[mirror_ubuntu-artful-kernel.git] / arch / parisc / include / asm / uaccess.h

#ifndef __PARISC_UACCESS_H
#define __PARISC_UACCESS_H

/*
 * User space memory access functions
 */
#include <asm/page.h>
#include <asm/cache.h>
#include <asm/errno.h>
#include <asm-generic/uaccess-unaligned.h>

#include <linux/bug.h>
#include <linux/string.h>
#include <linux/thread_info.h>

#define VERIFY_READ 0
#define VERIFY_WRITE 1

#define KERNEL_DS	((mm_segment_t){0})
#define USER_DS 	((mm_segment_t){1})

#define segment_eq(a, b) ((a).seg == (b).seg)

#define get_ds()	(KERNEL_DS)
#define get_fs()	(current_thread_info()->addr_limit)
#define set_fs(x)	(current_thread_info()->addr_limit = (x))

/*
 * Note that since kernel addresses are in a separate address space on
 * parisc, we don't need to do anything for access_ok().
 * We just let the page fault handler do the right thing. This also means
 * that put_user is the same as __put_user, etc.
 */

#define access_ok(type, uaddr, size) (1)

#define put_user __put_user
#define get_user __get_user

#if !defined(CONFIG_64BIT)
#define LDD_USER(ptr)		__get_user_asm64(ptr)
#define STD_USER(x, ptr)	__put_user_asm64(x, ptr)
#else
#define LDD_USER(ptr)		__get_user_asm("ldd", ptr)
#define STD_USER(x, ptr)	__put_user_asm("std", x, ptr)
#endif

/*
 * The exception table contains two values: the first is the relative offset to
 * the address of the instruction that is allowed to fault, and the second is
 * the relative offset to the address of the fixup routine. Since relative
 * addresses are used, 32bit values are sufficient even on 64bit kernel.
 */

#define ARCH_HAS_RELATIVE_EXTABLE
struct exception_table_entry {
	int insn;	/* relative address of insn that is allowed to fault. */
	int fixup;	/* relative address of fixup routine */
};

#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
	".section __ex_table,\"aw\"\n"			   \
	".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
	".previous\n"

/*
 * The page fault handler stores, in a per-cpu area, the following information
 * if a fixup routine is available.
 */
struct exception_data {
	unsigned long fault_ip;
	unsigned long fault_gp;
	unsigned long fault_space;
	unsigned long fault_addr;
};

/*
 * load_sr2() preloads the space register %%sr2 - based on the value of
 * get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
 * is 0), or with the current value of %%sr3 to access user space (USER_DS)
 * memory. The following __get_user_asm() and __put_user_asm() functions have
 * %%sr2 hard-coded to access the requested memory.
 */
#define load_sr2() \
	__asm__(" or,=  %0,%%r0,%%r0\n\t"	\
		" mfsp %%sr3,%0\n\t"		\
		" mtsp %0,%%sr2\n\t"		\
		: : "r"(get_fs()) : )

#define __get_user(x, ptr)                               \
({                                                       \
	register long __gu_err __asm__ ("r8") = 0;       \
	register long __gu_val __asm__ ("r9") = 0;       \
							 \
	load_sr2();					 \
	switch (sizeof(*(ptr))) {			 \
	    case 1: __get_user_asm("ldb", ptr); break;   \
	    case 2: __get_user_asm("ldh", ptr); break;   \
	    case 4: __get_user_asm("ldw", ptr); break;   \
	    case 8: LDD_USER(ptr);  break;		 \
	    default: BUILD_BUG(); break;		 \
	}                                                \
							 \
	(x) = (__force __typeof__(*(ptr))) __gu_val;	 \
	__gu_err;                                        \
})

#define __get_user_asm(ldx, ptr)                        \
	__asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t"	\
		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
		: "=r"(__gu_val), "=r"(__gu_err)        \
		: "r"(ptr), "1"(__gu_err)		\
		: "r1");

#if !defined(CONFIG_64BIT)

#define __get_user_asm64(ptr) 				\
	__asm__("\n1:\tldw 0(%%sr2,%2),%0"		\
		"\n2:\tldw 4(%%sr2,%2),%R0\n\t"		\
		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_2)\
		ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_get_user_skip_1)\
		: "=r"(__gu_val), "=r"(__gu_err)	\
		: "r"(ptr), "1"(__gu_err)		\
		: "r1");

