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							- #ifndef _ASM_IA64_UACCESS_H
 
- #define _ASM_IA64_UACCESS_H
 
- /*
 
-  * This file defines various macros to transfer memory areas across
 
-  * the user/kernel boundary.  This needs to be done carefully because
 
-  * this code is executed in kernel mode and uses user-specified
 
-  * addresses.  Thus, we need to be careful not to let the user to
 
-  * trick us into accessing kernel memory that would normally be
 
-  * inaccessible.  This code is also fairly performance sensitive,
 
-  * so we want to spend as little time doing safety checks as
 
-  * possible.
 
-  *
 
-  * To make matters a bit more interesting, these macros sometimes also
 
-  * called from within the kernel itself, in which case the address
 
-  * validity check must be skipped.  The get_fs() macro tells us what
 
-  * to do: if get_fs()==USER_DS, checking is performed, if
 
-  * get_fs()==KERNEL_DS, checking is bypassed.
 
-  *
 
-  * Note that even if the memory area specified by the user is in a
 
-  * valid address range, it is still possible that we'll get a page
 
-  * fault while accessing it.  This is handled by filling out an
 
-  * exception handler fixup entry for each instruction that has the
 
-  * potential to fault.  When such a fault occurs, the page fault
 
-  * handler checks to see whether the faulting instruction has a fixup
 
-  * associated and, if so, sets r8 to -EFAULT and clears r9 to 0 and
 
-  * then resumes execution at the continuation point.
 
-  *
 
-  * Based on <asm-alpha/uaccess.h>.
 
-  *
 
-  * Copyright (C) 1998, 1999, 2001-2004 Hewlett-Packard Co
 
-  *	David Mosberger-Tang <davidm@hpl.hp.com>
 
-  */
 
- #include <linux/compiler.h>
 
- #include <linux/errno.h>
 
- #include <linux/sched.h>
 
- #include <linux/page-flags.h>
 
- #include <linux/mm.h>
 
- #include <asm/intrinsics.h>
 
- #include <asm/pgtable.h>
 
- #include <asm/io.h>
 
- /*
 
-  * For historical reasons, the following macros are grossly misnamed:
 
-  */
 
- #define KERNEL_DS	((mm_segment_t) { ~0UL })		/* cf. access_ok() */
 
- #define USER_DS		((mm_segment_t) { TASK_SIZE-1 })	/* cf. access_ok() */
 
- #define VERIFY_READ	0
 
- #define VERIFY_WRITE	1
 
- #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)
 
- /*
 
-  * When accessing user memory, we need to make sure the entire area really is in
 
-  * user-level space.  In order to do this efficiently, we make sure that the page at
 
-  * address TASK_SIZE is never valid.  We also need to make sure that the address doesn't
 
-  * point inside the virtually mapped linear page table.
 
-  */
 
- #define __access_ok(addr, size, segment)						\
 
- ({											\
 
- 	__chk_user_ptr(addr);								\
 
- 	(likely((unsigned long) (addr) <= (segment).seg)				\
 
- 	 && ((segment).seg == KERNEL_DS.seg						\
 
- 	     || likely(REGION_OFFSET((unsigned long) (addr)) < RGN_MAP_LIMIT)));	\
 
- })
 
- #define access_ok(type, addr, size)	__access_ok((addr), (size), get_fs())
 
- /*
 
-  * These are the main single-value transfer routines.  They automatically
 
-  * use the right size if we just have the right pointer type.
 
-  *
 
-  * Careful to not
 
-  * (a) re-use the arguments for side effects (sizeof/typeof is ok)
 
-  * (b) require any knowledge of processes at this stage
 
-  */
 
- #define put_user(x, ptr)	__put_user_check((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)), get_fs())
 
- #define get_user(x, ptr)	__get_user_check((x), (ptr), sizeof(*(ptr)), get_fs())
 
- /*
 
-  * The "__xxx" versions do not do address space checking, useful when
 
-  * doing multiple accesses to the same area (the programmer has to do the
 
-  * checks by hand with "access_ok()")
 
-  */
 
- #define __put_user(x, ptr)	__put_user_nocheck((__typeof__(*(ptr))) (x), (ptr), sizeof(*(ptr)))
 
- #define __get_user(x, ptr)	__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
 
- extern long __put_user_unaligned_unknown (void);
 
- #define __put_user_unaligned(x, ptr)								\
 
- ({												\
 
- 	long __ret;										\
 
- 	switch (sizeof(*(ptr))) {								\
 
- 		case 1: __ret = __put_user((x), (ptr)); break;					\
 
- 		case 2: __ret = (__put_user((x), (u8 __user *)(ptr)))				\
 
- 			| (__put_user((x) >> 8, ((u8 __user *)(ptr) + 1))); break;		\
 
- 		case 4: __ret = (__put_user((x), (u16 __user *)(ptr)))				\
 
- 			| (__put_user((x) >> 16, ((u16 __user *)(ptr) + 1))); break;		\
 
- 		case 8: __ret = (__put_user((x), (u32 __user *)(ptr)))				\
 
- 			| (__put_user((x) >> 32, ((u32 __user *)(ptr) + 1))); break;		\
 
- 		default: __ret = __put_user_unaligned_unknown();				\
 
- 	}											\
 
- 	__ret;											\
 
- })
 
- extern long __get_user_unaligned_unknown (void);
 
