uaccess.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef __ALPHA_UACCESS_H
  3#define __ALPHA_UACCESS_H
  4
  5#include <asm-generic/access_ok.h>
  6/*
  7 * These are the main single-value transfer routines.  They automatically
  8 * use the right size if we just have the right pointer type.
  9 *
 10 * As the alpha uses the same address space for kernel and user
 11 * data, we can just do these as direct assignments.  (Of course, the
 12 * exception handling means that it's no longer "just"...)
 13 *
 14 * Careful to not
 15 * (a) re-use the arguments for side effects (sizeof/typeof is ok)
 16 * (b) require any knowledge of processes at this stage
 17 */
 18#define put_user(x, ptr) \
 19  __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
 20#define get_user(x, ptr) \
 21  __get_user_check((x), (ptr), sizeof(*(ptr)))
 22
 23/*
 24 * The "__xxx" versions do not do address space checking, useful when
 25 * doing multiple accesses to the same area (the programmer has to do the
 26 * checks by hand with "access_ok()")
 27 */
 28#define __put_user(x, ptr) \
 29  __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)))
 30#define __get_user(x, ptr) \
 31  __get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 32  
 33/*
 34 * The "lda %1, 2b-1b(%0)" bits are magic to get the assembler to
 35 * encode the bits we need for resolving the exception.  See the
 36 * more extensive comments with fixup_inline_exception below for
 37 * more information.
 38 */
 39#define EXC(label,cont,res,err)				\
 40	".section __ex_table,\"a\"\n"			\
 41	"	.long "#label"-.\n"			\
 42	"	lda "#res","#cont"-"#label"("#err")\n"	\
 43	".previous\n"
 44
 45extern void __get_user_unknown(void);
 46
 47#define __get_user_nocheck(x, ptr, size)			\
 48({								\
 49	long __gu_err = 0;					\
 50	unsigned long __gu_val;					\
 51	__chk_user_ptr(ptr);					\
 52	switch (size) {						\
 53	  case 1: __get_user_8(ptr); break;			\
 54	  case 2: __get_user_16(ptr); break;			\
 55	  case 4: __get_user_32(ptr); break;			\
 56	  case 8: __get_user_64(ptr); break;			\
 57	  default: __get_user_unknown(); break;			\
 58	}							\
 59	(x) = (__force __typeof__(*(ptr))) __gu_val;		\
 60	__gu_err;						\
 61})
 62
 63#define __get_user_check(x, ptr, size)				\
 64({								\
 65	long __gu_err = -EFAULT;				\
 66	unsigned long __gu_val = 0;				\
 67	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
 68	if (__access_ok(__gu_addr, size)) {			\
 69		__gu_err = 0;					\
 70		switch (size) {					\
 71		  case 1: __get_user_8(__gu_addr); break;	\
 72		  case 2: __get_user_16(__gu_addr); break;	\
 73		  case 4: __get_user_32(__gu_addr); break;	\
 74		  case 8: __get_user_64(__gu_addr); break;	\
 75		  default: __get_user_unknown(); break;		\
 76		}						\
 77	}							\
 78	(x) = (__force __typeof__(*(ptr))) __gu_val;		\
 79	__gu_err;						\
 80})
 81
 82struct __large_struct { unsigned long buf[100]; };
 83#define __m(x) (*(struct __large_struct __user *)(x))
 84
 85#define __get_user_64(addr)				\
 86	__asm__("1: ldq %0,%2\n"			\
 87	"2:\n"						\
 88	EXC(1b,2b,%0,%1)				\
 89		: "=r"(__gu_val), "=r"(__gu_err)	\
 90		: "m"(__m(addr)), "1"(__gu_err))
 91
 92#define __get_user_32(addr)				\
 93	__asm__("1: ldl %0,%2\n"			\
 94	"2:\n"						\
 95	EXC(1b,2b,%0,%1)				\
 96		: "=r"(__gu_val), "=r"(__gu_err)	\
 97		: "m"(__m(addr)), "1"(__gu_err))
 98
 99#define __get_user_16(addr)				\