#endif /* !defined(CONFIG_64BIT) */


#define __put_user(x, ptr)                                      \
({								\
	register long __pu_err __asm__ ("r8") = 0;      	\
        __typeof__(*(ptr)) __x = (__typeof__(*(ptr)))(x);	\
								\
	load_sr2();						\
	switch (sizeof(*(ptr))) {				\
	    case 1: __put_user_asm("stb", __x, ptr); break;     \
	    case 2: __put_user_asm("sth", __x, ptr); break;     \
	    case 4: __put_user_asm("stw", __x, ptr); break;     \
	    case 8: STD_USER(__x, ptr); break;			\
	    default: BUILD_BUG(); break;			\
	}                                                       \
								\
	__pu_err;						\
})

/*
 * The "__put_user/kernel_asm()" macros tell gcc they read from memory
 * instead of writing. This is because they do not write to any memory
 * gcc knows about, so there are no aliasing issues. These macros must
 * also be aware that "fixup_put_user_skip_[12]" are executed in the
 * context of the fault, and any registers used there must be listed
 * as clobbers. In this case only "r1" is used by the current routines.
 * r8/r9 are already listed as err/val.
 */

#define __put_user_asm(stx, x, ptr)                         \
	__asm__ __volatile__ (                              \
		"\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t"	    \
		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
		: "=r"(__pu_err)                            \
		: "r"(ptr), "r"(x), "0"(__pu_err)	    \
		: "r1")


#if !defined(CONFIG_64BIT)

#define __put_user_asm64(__val, ptr) do {	    	    \
	__asm__ __volatile__ (				    \
		"\n1:\tstw %2,0(%%sr2,%1)"		    \
		"\n2:\tstw %R2,4(%%sr2,%1)\n\t"		    \
		ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
		ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
		: "=r"(__pu_err)                            \
		: "r"(ptr), "r"(__val), "0"(__pu_err) \
		: "r1");				    \
} while (0)

#endif /* !defined(CONFIG_64BIT) */


/*
 * Complex access routines -- external declarations
 */

extern unsigned long lcopy_to_user(void __user *, const void *, unsigned long);
extern unsigned long lcopy_from_user(void *, const void __user *, unsigned long);
extern unsigned long lcopy_in_user(void __user *, const void __user *, unsigned long);
extern long strncpy_from_user(char *, const char __user *, long);
extern unsigned lclear_user(void __user *, unsigned long);
extern long lstrnlen_user(const char __user *, long);
/*
 * Complex access routines -- macros
 */
#define user_addr_max() (~0UL)

#define strnlen_user lstrnlen_user
#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
#define clear_user lclear_user
#define __clear_user lclear_user

unsigned long __must_check __copy_to_user(void __user *dst, const void *src,
					  unsigned long len);
unsigned long __must_check __copy_from_user(void *dst, const void __user *src,
					  unsigned long len);
unsigned long copy_in_user(void __user *dst, const void __user *src,
			   unsigned long len);
#define __copy_in_user copy_in_user
#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

extern void __compiletime_error("usercopy buffer size is too small")
__bad_copy_user(void);

static inline void copy_user_overflow(int size, unsigned long count)
{
	WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
}

static __always_inline unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long n)
{
	int sz = __compiletime_object_size(to);
	unsigned long ret = n;

	if (likely(sz < 0 || sz >= n)) {
		check_object_size(to, n, false);
		ret = __copy_from_user(to, from, n);
	} else if (!__builtin_constant_p(n))
		copy_user_overflow(sz, n);
	else
		__bad_copy_user();

	if (unlikely(ret))
		memset(to + (n - ret), 0, ret);

	return ret;
}

static __always_inline unsigned long __must_check
copy_to_user(void __user *to, const void *from, unsigned long n)
{
	int sz = __compiletime_object_size(from);

	if (likely(sz < 0 || sz >= n)) {
		check_object_size(from, n, true);
		n = __copy_to_user(to, from, n);
	} else if (!__builtin_constant_p(n))
		copy_user_overflow(sz, n);
	else
		__bad_copy_user();

	return n;
}

struct pt_regs;
int fixup_exception(struct pt_regs *regs);

