[deliverable/linux.git] / arch / arm / include / asm / uaccess.h

/*
 *  arch/arm/include/asm/uaccess.h
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#ifndef _ASMARM_UACCESS_H
#define _ASMARM_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/string.h>
#include <linux/thread_info.h>
#include <asm/errno.h>
#include <asm/memory.h>
#include <asm/domain.h>
#include <asm/unified.h>
#include <asm/compiler.h>

#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
#include <asm-generic/uaccess-unaligned.h>
#else
#define __get_user_unaligned __get_user
#define __put_user_unaligned __put_user
#endif

#define VERIFY_READ 0
#define VERIFY_WRITE 1

/*
 * The exception table consists of pairs of addresses: the first is the
 * address of an instruction that is allowed to fault, and the second is
 * the address at which the program should continue.  No registers are
 * modified, so it is entirely up to the continuation code to figure out
 * what to do.
 *
 * All the routines below use bits of fixup code that are out of line
 * with the main instruction path.  This means when everything is well,
 * we don't even have to jump over them.  Further, they do not intrude
 * on our cache or tlb entries.
 */

struct exception_table_entry
{
	unsigned long insn, fixup;
};

extern int fixup_exception(struct pt_regs *regs);

/*
 * These two functions allow hooking accesses to userspace to increase
 * system integrity by ensuring that the kernel can not inadvertantly
 * perform such accesses (eg, via list poison values) which could then
 * be exploited for priviledge escalation.
 */
static inline unsigned int uaccess_save_and_enable(void)
{
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
	unsigned int old_domain = get_domain();

	/* Set the current domain access to permit user accesses */
	set_domain((old_domain & ~domain_mask(DOMAIN_USER)) |
		   domain_val(DOMAIN_USER, DOMAIN_CLIENT));

	return old_domain;
#else
	return 0;
#endif
}

static inline void uaccess_restore(unsigned int flags)
{
#ifdef CONFIG_CPU_SW_DOMAIN_PAN
	/* Restore the user access mask */
	set_domain(flags);
#endif
}

/*
 * These two are intentionally not defined anywhere - if the kernel
 * code generates any references to them, that's a bug.
 */
extern int __get_user_bad(void);
extern int __put_user_bad(void);

/*
 * Note that this is actually 0x1,0000,0000
 */
#define KERNEL_DS	0x00000000
#define get_ds()	(KERNEL_DS)

#ifdef CONFIG_MMU

#define USER_DS		TASK_SIZE
#define get_fs()	(current_thread_info()->addr_limit)

static inline void set_fs(mm_segment_t fs)
{
	current_thread_info()->addr_limit = fs;
	modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
}

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

#define __addr_ok(addr) ({ \
	unsigned long flag; \
	__asm__("cmp %2, %0; movlo %0, #0" \
		: "=&r" (flag) \
		: "0" (current_thread_info()->addr_limit), "r" (addr) \
		: "cc"); \
	(flag == 0); })

/* We use 33-bit arithmetic here... */
#define __range_ok(addr, size) ({ \
	unsigned long flag, roksum; \
	__chk_user_ptr(addr);	\
	__asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
		: "=&r" (flag), "=&r" (roksum) \
		: "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
		: "cc"); \
	flag; })

/*
 * Single-value transfer routines.  They automatically use the right
 * size if we just have the right pointer type.  Note that the functions
 * which read from user space (*get_*) need to take care not to leak
 * kernel data even if the calling code is buggy and fails to check
 * the return value.  This means zeroing out the destination variable
 * or buffer on error.  Normally this is done out of line by the
 * fixup code, but there are a few places where it intrudes on the
 * main code path.  When we only write to user space, there is no
 * problem.
 */
extern int __get_user_1(void *);
extern int __get_user_2(void *);
extern int __get_user_4(void *);
extern int __get_user_32t_8(void *);
extern int __get_user_8(void *);
extern int __get_user_64t_1(void *);
extern int __get_user_64t_2(void *);
extern int __get_user_64t_4(void *);

#define __GUP_CLOBBER_1	"lr", "cc"
#ifdef CONFIG_CPU_USE_DOMAINS
#define __GUP_CLOBBER_2	"ip", "lr", "cc"
#else
#define __GUP_CLOBBER_2 "lr", "cc"
#endif
#define __GUP_CLOBBER_4	"lr", "cc"
#define __GUP_CLOBBER_32t_8 "lr", "cc"
#define __GUP_CLOBBER_8	"lr", "cc"

#define __get_user_x(__r2, __p, __e, __l, __s)				\
	   __asm__ __volatile__ (					\
		__asmeq("%0", "r0") __asmeq("%1", "r2")			\
		__asmeq("%3", "r1")					\
		"bl	__get_user_" #__s				\
		: "=&r" (__e), "=r" (__r2)				\
		: "0" (__p), "r" (__l)					\
		: __GUP_CLOBBER_##__s)

/* narrowing a double-word get into a single 32bit word register: */
#ifdef __ARMEB__
#define __get_user_x_32t(__r2, __p, __e, __l, __s)			\
	__get_user_x(__r2, __p, __e, __l, 32t_8)
#else
#define __get_user_x_32t __get_user_x
#endif

/*
 * storing result into proper least significant word of 64bit target var,
 * different only for big endian case where 64 bit __r2 lsw is r3:
 */
#ifdef __ARMEB__
#define __get_user_x_64t(__r2, __p, __e, __l, __s)		        \
	   __asm__ __volatile__ (					\
		__asmeq("%0", "r0") __asmeq("%1", "r2")			\
		__asmeq("%3", "r1")					\
		"bl	__get_user_64t_" #__s				\
		: "=&r" (__e), "=r" (__r2)				\
		: "0" (__p), "r" (__l)					\
		: __GUP_CLOBBER_##__s)
#else
#define __get_user_x_64t __get_user_x
#endif


