
110 * UML doesn't support lcall7 and lcall27.
111 * So, we don't really have a default ldt, but emulate
112 * an empty ldt of common host default ldt size.
113 */
114 if (clear_user(ptr, bytecount))
115 err = -EFAULT;
116
117 return err;
118}
119
120static int write_ldt(void __user * ptr, unsigned long bytecount, int func)
121{
122 uml_ldt_t *ldt = ¤t->mm->context.arch.ldt;
123 struct mm_id * mm_idp = ¤t->mm->context.id;
124 int i, err;
125 struct user_desc ldt_info;
126 struct ldt_entry entry0, *ldt_p;
127 void *addr = NULL;
128
129 err = -EINVAL;
130 if (bytecount != sizeof(ldt_info))
131 goto out;
132 err = -EFAULT;
133 if (copy_from_user(&ldt_info, ptr, sizeof(ldt_info)))
134 goto out;
135
136 err = -EINVAL;
137 if (ldt_info.entry_number >= LDT_ENTRIES)
138 goto out;
139 if (ldt_info.contents == 3) {
140 if (func == 1)
141 goto out;
142 if (ldt_info.seg_not_present == 0)
143 goto out;
144 }
145
146 mutex_lock(&ldt->lock);
147
148 err = write_ldt_entry(mm_idp, func, &ldt_info, &addr, 1);
149 if (err)
150 goto out_unlock;
151
152 if (ldt_info.entry_number >= ldt->entry_count &&
153 ldt_info.entry_number >= LDT_DIRECT_ENTRIES) {
154 for (i=ldt->entry_count/LDT_ENTRIES_PER_PAGE;
155 i*LDT_ENTRIES_PER_PAGE <= ldt_info.entry_number;
156 i++) {
157 if (i == 0)
158 memcpy(&entry0, ldt->u.entries,
159 sizeof(entry0));
160 ldt->u.pages[i] = (struct ldt_entry *)
161 __get_free_page(GFP_KERNEL|__GFP_ZERO);
162 if (!ldt->u.pages[i]) {
163 err = -ENOMEM;
164 /* Undo the change in host */
165 memset(&ldt_info, 0, sizeof(ldt_info));
166 write_ldt_entry(mm_idp, 1, &ldt_info, &addr, 1);
167 goto out_unlock;
168 }
169 if (i == 0) {
170 memcpy(ldt->u.pages[0], &entry0,
171 sizeof(entry0));
172 memcpy(ldt->u.pages[0]+1, ldt->u.entries+1,
173 sizeof(entry0)*(LDT_DIRECT_ENTRIES-1));
174 }
175 ldt->entry_count = (i + 1) * LDT_ENTRIES_PER_PAGE;
176 }
177 }
178 if (ldt->entry_count <= ldt_info.entry_number)
179 ldt->entry_count = ldt_info.entry_number + 1;
180
181 if (ldt->entry_count <= LDT_DIRECT_ENTRIES)
182 ldt_p = ldt->u.entries + ldt_info.entry_number;
183 else
184 ldt_p = ldt->u.pages[ldt_info.entry_number/LDT_ENTRIES_PER_PAGE] +
185 ldt_info.entry_number%LDT_ENTRIES_PER_PAGE;
186
187 if (ldt_info.base_addr == 0 && ldt_info.limit == 0 &&
188 (func == 1 || LDT_empty(&ldt_info))) {
189 ldt_p->a = 0;
190 ldt_p->b = 0;
191 }
192 else{
193 if (func == 1)
194 ldt_info.useable = 0;
195 ldt_p->a = LDT_entry_a(&ldt_info);
196 ldt_p->b = LDT_entry_b(&ldt_info);
197 }
198 err = 0;
199
200out_unlock:
201 mutex_unlock(&ldt->lock);
202out:
203 return err;
204}
205
206static long do_modify_ldt_skas(int func, void __user *ptr,
207 unsigned long bytecount)
208{
209 int ret = -ENOSYS;
210
211 switch (func) {
212 case 0:
213 ret = read_ldt(ptr, bytecount);
214 break;
215 case 1:
216 case 0x11:
217 ret = write_ldt(ptr, bytecount, func);
