forked from Minki/linux
csky: User access
The patch adds "user access from kernel" codes. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de>
This commit is contained in:
Guo Ren
parent
c5af58b769
commit
da55128194
416
arch/csky/include/asm/uaccess.h
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416
arch/csky/include/asm/uaccess.h
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@ -0,0 +1,416 @@
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/* SPDX-License-Identifier: GPL-2.0 */
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// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
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#ifndef __ASM_CSKY_UACCESS_H
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#define __ASM_CSKY_UACCESS_H
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/*
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* User space memory access functions
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*/
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#include <linux/compiler.h>
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/version.h>
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#include <asm/segment.h>
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#define VERIFY_READ 0
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#define VERIFY_WRITE 1
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static inline int access_ok(int type, const void *addr, unsigned long size)
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{
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unsigned long limit = current_thread_info()->addr_limit.seg;
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return (((unsigned long)addr < limit) &&
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((unsigned long)(addr + size) < limit));
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}
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static inline int verify_area(int type, const void *addr, unsigned long size)
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{
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return access_ok(type, addr, size) ? 0 : -EFAULT;
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}
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#define __addr_ok(addr) (access_ok(VERIFY_READ, addr, 0))
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extern int __put_user_bad(void);
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/*
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* Tell gcc we read from memory instead of writing: this is because
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* we do not write to any memory gcc knows about, so there are no
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* aliasing issues.
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*/
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/*
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* These are the main single-value transfer routines. They automatically
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* use the right size if we just have the right pointer type.
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*
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* This gets kind of ugly. We want to return _two_ values in "get_user()"
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* and yet we don't want to do any pointers, because that is too much
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* of a performance impact. Thus we have a few rather ugly macros here,
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* and hide all the ugliness from the user.
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*
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* The "__xxx" versions of the user access functions are versions that
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* do not verify the address space, that must have been done previously
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* with a separate "access_ok()" call (this is used when we do multiple
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* accesses to the same area of user memory).
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*
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* As we use the same address space for kernel and user data on
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* Ckcore, we can just do these as direct assignments. (Of course, the
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* exception handling means that it's no longer "just"...)
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*/
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#define put_user(x, ptr) \
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__put_user_check((x), (ptr), sizeof(*(ptr)))
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#define __put_user(x, ptr) \
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__put_user_nocheck((x), (ptr), sizeof(*(ptr)))
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#define __ptr(x) ((unsigned long *)(x))
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#define get_user(x, ptr) \
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__get_user_check((x), (ptr), sizeof(*(ptr)))
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#define __get_user(x, ptr) \
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__get_user_nocheck((x), (ptr), sizeof(*(ptr)))
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#define __put_user_nocheck(x, ptr, size) \
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({ \
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long __pu_err = 0; \
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typeof(*(ptr)) *__pu_addr = (ptr); \
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typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x); \
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if (__pu_addr) \
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__put_user_size(__pu_val, (__pu_addr), (size), \
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__pu_err); \
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__pu_err; \
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})
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#define __put_user_check(x, ptr, size) \
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({ \
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long __pu_err = -EFAULT; \
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typeof(*(ptr)) *__pu_addr = (ptr); \
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typeof(*(ptr)) __pu_val = (typeof(*(ptr)))(x); \
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if (access_ok(VERIFY_WRITE, __pu_addr, size) && __pu_addr) \
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__put_user_size(__pu_val, __pu_addr, (size), __pu_err); \
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__pu_err; \
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})
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#define __put_user_size(x, ptr, size, retval) \
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do { \
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retval = 0; \
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switch (size) { \
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case 1: \
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__put_user_asm_b(x, ptr, retval); \
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break; \
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case 2: \
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__put_user_asm_h(x, ptr, retval); \
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break; \
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case 4: \
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__put_user_asm_w(x, ptr, retval); \
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break; \
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case 8: \
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__put_user_asm_64(x, ptr, retval); \
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break; \
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default: \
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__put_user_bad(); \
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} \
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} while (0)
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/*
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* We don't tell gcc that we are accessing memory, but this is OK
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* because we do not write to any memory gcc knows about, so there
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* are no aliasing issues.
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*
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* Note that PC at a fault is the address *after* the faulting
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* instruction.