- #define __get_user_unaligned(x, ptr)								\
 
- ({												\
 
- 	long __ret;										\
 
- 	switch (sizeof(*(ptr))) {								\
 
- 		case 1: __ret = __get_user((x), (ptr)); break;					\
 
- 		case 2: __ret = (__get_user((x), (u8 __user *)(ptr)))				\
 
- 			| (__get_user((x) >> 8, ((u8 __user *)(ptr) + 1))); break;		\
 
- 		case 4: __ret = (__get_user((x), (u16 __user *)(ptr)))				\
 
- 			| (__get_user((x) >> 16, ((u16 __user *)(ptr) + 1))); break;		\
 
- 		case 8: __ret = (__get_user((x), (u32 __user *)(ptr)))				\
 
- 			| (__get_user((x) >> 32, ((u32 __user *)(ptr) + 1))); break;		\
 
- 		default: __ret = __get_user_unaligned_unknown();				\
 
- 	}											\
 
- 	__ret;											\
 
- })
 
- #ifdef ASM_SUPPORTED
 
-   struct __large_struct { unsigned long buf[100]; };
 
- # define __m(x) (*(struct __large_struct __user *)(x))
 
- /* We need to declare the __ex_table section before we can use it in .xdata.  */
 
- asm (".section \"__ex_table\", \"a\"\n\t.previous");
 
- # define __get_user_size(val, addr, n, err)							\
 
- do {												\
 
- 	register long __gu_r8 asm ("r8") = 0;							\
 
- 	register long __gu_r9 asm ("r9");							\
 
- 	asm ("\n[1:]\tld"#n" %0=%2%P2\t// %0 and %1 get overwritten by exception handler\n"	\
 
- 	     "\t.xdata4 \"__ex_table\", 1b-., 1f-.+4\n"						\
 
- 	     "[1:]"										\
 
- 	     : "=r"(__gu_r9), "=r"(__gu_r8) : "m"(__m(addr)), "1"(__gu_r8));			\
 
- 	(err) = __gu_r8;									\
 
- 	(val) = __gu_r9;									\
 
- } while (0)
 
- /*
 
-  * The "__put_user_size()" macro tells gcc it reads from memory instead of writing it.  This
 
-  * is because they do not write to any memory gcc knows about, so there are no aliasing
 
-  * issues.
 
-  */
 
- # define __put_user_size(val, addr, n, err)							\
 
- do {												\
 
- 	register long __pu_r8 asm ("r8") = 0;							\
 
- 	asm volatile ("\n[1:]\tst"#n" %1=%r2%P1\t// %0 gets overwritten by exception handler\n"	\
 
- 		      "\t.xdata4 \"__ex_table\", 1b-., 1f-.\n"					\
 
- 		      "[1:]"									\
 
- 		      : "=r"(__pu_r8) : "m"(__m(addr)), "rO"(val), "0"(__pu_r8));		\
 
- 	(err) = __pu_r8;									\
 
- } while (0)
 
- #else /* !ASM_SUPPORTED */
 
- # define RELOC_TYPE	2	/* ip-rel */
 
- # define __get_user_size(val, addr, n, err)				\
 
- do {									\
 
- 	__ld_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE);	\
 
- 	(err) = ia64_getreg(_IA64_REG_R8);				\
 
- 	(val) = ia64_getreg(_IA64_REG_R9);				\
 
- } while (0)
 
- # define __put_user_size(val, addr, n, err)							\
 
- do {												\
 
- 	__st_user("__ex_table", (unsigned long) addr, n, RELOC_TYPE, (unsigned long) (val));	\
 
- 	(err) = ia64_getreg(_IA64_REG_R8);							\
 
- } while (0)
 
- #endif /* !ASM_SUPPORTED */
 
- extern void __get_user_unknown (void);
 
- /*
 
-  * Evaluating arguments X, PTR, SIZE, and SEGMENT may involve subroutine-calls, which
 
-  * could clobber r8 and r9 (among others).  Thus, be careful not to evaluate it while
 
-  * using r8/r9.
 
-  */
 
- #define __do_get_user(check, x, ptr, size, segment)					\
 
- ({											\
 
- 	const __typeof__(*(ptr)) __user *__gu_ptr = (ptr);				\
 
- 	__typeof__ (size) __gu_size = (size);						\
 
- 	long __gu_err = -EFAULT;							\
 
- 	unsigned long __gu_val = 0;							\
 
- 	if (!check || __access_ok(__gu_ptr, size, segment))				\
 
- 		switch (__gu_size) {							\
 
- 		      case 1: __get_user_size(__gu_val, __gu_ptr, 1, __gu_err); break;	\
 
- 		      case 2: __get_user_size(__gu_val, __gu_ptr, 2, __gu_err); break;	\
 
- 		      case 4: __get_user_size(__gu_val, __gu_ptr, 4, __gu_err); break;	\
 
- 		      case 8: __get_user_size(__gu_val, __gu_ptr, 8, __gu_err); break;	\
 
- 		      default: __get_user_unknown(); break;				\
 
- 		}									\
 
- 	(x) = (__typeof__(*(__gu_ptr))) __gu_val;					\
 
- 	__gu_err;									\
 
- })
 
- #define __get_user_nocheck(x, ptr, size)	__do_get_user(0, x, ptr, size, KERNEL_DS)
 
- #define __get_user_check(x, ptr, size, segment)	__do_get_user(1, x, ptr, size, segment)
 
- extern void __put_user_unknown (void);
 
 
  |