1 #ifndef _ARCH_POWERPC_UACCESS_H
2 #define _ARCH_POWERPC_UACCESS_H
7 #include <linux/sched.h>
8 #include <linux/errno.h>
9 #include <asm/processor.h>
13 #define VERIFY_WRITE 1
16 * The fs value determines whether argument validity checking should be
17 * performed or not. If get_fs() == USER_DS, checking is performed, with
18 * get_fs() == KERNEL_DS, checking is bypassed.
20 * For historical reasons, these macros are grossly misnamed.
22 * The fs/ds values are now the highest legal address in the "segment".
23 * This simplifies the checking in the routines below.
26 #define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
28 #define KERNEL_DS MAKE_MM_SEG(~0UL)
30 /* We use TASK_SIZE_USER64 as TASK_SIZE is not constant */
31 #define USER_DS MAKE_MM_SEG(TASK_SIZE_USER64 - 1)
33 #define USER_DS MAKE_MM_SEG(TASK_SIZE - 1)
36 #define get_ds() (KERNEL_DS)
37 #define get_fs() (current->thread.fs)
38 #define set_fs(val) (current->thread.fs = (val))
40 #define segment_eq(a, b) ((a).seg == (b).seg)
44 * This check is sufficient because there is a large enough
45 * gap between user addresses and the kernel addresses
47 #define __access_ok(addr, size, segment) \
48 (((addr) <= (segment).seg) && ((size) <= (segment).seg))
52 #define __access_ok(addr, size, segment) \
53 (((addr) <= (segment).seg) && \
54 (((size) == 0) || (((size) - 1) <= ((segment).seg - (addr)))))
58 #define access_ok(type, addr, size) \
59 (__chk_user_ptr(addr), \
60 __access_ok((__force unsigned long)(addr), (size), get_fs()))
63 * The exception table consists of pairs of addresses: the first is the
64 * address of an instruction that is allowed to fault, and the second is
65 * the address at which the program should continue. No registers are
66 * modified, so it is entirely up to the continuation code to figure out
69 * All the routines below use bits of fixup code that are out of line
70 * with the main instruction path. This means when everything is well,
71 * we don't even have to jump over them. Further, they do not intrude
72 * on our cache or tlb entries.
75 struct exception_table_entry
{
81 * These are the main single-value transfer routines. They automatically
82 * use the right size if we just have the right pointer type.
84 * This gets kind of ugly. We want to return _two_ values in "get_user()"
85 * and yet we don't want to do any pointers, because that is too much
86 * of a performance impact. Thus we have a few rather ugly macros here,
87 * and hide all the ugliness from the user.
89 * The "__xxx" versions of the user access functions are versions that
90 * do not verify the address space, that must have been done previously
91 * with a separate "access_ok()" call (this is used when we do multiple
92 * accesses to the same area of user memory).
94 * As we use the same address space for kernel and user data on the
95 * PowerPC, we can just do these as direct assignments. (Of course, the
96 * exception handling means that it's no longer "just"...)
98 * The "user64" versions of the user access functions are versions that
99 * allow access of 64-bit data. The "get_user" functions do not
100 * properly handle 64-bit data because the value gets down cast to a long.
101 * The "put_user" functions already handle 64-bit data properly but we add
102 * "user64" versions for completeness
104 #define get_user(x, ptr) \
105 __get_user_check((x), (ptr), sizeof(*(ptr)))
106 #define put_user(x, ptr) \
107 __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
109 #define __get_user(x, ptr) \
110 __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
111 #define __put_user(x, ptr) \
112 __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
114 #ifndef __powerpc64__
115 #define __get_user64(x, ptr) \
116 __get_user64_nocheck((x), (ptr), sizeof(*(ptr)))
117 #define __put_user64(x, ptr) __put_user(x, ptr)
120 #define __get_user_inatomic(x, ptr) \
121 __get_user_nosleep((x), (ptr), sizeof(*(ptr)))
122 #define __put_user_inatomic(x, ptr) \
123 __put_user_nosleep((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
125 #define __get_user_unaligned __get_user
126 #define __put_user_unaligned __put_user
128 extern long __put_user_bad(void);
131 * We don't tell gcc that we are accessing memory, but this is OK
132 * because we do not write to any memory gcc knows about, so there
133 * are no aliasing issues.
