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

/*
 * Copyright 2010 Tilera Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU General Public License
 *   as published by the Free Software Foundation, version 2.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 *   NON INFRINGEMENT.  See the GNU General Public License for
 *   more details.
 */

#ifndef _ASM_TILE_UACCESS_H
#define _ASM_TILE_UACCESS_H

/*
 * User space memory access functions
 */
#include <linux/sched.h>
#include <linux/mm.h>
#include <asm-generic/uaccess-unaligned.h>
#include <asm/processor.h>
#include <asm/page.h>

#define VERIFY_READ	0
#define VERIFY_WRITE	1

/*
 * The fs value determines whether argument validity checking should be
 * performed or not.  If get_fs() == USER_DS, checking is performed, with
 * get_fs() == KERNEL_DS, checking is bypassed.
 *
 * For historical reasons, these macros are grossly misnamed.
 */
#define MAKE_MM_SEG(a)  ((mm_segment_t) { (a) })

#define KERNEL_DS	MAKE_MM_SEG(-1UL)
#define USER_DS		MAKE_MM_SEG(PAGE_OFFSET)

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

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

#ifndef __tilegx__
/*
 * We could allow mapping all 16 MB at 0xfc000000, but we set up a
 * special hack in arch_setup_additional_pages() to auto-create a mapping
 * for the first 16 KB, and it would seem strange to have different
 * user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
 */
static inline int is_arch_mappable_range(unsigned long addr,
					 unsigned long size)
{
	return (addr >= MEM_USER_INTRPT &&
		addr < (MEM_USER_INTRPT + INTRPT_SIZE) &&
		size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr);
}
#define is_arch_mappable_range is_arch_mappable_range
#else
#define is_arch_mappable_range(addr, size) 0
#endif

/*
 * Note that using this definition ignores is_arch_mappable_range(),
 * so on tilepro code that uses user_addr_max() is constrained not
 * to reference the tilepro user-interrupt region.
 */
#define user_addr_max() (current_thread_info()->addr_limit.seg)

/*
 * Test whether a block of memory is a valid user space address.
 * Returns 0 if the range is valid, nonzero otherwise.
 */
int __range_ok(unsigned long addr, unsigned long size);

/**
 * access_ok: - Checks if a user space pointer is valid
 * @type: Type of access: %VERIFY_READ or %VERIFY_WRITE.  Note that
 *        %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
 *        to write to a block, it is always safe to read from it.
 * @addr: User space pointer to start of block to check
 * @size: Size of block to check
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * Checks if a pointer to a block of memory in user space is valid.
 *
 * Returns true (nonzero) if the memory block may be valid, false (zero)
 * if it is definitely invalid.
 *
 * Note that, depending on architecture, this function probably just
 * checks that the pointer is in the user space range - after calling
 * this function, memory access functions may still return -EFAULT.
 */
#define access_ok(type, addr, size) ({ \
	__chk_user_ptr(addr); \
	likely(__range_ok((unsigned long)(addr), (size)) == 0);	\
})

/*
 * 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);

/*
 * This is a type: either unsigned long, if the argument fits into
 * that type, or otherwise unsigned long long.
 */
#define __inttype(x) \
	__typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))

/*
 * Support macros for __get_user().
 * Note that __get_user() and __put_user() assume proper alignment.
 */

#ifdef __LP64__
#define _ASM_PTR	".quad"
#define _ASM_ALIGN	".align 8"
#else
#define _ASM_PTR	".long"
#define _ASM_ALIGN	".align 4"
#endif

#define __get_user_asm(OP, x, ptr, ret)					\
	asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n"		\
		     ".pushsection .fixup,\"ax\"\n"			\
		     "0: { movei %1, 0; movei %0, %3 }\n"		\
		     "j 9f\n"						\
		     ".section __ex_table,\"a\"\n"			\
		     _ASM_ALIGN "\n"					\
		     _ASM_PTR " 1b, 0b\n"				\
		     ".popsection\n"					\
		     "9:"						\
		     : "=r" (ret), "=r" (x)				\
		     : "r" (ptr), "i" (-EFAULT))

#ifdef __tilegx__
#define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret)
#define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret)
#define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret)
#define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret)
#else
#define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret)
#define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret)
#define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret)
#ifdef __LITTLE_ENDIAN
#define __lo32(a, b) a
#define __hi32(a, b) b
#else
#define __lo32(a, b) b
#define __hi32(a, b) a
#endif
#define __get_user_8(x, ptr, ret)					\
	({								\
		unsigned int __a, __b;					\
		asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n"	\
			     "2: { lw %2, %2; movei %0, 0 }\n"		\
			     ".pushsection .fixup,\"ax\"\n"		\
			     "0: { movei %1, 0; movei %2, 0 }\n"	\
			     "{ movei %0, %4; j 9f }\n"			\
			     ".section __ex_table,\"a\"\n"		\
			     ".align 4\n"				\
			     ".word 1b, 0b\n"				\
			     ".word 2b, 0b\n"				\
			     ".popsection\n"				\
			     "9:"					\
			     : "=r" (ret), "=r" (__a), "=&r" (__b)	\
			     : "r" (ptr), "i" (-EFAULT));		\
		(x) = (__force __typeof(x))(__inttype(x))		\
			(((u64)__hi32(__a, __b) << 32) |		\
			 __lo32(__a, __b));				\
	})
#endif

extern int __get_user_bad(void)
  __attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8")));