#define __get_user_check(x, p)						\
	({								\
		unsigned long __limit = current_thread_info()->addr_limit - 1; \
		register const typeof(*(p)) __user *__p asm("r0") = (p);\
		register typeof(x) __r2 asm("r2");			\
		register unsigned long __l asm("r1") = __limit;		\
		register int __e asm("r0");				\
		unsigned int __ua_flags = uaccess_save_and_enable();	\
		switch (sizeof(*(__p))) {				\
		case 1:							\
			if (sizeof((x)) >= 8)				\
				__get_user_x_64t(__r2, __p, __e, __l, 1); \
			else						\
				__get_user_x(__r2, __p, __e, __l, 1);	\
			break;						\
		case 2:							\
			if (sizeof((x)) >= 8)				\
				__get_user_x_64t(__r2, __p, __e, __l, 2); \
			else						\
				__get_user_x(__r2, __p, __e, __l, 2);	\
			break;						\
		case 4:							\
			if (sizeof((x)) >= 8)				\
				__get_user_x_64t(__r2, __p, __e, __l, 4); \
			else						\
				__get_user_x(__r2, __p, __e, __l, 4);	\
			break;						\
		case 8:							\
			if (sizeof((x)) < 8)				\
				__get_user_x_32t(__r2, __p, __e, __l, 4); \
			else						\
				__get_user_x(__r2, __p, __e, __l, 8);	\
			break;						\
		default: __e = __get_user_bad(); break;			\
		}							\
		uaccess_restore(__ua_flags);				\
		x = (typeof(*(p))) __r2;				\
		__e;							\
	})

#define get_user(x, p)							\
	({								\
		might_fault();						\
		__get_user_check(x, p);					\
	 })

extern int __put_user_1(void *, unsigned int);
extern int __put_user_2(void *, unsigned int);
extern int __put_user_4(void *, unsigned int);
extern int __put_user_8(void *, unsigned long long);

#define __put_user_x(__r2, __p, __e, __l, __s)				\
	   __asm__ __volatile__ (					\
		__asmeq("%0", "r0") __asmeq("%2", "r2")			\
		__asmeq("%3", "r1")					\
		"bl	__put_user_" #__s				\
		: "=&r" (__e)						\
		: "0" (__p), "r" (__r2), "r" (__l)			\
		: "ip", "lr", "cc")

#define __put_user_check(x, p)						\
	({								\
		unsigned long __limit = current_thread_info()->addr_limit - 1; \
		const typeof(*(p)) __user *__tmp_p = (p);		\
		register const typeof(*(p)) __r2 asm("r2") = (x);	\
		register const typeof(*(p)) __user *__p asm("r0") = __tmp_p; \
		register unsigned long __l asm("r1") = __limit;		\
		register int __e asm("r0");				\
		unsigned int __ua_flags = uaccess_save_and_enable();	\
		switch (sizeof(*(__p))) {				\
		case 1:							\
			__put_user_x(__r2, __p, __e, __l, 1);		\
			break;						\
		case 2:							\
			__put_user_x(__r2, __p, __e, __l, 2);		\
			break;						\
		case 4:							\
			__put_user_x(__r2, __p, __e, __l, 4);		\
			break;						\
		case 8:							\
			__put_user_x(__r2, __p, __e, __l, 8);		\
			break;						\
		default: __e = __put_user_bad(); break;			\
		}							\
		uaccess_restore(__ua_flags);				\
		__e;							\
	})

#define put_user(x, p)							\
	({								\
		might_fault();						\
		__put_user_check(x, p);					\
	 })

#else /* CONFIG_MMU */

/*
 * uClinux has only one addr space, so has simplified address limits.
 */
#define USER_DS			KERNEL_DS

#define segment_eq(a, b)		(1)
#define __addr_ok(addr)		((void)(addr), 1)
#define __range_ok(addr, size)	((void)(addr), 0)
#define get_fs()		(KERNEL_DS)

static inline void set_fs(mm_segment_t fs)
{
}

#define get_user(x, p)	__get_user(x, p)
#define put_user(x, p)	__put_user(x, p)

#endif /* CONFIG_MMU */

#define access_ok(type, addr, size)	(__range_ok(addr, size) == 0)

#define user_addr_max() \
	(segment_eq(get_fs(), KERNEL_DS) ? ~0UL : get_fs())

/*
 * The "__xxx" versions of the user access functions do not verify the
 * address space - it must have been done previously with a separate
 * "access_ok()" call.
 *
 * The "xxx_error" versions set the third argument to EFAULT if an
 * error occurs, and leave it unchanged on success.  Note that these
 * versions are void (ie, don't return a value as such).
 */
#define __get_user(x, ptr)						\
({									\
	long __gu_err = 0;						\
	__get_user_err((x), (ptr), __gu_err);				\
	__gu_err;							\
})

#define __get_user_error(x, ptr, err)					\
({									\
	__get_user_err((x), (ptr), err);				\
	(void) 0;							\
})

#define __get_user_err(x, ptr, err)					\
do {									\
	unsigned long __gu_addr = (unsigned long)(ptr);			\
	unsigned long __gu_val;						\
	unsigned int __ua_flags;					\
	__chk_user_ptr(ptr);						\
	might_fault();							\
	__ua_flags = uaccess_save_and_enable();				\
	switch (sizeof(*(ptr))) {					\
	case 1:	__get_user_asm_byte(__gu_val, __gu_addr, err);	break;	\
	case 2:	__get_user_asm_half(__gu_val, __gu_addr, err);	break;	\
	case 4:	__get_user_asm_word(__gu_val, __gu_addr, err);	break;	\
	default: (__gu_val) = __get_user_bad();				\
	}								\
	uaccess_restore(__ua_flags);					\
	(x) = (__typeof__(*(ptr)))__gu_val;				\
} while (0)

#define __get_user_asm(x, addr, err, instr)			\
	__asm__ __volatile__(					\
	"1:	" TUSER(instr) " %1, [%2], #0\n"		\
	"2:\n"							\
	"	.pushsection .text.fixup,\"ax\"\n"		\
	"	.align	2\n"					\
	"3:	mov	%0, %3\n"				\
	"	mov	%1, #0\n"				\
	"	b	2b\n"					\
	"	.popsection\n"					\
	"	.pushsection __ex_table,\"a\"\n"		\
	"	.align	3\n"					\
	"	.long	1b, 3b\n"				\
	"	.popsection"					\
	: "+r" (err), "=&r" (x)					\
	: "r" (addr), "i" (-EFAULT)				\
	: "cc")