218 break;
219 case 2:
220 ret = read_default_ldt(ptr, bytecount);
221 break;
222 }
223 return ret;
224}
225
226static DEFINE_SPINLOCK(host_ldt_lock);
227static short dummy_list[9] = {0, -1};
228static short * host_ldt_entries = NULL;
229
230static void ldt_get_host_info(void)
231{
232 long ret;
233 struct ldt_entry * ldt;
234 short *tmp;
235 int i, size, k, order;
236
237 spin_lock(&host_ldt_lock);
238
239 if (host_ldt_entries != NULL) {
240 spin_unlock(&host_ldt_lock);
241 return;
242 }
243 host_ldt_entries = dummy_list+1;
244
245 spin_unlock(&host_ldt_lock);
246
247 for (i = LDT_PAGES_MAX-1, order=0; i; i>>=1, order++)
248 ;
249
250 ldt = (struct ldt_entry *)
251 __get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
252 if (ldt == NULL) {
253 printk(KERN_ERR "ldt_get_host_info: couldn't allocate buffer "
254 "for host ldt\n");
255 return;
256 }
257
258 ret = modify_ldt(0, ldt, (1<<order)*PAGE_SIZE);
259 if (ret < 0) {
260 printk(KERN_ERR "ldt_get_host_info: couldn't read host ldt\n");
261 goto out_free;
262 }
263 if (ret == 0) {
264 /* default_ldt is active, simply write an empty entry 0 */
265 host_ldt_entries = dummy_list;
266 goto out_free;
267 }
268
269 for (i=0, size=0; i<ret/LDT_ENTRY_SIZE; i++) {
270 if (ldt[i].a != 0 || ldt[i].b != 0)
271 size++;
272 }
273
274 if (size < ARRAY_SIZE(dummy_list))
275 host_ldt_entries = dummy_list;
276 else {
277 size = (size + 1) * sizeof(dummy_list[0]);
278 tmp = kmalloc(size, GFP_KERNEL);
279 if (tmp == NULL) {
280 printk(KERN_ERR "ldt_get_host_info: couldn't allocate "
281 "host ldt list\n");
282 goto out_free;
283 }
284 host_ldt_entries = tmp;
285 }
286
287 for (i=0, k=0; i<ret/LDT_ENTRY_SIZE; i++) {
288 if (ldt[i].a != 0 || ldt[i].b != 0)
289 host_ldt_entries[k++] = i;
290 }
291 host_ldt_entries[k] = -1;
292
293out_free:
294 free_pages((unsigned long)ldt, order);
295}
296
297long init_new_ldt(struct mm_context *new_mm, struct mm_context *from_mm)
298{
299 struct user_desc desc;
300 short * num_p;
301 int i;
302 long page, err=0;
303 void *addr = NULL;
304
305
306 mutex_init(&new_mm->arch.ldt.lock);
307
308 if (!from_mm) {
309 memset(&desc, 0, sizeof(desc));
310 /*
311 * Now we try to retrieve info about the ldt, we
312 * inherited from the host. All ldt-entries found
313 * will be reset in the following loop
314 */
315 ldt_get_host_info();
316 for (num_p=host_ldt_entries; *num_p != -1; num_p++) {
317 desc.entry_number = *num_p;
318 err = write_ldt_entry(&new_mm->id, 1, &desc,
319 &addr, *(num_p + 1) == -1);
320 if (err)
321 break;
322 }
323 new_mm->arch.ldt.entry_count = 0;
324
325 goto out;
326 }
327
328 /*
329 * Our local LDT is used to supply the data for
330 * modify_ldt(READLDT), if PTRACE_LDT isn't available,
331 * i.e., we have to use the stub for modify_ldt, which
332 * can't handle the big read buffer of up to 64kB.