/**
 * __get_user: - Get a simple variable from user space, with less checking.
 * @x:   Variable to store result.
 * @ptr: Source address, in user space.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * This macro copies a single simple variable from user space to kernel
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and the result of
 * dereferencing @ptr must be assignable to @x without a cast.
 *
 * Returns zero on success, or -EFAULT on error.
 * On error, the variable @x is set to zero.
 *
 * Caller must check the pointer with access_ok() before calling this
 * function.
 */
#define __get_user(x, ptr)						\
	({								\
		int __ret;						\
		typeof(x) _x;						\
		__chk_user_ptr(ptr);					\
		switch (sizeof(*(ptr))) {				\
		case 1: __get_user_1(_x, ptr, __ret); break;		\
		case 2: __get_user_2(_x, ptr, __ret); break;		\
		case 4: __get_user_4(_x, ptr, __ret); break;		\
		case 8: __get_user_8(_x, ptr, __ret); break;		\
		default: __ret = __get_user_bad(); break;		\
		}							\
		(x) = (typeof(*(ptr))) _x;				\
		__ret;							\
	})

/* Support macros for __put_user(). */

#define __put_user_asm(OP, x, ptr, ret)			\
	asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n"		\
		     ".pushsection .fixup,\"ax\"\n"			\
		     "0: { movei %0, %3; j 9f }\n"			\
		     ".section __ex_table,\"a\"\n"			\
		     _ASM_ALIGN "\n"					\
		     _ASM_PTR " 1b, 0b\n"				\
		     ".popsection\n"					\
		     "9:"						\
		     : "=r" (ret)					\
		     : "r" (ptr), "r" (x), "i" (-EFAULT))

#ifdef __tilegx__
#define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret)
#define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret)
#define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret)
#define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret)
#else
#define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret)
#define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret)
#define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret)
#define __put_user_8(x, ptr, ret)					\
	({								\
		u64 __x = (__force __inttype(x))(x);			\
		int __lo = (int) __x, __hi = (int) (__x >> 32);		\
		asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n"	\
			     "2: { sw %0, %3; movei %0, 0 }\n"		\
			     ".pushsection .fixup,\"ax\"\n"		\
			     "0: { movei %0, %4; j 9f }\n"		\
			     ".section __ex_table,\"a\"\n"		\
			     ".align 4\n"				\
			     ".word 1b, 0b\n"				\
			     ".word 2b, 0b\n"				\
			     ".popsection\n"				\
			     "9:"					\
			     : "=&r" (ret)				\
			     : "r" (ptr), "r" (__lo32(__lo, __hi)),	\
			     "r" (__hi32(__lo, __hi)), "i" (-EFAULT));	\
	})
#endif

extern int __put_user_bad(void)
  __attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8")));

/**
 * __put_user: - Write a simple value into user space, with less checking.
 * @x:   Value to copy to user space.
 * @ptr: Destination address, in user space.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * This macro copies a single simple value from kernel space to user
 * space.  It supports simple types like char and int, but not larger
 * data types like structures or arrays.
 *
 * @ptr must have pointer-to-simple-variable type, and @x must be assignable
 * to the result of dereferencing @ptr.
 *
 * Caller must check the pointer with access_ok() before calling this
 * function.
 *
 * Returns zero on success, or -EFAULT on error.
 */
#define __put_user(x, ptr)						\
({									\
	int __ret;							\
	typeof(*(ptr)) _x = (x);					\
	__chk_user_ptr(ptr);						\
	switch (sizeof(*(ptr))) {					\
	case 1: __put_user_1(_x, ptr, __ret); break;			\
	case 2: __put_user_2(_x, ptr, __ret); break;			\
	case 4: __put_user_4(_x, ptr, __ret); break;			\
	case 8: __put_user_8(_x, ptr, __ret); break;			\
	default: __ret = __put_user_bad(); break;			\
	}								\
	__ret;								\
})

/*
 * The versions of get_user and put_user without initial underscores
 * check the address of their arguments to make sure they are not
 * in kernel space.
 */
#define put_user(x, ptr)						\
({									\
	__typeof__(*(ptr)) __user *__Pu_addr = (ptr);			\
	access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ?	\
		__put_user((x), (__Pu_addr)) :				\
		-EFAULT;						\
})