#define __get_user_asm_byte(x, addr, err)			\
	__get_user_asm(x, addr, err, ldrb)

#ifndef __ARMEB__
#define __get_user_asm_half(x, __gu_addr, err)			\
({								\
	unsigned long __b1, __b2;				\
	__get_user_asm_byte(__b1, __gu_addr, err);		\
	__get_user_asm_byte(__b2, __gu_addr + 1, err);		\
	(x) = __b1 | (__b2 << 8);				\
})
#else
#define __get_user_asm_half(x, __gu_addr, err)			\
({								\
	unsigned long __b1, __b2;				\
	__get_user_asm_byte(__b1, __gu_addr, err);		\
	__get_user_asm_byte(__b2, __gu_addr + 1, err);		\
	(x) = (__b1 << 8) | __b2;				\
})
#endif

#define __get_user_asm_word(x, addr, err)			\
	__get_user_asm(x, addr, err, ldr)

#define __put_user(x, ptr)						\
({									\
	long __pu_err = 0;						\
	__put_user_err((x), (ptr), __pu_err);				\
	__pu_err;							\
})

#define __put_user_error(x, ptr, err)					\
({									\
	__put_user_err((x), (ptr), err);				\
	(void) 0;							\
})

#define __put_user_err(x, ptr, err)					\
do {									\
	unsigned long __pu_addr = (unsigned long)(ptr);			\
	unsigned int __ua_flags;					\
	__typeof__(*(ptr)) __pu_val = (x);				\
	__chk_user_ptr(ptr);						\
	might_fault();							\
	__ua_flags = uaccess_save_and_enable();				\
	switch (sizeof(*(ptr))) {					\
	case 1: __put_user_asm_byte(__pu_val, __pu_addr, err);	break;	\
	case 2: __put_user_asm_half(__pu_val, __pu_addr, err);	break;	\
	case 4: __put_user_asm_word(__pu_val, __pu_addr, err);	break;	\
	case 8:	__put_user_asm_dword(__pu_val, __pu_addr, err);	break;	\
	default: __put_user_bad();					\
	}								\
	uaccess_restore(__ua_flags);					\
} while (0)

#define __put_user_asm(x, __pu_addr, err, instr)		\
	__asm__ __volatile__(					\
	"1:	" TUSER(instr) " %1, [%2], #0\n"		\
	"2:\n"							\
	"	.pushsection .text.fixup,\"ax\"\n"		\
	"	.align	2\n"					\
	"3:	mov	%0, %3\n"				\
	"	b	2b\n"					\
	"	.popsection\n"					\
	"	.pushsection __ex_table,\"a\"\n"		\
	"	.align	3\n"					\
	"	.long	1b, 3b\n"				\
	"	.popsection"					\
	: "+r" (err)						\
	: "r" (x), "r" (__pu_addr), "i" (-EFAULT)		\
	: "cc")

#define __put_user_asm_byte(x, __pu_addr, err)			\
	__put_user_asm(x, __pu_addr, err, strb)

#ifndef __ARMEB__
#define __put_user_asm_half(x, __pu_addr, err)			\
({								\
	unsigned long __temp = (__force unsigned long)(x);	\
	__put_user_asm_byte(__temp, __pu_addr, err);		\
	__put_user_asm_byte(__temp >> 8, __pu_addr + 1, err);	\
})
#else
#define __put_user_asm_half(x, __pu_addr, err)			\
({								\
	unsigned long __temp = (__force unsigned long)(x);	\
	__put_user_asm_byte(__temp >> 8, __pu_addr, err);	\
	__put_user_asm_byte(__temp, __pu_addr + 1, err);	\
})
#endif

#define __put_user_asm_word(x, __pu_addr, err)			\
	__put_user_asm(x, __pu_addr, err, str)

#ifndef __ARMEB__
#define	__reg_oper0	"%R2"
#define	__reg_oper1	"%Q2"
#else
#define	__reg_oper0	"%Q2"
#define	__reg_oper1	"%R2"
#endif

#define __put_user_asm_dword(x, __pu_addr, err)			\
	__asm__ __volatile__(					\
 ARM(	"1:	" TUSER(str) "	" __reg_oper1 ", [%1], #4\n"	) \
 ARM(	"2:	" TUSER(str) "	" __reg_oper0 ", [%1]\n"	) \
 THUMB(	"1:	" TUSER(str) "	" __reg_oper1 ", [%1]\n"	) \
 THUMB(	"2:	" TUSER(str) "	" __reg_oper0 ", [%1, #4]\n"	) \
	"3:\n"							\
	"	.pushsection .text.fixup,\"ax\"\n"		\
	"	.align	2\n"					\
	"4:	mov	%0, %3\n"				\
	"	b	3b\n"					\
	"	.popsection\n"					\
	"	.pushsection __ex_table,\"a\"\n"		\
	"	.align	3\n"					\
	"	.long	1b, 4b\n"				\
	"	.long	2b, 4b\n"				\
	"	.popsection"					\
	: "+r" (err), "+r" (__pu_addr)				\
	: "r" (x), "i" (-EFAULT)				\
	: "cc")