333 */
334 mutex_lock(&from_mm->arch.ldt.lock);
335 if (from_mm->arch.ldt.entry_count <= LDT_DIRECT_ENTRIES)
336 memcpy(new_mm->arch.ldt.u.entries, from_mm->arch.ldt.u.entries,
337 sizeof(new_mm->arch.ldt.u.entries));
338 else {
339 i = from_mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
340 while (i-->0) {
341 page = __get_free_page(GFP_KERNEL|__GFP_ZERO);
342 if (!page) {
343 err = -ENOMEM;
344 break;
345 }
346 new_mm->arch.ldt.u.pages[i] =
347 (struct ldt_entry *) page;
348 memcpy(new_mm->arch.ldt.u.pages[i],
349 from_mm->arch.ldt.u.pages[i], PAGE_SIZE);
350 }
351 }
352 new_mm->arch.ldt.entry_count = from_mm->arch.ldt.entry_count;
353 mutex_unlock(&from_mm->arch.ldt.lock);
354
355 out:
356 return err;
357}
358
359
360void free_ldt(struct mm_context *mm)
361{
362 int i;
363
364 if (mm->arch.ldt.entry_count > LDT_DIRECT_ENTRIES) {
365 i = mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
366 while (i-- > 0)
367 free_page((long) mm->arch.ldt.u.pages[i]);
368 }
369 mm->arch.ldt.entry_count = 0;
370}
371
372int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount)
373{
374 return do_modify_ldt_skas(func, ptr, bytecount);
375}
1/*
2 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <linux/mm.h>
7#include <linux/sched.h>
8#include <linux/slab.h>
9#include <linux/syscalls.h>
10#include <linux/uaccess.h>
11#include <asm/unistd.h>
12#include <os.h>
13#include <skas.h>
14#include <sysdep/tls.h>
15
16static inline int modify_ldt (int func, void *ptr, unsigned long bytecount)
17{
18 return syscall(__NR_modify_ldt, func, ptr, bytecount);
19}
20
21static long write_ldt_entry(struct mm_id *mm_idp, int func,
22 struct user_desc *desc, void **addr, int done)
23{
24 long res;
25 void *stub_addr;
26 res = syscall_stub_data(mm_idp, (unsigned long *)desc,
27 (sizeof(*desc) + sizeof(long) - 1) &
28 ~(sizeof(long) - 1),
29 addr, &stub_addr);
30 if (!res) {
31 unsigned long args[] = { func,
32 (unsigned long)stub_addr,
33 sizeof(*desc),
34 0, 0, 0 };
35 res = run_syscall_stub(mm_idp, __NR_modify_ldt, args,
36 0, addr, done);
37 }
38
39 return res;
40}
41
42/*
43 * In skas mode, we hold our own ldt data in UML.
44 * Thus, the code implementing sys_modify_ldt_skas
45 * is very similar to (and mostly stolen from) sys_modify_ldt
46 * for arch/i386/kernel/ldt.c
47 * The routines copied and modified in part are:
48 * - read_ldt
49 * - read_default_ldt
50 * - write_ldt
51 * - sys_modify_ldt_skas
52 */
53
54static int read_ldt(void __user * ptr, unsigned long bytecount)
55{
56 int i, err = 0;
57 unsigned long size;
58 uml_ldt_t *ldt = ¤t->mm->context.arch.ldt;
59
60 if (!ldt->entry_count)
61 goto out;
62 if (bytecount > LDT_ENTRY_SIZE*LDT_ENTRIES)
63 bytecount = LDT_ENTRY_SIZE*LDT_ENTRIES;
64 err = bytecount;
65
66 mutex_lock(&ldt->lock);
67 if (ldt->entry_count <= LDT_DIRECT_ENTRIES) {
68 size = LDT_ENTRY_SIZE*LDT_DIRECT_ENTRIES;
69 if (size > bytecount)
70 size = bytecount;
71 if (copy_to_user(ptr, ldt->u.entries, size))
72 err = -EFAULT;
73 bytecount -= size;
74 ptr += size;
75 }
76 else {
77 for (i=0; i<ldt->entry_count/LDT_ENTRIES_PER_PAGE && bytecount;
78 i++) {
79 size = PAGE_SIZE;
80 if (size > bytecount)
81 size = bytecount;
82 if (copy_to_user(ptr, ldt->u.pages[i], size)) {
83 err = -EFAULT;
84 break;
85 }
86 bytecount -= size;
87 ptr += size;
88 }
89 }
90 mutex_unlock(&ldt->lock);
91
92 if (bytecount == 0 || err == -EFAULT)
93 goto out;
94
95 if (clear_user(ptr, bytecount))
96 err = -EFAULT;
97
98out:
99 return err;
100}
101
102static int read_default_ldt(void __user * ptr, unsigned long bytecount)
103{
104 int err;
105
106 if (bytecount > 5*LDT_ENTRY_SIZE)
107 bytecount = 5*LDT_ENTRY_SIZE;
108
109 err = bytecount;
110 /*
111 * UML doesn't support lcall7 and lcall27.
112 * So, we don't really have a default ldt, but emulate
113 * an empty ldt of common host default ldt size.