#define get_user(x, ptr)						\
({									\
	__typeof__(*(ptr)) const __user *__Gu_addr = (ptr);		\
	access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ?	\
		__get_user((x), (__Gu_addr)) :				\
		((x) = 0, -EFAULT);					\
})

/**
 * __copy_to_user() - copy data into user space, with less checking.
 * @to:   Destination address, in user space.
 * @from: Source address, in kernel space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * Copy data from kernel space to user space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * An alternate version - __copy_to_user_inatomic() - is designed
 * to be called from atomic context, typically bracketed by calls
 * to pagefault_disable() and pagefault_enable().
 */
extern unsigned long __must_check __copy_to_user_inatomic(
	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)
{
	might_fault();
	return __copy_to_user_inatomic(to, from, 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;
}

/**
 * __copy_from_user() - copy data from user space, with less checking.
 * @to:   Destination address, in kernel space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * Copy data from user space to kernel space.  Caller must check
 * the specified block with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 *
 * If some data could not be copied, this function will pad the copied
 * data to the requested size using zero bytes.
 *
 * An alternate version - __copy_from_user_inatomic() - is designed
 * to be called from atomic context, typically bracketed by calls
 * to pagefault_disable() and pagefault_enable().  This version
 * does *NOT* pad with zeros.
 */
extern unsigned long __must_check __copy_from_user_inatomic(
	void *to, const void __user *from, unsigned long n);
extern unsigned long __must_check __copy_from_user_zeroing(
	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)
{
       might_fault();
       return __copy_from_user_zeroing(to, from, n);
}

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
		memset(to, 0, n);
	return n;
}

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

	if (likely(sz == -1 || sz >= n))
		n = _copy_from_user(to, from, n);
	else if (!__builtin_constant_p(n))
		copy_user_overflow(sz, n);
	else
		__bad_copy_user();

	return n;
}

#ifdef __tilegx__
/**
 * __copy_in_user() - copy data within user space, with less checking.
 * @to:   Destination address, in user space.
 * @from: Source address, in user space.
 * @n:    Number of bytes to copy.
 *
 * Context: User context only. This function may sleep if pagefaults are
 *          enabled.
 *
 * Copy data from user space to user space.  Caller must check
 * the specified blocks with access_ok() before calling this function.
 *
 * Returns number of bytes that could not be copied.
 * On success, this will be zero.
 */
extern unsigned long __copy_in_user_inatomic(
	void __user *to, const void __user *from, unsigned long n);

static inline unsigned long __must_check
__copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
	might_fault();
	return __copy_in_user_inatomic(to, from, n);
}

static inline unsigned long __must_check
copy_in_user(void __user *to, const void __user *from, unsigned long n)
{
	if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
		n = __copy_in_user(to, from, n);
	return n;
}
#endif


extern long strnlen_user(const char __user *str, long n);
extern long strlen_user(const char __user *str);
extern long strncpy_from_user(char *dst, const char __user *src, long);

/**
 * clear_user: - Zero a block of memory in user space.
 * @mem:   Destination address, in user space.
 * @len:   Number of bytes to zero.
 *
 * Zero a block of memory in user space.
 *
 * Returns number of bytes that could not be cleared.
 * On success, this will be zero.
 */
extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __clear_user(
	void __user *mem, unsigned long len)
{
	might_fault();
	return clear_user_asm(mem, len);
}
static inline unsigned long __must_check clear_user(
	void __user *mem, unsigned long len)
{
	if (access_ok(VERIFY_WRITE, mem, len))
		return __clear_user(mem, len);
	return len;
}

/**
 * flush_user: - Flush a block of memory in user space from cache.
 * @mem:   Destination address, in user space.
 * @len:   Number of bytes to flush.
 *
 * Returns number of bytes that could not be flushed.
 * On success, this will be zero.
 */
extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __flush_user(
	void __user *mem, unsigned long len)
{
	int retval;

	might_fault();
	retval = flush_user_asm(mem, len);
	mb_incoherent();
	return retval;
}

static inline unsigned long __must_check flush_user(
	void __user *mem, unsigned long len)
{
	if (access_ok(VERIFY_WRITE, mem, len))
		return __flush_user(mem, len);
	return len;
}

/**
 * finv_user: - Flush-inval a block of memory in user space from cache.
 * @mem:   Destination address, in user space.
 * @len:   Number of bytes to invalidate.
 *
 * Returns number of bytes that could not be flush-invalidated.
 * On success, this will be zero.
 */
extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
static inline unsigned long __must_check __finv_user(
	void __user *mem, unsigned long len)
{
	int retval;

	might_fault();
	retval = finv_user_asm(mem, len);
	mb_incoherent();
	return retval;
}
static inline unsigned long __must_check finv_user(
	void __user *mem, unsigned long len)
{
	if (access_ok(VERIFY_WRITE, mem, len))
		return __finv_user(mem, len);
	return len;
}

