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Diffstat (limited to 'include/asm-xtensa/uaccess.h')
| -rw-r--r-- | include/asm-xtensa/uaccess.h | 500 |
1 files changed, 0 insertions, 500 deletions
diff --git a/include/asm-xtensa/uaccess.h b/include/asm-xtensa/uaccess.h deleted file mode 100644 index b8528426ab1..00000000000 --- a/include/asm-xtensa/uaccess.h +++ /dev/null @@ -1,500 +0,0 @@ -/* - * include/asm-xtensa/uaccess.h - * - * User space memory access functions - * - * These routines provide basic accessing functions to the user memory - * space for the kernel. This header file provides fuctions such as: - * - * This file is subject to the terms and conditions of the GNU General Public - * License. See the file "COPYING" in the main directory of this archive - * for more details. - * - * Copyright (C) 2001 - 2005 Tensilica Inc. - */ - -#ifndef _XTENSA_UACCESS_H -#define _XTENSA_UACCESS_H - -#include <linux/errno.h> - -#define VERIFY_READ 0 -#define VERIFY_WRITE 1 - -#ifdef __ASSEMBLY__ - -#include <asm/current.h> -#include <asm/asm-offsets.h> -#include <asm/processor.h> -#include <asm/types.h> - -/* - * These assembly macros mirror the C macros that follow below. They - * should always have identical functionality. See - * arch/xtensa/kernel/sys.S for usage. - */ - -#define KERNEL_DS 0 -#define USER_DS 1 - -#define get_ds (KERNEL_DS) - -/* - * get_fs reads current->thread.current_ds into a register. - * On Entry: - * <ad> anything - * <sp> stack - * On Exit: - * <ad> contains current->thread.current_ds - */ - .macro get_fs ad, sp - GET_CURRENT(\ad,\sp) - l32i \ad, \ad, THREAD_CURRENT_DS - .endm - -/* - * set_fs sets current->thread.current_ds to some value. - * On Entry: - * <at> anything (temp register) - * <av> value to write - * <sp> stack - * On Exit: - * <at> destroyed (actually, current) - * <av> preserved, value to write - */ - .macro set_fs at, av, sp - GET_CURRENT(\at,\sp) - s32i \av, \at, THREAD_CURRENT_DS - .endm - -/* - * kernel_ok determines whether we should bypass addr/size checking. - * See the equivalent C-macro version below for clarity. - * On success, kernel_ok branches to a label indicated by parameter - * <success>. This implies that the macro falls through to the next - * insruction on an error. - * - * Note that while this macro can be used independently, we designed - * in for optimal use in the access_ok macro below (i.e., we fall - * through on error). - * - * On Entry: - * <at> anything (temp register) - * <success> label to branch to on success; implies - * fall-through macro on error - * <sp> stack pointer - * On Exit: - * <at> destroyed (actually, current->thread.current_ds) - */ - -#if ((KERNEL_DS != 0) || (USER_DS == 0)) -# error Assembly macro kernel_ok fails -#endif - .macro kernel_ok at, sp, success - get_fs \at, \sp - beqz \at, \success - .endm - -/* - * user_ok determines whether the access to user-space memory is allowed. - * See the equivalent C-macro version below for clarity. - * - * On error, user_ok branches to a label indicated by parameter - * <error>. This implies that the macro falls through to the next - * instruction on success. - * - * Note that while this macro can be used independently, we designed - * in for optimal use in the access_ok macro below (i.e., we fall - * through on success). - * - * On Entry: - * <aa> register containing memory address - * <as> register containing memory size - * <at> temp register - * <error> label to branch to on error; implies fall-through - * macro on success - * On Exit: - * <aa> preserved - * <as> preserved - * <at> destroyed (actually, (TASK_SIZE + 1 - size)) - */ - .macro user_ok aa, as, at, error - movi \at, __XTENSA_UL_CONST(TASK_SIZE) - bgeu \as, \at, \error - sub \at, \at, \as - bgeu \aa, \at, \error - .endm - -/* - * access_ok determines whether a memory access is allowed. See the - * equivalent C-macro version below for clarity. - * - * On error, access_ok branches to a label indicated by parameter - * <error>. This implies that the macro falls through to the next - * instruction on success. - * - * Note that we assume success is the common case, and we optimize the - * branch fall-through case on success. - * - * On Entry: - * <aa> register containing memory address - * <as> register containing memory size - * <at> temp register - * <sp> - * <error> label to branch to on error; implies fall-through - * macro on success - * On Exit: - * <aa> preserved - * <as> preserved - * <at> destroyed - */ - .macro access_ok aa, as, at, sp, error - kernel_ok \at, \sp, .Laccess_ok_\@ - user_ok \aa, \as, \at, \error -.Laccess_ok_\@: - .endm - -#else /* __ASSEMBLY__ not defined */ - -#include <linux/sched.h> -#include <asm/types.h> - -/* - * 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 (Data Segment Register?), these macros are - * grossly misnamed. - */ - -#define KERNEL_DS ((mm_segment_t) { 0 }) -#define USER_DS ((mm_segment_t) { 1 }) - -#define get_ds() (KERNEL_DS) -#define get_fs() (current->thread.current_ds) -#define set_fs(val) (current->thread.current_ds = (val)) - -#define segment_eq(a,b) ((a).seg == (b).seg) - -#define __kernel_ok (segment_eq(get_fs(), KERNEL_DS)) -#define __user_ok(addr,size) (((size) <= TASK_SIZE)&&((addr) <= TASK_SIZE-(size))) -#define __access_ok(addr,size) (__kernel_ok || __user_ok((addr),(size))) -#define access_ok(type,addr,size) __access_ok((unsigned long)(addr),(size)) - -/* - * These are the main single-value transfer routines. They - * automatically use the right size if we just have the right pointer - * type. - * - * This gets kind of ugly. We want to return _two_ values in - * "get_user()" and yet we don't want to do any pointers, because that - * is too much of a performance impact. Thus we have a few rather ugly - * macros here, and hide all the uglyness from the user. - * - * Careful to not - * (a) re-use the arguments for side effects (sizeof is ok) - * (b) require any knowledge of processes at this stage - */ -#define put_user(x,ptr) __put_user_check((x),(ptr),sizeof(*(ptr))) -#define get_user(x,ptr) __get_user_check((x),(ptr),sizeof(*(ptr))) - -/* - * The "__xxx" versions of the user access functions are versions that - * do not verify the address space, that must have been done previously - * with a separate "access_ok()" call (this is used when we do multiple - * accesses to the same area of user memory). - */ -#define __put_user(x,ptr) __put_user_nocheck((x),(ptr),sizeof(*(ptr))) -#define __get_user(x,ptr) __get_user_nocheck((x),(ptr),sizeof(*(ptr))) - - -extern long __put_user_bad(void); - -#define __put_user_nocheck(x,ptr,size) \ -({ \ - long __pu_err; \ - __put_user_size((x),(ptr),(size),__pu_err); \ - __pu_err; \ -}) - -#define __put_user_check(x,ptr,size) \ -({ \ - long __pu_err = -EFAULT; \ - __typeof__(*(ptr)) *__pu_addr = (ptr); \ - if (access_ok(VERIFY_WRITE,__pu_addr,size)) \ - __put_user_size((x),__pu_addr,(size),__pu_err); \ - __pu_err; \ -}) - -#define __put_user_size(x,ptr,size,retval) \ -do { \ - int __cb; \ - retval = 0; \ - switch (size) { \ - case 1: __put_user_asm(x,ptr,retval,1,"s8i",__cb); break; \ - case 2: __put_user_asm(x,ptr,retval,2,"s16i",__cb); break; \ - case 4: __put_user_asm(x,ptr,retval,4,"s32i",__cb); break; \ - case 8: { \ - __typeof__(*ptr) __v64 = x; \ - retval = __copy_to_user(ptr,&__v64,8); \ - break; \ - } \ - default: __put_user_bad(); \ - } \ -} while (0) - - -/* - * Consider a case of a user single load/store would cause both an - * unaligned exception and an MMU-related exception (unaligned - * exceptions happen first): - * - * User code passes a bad variable ptr to a system call. - * Kernel tries to access the variable. - * Unaligned exception occurs. - * Unaligned exception handler tries to make aligned accesses. - * Double exception occurs for MMU-related cause (e.g., page not mapped). - * do_page_fault() thinks the fault address belongs to the kernel, not the - * user, and panics. - * - * The kernel currently prohibits user unaligned accesses. We use the - * __check_align_* macros to check for unaligned addresses before - * accessing user space so we don't crash the kernel. Both - * __put_user_asm and __get_user_asm use these alignment macros, so - * macro-specific labels such as 0f, 1f, %0, %2, and %3 must stay in - * sync. - */ - -#define __check_align_1 "" - -#define __check_align_2 \ - " _bbci.l %3, 0, 1f \n" \ - " movi %0, %4 \n" \ - " _j 2f \n" - -#define __check_align_4 \ - " _bbsi.l %3, 0, 0f \n" \ - " _bbci.l %3, 1, 1f \n" \ - "0: movi %0, %4 \n" \ - " _j 2f \n" - - -/* - * We don't tell gcc that we are accessing memory, but this is OK - * because we do not write to any memory gcc knows about, so there - * are no aliasing issues. - * - * WARNING: If you modify this macro at all, verify that the - * __check_align_* macros still work. - */ -#define __put_user_asm(x, addr, err, align, insn, cb) \ - __asm__ __volatile__( \ - __check_align_##align \ - "1: "insn" %2, %3, 0 \n" \ - "2: \n" \ - " .section .fixup,\"ax\" \n" \ - " .align 4 \n" \ - "4: \n" \ - " .long 2b \n" \ - "5: \n" \ - " l32r %1, 4b \n" \ - " movi %0, %4 \n" \ - " jx %1 \n" \ - " .previous \n" \ - " .section __ex_table,\"a\" \n" \ - " .long 1b, 5b \n" \ - " .previous" \ - :"=r" (err), "=r" (cb) \ - :"r" ((int)(x)), "r" (addr), "i" (-EFAULT), "0" (err)) - -#define __get_user_nocheck(x,ptr,size) \ -({ \ - long __gu_err, __gu_val; \ - __get_user_size(__gu_val,(ptr),(size),__gu_err); \ - (x) = (__typeof__(*(ptr)))__gu_val; \ - __gu_err; \ -}) - -#define __get_user_check(x,ptr,size) \ -({ \ - long __gu_err = -EFAULT, __gu_val = 0; \ - const __typeof__(*(ptr)) *__gu_addr = (ptr); \ - if (access_ok(VERIFY_READ,__gu_addr,size)) \ - __get_user_size(__gu_val,__gu_addr,(size),__gu_err); \ - (x) = (__typeof__(*(ptr)))__gu_val; \ - __gu_err; \ -}) - -extern long __get_user_bad(void); - -#define __get_user_size(x,ptr,size,retval) \ -do { \ - int __cb; \ - retval = 0; \ - switch (size) { \ - case 1: __get_user_asm(x,ptr,retval,1,"l8ui",__cb); break; \ - case 2: __get_user_asm(x,ptr,retval,2,"l16ui",__cb); break; \ - case 4: __get_user_asm(x,ptr,retval,4,"l32i",__cb); break; \ - case 8: retval = __copy_from_user(&x,ptr,8); break; \ - default: (x) = __get_user_bad(); \ - } \ -} while (0) - - -/* - * WARNING: If you modify this macro at all, verify that the - * __check_align_* macros still work. - */ -#define __get_user_asm(x, addr, err, align, insn, cb) \ - __asm__ __volatile__( \ - __check_align_##align \ - "1: "insn" %2, %3, 0 \n" \ - "2: \n" \ - " .section .fixup,\"ax\" \n" \ - " .align 4 \n" \ - "4: \n" \ - " .long 2b \n" \ - "5: \n" \ - " l32r %1, 4b \n" \ - " movi %2, 0 \n" \ - " movi %0, %4 \n" \ - " jx %1 \n" \ - " .previous \n" \ - " .section __ex_table,\"a\" \n" \ - " .long 1b, 5b \n" \ - " .previous" \ - :"=r" (err), "=r" (cb), "=r" (x) \ - :"r" (addr), "i" (-EFAULT), "0" (err)) - - -/* - * Copy to/from user space - */ - -/* - * We use a generic, arbitrary-sized copy subroutine. The Xtensa - * architecture would cause heavy code bloat if we tried to inline - * these functions and provide __constant_copy_* equivalents like the - * i386 versions. __xtensa_copy_user is quite efficient. See the - * .fixup section of __xtensa_copy_user for a discussion on the - * X_zeroing equivalents for Xtensa. - */ - -extern unsigned __xtensa_copy_user(void *to, const void *from, unsigned n); -#define __copy_user(to,from,size) __xtensa_copy_user(to,from,size) - - -static inline unsigned long -__generic_copy_from_user_nocheck(void *to, const void *from, unsigned long n) -{ - return __copy_user(to,from,n); -} - -static inline unsigned long -__generic_copy_to_user_nocheck(void *to, const void *from, unsigned long n) -{ - return __copy_user(to,from,n); -} - -static inline unsigned long -__generic_copy_to_user(void *to, const void *from, unsigned long n) -{ - prefetch(from); - if (access_ok(VERIFY_WRITE, to, n)) - return __copy_user(to,from,n); - return n; -} - -static inline unsigned long -__generic_copy_from_user(void *to, const void *from, unsigned long n) -{ - prefetchw(to); - if (access_ok(VERIFY_READ, from, n)) - return __copy_user(to,from,n); - else - memset(to, 0, n); - return n; -} - -#define copy_to_user(to,from,n) __generic_copy_to_user((to),(from),(n)) -#define copy_from_user(to,from,n) __generic_copy_from_user((to),(from),(n)) -#define __copy_to_user(to,from,n) __generic_copy_to_user_nocheck((to),(from),(n)) -#define __copy_from_user(to,from,n) __generic_copy_from_user_nocheck((to),(from),(n)) -#define __copy_to_user_inatomic __copy_to_user -#define __copy_from_user_inatomic __copy_from_user - - -/* - * We need to return the number of bytes not cleared. Our memset() - * returns zero if a problem occurs while accessing user-space memory. - * In that event, return no memory cleared. Otherwise, zero for - * success. - */ - -static inline unsigned long -__xtensa_clear_user(void *addr, unsigned long size) -{ - if ( ! memset(addr, 0, size) ) - return size; - return 0; -} - -static inline unsigned long -clear_user(void *addr, unsigned long size) -{ - if (access_ok(VERIFY_WRITE, addr, size)) - return __xtensa_clear_user(addr, size); - return size ? -EFAULT : 0; -} - -#define __clear_user __xtensa_clear_user - - -extern long __strncpy_user(char *, const char *, long); -#define __strncpy_from_user __strncpy_user - -static inline long -strncpy_from_user(char *dst, const char *src, long count) -{ - if (access_ok(VERIFY_READ, src, 1)) - return __strncpy_from_user(dst, src, count); - return -EFAULT; -} - - -#define strlen_user(str) strnlen_user((str), TASK_SIZE - 1) - -/* - * Return the size of a string (including the ending 0!) - */ -extern long __strnlen_user(const char *, long); - -static inline long strnlen_user(const char *str, long len) -{ - unsigned long top = __kernel_ok ? ~0UL : TASK_SIZE - 1; - - if ((unsigned long)str > top) - return 0; - return __strnlen_user(str, len); -} - - -struct exception_table_entry -{ - unsigned long insn, fixup; -}; - -/* Returns 0 if exception not found and fixup.unit otherwise. */ - -extern unsigned long search_exception_table(unsigned long addr); -extern void sort_exception_table(void); - -/* Returns the new pc */ -#define fixup_exception(map_reg, fixup_unit, pc) \ -({ \ - fixup_unit; \ -}) - -#endif /* __ASSEMBLY__ */ -#endif /* _XTENSA_UACCESS_H */ |