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6#include <linux/err.h>
7#include <linux/highmem.h>
8#include <linux/mm.h>
9#include <linux/module.h>
10#include <linux/sched.h>
11#include <asm/current.h>
12#include <asm/page.h>
13#include <kern_util.h>
14#include <asm/futex.h>
15#include <os.h>
16
17pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)
18{
19 pgd_t *pgd;
20 p4d_t *p4d;
21 pud_t *pud;
22 pmd_t *pmd;
23
24 if (mm == NULL)
25 return NULL;
26
27 pgd = pgd_offset(mm, addr);
28 if (!pgd_present(*pgd))
29 return NULL;
30
31 p4d = p4d_offset(pgd, addr);
32 if (!p4d_present(*p4d))
33 return NULL;
34
35 pud = pud_offset(p4d, addr);
36 if (!pud_present(*pud))
37 return NULL;
38
39 pmd = pmd_offset(pud, addr);
40 if (!pmd_present(*pmd))
41 return NULL;
42
43 return pte_offset_kernel(pmd, addr);
44}
45
46static pte_t *maybe_map(unsigned long virt, int is_write)
47{
48 pte_t *pte = virt_to_pte(current->mm, virt);
49 int err, dummy_code;
50
51 if ((pte == NULL) || !pte_present(*pte) ||
52 (is_write && !pte_write(*pte))) {
53 err = handle_page_fault(virt, 0, is_write, 1, &dummy_code);
54 if (err)
55 return NULL;
56 pte = virt_to_pte(current->mm, virt);
57 }
58 if (!pte_present(*pte))
59 pte = NULL;
60
61 return pte;
62}
63
64static int do_op_one_page(unsigned long addr, int len, int is_write,
65 int (*op)(unsigned long addr, int len, void *arg), void *arg)
66{
67 struct page *page;
68 pte_t *pte;
69 int n;
70
71 pte = maybe_map(addr, is_write);
72 if (pte == NULL)
73 return -1;
74
75 page = pte_page(*pte);
76#ifdef CONFIG_64BIT
77 pagefault_disable();
78 addr = (unsigned long) page_address(page) +
79 (addr & ~PAGE_MASK);
80#else
81 addr = (unsigned long) kmap_atomic(page) +
82 (addr & ~PAGE_MASK);
83#endif
84 n = (*op)(addr, len, arg);
85
86#ifdef CONFIG_64BIT
87 pagefault_enable();
88#else
89 kunmap_atomic((void *)addr);
90#endif
91
92 return n;
93}
94
95static long buffer_op(unsigned long addr, int len, int is_write,
96 int (*op)(unsigned long, int, void *), void *arg)
97{
98 long size, remain, n;
99
100 size = min(PAGE_ALIGN(addr) - addr, (unsigned long) len);
101 remain = len;
102
103 n = do_op_one_page(addr, size, is_write, op, arg);
104 if (n != 0) {
105 remain = (n < 0 ? remain : 0);
106 goto out;
107 }
108
109 addr += size;
110 remain -= size;
111 if (remain == 0)
112 goto out;
113
114 while (addr < ((addr + remain) & PAGE_MASK)) {
115 n = do_op_one_page(addr, PAGE_SIZE, is_write, op, arg);
116 if (n != 0) {
117 remain = (n < 0 ? remain : 0);
118 goto out;
119 }
120
121 addr += PAGE_SIZE;
122 remain -= PAGE_SIZE;
123 }
124 if (remain == 0)
125 goto out;
126
127 n = do_op_one_page(addr, remain, is_write, op, arg);
128 if (n != 0) {
129 remain = (n < 0 ? remain : 0);
130 goto out;
131 }
132
133 return 0;
134 out:
135 return remain;
136}
137
138static int copy_chunk_from_user(unsigned long from, int len, void *arg)
139{
140 unsigned long *to_ptr = arg, to = *to_ptr;
141
142 memcpy((void *) to, (void *) from, len);
143 *to_ptr += len;
144 return 0;
145}
146
147unsigned long raw_copy_from_user(void *to, const void __user *from, unsigned long n)
148{
149 return buffer_op((unsigned long) from, n, 0, copy_chunk_from_user, &to);
150}
151EXPORT_SYMBOL(raw_copy_from_user);
152
153static int copy_chunk_to_user(unsigned long to, int len, void *arg)
154{
155 unsigned long *from_ptr = arg, from = *from_ptr;
156
157 memcpy((void *) to, (void *) from, len);
158 *from_ptr += len;
159 return 0;
160}
161
162unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long n)
163{
164 return buffer_op((unsigned long) to, n, 1, copy_chunk_to_user, &from);
165}
166EXPORT_SYMBOL(raw_copy_to_user);
167