#endif /* _ASM_TILE_UACCESS_H */
Commit	Line	Data
867e359b CM	1	/*
	2	* Copyright 2010 Tilera Corporation. All Rights Reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation, version 2.
	7	*
	8	* This program is distributed in the hope that it will be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
	11	* NON INFRINGEMENT. See the GNU General Public License for
	12	* more details.
	13	*/
	14
	15	#ifndef _ASM_TILE_UACCESS_H
	16	#define _ASM_TILE_UACCESS_H
	17
	18	/*
	19	* User space memory access functions
	20	*/
	21	#include <linux/sched.h>
	22	#include <linux/mm.h>
	23	#include <asm-generic/uaccess-unaligned.h>
	24	#include <asm/processor.h>
	25	#include <asm/page.h>
	26
	27	#define VERIFY_READ 0
	28	#define VERIFY_WRITE 1
	29
	30	/*
	31	* The fs value determines whether argument validity checking should be
	32	* performed or not. If get_fs() == USER_DS, checking is performed, with
	33	* get_fs() == KERNEL_DS, checking is bypassed.
	34	*
	35	* For historical reasons, these macros are grossly misnamed.
	36	*/
	37	#define MAKE_MM_SEG(a) ((mm_segment_t) { (a) })
	38
	39	#define KERNEL_DS MAKE_MM_SEG(-1UL)
	40	#define USER_DS MAKE_MM_SEG(PAGE_OFFSET)
	41
	42	#define get_ds() (KERNEL_DS)
	43	#define get_fs() (current_thread_info()->addr_limit)
	44	#define set_fs(x) (current_thread_info()->addr_limit = (x))
	45
	46	#define segment_eq(a, b) ((a).seg == (b).seg)
	47
	48	#ifndef __tilegx__
	49	/*
	50	* We could allow mapping all 16 MB at 0xfc000000, but we set up a
	51	* special hack in arch_setup_additional_pages() to auto-create a mapping
	52	* for the first 16 KB, and it would seem strange to have different
	53	* user-accessible semantics for memory at 0xfc000000 and above 0xfc004000.
	54	*/
	55	static inline int is_arch_mappable_range(unsigned long addr,
	56	unsigned long size)
	57	{
	58	return (addr >= MEM_USER_INTRPT &&
	59	addr < (MEM_USER_INTRPT + INTRPT_SIZE) &&
	60	size <= (MEM_USER_INTRPT + INTRPT_SIZE) - addr);
	61	}
	62	#define is_arch_mappable_range is_arch_mappable_range
	63	#else
	64	#define is_arch_mappable_range(addr, size) 0
65	#endif
66
5bf6c07a CM	67	/*
	68	* Note that using this definition ignores is_arch_mappable_range(),
	69	* so on tilepro code that uses user_addr_max() is constrained not
	70	* to reference the tilepro user-interrupt region.
	71	*/
	72	#define user_addr_max() (current_thread_info()->addr_limit.seg)
	73
867e359b CM	74	/*
	75	* Test whether a block of memory is a valid user space address.
	76	* Returns 0 if the range is valid, nonzero otherwise.
	77	*/
	78	int __range_ok(unsigned long addr, unsigned long size);
	79
	80	/**
	81	* access_ok: - Checks if a user space pointer is valid
	82	* @type: Type of access: %VERIFY_READ or %VERIFY_WRITE. Note that
	83	* %VERIFY_WRITE is a superset of %VERIFY_READ - if it is safe
	84	* to write to a block, it is always safe to read from it.
	85	* @addr: User space pointer to start of block to check
	86	* @size: Size of block to check
	87	*
b3c395ef DH	88	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	89	* enabled.
867e359b CM	90	*
	91	* Checks if a pointer to a block of memory in user space is valid.
	92	*
	93	* Returns true (nonzero) if the memory block may be valid, false (zero)
	94	* if it is definitely invalid.
	95	*
	96	* Note that, depending on architecture, this function probably just
	97	* checks that the pointer is in the user space range - after calling
	98	* this function, memory access functions may still return -EFAULT.
	99	*/
0707ad30 CM	100	#define access_ok(type, addr, size) ({ \
	101	__chk_user_ptr(addr); \
	102	likely(__range_ok((unsigned long)(addr), (size)) == 0); \
	103	})
867e359b CM	104
	105	/*
	106	* The exception table consists of pairs of addresses: the first is the
	107	* address of an instruction that is allowed to fault, and the second is
	108	* the address at which the program should continue. No registers are
	109	* modified, so it is entirely up to the continuation code to figure out
	110	* what to do.
	111	*