#endif /* __PARISC_UACCESS_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef __PARISC_UACCESS_H
	2	#define __PARISC_UACCESS_H
	3
	4	/*
	5	* User space memory access functions
	6	*/
1da177e4	7	#include <asm/page.h>
1da177e4	8	#include <asm/cache.h>
888c31fc	9	#include <asm/errno.h>
5b17e1cd	10	#include <asm-generic/uaccess-unaligned.h>
1da177e4	11
8dd95c68	12	#include <linux/bug.h>
aace880f	13	#include <linux/string.h>
9e91db6b	14	#include <linux/thread_info.h>
8dd95c68	15
1da177e4 LT	16	#define VERIFY_READ 0
	17	#define VERIFY_WRITE 1
	18
	19	#define KERNEL_DS ((mm_segment_t){0})
	20	#define USER_DS ((mm_segment_t){1})
	21
b9762e7b	22	#define segment_eq(a, b) ((a).seg == (b).seg)
1da177e4 LT	23
	24	#define get_ds() (KERNEL_DS)
	25	#define get_fs() (current_thread_info()->addr_limit)
	26	#define set_fs(x) (current_thread_info()->addr_limit = (x))
	27
	28	/*
	29	* Note that since kernel addresses are in a separate address space on
e49332bd	30	* parisc, we don't need to do anything for access_ok().
1da177e4 LT	31	* We just let the page fault handler do the right thing. This also means
	32	* that put_user is the same as __put_user, etc.
	33	*/
	34
09b871ff	35	#define access_ok(type, uaddr, size) (1)
1da177e4	36
1da177e4 LT	37	#define put_user __put_user
	38	#define get_user __get_user
	39
ca72a223	40	#if !defined(CONFIG_64BIT)
d2ad824f	41	#define LDD_USER(ptr) __get_user_asm64(ptr)
b9762e7b	42	#define STD_USER(x, ptr) __put_user_asm64(x, ptr)
1da177e4	43	#else
b9762e7b	44	#define LDD_USER(ptr) __get_user_asm("ldd", ptr)
b9762e7b	45	#define STD_USER(x, ptr) __put_user_asm("std", x, ptr)
1da177e4 LT	46	#endif
	47
	48	/*
cb910c17 HD	49	* The exception table contains two values: the first is the relative offset to
	50	* the address of the instruction that is allowed to fault, and the second is
	51	* the relative offset to the address of the fixup routine. Since relative
	52	* addresses are used, 32bit values are sufficient even on 64bit kernel.
1da177e4 LT	53	*/
1da177e4 LT	54
0de79858	55	#define ARCH_HAS_RELATIVE_EXTABLE
1da177e4	56	struct exception_table_entry {
0de79858 HD	57	int insn; /* relative address of insn that is allowed to fault. */
0de79858 HD	58	int fixup; /* relative address of fixup routine */
1da177e4 LT	59	};
1da177e4 LT	60
0b3d643f HD	61	#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
0b3d643f HD	62	".section __ex_table,\"aw\"\n" \
0de79858	63	".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
0b3d643f HD	64	".previous\n"
0b3d643f HD	65
1da177e4 LT	66	/*
	67	* The page fault handler stores, in a per-cpu area, the following information
	68	* if a fixup routine is available.
	69	*/
	70	struct exception_data {
	71	unsigned long fault_ip;
2ef4dfd9	72	unsigned long fault_gp;
1da177e4 LT	73	unsigned long fault_space;
	74	unsigned long fault_addr;
	75	};
	76
06bff6b9 HD	77	/*
	78	* load_sr2() preloads the space register %%sr2 - based on the value of
	79	* get_fs() - with either a value of 0 to access kernel space (KERNEL_DS which
	80	* is 0), or with the current value of %%sr3 to access user space (USER_DS)
	81	* memory. The following __get_user_asm() and __put_user_asm() functions have
	82	* %%sr2 hard-coded to access the requested memory.