135 #define __put_user_asm(x, addr, err, op) \
136 __asm__ __volatile__( \
137 "1: " op " %1,0(%2) # put_user\n" \
139 ".section .fixup,\"ax\"\n" \
143 ".section __ex_table,\"a\"\n" \
148 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\
149 "i"(sizeof(unsigned long)))
152 #define __put_user_asm2(x, ptr, retval) \
153 __put_user_asm(x, ptr, retval, "std")
154 #else /* __powerpc64__ */
155 #define __put_user_asm2(x, addr, err) \
156 __asm__ __volatile__( \
157 "1: stw %1,0(%2)\n" \
158 "2: stw %1+1,4(%2)\n" \
160 ".section .fixup,\"ax\"\n" \
164 ".section __ex_table,\"a\"\n" \
170 : "r" (x), "b" (addr), "i" (-EFAULT), "0" (err),\
171 "i"(sizeof(unsigned long)))
172 #endif /* __powerpc64__ */
174 #define __put_user_size(x, ptr, size, retval) \
178 case 1: __put_user_asm(x, ptr, retval, "stb"); break; \
179 case 2: __put_user_asm(x, ptr, retval, "sth"); break; \
180 case 4: __put_user_asm(x, ptr, retval, "stw"); break; \
181 case 8: __put_user_asm2(x, ptr, retval); break; \
182 default: __put_user_bad(); \
186 #define __put_user_nocheck(x, ptr, size) \
189 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
190 if (!is_kernel_addr((unsigned long)__pu_addr)) \
192 __chk_user_ptr(ptr); \
193 __put_user_size((x), __pu_addr, (size), __pu_err); \
197 #define __put_user_check(x, ptr, size) \
199 long __pu_err = -EFAULT; \
200 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
202 if (access_ok(VERIFY_WRITE, __pu_addr, size)) \
203 __put_user_size((x), __pu_addr, (size), __pu_err); \
207 #define __put_user_nosleep(x, ptr, size) \
210 __typeof__(*(ptr)) __user *__pu_addr = (ptr); \
211 __chk_user_ptr(ptr); \
212 __put_user_size((x), __pu_addr, (size), __pu_err); \
217 extern long __get_user_bad(void);
219 #define __get_user_asm(x, addr, err, op) \
220 __asm__ __volatile__( \
221 "1: "op" %1,0(%2) # get_user\n" \
223 ".section .fixup,\"ax\"\n" \
228 ".section __ex_table,\"a\"\n" \
232 : "=r" (err), "=r" (x) \
233 : "b" (addr), "i" (-EFAULT), "0" (err), \
234 "i"(sizeof(unsigned long)))
237 #define __get_user_asm2(x, addr, err) \
238 __get_user_asm(x, addr, err, "ld")
239 #else /* __powerpc64__ */
240 #define __get_user_asm2(x, addr, err) \
241 __asm__ __volatile__( \
242 "1: lwz %1,0(%2)\n" \
243 "2: lwz %1+1,4(%2)\n" \
245 ".section .fixup,\"ax\"\n" \
251 ".section __ex_table,\"a\"\n" \
256 : "=r" (err), "=&r" (x) \
257 : "b" (addr), "i" (-EFAULT), "0" (err), \
258 "i"(sizeof(unsigned long)))
259 #endif /* __powerpc64__ */
261 #define __get_user_size(x, ptr, size, retval) \
264 __chk_user_ptr(ptr); \
265 if (size > sizeof(x)) \
266 (x) = __get_user_bad(); \
268 case 1: __get_user_asm(x, ptr, retval, "lbz"); break; \
269 case 2: __get_user_asm(x, ptr, retval, "lhz"); break; \
270 case 4: __get_user_asm(x, ptr, retval, "lwz"); break; \
271 case 8: __get_user_asm2(x, ptr, retval); break; \
272 default: (x) = __get_user_bad(); \
276 #define __get_user_nocheck(x, ptr, size) \
279 unsigned long __gu_val; \
280 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
281 __chk_user_ptr(ptr); \
282 if (!is_kernel_addr((unsigned long)__gu_addr)) \
284 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
285 (x) = (__typeof__(*(ptr)))__gu_val; \
289 #ifndef __powerpc64__
290 #define __get_user64_nocheck(x, ptr, size) \
293 long long __gu_val; \
294 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
295 __chk_user_ptr(ptr); \
296 if (!is_kernel_addr((unsigned long)__gu_addr)) \
298 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
299 (x) = (__typeof__(*(ptr)))__gu_val; \
302 #endif /* __powerpc64__ */
304 #define __get_user_check(x, ptr, size) \
306 long __gu_err = -EFAULT; \
307 unsigned long __gu_val = 0; \
308 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
310 if (access_ok(VERIFY_READ, __gu_addr, (size))) \
311 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
312 (x) = (__typeof__(*(ptr)))__gu_val; \
316 #define __get_user_nosleep(x, ptr, size) \
319 unsigned long __gu_val; \
320 const __typeof__(*(ptr)) __user *__gu_addr = (ptr); \
321 __chk_user_ptr(ptr); \
322 __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \
323 (x) = (__typeof__(*(ptr)))__gu_val; \
328 /* more complex routines */
330 extern unsigned long __copy_tofrom_user(void __user
*to
,
331 const void __user
*from
, unsigned long size
);
333 #ifndef __powerpc64__
335 static inline unsigned long copy_from_user(void *to
,
336 const void __user
*from
, unsigned long n
)
340 if (access_ok(VERIFY_READ
, from
, n
))
341 return __copy_tofrom_user((__force
void __user
*)to
, from
, n
);
342 if ((unsigned long)from
< TASK_SIZE
) {
343 over
= (unsigned long)from
+ n
- TASK_SIZE
;
344 return __copy_tofrom_user((__force
void __user
*)to
, from
,
350 static inline unsigned long copy_to_user(void __user
*to
,
351 const void *from
, unsigned long n
)
355 if (access_ok(VERIFY_WRITE
, to
, n
))
356 return __copy_tofrom_user(to
, (__force
void __user
*)from
, n
);
357 if ((unsigned long)to
< TASK_SIZE
) {
358 over
= (unsigned long)to
+ n
- TASK_SIZE
;
359 return __copy_tofrom_user(to
, (__force
void __user
*)from
,
365 #else /* __powerpc64__ */
367 #define __copy_in_user(to, from, size) \
368 __copy_tofrom_user((to), (from), (size))
370 extern unsigned long copy_from_user(void *to
, const void __user
*from
,
372 extern unsigned long copy_to_user(void __user
*to
, const void *from
,
374 extern unsigned long copy_in_user(void __user
*to
, const void __user
*from
,
377 #endif /* __powerpc64__ */
379 static inline unsigned long __copy_from_user_inatomic(void *to
,
380 const void __user
*from
, unsigned long n
)
382 if (__builtin_constant_p(n
) && (n
<= 8)) {
387 __get_user_size(*(u8
*)to
, from
, 1, ret
);
390 __get_user_size(*(u16
*)to
, from
, 2, ret
);
393 __get_user_size(*(u32
*)to
, from
, 4, ret
);
396 __get_user_size(*(u64
*)to
, from
, 8, ret
);
402 return __copy_tofrom_user((__force
void __user
*)to
, from
, n
);
405 static inline unsigned long __copy_to_user_inatomic(void __user
*to
,
406 const void *from
, unsigned long n
)
408 if (__builtin_constant_p(n
) && (n
<= 8)) {
413 __put_user_size(*(u8
*)from
, (u8 __user
*)to
, 1, ret
);
416 __put_user_size(*(u16
*)from
, (u16 __user
*)to
, 2, ret
);
419 __put_user_size(*(u32
*)from
, (u32 __user
*)to
, 4, ret
);
422 __put_user_size(*(u64
*)from
, (u64 __user
*)to
, 8, ret
);
428 return __copy_tofrom_user(to
, (__force
const void __user
*)from
, n
);
431 static inline unsigned long __copy_from_user(void *to
,
432 const void __user
*from
, unsigned long size
)
435 return __copy_from_user_inatomic(to
, from
, size
);
438 static inline unsigned long __copy_to_user(void __user
*to
,
439 const void *from
, unsigned long size
)
442 return __copy_to_user_inatomic(to
, from
, size
);
445 extern unsigned long __clear_user(void __user
*addr
, unsigned long size
);
447 static inline unsigned long clear_user(void __user
*addr
, unsigned long size
)
450 if (likely(access_ok(VERIFY_WRITE
, addr
, size
)))
451 return __clear_user(addr
, size
);
452 if ((unsigned long)addr
< TASK_SIZE
) {
453 unsigned long over
= (unsigned long)addr
+ size
- TASK_SIZE
;
454 return __clear_user(addr
, size
- over
) + over
;
459 extern int __strncpy_from_user(char *dst
, const char __user
*src
, long count
);
461 static inline long strncpy_from_user(char *dst
, const char __user
*src
,
465 if (likely(access_ok(VERIFY_READ
, src
, 1)))
466 return __strncpy_from_user(dst
, src
, count
);
471 * Return the size of a string (including the ending 0)
475 extern int __strnlen_user(const char __user
*str
, long len
, unsigned long top
);
478 * Returns the length of the string at str (including the null byte),
479 * or 0 if we hit a page we can't access,
480 * or something > len if we didn't find a null byte.
482 * The `top' parameter to __strnlen_user is to make sure that
483 * we can never overflow from the user area into kernel space.
485 static inline int strnlen_user(const char __user
*str
, long len
)
487 unsigned long top
= current
->thread
.fs
.seg
;
489 if ((unsigned long)str
> top
)
491 return __strnlen_user(str
, len
, top
);
494 #define strlen_user(str) strnlen_user((str), 0x7ffffffe)
496 #endif /* __ASSEMBLY__ */
497 #endif /* __KERNEL__ */
499 #endif /* _ARCH_POWERPC_UACCESS_H */