114 */
115 if (clear_user(ptr, bytecount))
116 err = -EFAULT;
117
118 return err;
119}
120
121static int write_ldt(void __user * ptr, unsigned long bytecount, int func)
122{
123 uml_ldt_t *ldt = ¤t->mm->context.arch.ldt;
124 struct mm_id * mm_idp = ¤t->mm->context.id;
125 int i, err;
126 struct user_desc ldt_info;
127 struct ldt_entry entry0, *ldt_p;
128 void *addr = NULL;
129
130 err = -EINVAL;
131 if (bytecount != sizeof(ldt_info))
132 goto out;
133 err = -EFAULT;
134 if (copy_from_user(&ldt_info, ptr, sizeof(ldt_info)))
135 goto out;
136
137 err = -EINVAL;
138 if (ldt_info.entry_number >= LDT_ENTRIES)
139 goto out;
140 if (ldt_info.contents == 3) {
141 if (func == 1)
142 goto out;
143 if (ldt_info.seg_not_present == 0)
144 goto out;
145 }
146
147 mutex_lock(&ldt->lock);
148
149 err = write_ldt_entry(mm_idp, func, &ldt_info, &addr, 1);
150 if (err)
151 goto out_unlock;
152
153 if (ldt_info.entry_number >= ldt->entry_count &&
154 ldt_info.entry_number >= LDT_DIRECT_ENTRIES) {
155 for (i=ldt->entry_count/LDT_ENTRIES_PER_PAGE;
156 i*LDT_ENTRIES_PER_PAGE <= ldt_info.entry_number;
157 i++) {
158 if (i == 0)
159 memcpy(&entry0, ldt->u.entries,
160 sizeof(entry0));
161 ldt->u.pages[i] = (struct ldt_entry *)
162 __get_free_page(GFP_KERNEL|__GFP_ZERO);
163 if (!ldt->u.pages[i]) {
164 err = -ENOMEM;
165 /* Undo the change in host */
166 memset(&ldt_info, 0, sizeof(ldt_info));
167 write_ldt_entry(mm_idp, 1, &ldt_info, &addr, 1);
168 goto out_unlock;
169 }
170 if (i == 0) {
171 memcpy(ldt->u.pages[0], &entry0,
172 sizeof(entry0));
173 memcpy(ldt->u.pages[0]+1, ldt->u.entries+1,
174 sizeof(entry0)*(LDT_DIRECT_ENTRIES-1));
175 }
176 ldt->entry_count = (i + 1) * LDT_ENTRIES_PER_PAGE;
177 }
178 }
179 if (ldt->entry_count <= ldt_info.entry_number)
180 ldt->entry_count = ldt_info.entry_number + 1;
181
182 if (ldt->entry_count <= LDT_DIRECT_ENTRIES)
183 ldt_p = ldt->u.entries + ldt_info.entry_number;
184 else
185 ldt_p = ldt->u.pages[ldt_info.entry_number/LDT_ENTRIES_PER_PAGE] +
186 ldt_info.entry_number%LDT_ENTRIES_PER_PAGE;
187
188 if (ldt_info.base_addr == 0 && ldt_info.limit == 0 &&
189 (func == 1 || LDT_empty(&ldt_info))) {
190 ldt_p->a = 0;
191 ldt_p->b = 0;
192 }
193 else{
194 if (func == 1)
195 ldt_info.useable = 0;
196 ldt_p->a = LDT_entry_a(&ldt_info);
197 ldt_p->b = LDT_entry_b(&ldt_info);
198 }
199 err = 0;
200
201out_unlock:
202 mutex_unlock(&ldt->lock);
203out:
204 return err;
205}
206
207static long do_modify_ldt_skas(int func, void __user *ptr,
208 unsigned long bytecount)
209{
210 int ret = -ENOSYS;
211
212 switch (func) {
213 case 0:
214 ret = read_ldt(ptr, bytecount);
215 break;
216 case 1:
217 case 0x11:
218 ret = write_ldt(ptr, bytecount, func);
219 break;
220 case 2:
221 ret = read_default_ldt(ptr, bytecount);
222 break;
223 }
224 return ret;
225}
226
227static DEFINE_SPINLOCK(host_ldt_lock);
228static short dummy_list[9] = {0, -1};
229static short * host_ldt_entries = NULL;
230
231static void ldt_get_host_info(void)
232{
233 long ret;
234 struct ldt_entry * ldt;
235 short *tmp;
236 int i, size, k, order;
237
238 spin_lock(&host_ldt_lock);
239
240 if (host_ldt_entries != NULL) {
241 spin_unlock(&host_ldt_lock);
242 return;
243 }
244 host_ldt_entries = dummy_list+1;
245
246 spin_unlock(&host_ldt_lock);
247
248 for (i = LDT_PAGES_MAX-1, order=0; i; i>>=1, order++)
249 ;
250
251 ldt = (struct ldt_entry *)