	83	*/
	84	#define load_sr2() \
	85	__asm__(" or,= %0,%%r0,%%r0\n\t" \
	86	" mfsp %%sr3,%0\n\t" \
	87	" mtsp %0,%%sr2\n\t" \
	88	: : "r"(get_fs()) : )
	89
b9762e7b MT	90	#define __get_user(x, ptr) \
	91	({ \
	92	register long __gu_err __asm__ ("r8") = 0; \
	93	register long __gu_val __asm__ ("r9") = 0; \
	94	\
06bff6b9 HD	95	load_sr2(); \
06bff6b9 HD	96	switch (sizeof(*(ptr))) { \
b9762e7b MT	97	case 1: __get_user_asm("ldb", ptr); break; \
	98	case 2: __get_user_asm("ldh", ptr); break; \
	99	case 4: __get_user_asm("ldw", ptr); break; \
	100	case 8: LDD_USER(ptr); break; \
	101	default: BUILD_BUG(); break; \
b9762e7b MT	102	} \
	103	\
	104	(x) = (__force __typeof__(*(ptr))) __gu_val; \
	105	__gu_err; \
1da177e4 LT	106	})
1da177e4 LT	107
b9762e7b	108	#define __get_user_asm(ldx, ptr) \
06bff6b9	109	__asm__("\n1:\t" ldx "\t0(%%sr2,%2),%0\n\t" \
b9762e7b	110	ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_1)\
1da177e4 LT	111	: "=r"(__gu_val), "=r"(__gu_err) \
	112	: "r"(ptr), "1"(__gu_err) \
	113	: "r1");
1da177e4	114
d2ad824f HD	115	#if !defined(CONFIG_64BIT)
	116
	117	#define __get_user_asm64(ptr) \
	118	__asm__("\n1:\tldw 0(%%sr2,%2),%0" \
	119	"\n2:\tldw 4(%%sr2,%2),%R0\n\t" \
	120	ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_get_user_skip_2)\
	121	ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_get_user_skip_1)\
	122	: "=r"(__gu_val), "=r"(__gu_err) \
	123	: "r"(ptr), "1"(__gu_err) \
	124	: "r1");
	125
	126	#endif /* !defined(CONFIG_64BIT) */
	127
	128
b9762e7b	129	#define __put_user(x, ptr) \
1da177e4 LT	130	({ \
	131	register long __pu_err __asm__ ("r8") = 0; \
	132	__typeof__((ptr)) __x = (__typeof__((ptr)))(x); \
	133	\
06bff6b9 HD	134	load_sr2(); \
06bff6b9 HD	135	switch (sizeof(*(ptr))) { \
b9762e7b MT	136	case 1: __put_user_asm("stb", __x, ptr); break; \
	137	case 2: __put_user_asm("sth", __x, ptr); break; \
	138	case 4: __put_user_asm("stw", __x, ptr); break; \
	139	case 8: STD_USER(__x, ptr); break; \
8dd95c68	140	default: BUILD_BUG(); break; \
1da177e4 LT	141	} \
	142	\
	143	__pu_err; \
	144	})
	145
	146	/*
	147	* The "__put_user/kernel_asm()" macros tell gcc they read from memory
	148	* instead of writing. This is because they do not write to any memory
3fd3a74f CD	149	* gcc knows about, so there are no aliasing issues. These macros must
	150	* also be aware that "fixup_put_user_skip_[12]" are executed in the
	151	* context of the fault, and any registers used there must be listed
	152	* as clobbers. In this case only "r1" is used by the current routines.
	153	* r8/r9 are already listed as err/val.
1da177e4 LT	154	*/
1da177e4 LT	155
b9762e7b	156	#define __put_user_asm(stx, x, ptr) \
1da177e4	157	__asm__ __volatile__ ( \
06bff6b9	158	"\n1:\t" stx "\t%2,0(%%sr2,%1)\n\t" \
b9762e7b	159	ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_1)\
1da177e4 LT	160	: "=r"(__pu_err) \
	161	: "r"(ptr), "r"(x), "0"(__pu_err) \
	162	: "r1")
	163
1da177e4	164
ca72a223	165	#if !defined(CONFIG_64BIT)
94a1981d	166
b9762e7b	167	#define __put_user_asm64(__val, ptr) do { \
1da177e4	168	__asm__ __volatile__ ( \
06bff6b9 HD	169	"\n1:\tstw %2,0(%%sr2,%1)" \
06bff6b9 HD	170	"\n2:\tstw %R2,4(%%sr2,%1)\n\t" \
b9762e7b MT	171	ASM_EXCEPTIONTABLE_ENTRY(1b, fixup_put_user_skip_2)\