#ifdef CONFIG_MMU
extern unsigned long __must_check
arm_copy_from_user(void *to, const void __user *from, unsigned long n);

static inline unsigned long __must_check
__copy_from_user(void *to, const void __user *from, unsigned long n)
{
	unsigned int __ua_flags = uaccess_save_and_enable();
	n = arm_copy_from_user(to, from, n);
	uaccess_restore(__ua_flags);
	return n;
}

extern unsigned long __must_check
arm_copy_to_user(void __user *to, const void *from, unsigned long n);
extern unsigned long __must_check
__copy_to_user_std(void __user *to, const void *from, unsigned long n);

static inline unsigned long __must_check
__copy_to_user(void __user *to, const void *from, unsigned long n)
{
#ifndef CONFIG_UACCESS_WITH_MEMCPY
	unsigned int __ua_flags = uaccess_save_and_enable();
	n = arm_copy_to_user(to, from, n);
	uaccess_restore(__ua_flags);
	return n;
#else
	return arm_copy_to_user(to, from, n);
#endif
}

extern unsigned long __must_check
arm_clear_user(void __user *addr, unsigned long n);
extern unsigned long __must_check
__clear_user_std(void __user *addr, unsigned long n);

static inline unsigned long __must_check
__clear_user(void __user *addr, unsigned long n)
{
	unsigned int __ua_flags = uaccess_save_and_enable();
	n = arm_clear_user(addr, n);
	uaccess_restore(__ua_flags);
	return n;
}

#else
#define __copy_from_user(to, from, n)	(memcpy(to, (void __force *)from, n), 0)
#define __copy_to_user(to, from, n)	(memcpy((void __force *)to, from, n), 0)
#define __clear_user(addr, n)		(memset((void __force *)addr, 0, n), 0)
#endif

static inline unsigned long __must_check copy_from_user(void *to, const void __user *from, unsigned long n)
{
	if (access_ok(VERIFY_READ, from, n))
		n = __copy_from_user(to, from, n);
	else /* security hole - plug it */
		memset(to, 0, n);
	return n;
}

static inline unsigned long __must_check copy_to_user(void __user *to, const void *from, unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n))
		n = __copy_to_user(to, from, n);
	return n;
}

#define __copy_to_user_inatomic __copy_to_user
#define __copy_from_user_inatomic __copy_from_user

static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n))
		n = __clear_user(to, n);
	return n;
}

/* These are from lib/ code, and use __get_user() and friends */
extern long strncpy_from_user(char *dest, const char __user *src, long count);

extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *str, long n);