100	__asm__("1: ldwu %0,%2\n"			\
101	"2:\n"						\
102	EXC(1b,2b,%0,%1)				\
103		: "=r"(__gu_val), "=r"(__gu_err)	\
104		: "m"(__m(addr)), "1"(__gu_err))
105
106#define __get_user_8(addr)				\
107	__asm__("1: ldbu %0,%2\n"			\
108	"2:\n"						\
109	EXC(1b,2b,%0,%1)				\
110		: "=r"(__gu_val), "=r"(__gu_err)	\
111		: "m"(__m(addr)), "1"(__gu_err))
112
113extern void __put_user_unknown(void);
114
115#define __put_user_nocheck(x, ptr, size)			\
116({								\
117	long __pu_err = 0;					\
118	__chk_user_ptr(ptr);					\
119	switch (size) {						\
120	  case 1: __put_user_8(x, ptr); break;			\
121	  case 2: __put_user_16(x, ptr); break;			\
122	  case 4: __put_user_32(x, ptr); break;			\
123	  case 8: __put_user_64(x, ptr); break;			\
124	  default: __put_user_unknown(); break;			\
125	}							\
126	__pu_err;						\
127})
128
129#define __put_user_check(x, ptr, size)				\
130({								\
131	long __pu_err = -EFAULT;				\
132	__typeof__(*(ptr)) __user *__pu_addr = (ptr);		\
133	if (__access_ok(__pu_addr, size)) {			\
134		__pu_err = 0;					\
135		switch (size) {					\
136		  case 1: __put_user_8(x, __pu_addr); break;	\
137		  case 2: __put_user_16(x, __pu_addr); break;	\
138		  case 4: __put_user_32(x, __pu_addr); break;	\
139		  case 8: __put_user_64(x, __pu_addr); break;	\
140		  default: __put_user_unknown(); break;		\
141		}						\
142	}							\
143	__pu_err;						\
144})
145
146/*
147 * The "__put_user_xx()" macros tell gcc they read from memory
148 * instead of writing: this is because they do not write to
149 * any memory gcc knows about, so there are no aliasing issues
150 */
151#define __put_user_64(x, addr)					\
152__asm__ __volatile__("1: stq %r2,%1\n"				\
153	"2:\n"							\
154	EXC(1b,2b,$31,%0)					\
155		: "=r"(__pu_err)				\
156		: "m" (__m(addr)), "rJ" (x), "0"(__pu_err))
157
158#define __put_user_32(x, addr)					\
159__asm__ __volatile__("1: stl %r2,%1\n"				\
160	"2:\n"							\
161	EXC(1b,2b,$31,%0)					\
162		: "=r"(__pu_err)				\
163		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
164
165#define __put_user_16(x, addr)					\
166__asm__ __volatile__("1: stw %r2,%1\n"				\
167	"2:\n"							\
168	EXC(1b,2b,$31,%0)					\
169		: "=r"(__pu_err)				\
170		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
171
172#define __put_user_8(x, addr)					\
173__asm__ __volatile__("1: stb %r2,%1\n"				\
174	"2:\n"							\
175	EXC(1b,2b,$31,%0)					\
176		: "=r"(__pu_err)				\
177		: "m"(__m(addr)), "rJ"(x), "0"(__pu_err))
178
179/*
180 * Complex access routines
181 */
182
183extern long __copy_user(void *to, const void *from, long len);
184
185static inline unsigned long
186raw_copy_from_user(void *to, const void __user *from, unsigned long len)
187{
188	return __copy_user(to, (__force const void *)from, len);
189}
190
191static inline unsigned long
192raw_copy_to_user(void __user *to, const void *from, unsigned long len)
193{
194	return __copy_user((__force void *)to, from, len);
195}
196
197extern long __clear_user(void __user *to, long len);
198
199static inline long
200clear_user(void __user *to, long len)
201{
202	if (__access_ok(to, len))
203		len = __clear_user(to, len);
204	return len;
205}
206
207extern long strncpy_from_user(char *dest, const char __user *src, long count);
208extern __must_check long strnlen_user(const char __user *str, long n);
209
210#include <asm/extable.h>
211
212#endif /* __ALPHA_UACCESS_H */