| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208 | #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);
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