#endif /* _ASMARM_UACCESS_H */
Commit	Line	Data
1da177e4	1	/*
4baa9922	2	* arch/arm/include/asm/uaccess.h
1da177e4 LT	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
	8	#ifndef _ASMARM_UACCESS_H
	9	#define _ASMARM_UACCESS_H
	10
	11	/*
	12	* User space memory access functions
	13	*/
87c52578 RK	14	#include <linux/string.h>
87c52578 RK	15	#include <linux/thread_info.h>
1da177e4 LT	16	#include <asm/errno.h>
	17	#include <asm/memory.h>
	18	#include <asm/domain.h>
8b592783	19	#include <asm/unified.h>
9f97da78	20	#include <asm/compiler.h>
1da177e4	21
afdd3bba	22	#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
c89efa73 NP	23	#include <asm-generic/uaccess-unaligned.h>
	24	#else
	25	#define __get_user_unaligned __get_user
	26	#define __put_user_unaligned __put_user
	27	#endif
	28
1da177e4 LT	29	#define VERIFY_READ 0
	30	#define VERIFY_WRITE 1
	31
	32	/*
	33	* The exception table consists of pairs of addresses: the first is the
	34	* address of an instruction that is allowed to fault, and the second is
	35	* the address at which the program should continue. No registers are
	36	* modified, so it is entirely up to the continuation code to figure out
	37	* what to do.
	38	*
	39	* All the routines below use bits of fixup code that are out of line
	40	* with the main instruction path. This means when everything is well,
	41	* we don't even have to jump over them. Further, they do not intrude
	42	* on our cache or tlb entries.
	43	*/
	44
	45	struct exception_table_entry
	46	{
	47	unsigned long insn, fixup;
	48	};
	49
	50	extern int fixup_exception(struct pt_regs *regs);
	51
3fba7e23 RK	52	/*
	53	* These two functions allow hooking accesses to userspace to increase
	54	* system integrity by ensuring that the kernel can not inadvertantly
	55	* perform such accesses (eg, via list poison values) which could then
	56	* be exploited for priviledge escalation.
	57	*/
	58	static inline unsigned int uaccess_save_and_enable(void)
	59	{
a5e090ac RK	60	#ifdef CONFIG_CPU_SW_DOMAIN_PAN
	61	unsigned int old_domain = get_domain();
	62
	63	/* Set the current domain access to permit user accesses */
	64	set_domain((old_domain & ~domain_mask(DOMAIN_USER)) \|
	65	domain_val(DOMAIN_USER, DOMAIN_CLIENT));
	66
	67	return old_domain;
	68	#else
3fba7e23	69	return 0;
a5e090ac	70	#endif
3fba7e23 RK	71	}
	72
	73	static inline void uaccess_restore(unsigned int flags)
	74	{
a5e090ac RK	75	#ifdef CONFIG_CPU_SW_DOMAIN_PAN
	76	/* Restore the user access mask */
	77	set_domain(flags);
	78	#endif
3fba7e23 RK	79	}
3fba7e23 RK	80
9641c7cc RK	81	/*
	82	* These two are intentionally not defined anywhere - if the kernel
	83	* code generates any references to them, that's a bug.
	84	*/
	85	extern int __get_user_bad(void);
	86	extern int __put_user_bad(void);
	87
1da177e4 LT	88	/*
	89	* Note that this is actually 0x1,0000,0000
	90	*/
	91	#define KERNEL_DS 0x00000000
1da177e4	92	#define get_ds() (KERNEL_DS)
9641c7cc RK	93
	94	#ifdef CONFIG_MMU
	95
	96	#define USER_DS TASK_SIZE
1da177e4 LT	97	#define get_fs() (current_thread_info()->addr_limit)
1da177e4 LT	98
9641c7cc	99	static inline void set_fs(mm_segment_t fs)
1da177e4 LT	100	{
	101	current_thread_info()->addr_limit = fs;
	102	modify_domain(DOMAIN_KERNEL, fs ? DOMAIN_CLIENT : DOMAIN_MANAGER);
	103	}
	104
295bb01e	105	#define segment_eq(a, b) ((a) == (b))
1da177e4 LT	106
	107	#define __addr_ok(addr) ({ \
	108	unsigned long flag; \
	109	__asm__("cmp %2, %0; movlo %0, #0" \
	110	: "=&r" (flag) \
	111	: "0" (current_thread_info()->addr_limit), "r" (addr) \
	112	: "cc"); \
	113	(flag == 0); })
	114
	115	/* We use 33-bit arithmetic here... */
295bb01e	116	#define __range_ok(addr, size) ({ \
16cf5b39	117	unsigned long flag, roksum; \
1da177e4 LT	118	__chk_user_ptr(addr); \
1da177e4 LT	119	__asm__("adds %1, %2, %3; sbcccs %1, %1, %0; movcc %0, #0" \
16cf5b39	120	: "=&r" (flag), "=&r" (roksum) \
1da177e4 LT	121	: "r" (addr), "Ir" (size), "0" (current_thread_info()->addr_limit) \
	122	: "cc"); \
	123	flag; })
	124
1da177e4 LT	125	/*
	126	* Single-value transfer routines. They automatically use the right
	127	* size if we just have the right pointer type. Note that the functions
	128	* which read from user space (get_) need to take care not to leak
	129	* kernel data even if the calling code is buggy and fails to check
	130	* the return value. This means zeroing out the destination variable
	131	* or buffer on error. Normally this is done out of line by the
	132	* fixup code, but there are a few places where it intrudes on the
	133	* main code path. When we only write to user space, there is no
	134	* problem.
1da177e4	135	*/
1da177e4 LT	136	extern int __get_user_1(void *);
	137	extern int __get_user_2(void *);
	138	extern int __get_user_4(void *);
d9981380	139	extern int __get_user_32t_8(void *);
e38361d0	140	extern int __get_user_8(void *);
d9981380 VK	141	extern int __get_user_64t_1(void *);
	142	extern int __get_user_64t_2(void *);
	143	extern int __get_user_64t_4(void *);
1da177e4	144
8404663f RK	145	#define __GUP_CLOBBER_1 "lr", "cc"
	146	#ifdef CONFIG_CPU_USE_DOMAINS
	147	#define __GUP_CLOBBER_2 "ip", "lr", "cc"
	148	#else
	149	#define __GUP_CLOBBER_2 "lr", "cc"
	150	#endif