	112	* All the routines below use bits of fixup code that are out of line
	113	* with the main instruction path. This means when everything is well,
	114	* we don't even have to jump over them. Further, they do not intrude
	115	* on our cache or tlb entries.
	116	*/
	117
	118	struct exception_table_entry {
	119	unsigned long insn, fixup;
	120	};
	121
	122	extern int fixup_exception(struct pt_regs *regs);
	123
f3c92712 CM	124	/*
	125	* This is a type: either unsigned long, if the argument fits into
	126	* that type, or otherwise unsigned long long.
	127	*/
	128	#define __inttype(x) \
	129	__typeof__(__builtin_choose_expr(sizeof(x) > sizeof(0UL), 0ULL, 0UL))
	130
867e359b	131	/*
47d632f9	132	* Support macros for __get_user().
47d632f9	133	* Note that __get_user() and __put_user() assume proper alignment.
867e359b	134	*/
867e359b	135
47d632f9 CM	136	#ifdef __LP64__
47d632f9 CM	137	#define _ASM_PTR ".quad"
d4d9eab4	138	#define _ASM_ALIGN ".align 8"
47d632f9 CM	139	#else
47d632f9 CM	140	#define _ASM_PTR ".long"
d4d9eab4	141	#define _ASM_ALIGN ".align 4"
47d632f9 CM	142	#endif
	143
	144	#define __get_user_asm(OP, x, ptr, ret) \
	145	asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \
	146	".pushsection .fixup,\"ax\"\n" \
	147	"0: { movei %1, 0; movei %0, %3 }\n" \
	148	"j 9f\n" \
	149	".section __ex_table,\"a\"\n" \
d4d9eab4	150	_ASM_ALIGN "\n" \
47d632f9 CM	151	_ASM_PTR " 1b, 0b\n" \
	152	".popsection\n" \
	153	"9:" \
	154	: "=r" (ret), "=r" (x) \
	155	: "r" (ptr), "i" (-EFAULT))
	156
	157	#ifdef __tilegx__
	158	#define __get_user_1(x, ptr, ret) __get_user_asm(ld1u, x, ptr, ret)
	159	#define __get_user_2(x, ptr, ret) __get_user_asm(ld2u, x, ptr, ret)
6699c8cd	160	#define __get_user_4(x, ptr, ret) __get_user_asm(ld4s, x, ptr, ret)
47d632f9 CM	161	#define __get_user_8(x, ptr, ret) __get_user_asm(ld, x, ptr, ret)
	162	#else
	163	#define __get_user_1(x, ptr, ret) __get_user_asm(lb_u, x, ptr, ret)
	164	#define __get_user_2(x, ptr, ret) __get_user_asm(lh_u, x, ptr, ret)
	165	#define __get_user_4(x, ptr, ret) __get_user_asm(lw, x, ptr, ret)
	166	#ifdef __LITTLE_ENDIAN
	167	#define __lo32(a, b) a
	168	#define __hi32(a, b) b
	169	#else
	170	#define __lo32(a, b) b
	171	#define __hi32(a, b) a
	172	#endif
	173	#define __get_user_8(x, ptr, ret) \
	174	({ \
	175	unsigned int __a, __b; \
	176	asm volatile("1: { lw %1, %3; addi %2, %3, 4 }\n" \
	177	"2: { lw %2, %2; movei %0, 0 }\n" \
	178	".pushsection .fixup,\"ax\"\n" \
	179	"0: { movei %1, 0; movei %2, 0 }\n" \
	180	"{ movei %0, %4; j 9f }\n" \
	181	".section __ex_table,\"a\"\n" \
d4d9eab4	182	".align 4\n" \
47d632f9 CM	183	".word 1b, 0b\n" \
	184	".word 2b, 0b\n" \
	185	".popsection\n" \
	186	"9:" \
	187	: "=r" (ret), "=r" (__a), "=&r" (__b) \
	188	: "r" (ptr), "i" (-EFAULT)); \
f3c92712	189	(x) = (__force __typeof(x))(__inttype(x)) \
47d632f9 CM	190	(((u64)__hi32(__a, __b) << 32) \| \
	191	__lo32(__a, __b)); \
	192	})
	193	#endif
	194
	195	extern int __get_user_bad(void)
	196	__attribute__((warning("sizeof __get_user argument not 1, 2, 4 or 8")));
867e359b	197
867e359b CM	198	/**
	199	* __get_user: - Get a simple variable from user space, with less checking.
	200	* @x: Variable to store result.
	201	* @ptr: Source address, in user space.
	202	*
b3c395ef DH	203	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	204	* enabled.
867e359b CM	205	*
	206	* This macro copies a single simple variable from user space to kernel
	207	* space. It supports simple types like char and int, but not larger
	208	* data types like structures or arrays.
	209	*
	210	* @ptr must have pointer-to-simple-variable type, and the result of
	211	* dereferencing @ptr must be assignable to @x without a cast.
	212	*
	213	* Returns zero on success, or -EFAULT on error.
	214	* On error, the variable @x is set to zero.
	215	*
	216	* Caller must check the pointer with access_ok() before calling this
	217	* function.
	218	*/
	219	#define __get_user(x, ptr) \
47d632f9 CM	220	({ \
47d632f9 CM	221	int __ret; \