168static int strncpy_chunk_from_user(unsigned long from, int len, void *arg)
169{
170 char **to_ptr = arg, *to = *to_ptr;
171 int n;
172
173 strncpy(to, (void *) from, len);
174 n = strnlen(to, len);
175 *to_ptr += n;
176
177 if (n < len)
178 return 1;
179 return 0;
180}
181
182long strncpy_from_user(char *dst, const char __user *src, long count)
183{
184 long n;
185 char *ptr = dst;
186
187 if (!access_ok(src, 1))
188 return -EFAULT;
189 n = buffer_op((unsigned long) src, count, 0, strncpy_chunk_from_user,
190 &ptr);
191 if (n != 0)
192 return -EFAULT;
193 return strnlen(dst, count);
194}
195EXPORT_SYMBOL(strncpy_from_user);
196
197static int clear_chunk(unsigned long addr, int len, void *unused)
198{
199 memset((void *) addr, 0, len);
200 return 0;
201}
202
203unsigned long __clear_user(void __user *mem, unsigned long len)
204{
205 return buffer_op((unsigned long) mem, len, 1, clear_chunk, NULL);
206}
207EXPORT_SYMBOL(__clear_user);
208
209static int strnlen_chunk(unsigned long str, int len, void *arg)
210{
211 int *len_ptr = arg, n;
212
213 n = strnlen((void *) str, len);
214 *len_ptr += n;
215
216 if (n < len)
217 return 1;
218 return 0;
219}
220
221long strnlen_user(const char __user *str, long len)
222{
223 int count = 0, n;
224
225 if (!access_ok(str, 1))
226 return -EFAULT;
227 n = buffer_op((unsigned long) str, len, 0, strnlen_chunk, &count);
228 if (n == 0)
229 return count + 1;
230 return 0;
231}
232EXPORT_SYMBOL(strnlen_user);
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249int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
250{
251 int oldval, ret;
252 struct page *page;
253 unsigned long addr = (unsigned long) uaddr;
254 pte_t *pte;
255
256 ret = -EFAULT;
257 if (!access_ok(uaddr, sizeof(*uaddr)))
258 return -EFAULT;
259 preempt_disable();
260 pte = maybe_map(addr, 1);
261 if (pte == NULL)
262 goto out_inuser;
263
264 page = pte_page(*pte);
265#ifdef CONFIG_64BIT
266 pagefault_disable();
267 addr = (unsigned long) page_address(page) +
268 (((unsigned long) addr) & ~PAGE_MASK);
269#else
270 addr = (unsigned long) kmap_atomic(page) +
271 ((unsigned long) addr & ~PAGE_MASK);
272#endif
273 uaddr = (u32 *) addr;
274 oldval = *uaddr;
275
276 ret = 0;
277
278 switch (op) {
279 case FUTEX_OP_SET:
280 *uaddr = oparg;
281 break;
282 case FUTEX_OP_ADD:
283 *uaddr += oparg;
284 break;
285 case FUTEX_OP_OR:
286 *uaddr |= oparg;
287 break;
288 case FUTEX_OP_ANDN:
289 *uaddr &= ~oparg;
290 break;
291 case FUTEX_OP_XOR:
292 *uaddr ^= oparg;
293 break;
294 default:
295 ret = -ENOSYS;
296 }
297#ifdef CONFIG_64BIT
298 pagefault_enable();
299#else
300 kunmap_atomic((void *)addr);
301#endif
302
303out_inuser:
304 preempt_enable();
305
306 if (ret == 0)
307 *oval = oldval;
308
309 return ret;
310}
311EXPORT_SYMBOL(arch_futex_atomic_op_inuser);
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328int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
329 u32 oldval, u32 newval)
330{
331 struct page *page;
332 pte_t *pte;
333 int ret = -EFAULT;
334
335 if (!access_ok(uaddr, sizeof(*uaddr)))
336 return -EFAULT;
337
338 preempt_disable();
339 pte = maybe_map((unsigned long) uaddr, 1);
340 if (pte == NULL)
341 goto out_inatomic;
342
343 page = pte_page(*pte);
344#ifdef CONFIG_64BIT
345 pagefault_disable();
346 uaddr = page_address(page) + (((unsigned long) uaddr) & ~PAGE_MASK);
347#else
348 uaddr = kmap_atomic(page) + ((unsigned long) uaddr & ~PAGE_MASK);
349#endif
350
351 *uval = *uaddr;
352
353 ret = cmpxchg(uaddr, oldval, newval);
354
355#ifdef CONFIG_64BIT
356 pagefault_enable();
357#else
358 kunmap_atomic(uaddr);
359#endif
360 ret = 0;
361
362out_inatomic:
363 preempt_enable();
364 return ret;
365}
366EXPORT_SYMBOL(futex_atomic_cmpxchg_inatomic);
367