	151	#define __GUP_CLOBBER_4 "lr", "cc"
d9981380	152	#define __GUP_CLOBBER_32t_8 "lr", "cc"
e38361d0	153	#define __GUP_CLOBBER_8 "lr", "cc"
8404663f	154
295bb01e	155	#define __get_user_x(__r2, __p, __e, __l, __s) \
1da177e4 LT	156	__asm__ __volatile__ ( \
1da177e4 LT	157	__asmeq("%0", "r0") __asmeq("%1", "r2") \
8404663f	158	__asmeq("%3", "r1") \
1da177e4 LT	159	"bl __get_user_" #__s \
1da177e4 LT	160	: "=&r" (__e), "=r" (__r2) \
8404663f RK	161	: "0" (__p), "r" (__l) \
8404663f RK	162	: __GUP_CLOBBER_##__s)
1da177e4	163
e38361d0 DT	164	/* narrowing a double-word get into a single 32bit word register: */
e38361d0 DT	165	#ifdef __ARMEB__
295bb01e	166	#define __get_user_x_32t(__r2, __p, __e, __l, __s) \
d9981380	167	__get_user_x(__r2, __p, __e, __l, 32t_8)
e38361d0	168	#else
d9981380	169	#define __get_user_x_32t __get_user_x
e38361d0 DT	170	#endif
e38361d0 DT	171
d9981380 VK	172	/*
	173	* storing result into proper least significant word of 64bit target var,
	174	* different only for big endian case where 64 bit __r2 lsw is r3:
	175	*/
	176	#ifdef __ARMEB__
	177	#define __get_user_x_64t(__r2, __p, __e, __l, __s) \
	178	__asm__ __volatile__ ( \
	179	__asmeq("%0", "r0") __asmeq("%1", "r2") \
	180	__asmeq("%3", "r1") \
	181	"bl __get_user_64t_" #__s \
	182	: "=&r" (__e), "=r" (__r2) \
	183	: "0" (__p), "r" (__l) \
	184	: __GUP_CLOBBER_##__s)
	185	#else
	186	#define __get_user_x_64t __get_user_x
	187	#endif
	188
	189
295bb01e	190	#define __get_user_check(x, p) \
1da177e4	191	({ \
8404663f	192	unsigned long __limit = current_thread_info()->addr_limit - 1; \
c5a69d57	193	register const typeof((p)) __user __p asm("r0") = (p);\
e38361d0	194	register typeof(x) __r2 asm("r2"); \
8404663f	195	register unsigned long __l asm("r1") = __limit; \
1da177e4	196	register int __e asm("r0"); \
3fba7e23	197	unsigned int __ua_flags = uaccess_save_and_enable(); \
1da177e4 LT	198	switch (sizeof(*(__p))) { \
1da177e4 LT	199	case 1: \
d9981380 VK	200	if (sizeof((x)) >= 8) \
	201	__get_user_x_64t(__r2, __p, __e, __l, 1); \
	202	else \
	203	__get_user_x(__r2, __p, __e, __l, 1); \
8404663f	204	break; \
1da177e4	205	case 2: \
d9981380 VK	206	if (sizeof((x)) >= 8) \
	207	__get_user_x_64t(__r2, __p, __e, __l, 2); \
	208	else \
	209	__get_user_x(__r2, __p, __e, __l, 2); \
1da177e4 LT	210	break; \
1da177e4 LT	211	case 4: \
d9981380 VK	212	if (sizeof((x)) >= 8) \
	213	__get_user_x_64t(__r2, __p, __e, __l, 4); \
	214	else \
	215	__get_user_x(__r2, __p, __e, __l, 4); \
1da177e4	216	break; \
e38361d0 DT	217	case 8: \
e38361d0 DT	218	if (sizeof((x)) < 8) \
d9981380	219	__get_user_x_32t(__r2, __p, __e, __l, 4); \
e38361d0 DT	220	else \
	221	__get_user_x(__r2, __p, __e, __l, 8); \
	222	break; \
1da177e4 LT	223	default: __e = __get_user_bad(); break; \
1da177e4 LT	224	} \
3fba7e23	225	uaccess_restore(__ua_flags); \
d2c5b690	226	x = (typeof(*(p))) __r2; \
1da177e4 LT	227	__e; \
	228	})
	229
295bb01e	230	#define get_user(x, p) \
ad72907a WD	231	({ \
ad72907a WD	232	might_fault(); \
295bb01e	233	__get_user_check(x, p); \
ad72907a WD	234	})
ad72907a WD	235
9641c7cc RK	236	extern int __put_user_1(void *, unsigned int);
	237	extern int __put_user_2(void *, unsigned int);
	238	extern int __put_user_4(void *, unsigned int);
	239	extern int __put_user_8(void *, unsigned long long);
	240
295bb01e	241	#define __put_user_x(__r2, __p, __e, __l, __s) \
9641c7cc RK	242	__asm__ __volatile__ ( \
9641c7cc RK	243	__asmeq("%0", "r0") __asmeq("%2", "r2") \
8404663f	244	__asmeq("%3", "r1") \
9641c7cc RK	245	"bl __put_user_" #__s \
9641c7cc RK	246	: "=&r" (__e) \
8404663f	247	: "0" (__p), "r" (__r2), "r" (__l) \
9641c7cc RK	248	: "ip", "lr", "cc")
9641c7cc RK	249
295bb01e	250	#define __put_user_check(x, p) \
9641c7cc	251	({ \
8404663f	252	unsigned long __limit = current_thread_info()->addr_limit - 1; \
537094b6	253	const typeof((p)) __user __tmp_p = (p); \
c5a69d57	254	register const typeof(*(p)) __r2 asm("r2") = (x); \
537094b6	255	register const typeof((p)) __user __p asm("r0") = __tmp_p; \
8404663f	256	register unsigned long __l asm("r1") = __limit; \
9641c7cc	257	register int __e asm("r0"); \
3fba7e23	258	unsigned int __ua_flags = uaccess_save_and_enable(); \
9641c7cc RK	259	switch (sizeof(*(__p))) { \
9641c7cc RK	260	case 1: \
8404663f	261	__put_user_x(__r2, __p, __e, __l, 1); \
9641c7cc RK	262	break; \
9641c7cc RK	263	case 2: \
8404663f	264	__put_user_x(__r2, __p, __e, __l, 2); \
9641c7cc RK	265	break; \
9641c7cc RK	266	case 4: \
8404663f	267	__put_user_x(__r2, __p, __e, __l, 4); \
9641c7cc RK	268	break; \
9641c7cc RK	269	case 8: \
8404663f	270	__put_user_x(__r2, __p, __e, __l, 8); \
9641c7cc RK	271	break; \
	272	default: __e = __put_user_bad(); break; \
	273	} \
3fba7e23	274	uaccess_restore(__ua_flags); \
9641c7cc RK	275	__e; \
	276	})
	277
295bb01e	278	#define put_user(x, p) \
ad72907a WD	279	({ \
ad72907a WD	280	might_fault(); \
295bb01e	281	__put_user_check(x, p); \
ad72907a WD	282	})
ad72907a WD	283
9641c7cc RK	284	#else /* CONFIG_MMU */
	285
	286	/*
	287	* uClinux has only one addr space, so has simplified address limits.
	288	*/
	289	#define USER_DS KERNEL_DS
	290
295bb01e MT	291	#define segment_eq(a, b) (1)
	292	#define __addr_ok(addr) ((void)(addr), 1)