b9f70575	222	typeof(x) _x; \
47d632f9 CM	223	__chk_user_ptr(ptr); \
47d632f9 CM	224	switch (sizeof(*(ptr))) { \
b9f70575 CM	225	case 1: __get_user_1(_x, ptr, __ret); break; \
	226	case 2: __get_user_2(_x, ptr, __ret); break; \
	227	case 4: __get_user_4(_x, ptr, __ret); break; \
	228	case 8: __get_user_8(_x, ptr, __ret); break; \
47d632f9 CM	229	default: __ret = __get_user_bad(); break; \
47d632f9 CM	230	} \
b9f70575	231	(x) = (typeof(*(ptr))) _x; \
47d632f9 CM	232	__ret; \
	233	})
	234
	235	/* Support macros for __put_user(). */
	236
	237	#define __put_user_asm(OP, x, ptr, ret) \
	238	asm volatile("1: {" #OP " %1, %2; movei %0, 0 }\n" \
	239	".pushsection .fixup,\"ax\"\n" \
	240	"0: { movei %0, %3; j 9f }\n" \
	241	".section __ex_table,\"a\"\n" \
d4d9eab4	242	_ASM_ALIGN "\n" \
47d632f9 CM	243	_ASM_PTR " 1b, 0b\n" \
	244	".popsection\n" \
	245	"9:" \
	246	: "=r" (ret) \
	247	: "r" (ptr), "r" (x), "i" (-EFAULT))
	248
	249	#ifdef __tilegx__
	250	#define __put_user_1(x, ptr, ret) __put_user_asm(st1, x, ptr, ret)
	251	#define __put_user_2(x, ptr, ret) __put_user_asm(st2, x, ptr, ret)
	252	#define __put_user_4(x, ptr, ret) __put_user_asm(st4, x, ptr, ret)
	253	#define __put_user_8(x, ptr, ret) __put_user_asm(st, x, ptr, ret)
	254	#else
	255	#define __put_user_1(x, ptr, ret) __put_user_asm(sb, x, ptr, ret)
	256	#define __put_user_2(x, ptr, ret) __put_user_asm(sh, x, ptr, ret)
	257	#define __put_user_4(x, ptr, ret) __put_user_asm(sw, x, ptr, ret)
	258	#define __put_user_8(x, ptr, ret) \
	259	({ \
f3c92712	260	u64 __x = (__force __inttype(x))(x); \
47d632f9 CM	261	int __lo = (int) __x, __hi = (int) (__x >> 32); \
	262	asm volatile("1: { sw %1, %2; addi %0, %1, 4 }\n" \
	263	"2: { sw %0, %3; movei %0, 0 }\n" \
	264	".pushsection .fixup,\"ax\"\n" \
	265	"0: { movei %0, %4; j 9f }\n" \
	266	".section __ex_table,\"a\"\n" \
d4d9eab4	267	".align 4\n" \
47d632f9 CM	268	".word 1b, 0b\n" \
	269	".word 2b, 0b\n" \
	270	".popsection\n" \
	271	"9:" \
	272	: "=&r" (ret) \
	273	: "r" (ptr), "r" (__lo32(__lo, __hi)), \
	274	"r" (__hi32(__lo, __hi)), "i" (-EFAULT)); \
	275	})
	276	#endif
	277
	278	extern int __put_user_bad(void)
	279	__attribute__((warning("sizeof __put_user argument not 1, 2, 4 or 8")));
867e359b CM	280
	281	/**
	282	* __put_user: - Write a simple value into user space, with less checking.
	283	* @x: Value to copy to user space.
	284	* @ptr: Destination address, in user space.
	285	*
b3c395ef DH	286	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	287	* enabled.
867e359b CM	288	*
	289	* This macro copies a single simple value from kernel space to user
	290	* space. It supports simple types like char and int, but not larger
	291	* data types like structures or arrays.
	292	*
	293	* @ptr must have pointer-to-simple-variable type, and @x must be assignable
	294	* to the result of dereferencing @ptr.
	295	*
	296	* Caller must check the pointer with access_ok() before calling this
	297	* function.
	298	*
	299	* Returns zero on success, or -EFAULT on error.
867e359b CM	300	*/
	301	#define __put_user(x, ptr) \
	302	({ \
47d632f9	303	int __ret; \
b9f70575	304	typeof(*(ptr)) _x = (x); \
47d632f9 CM	305	__chk_user_ptr(ptr); \
47d632f9 CM	306	switch (sizeof(*(ptr))) { \
b9f70575 CM	307	case 1: __put_user_1(_x, ptr, __ret); break; \
	308	case 2: __put_user_2(_x, ptr, __ret); break; \
	309	case 4: __put_user_4(_x, ptr, __ret); break; \
	310	case 8: __put_user_8(_x, ptr, __ret); break; \
47d632f9	311	default: __ret = __put_user_bad(); break; \
867e359b	312	} \
47d632f9	313	__ret; \
867e359b CM	314	})
	315
	316	/*
	317	* The versions of get_user and put_user without initial underscores
	318	* check the address of their arguments to make sure they are not
	319	* in kernel space.
	320	*/
	321	#define put_user(x, ptr) \
	322	({ \
	323	__typeof__((ptr)) __user __Pu_addr = (ptr); \
	324	access_ok(VERIFY_WRITE, (__Pu_addr), sizeof(*(__Pu_addr))) ? \
	325	__put_user((x), (__Pu_addr)) : \
	326	-EFAULT; \
	327	})
	328
	329	#define get_user(x, ptr) \