b9762e7b MT	172	ASM_EXCEPTIONTABLE_ENTRY(2b, fixup_put_user_skip_1)\
1da177e4	173	: "=r"(__pu_err) \
0f28b628	174	: "r"(ptr), "r"(__val), "0"(__pu_err) \
1da177e4 LT	175	: "r1"); \
	176	} while (0)
	177
ca72a223	178	#endif /* !defined(CONFIG_64BIT) */
1da177e4 LT	179
	180
	181	/*
	182	* Complex access routines -- external declarations
	183	*/
	184
	185	extern unsigned long lcopy_to_user(void __user , const void , unsigned long);
	186	extern unsigned long lcopy_from_user(void , const void __user , unsigned long);
	187	extern unsigned long lcopy_in_user(void __user , const void __user , unsigned long);
b1195c0e	188	extern long strncpy_from_user(char , const char __user , long);
b9762e7b MT	189	extern unsigned lclear_user(void __user *, unsigned long);
b9762e7b MT	190	extern long lstrnlen_user(const char __user *, long);
1da177e4 LT	191	/*
	192	* Complex access routines -- macros
	193	*/
a0ffa8f0	194	#define user_addr_max() (~0UL)
1da177e4	195
1da177e4 LT	196	#define strnlen_user lstrnlen_user
	197	#define strlen_user(str) lstrnlen_user(str, 0x7fffffffL)
	198	#define clear_user lclear_user
	199	#define __clear_user lclear_user
	200
9e91db6b HD	201	unsigned long __must_check __copy_to_user(void __user dst, const void src,
	202	unsigned long len);
	203	unsigned long __must_check __copy_from_user(void dst, const void __user src,
	204	unsigned long len);
	205	unsigned long copy_in_user(void __user dst, const void __user src,
	206	unsigned long len);
1da177e4 LT	207	#define __copy_in_user copy_in_user
	208	#define __copy_to_user_inatomic __copy_to_user
	209	#define __copy_from_user_inatomic __copy_from_user
	210
0d025d27 JP	211	extern void __compiletime_error("usercopy buffer size is too small")
	212	__bad_copy_user(void);
	213
	214	static inline void copy_user_overflow(int size, unsigned long count)
	215	{
	216	WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
	217	}
888c31fc	218
9e91db6b HD	219	static __always_inline unsigned long __must_check
9e91db6b HD	220	copy_from_user(void to, const void __user from, unsigned long n)
888c31fc	221	{
9e91db6b HD	222	int sz = __compiletime_object_size(to);
9e91db6b HD	223	unsigned long ret = n;
888c31fc	224
9e91db6b HD	225	if (likely(sz < 0 \|\| sz >= n)) {
	226	check_object_size(to, n, false);
	227	ret = __copy_from_user(to, from, n);
	228	} else if (!__builtin_constant_p(n))
0d025d27 JP	229	copy_user_overflow(sz, n);
0d025d27 JP	230	else
9e91db6b	231	__bad_copy_user();
888c31fc	232
aace880f AV	233	if (unlikely(ret))
aace880f AV	234	memset(to + (n - ret), 0, ret);
9e91db6b HD	235
	236	return ret;
	237	}
	238
	239	static __always_inline unsigned long __must_check
	240	copy_to_user(void __user to, const void from, unsigned long n)
	241	{
	242	int sz = __compiletime_object_size(from);
	243
	244	if (likely(sz < 0 \|\| sz >= n)) {
	245	check_object_size(from, n, true);
	246	n = __copy_to_user(to, from, n);
	247	} else if (!__builtin_constant_p(n))
	248	copy_user_overflow(sz, n);
	249	else
	250	__bad_copy_user();
	251
	252	return n;
888c31fc HD	253	}
888c31fc HD	254
e448372c	255	struct pt_regs;
c61c25eb KM	256	int fixup_exception(struct pt_regs *regs);
c61c25eb KM	257
1da177e4	258	#endif /* __PARISC_UACCESS_H */