	293	#define __range_ok(addr, size) ((void)(addr), 0)
9641c7cc RK	294	#define get_fs() (KERNEL_DS)
	295
	296	static inline void set_fs(mm_segment_t fs)
	297	{
	298	}
	299
295bb01e MT	300	#define get_user(x, p) __get_user(x, p)
295bb01e MT	301	#define put_user(x, p) __put_user(x, p)
9641c7cc RK	302
	303	#endif /* CONFIG_MMU */
	304
295bb01e	305	#define access_ok(type, addr, size) (__range_ok(addr, size) == 0)
9641c7cc	306
8c56cc8b	307	#define user_addr_max() \
83de911c	308	(segment_eq(get_fs(), KERNEL_DS) ? ~0UL : get_fs())
8c56cc8b	309
9641c7cc RK	310	/*
	311	* The "__xxx" versions of the user access functions do not verify the
	312	* address space - it must have been done previously with a separate
	313	* "access_ok()" call.
	314	*
	315	* The "xxx_error" versions set the third argument to EFAULT if an
	316	* error occurs, and leave it unchanged on success. Note that these
	317	* versions are void (ie, don't return a value as such).
	318	*/
295bb01e	319	#define __get_user(x, ptr) \
1da177e4 LT	320	({ \
1da177e4 LT	321	long __gu_err = 0; \
295bb01e	322	__get_user_err((x), (ptr), __gu_err); \
1da177e4 LT	323	__gu_err; \
	324	})
	325
295bb01e	326	#define __get_user_error(x, ptr, err) \
1da177e4	327	({ \
295bb01e	328	__get_user_err((x), (ptr), err); \
1da177e4 LT	329	(void) 0; \
	330	})
	331
295bb01e	332	#define __get_user_err(x, ptr, err) \
1da177e4 LT	333	do { \
	334	unsigned long __gu_addr = (unsigned long)(ptr); \
	335	unsigned long __gu_val; \
3fba7e23	336	unsigned int __ua_flags; \
1da177e4	337	__chk_user_ptr(ptr); \
ad72907a	338	might_fault(); \
3fba7e23	339	__ua_flags = uaccess_save_and_enable(); \
1da177e4	340	switch (sizeof(*(ptr))) { \
295bb01e MT	341	case 1: __get_user_asm_byte(__gu_val, __gu_addr, err); break; \
	342	case 2: __get_user_asm_half(__gu_val, __gu_addr, err); break; \
	343	case 4: __get_user_asm_word(__gu_val, __gu_addr, err); break; \
1da177e4 LT	344	default: (__gu_val) = __get_user_bad(); \
1da177e4 LT	345	} \
3fba7e23	346	uaccess_restore(__ua_flags); \
1da177e4 LT	347	(x) = (__typeof__(*(ptr)))__gu_val; \
	348	} while (0)
	349
b64d1f66	350	#define __get_user_asm(x, addr, err, instr) \
1da177e4	351	__asm__ __volatile__( \
b64d1f66	352	"1: " TUSER(instr) " %1, [%2], #0\n" \
1da177e4	353	"2:\n" \
c4a84ae3	354	" .pushsection .text.fixup,\"ax\"\n" \
1da177e4 LT	355	" .align 2\n" \
	356	"3: mov %0, %3\n" \
	357	" mov %1, #0\n" \
	358	" b 2b\n" \
4260415f RK	359	" .popsection\n" \
4260415f RK	360	" .pushsection __ex_table,\"a\"\n" \
1da177e4 LT	361	" .align 3\n" \
1da177e4 LT	362	" .long 1b, 3b\n" \
4260415f	363	" .popsection" \
1da177e4 LT	364	: "+r" (err), "=&r" (x) \
	365	: "r" (addr), "i" (-EFAULT) \
	366	: "cc")
	367
b64d1f66 RK	368	#define __get_user_asm_byte(x, addr, err) \
	369	__get_user_asm(x, addr, err, ldrb)
	370
1da177e4	371	#ifndef __ARMEB__
295bb01e	372	#define __get_user_asm_half(x, __gu_addr, err) \
1da177e4 LT	373	({ \
	374	unsigned long __b1, __b2; \
	375	__get_user_asm_byte(__b1, __gu_addr, err); \
	376	__get_user_asm_byte(__b2, __gu_addr + 1, err); \
	377	(x) = __b1 \| (__b2 << 8); \
	378	})
	379	#else
295bb01e	380	#define __get_user_asm_half(x, __gu_addr, err) \
1da177e4 LT	381	({ \
	382	unsigned long __b1, __b2; \
	383	__get_user_asm_byte(__b1, __gu_addr, err); \
	384	__get_user_asm_byte(__b2, __gu_addr + 1, err); \
	385	(x) = (__b1 << 8) \| __b2; \
	386	})
	387	#endif
	388
295bb01e	389	#define __get_user_asm_word(x, addr, err) \
b64d1f66	390	__get_user_asm(x, addr, err, ldr)
1da177e4	391
295bb01e	392	#define __put_user(x, ptr) \
1da177e4 LT	393	({ \
1da177e4 LT	394	long __pu_err = 0; \
295bb01e	395	__put_user_err((x), (ptr), __pu_err); \
1da177e4 LT	396	__pu_err; \
	397	})
	398
295bb01e	399	#define __put_user_error(x, ptr, err) \
1da177e4	400	({ \
295bb01e	401	__put_user_err((x), (ptr), err); \
1da177e4 LT	402	(void) 0; \
	403	})
	404
295bb01e	405	#define __put_user_err(x, ptr, err) \
1da177e4 LT	406	do { \
1da177e4 LT	407	unsigned long __pu_addr = (unsigned long)(ptr); \
3fba7e23	408	unsigned int __ua_flags; \
1da177e4 LT	409	__typeof__(*(ptr)) __pu_val = (x); \
1da177e4 LT	410	__chk_user_ptr(ptr); \
ad72907a	411	might_fault(); \
3fba7e23	412	__ua_flags = uaccess_save_and_enable(); \
1da177e4	413	switch (sizeof(*(ptr))) { \
295bb01e MT	414	case 1: __put_user_asm_byte(__pu_val, __pu_addr, err); break; \
	415	case 2: __put_user_asm_half(__pu_val, __pu_addr, err); break; \
	416	case 4: __put_user_asm_word(__pu_val, __pu_addr, err); break; \
	417	case 8: __put_user_asm_dword(__pu_val, __pu_addr, err); break; \
1da177e4 LT	418	default: __put_user_bad(); \
1da177e4 LT	419	} \
3fba7e23	420	uaccess_restore(__ua_flags); \
1da177e4 LT	421	} while (0)
1da177e4 LT	422
b64d1f66	423	#define __put_user_asm(x, __pu_addr, err, instr) \
1da177e4	424	__asm__ __volatile__( \
b64d1f66	425	"1: " TUSER(instr) " %1, [%2], #0\n" \
1da177e4	426	"2:\n" \
c4a84ae3	427	" .pushsection .text.fixup,\"ax\"\n" \
1da177e4 LT	428	" .align 2\n" \
	429	"3: mov %0, %3\n" \
	430	" b 2b\n" \
4260415f RK	431	" .popsection\n" \
4260415f RK	432	" .pushsection __ex_table,\"a\"\n" \
1da177e4 LT	433	" .align 3\n" \
1da177e4 LT	434	" .long 1b, 3b\n" \
4260415f	435	" .popsection" \
1da177e4 LT	436	: "+r" (err) \