	330	({ \
	331	__typeof__((ptr)) const __user __Gu_addr = (ptr); \
	332	access_ok(VERIFY_READ, (__Gu_addr), sizeof(*(__Gu_addr))) ? \
	333	__get_user((x), (__Gu_addr)) : \
	334	((x) = 0, -EFAULT); \
	335	})
	336
	337	/**
	338	* __copy_to_user() - copy data into user space, with less checking.
	339	* @to: Destination address, in user space.
	340	* @from: Source address, in kernel space.
	341	* @n: Number of bytes to copy.
	342	*
b3c395ef DH	343	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	344	* enabled.
867e359b CM	345	*
	346	* Copy data from kernel space to user space. Caller must check
	347	* the specified block with access_ok() before calling this function.
	348	*
	349	* Returns number of bytes that could not be copied.
	350	* On success, this will be zero.
	351	*
	352	* An alternate version - __copy_to_user_inatomic() - is designed
	353	* to be called from atomic context, typically bracketed by calls
	354	* to pagefault_disable() and pagefault_enable().
	355	*/
	356	extern unsigned long __must_check __copy_to_user_inatomic(
	357	void __user to, const void from, unsigned long n);
	358
	359	static inline unsigned long __must_check
	360	__copy_to_user(void __user to, const void from, unsigned long n)
	361	{
	362	might_fault();
	363	return __copy_to_user_inatomic(to, from, n);
	364	}
	365
	366	static inline unsigned long __must_check
	367	copy_to_user(void __user to, const void from, unsigned long n)
	368	{
	369	if (access_ok(VERIFY_WRITE, to, n))
	370	n = __copy_to_user(to, from, n);
	371	return n;
	372	}
	373
	374	/**
	375	* __copy_from_user() - copy data from user space, with less checking.
	376	* @to: Destination address, in kernel space.
	377	* @from: Source address, in user space.
	378	* @n: Number of bytes to copy.
	379	*
b3c395ef DH	380	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	381	* enabled.
867e359b CM	382	*
	383	* Copy data from user space to kernel space. Caller must check
	384	* the specified block with access_ok() before calling this function.
	385	*
	386	* Returns number of bytes that could not be copied.
	387	* On success, this will be zero.
	388	*
	389	* If some data could not be copied, this function will pad the copied
	390	* data to the requested size using zero bytes.
	391	*
	392	* An alternate version - __copy_from_user_inatomic() - is designed
	393	* to be called from atomic context, typically bracketed by calls
	394	* to pagefault_disable() and pagefault_enable(). This version
	395	* does NOT pad with zeros.
	396	*/
	397	extern unsigned long __must_check __copy_from_user_inatomic(
	398	void to, const void __user from, unsigned long n);
	399	extern unsigned long __must_check __copy_from_user_zeroing(
	400	void to, const void __user from, unsigned long n);
	401
	402	static inline unsigned long __must_check
	403	__copy_from_user(void to, const void __user from, unsigned long n)
	404	{
	405	might_fault();
	406	return __copy_from_user_zeroing(to, from, n);
	407	}
	408
	409	static inline unsigned long __must_check
	410	_copy_from_user(void to, const void __user from, unsigned long n)
	411	{
	412	if (access_ok(VERIFY_READ, from, n))
	413	n = __copy_from_user(to, from, n);
	414	else
	415	memset(to, 0, n);
	416	return n;
	417	}
	418
0d025d27 JP	419	extern void __compiletime_error("usercopy buffer size is too small")
	420	__bad_copy_user(void);
	421
	422	static inline void copy_user_overflow(int size, unsigned long count)
	423	{
	424	WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
	425	}
867e359b CM	426
	427	static inline unsigned long __must_check copy_from_user(void *to,
	428	const void __user *from,
	429	unsigned long n)
	430	{
	431	int sz = __compiletime_object_size(to);
	432
	433	if (likely(sz == -1 \|\| sz >= n))
	434	n = _copy_from_user(to, from, n);
0d025d27 JP	435	else if (!__builtin_constant_p(n))
0d025d27 JP	436	copy_user_overflow(sz, n);
867e359b	437	else
0d025d27	438	__bad_copy_user();
867e359b CM	439
	440	return n;
	441	}
867e359b CM	442
	443	#ifdef __tilegx__
	444	/**