252 __get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
253 if (ldt == NULL) {
254 printk(KERN_ERR "ldt_get_host_info: couldn't allocate buffer "
255 "for host ldt\n");
256 return;
257 }
258
259 ret = modify_ldt(0, ldt, (1<<order)*PAGE_SIZE);
260 if (ret < 0) {
261 printk(KERN_ERR "ldt_get_host_info: couldn't read host ldt\n");
262 goto out_free;
263 }
264 if (ret == 0) {
265 /* default_ldt is active, simply write an empty entry 0 */
266 host_ldt_entries = dummy_list;
267 goto out_free;
268 }
269
270 for (i=0, size=0; i<ret/LDT_ENTRY_SIZE; i++) {
271 if (ldt[i].a != 0 || ldt[i].b != 0)
272 size++;
273 }
274
275 if (size < ARRAY_SIZE(dummy_list))
276 host_ldt_entries = dummy_list;
277 else {
278 size = (size + 1) * sizeof(dummy_list[0]);
279 tmp = kmalloc(size, GFP_KERNEL);
280 if (tmp == NULL) {
281 printk(KERN_ERR "ldt_get_host_info: couldn't allocate "
282 "host ldt list\n");
283 goto out_free;
284 }
285 host_ldt_entries = tmp;
286 }
287
288 for (i=0, k=0; i<ret/LDT_ENTRY_SIZE; i++) {
289 if (ldt[i].a != 0 || ldt[i].b != 0)
290 host_ldt_entries[k++] = i;
291 }
292 host_ldt_entries[k] = -1;
293
294out_free:
295 free_pages((unsigned long)ldt, order);
296}
297
298long init_new_ldt(struct mm_context *new_mm, struct mm_context *from_mm)
299{
300 struct user_desc desc;
301 short * num_p;
302 int i;
303 long page, err=0;
304 void *addr = NULL;
305
306
307 mutex_init(&new_mm->arch.ldt.lock);
308
309 if (!from_mm) {
310 memset(&desc, 0, sizeof(desc));
311 /*
312 * Now we try to retrieve info about the ldt, we
313 * inherited from the host. All ldt-entries found
314 * will be reset in the following loop
315 */
316 ldt_get_host_info();
317 for (num_p=host_ldt_entries; *num_p != -1; num_p++) {
318 desc.entry_number = *num_p;
319 err = write_ldt_entry(&new_mm->id, 1, &desc,
320 &addr, *(num_p + 1) == -1);
321 if (err)
322 break;
323 }
324 new_mm->arch.ldt.entry_count = 0;
325
326 goto out;
327 }
328
329 /*
330 * Our local LDT is used to supply the data for
331 * modify_ldt(READLDT), if PTRACE_LDT isn't available,
332 * i.e., we have to use the stub for modify_ldt, which
333 * can't handle the big read buffer of up to 64kB.
334 */
335 mutex_lock(&from_mm->arch.ldt.lock);
336 if (from_mm->arch.ldt.entry_count <= LDT_DIRECT_ENTRIES)
337 memcpy(new_mm->arch.ldt.u.entries, from_mm->arch.ldt.u.entries,
338 sizeof(new_mm->arch.ldt.u.entries));
339 else {
340 i = from_mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
341 while (i-->0) {
342 page = __get_free_page(GFP_KERNEL|__GFP_ZERO);
343 if (!page) {
344 err = -ENOMEM;
345 break;
346 }
347 new_mm->arch.ldt.u.pages[i] =
348 (struct ldt_entry *) page;
349 memcpy(new_mm->arch.ldt.u.pages[i],
350 from_mm->arch.ldt.u.pages[i], PAGE_SIZE);
351 }
352 }
353 new_mm->arch.ldt.entry_count = from_mm->arch.ldt.entry_count;
354 mutex_unlock(&from_mm->arch.ldt.lock);
355
356 out:
357 return err;
358}
359
360
361void free_ldt(struct mm_context *mm)
362{
363 int i;
364
365 if (mm->arch.ldt.entry_count > LDT_DIRECT_ENTRIES) {
366 i = mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
367 while (i-- > 0)
368 free_page((long) mm->arch.ldt.u.pages[i]);
369 }
370 mm->arch.ldt.entry_count = 0;
371}
372
373SYSCALL_DEFINE3(modify_ldt, int , func , void __user * , ptr ,
374 unsigned long , bytecount)
375{
376 /* See non-um modify_ldt() for why we do this cast */
377 return (unsigned int)do_modify_ldt_skas(func, ptr, bytecount);
378}