	437	: "r" (x), "r" (__pu_addr), "i" (-EFAULT) \
	438	: "cc")
	439
b64d1f66 RK	440	#define __put_user_asm_byte(x, __pu_addr, err) \
	441	__put_user_asm(x, __pu_addr, err, strb)
	442
1da177e4	443	#ifndef __ARMEB__
295bb01e	444	#define __put_user_asm_half(x, __pu_addr, err) \
1da177e4	445	({ \
e8b94dea	446	unsigned long __temp = (__force unsigned long)(x); \
1da177e4 LT	447	__put_user_asm_byte(__temp, __pu_addr, err); \
	448	__put_user_asm_byte(__temp >> 8, __pu_addr + 1, err); \
	449	})
	450	#else
295bb01e	451	#define __put_user_asm_half(x, __pu_addr, err) \
1da177e4	452	({ \
e8b94dea	453	unsigned long __temp = (__force unsigned long)(x); \
1da177e4 LT	454	__put_user_asm_byte(__temp >> 8, __pu_addr, err); \
	455	__put_user_asm_byte(__temp, __pu_addr + 1, err); \
	456	})
	457	#endif
	458
295bb01e	459	#define __put_user_asm_word(x, __pu_addr, err) \
b64d1f66	460	__put_user_asm(x, __pu_addr, err, str)
1da177e4 LT	461
	462	#ifndef __ARMEB__
	463	#define __reg_oper0 "%R2"
	464	#define __reg_oper1 "%Q2"
	465	#else
	466	#define __reg_oper0 "%Q2"
	467	#define __reg_oper1 "%R2"
	468	#endif
	469
295bb01e	470	#define __put_user_asm_dword(x, __pu_addr, err) \
1da177e4	471	__asm__ __volatile__( \
4e7682d0 CM	472	ARM( "1: " TUSER(str) " " __reg_oper1 ", [%1], #4\n" ) \
	473	ARM( "2: " TUSER(str) " " __reg_oper0 ", [%1]\n" ) \
	474	THUMB( "1: " TUSER(str) " " __reg_oper1 ", [%1]\n" ) \
	475	THUMB( "2: " TUSER(str) " " __reg_oper0 ", [%1, #4]\n" ) \
1da177e4	476	"3:\n" \
c4a84ae3	477	" .pushsection .text.fixup,\"ax\"\n" \
1da177e4 LT	478	" .align 2\n" \
	479	"4: mov %0, %3\n" \
	480	" b 3b\n" \
4260415f RK	481	" .popsection\n" \
4260415f RK	482	" .pushsection __ex_table,\"a\"\n" \
1da177e4 LT	483	" .align 3\n" \
	484	" .long 1b, 4b\n" \
	485	" .long 2b, 4b\n" \
4260415f	486	" .popsection" \
1da177e4 LT	487	: "+r" (err), "+r" (__pu_addr) \
	488	: "r" (x), "i" (-EFAULT) \
	489	: "cc")
	490
02fcb974	491
9641c7cc	492	#ifdef CONFIG_MMU
3fba7e23 RK	493	extern unsigned long __must_check
	494	arm_copy_from_user(void to, const void __user from, unsigned long n);
	495
	496	static inline unsigned long __must_check
	497	__copy_from_user(void to, const void __user from, unsigned long n)
	498	{
	499	unsigned int __ua_flags = uaccess_save_and_enable();
	500	n = arm_copy_from_user(to, from, n);
	501	uaccess_restore(__ua_flags);
	502	return n;
	503	}
	504
	505	extern unsigned long __must_check
	506	arm_copy_to_user(void __user to, const void from, unsigned long n);
	507	extern unsigned long __must_check
	508	__copy_to_user_std(void __user to, const void from, unsigned long n);
	509
	510	static inline unsigned long __must_check
	511	__copy_to_user(void __user to, const void from, unsigned long n)
	512	{
c014953d	513	#ifndef CONFIG_UACCESS_WITH_MEMCPY
3fba7e23 RK	514	unsigned int __ua_flags = uaccess_save_and_enable();
	515	n = arm_copy_to_user(to, from, n);
	516	uaccess_restore(__ua_flags);
	517	return n;
c014953d RK	518	#else
	519	return arm_copy_to_user(to, from, n);
	520	#endif
3fba7e23 RK	521	}
	522
	523	extern unsigned long __must_check
	524	arm_clear_user(void __user *addr, unsigned long n);
	525	extern unsigned long __must_check
	526	__clear_user_std(void __user *addr, unsigned long n);
	527
	528	static inline unsigned long __must_check
	529	__clear_user(void __user *addr, unsigned long n)
	530	{
	531	unsigned int __ua_flags = uaccess_save_and_enable();
	532	n = arm_clear_user(addr, n);
	533	uaccess_restore(__ua_flags);
	534	return n;
	535	}
	536
9641c7cc	537	#else
295bb01e MT	538	#define __copy_from_user(to, from, n) (memcpy(to, (void __force *)from, n), 0)
	539	#define __copy_to_user(to, from, n) (memcpy((void __force *)to, from, n), 0)
	540	#define __clear_user(addr, n) (memset((void __force *)addr, 0, n), 0)
9641c7cc RK	541	#endif
9641c7cc RK	542
99573298	543	static inline unsigned long __must_check copy_from_user(void to, const void __user from, unsigned long n)
1da177e4 LT	544	{
1da177e4 LT	545	if (access_ok(VERIFY_READ, from, n))
02fcb974	546	n = __copy_from_user(to, from, n);
1da177e4	547	else /* security hole - plug it */
59f0cb0f	548	memset(to, 0, n);
1da177e4 LT	549	return n;
	550	}
	551
99573298	552	static inline unsigned long __must_check copy_to_user(void __user to, const void from, unsigned long n)
1da177e4 LT	553	{
1da177e4 LT	554	if (access_ok(VERIFY_WRITE, to, n))
02fcb974	555	n = __copy_to_user(to, from, n);
1da177e4 LT	556	return n;
	557	}
	558
1da177e4 LT	559	#define __copy_to_user_inatomic __copy_to_user
	560	#define __copy_from_user_inatomic __copy_from_user
	561
99573298	562	static inline unsigned long __must_check clear_user(void __user *to, unsigned long n)
1da177e4 LT	563	{
1da177e4 LT	564	if (access_ok(VERIFY_WRITE, to, n))
02fcb974	565	n = __clear_user(to, n);
1da177e4 LT	566	return n;
	567	}
	568
3fba7e23	569	/* These are from lib/ code, and use __get_user() and friends */
8c56cc8b	570	extern long strncpy_from_user(char dest, const char __user src, long count);
1da177e4	571
8c56cc8b WD	572	extern __must_check long strlen_user(const char __user *str);
8c56cc8b WD	573	extern __must_check long strnlen_user(const char __user *str, long n);
1da177e4 LT	574
1da177e4 LT	575	#endif /* _ASMARM_UACCESS_H */