	445	* __copy_in_user() - copy data within user space, with less checking.
	446	* @to: Destination address, in user space.
47d632f9	447	* @from: Source address, in user space.
867e359b CM	448	* @n: Number of bytes to copy.
867e359b CM	449	*
b3c395ef DH	450	* Context: User context only. This function may sleep if pagefaults are
b3c395ef DH	451	* enabled.
867e359b CM	452	*
	453	* Copy data from user space to user space. Caller must check
	454	* the specified blocks with access_ok() before calling this function.
	455	*
	456	* Returns number of bytes that could not be copied.
	457	* On success, this will be zero.
	458	*/
c745a8a1	459	extern unsigned long __copy_in_user_inatomic(
867e359b CM	460	void __user to, const void __user from, unsigned long n);
	461
	462	static inline unsigned long __must_check
	463	__copy_in_user(void __user to, const void __user from, unsigned long n)
	464	{
f8abe86c	465	might_fault();
c745a8a1	466	return __copy_in_user_inatomic(to, from, n);
867e359b CM	467	}
	468
	469	static inline unsigned long __must_check
	470	copy_in_user(void __user to, const void __user from, unsigned long n)
	471	{
	472	if (access_ok(VERIFY_WRITE, to, n) && access_ok(VERIFY_READ, from, n))
	473	n = __copy_in_user(to, from, n);
	474	return n;
	475	}
	476	#endif
	477
	478
5bf6c07a CM	479	extern long strnlen_user(const char __user *str, long n);
	480	extern long strlen_user(const char __user *str);
	481	extern long strncpy_from_user(char dst, const char __user src, long);
867e359b CM	482
	483	/**
	484	* clear_user: - Zero a block of memory in user space.
	485	* @mem: Destination address, in user space.
	486	* @len: Number of bytes to zero.
	487	*
	488	* Zero a block of memory in user space.
	489	*
	490	* Returns number of bytes that could not be cleared.
	491	* On success, this will be zero.
	492	*/
	493	extern unsigned long clear_user_asm(void __user *mem, unsigned long len);
	494	static inline unsigned long __must_check __clear_user(
	495	void __user *mem, unsigned long len)
	496	{
	497	might_fault();
	498	return clear_user_asm(mem, len);
	499	}
	500	static inline unsigned long __must_check clear_user(
	501	void __user *mem, unsigned long len)
	502	{
	503	if (access_ok(VERIFY_WRITE, mem, len))
	504	return __clear_user(mem, len);
	505	return len;
	506	}
	507
	508	/**
	509	* flush_user: - Flush a block of memory in user space from cache.
	510	* @mem: Destination address, in user space.
	511	* @len: Number of bytes to flush.
	512	*
	513	* Returns number of bytes that could not be flushed.
	514	* On success, this will be zero.
	515	*/
	516	extern unsigned long flush_user_asm(void __user *mem, unsigned long len);
	517	static inline unsigned long __must_check __flush_user(
	518	void __user *mem, unsigned long len)
	519	{
	520	int retval;
	521
	522	might_fault();
	523	retval = flush_user_asm(mem, len);
	524	mb_incoherent();
	525	return retval;
	526	}
	527
	528	static inline unsigned long __must_check flush_user(
	529	void __user *mem, unsigned long len)
	530	{
	531	if (access_ok(VERIFY_WRITE, mem, len))
	532	return __flush_user(mem, len);
	533	return len;
	534	}
	535
867e359b CM	536	/**
	537	* finv_user: - Flush-inval a block of memory in user space from cache.
	538	* @mem: Destination address, in user space.
	539	* @len: Number of bytes to invalidate.
	540	*
	541	* Returns number of bytes that could not be flush-invalidated.
	542	* On success, this will be zero.
	543	*/
	544	extern unsigned long finv_user_asm(void __user *mem, unsigned long len);
	545	static inline unsigned long __must_check __finv_user(
	546	void __user *mem, unsigned long len)
	547	{
	548	int retval;
	549
	550	might_fault();
	551	retval = finv_user_asm(mem, len);
	552	mb_incoherent();
	553	return retval;
	554	}
	555	static inline unsigned long __must_check finv_user(
	556	void __user *mem, unsigned long len)
	557	{
	558	if (access_ok(VERIFY_WRITE, mem, len))
	559	return __finv_user(mem, len);
	560	return len;
	561	}
	562
	563	#endif /* _ASM_TILE_UACCESS_H */