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*/
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#define __put_user_asm_b(x, ptr, err) \
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do { \
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int errcode; \
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asm volatile( \
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"1: stb %1, (%2,0) \n" \
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" br 3f \n" \
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"2: mov %0, %3 \n" \
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" br 3f \n" \
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".section __ex_table, \"a\" \n" \
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".align 2 \n" \
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".long 1b,2b \n" \
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".previous \n" \
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"3: \n" \
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: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \
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: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \
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: "memory"); \
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} while (0)
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#define __put_user_asm_h(x, ptr, err) \
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do { \
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int errcode; \
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asm volatile( \
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"1: sth %1, (%2,0) \n" \
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" br 3f \n" \
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"2: mov %0, %3 \n" \
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" br 3f \n" \
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".section __ex_table, \"a\" \n" \
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".align 2 \n" \
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".long 1b,2b \n" \
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".previous \n" \
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"3: \n" \
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: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \
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: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \
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: "memory"); \
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} while (0)
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#define __put_user_asm_w(x, ptr, err) \
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do { \
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int errcode; \
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asm volatile( \
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"1: stw %1, (%2,0) \n" \
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" br 3f \n" \
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"2: mov %0, %3 \n" \
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" br 3f \n" \
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".section __ex_table,\"a\" \n" \
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".align 2 \n" \
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".long 1b, 2b \n" \
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".previous \n" \
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"3: \n" \
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: "=r"(err), "=r"(x), "=r"(ptr), "=r"(errcode) \
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: "0"(err), "1"(x), "2"(ptr), "3"(-EFAULT) \
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: "memory"); \
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} while (0)
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#define __put_user_asm_64(x, ptr, err) \
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do { \
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int tmp; \
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int errcode; \
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typeof(*(ptr))src = (typeof(*(ptr)))x; \
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typeof(*(ptr))*psrc = &src; \
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\
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asm volatile( \
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" ldw %3, (%1, 0) \n" \
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"1: stw %3, (%2, 0) \n" \
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" ldw %3, (%1, 4) \n" \
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"2: stw %3, (%2, 4) \n" \
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" br 4f \n" \
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"3: mov %0, %4 \n" \
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" br 4f \n" \
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".section __ex_table, \"a\" \n" \
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".align 2 \n" \
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".long 1b, 3b \n" \
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".long 2b, 3b \n" \
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".previous \n" \
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"4: \n" \
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: "=r"(err), "=r"(psrc), "=r"(ptr), \
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"=r"(tmp), "=r"(errcode) \
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: "0"(err), "1"(psrc), "2"(ptr), "3"(0), "4"(-EFAULT) \
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: "memory"); \
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} while (0)
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#define __get_user_nocheck(x, ptr, size) \
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({ \
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long __gu_err; \
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__get_user_size(x, (ptr), (size), __gu_err); \
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__gu_err; \
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})
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#define __get_user_check(x, ptr, size) \
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({ \
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int __gu_err = -EFAULT; \
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const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \
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if (access_ok(VERIFY_READ, __gu_ptr, size) && __gu_ptr) \
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__get_user_size(x, __gu_ptr, size, __gu_err); \
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__gu_err; \
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})
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#define __get_user_size(x, ptr, size, retval) \
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do { \
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switch (size) { \
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case 1: \
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__get_user_asm_common((x), ptr, "ldb", retval); \
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break; \
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case 2: \
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__get_user_asm_common((x), ptr, "ldh", retval); \
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break; \
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case 4: \
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__get_user_asm_common((x), ptr, "ldw", retval); \
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break; \
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default: \
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x = 0; \
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(retval) = __get_user_bad(); \
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} \
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} while (0)
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#define __get_user_asm_common(x, ptr, ins, err) \
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do { \
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int errcode; \
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asm volatile( \
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"1: " ins " %1, (%4,0) \n" \
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" br 3f \n" \
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/* Fix up codes */ \
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"2: mov %0, %2 \n" \
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" movi %1, 0 \n" \
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" br 3f \n" \
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".section __ex_table,\"a\" \n" \
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".align 2 \n" \
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".long 1b, 2b \n" \
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".previous \n" \
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"3: \n" \
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: "=r"(err), "=r"(x), "=r"(errcode) \
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: "0"(0), "r"(ptr), "2"(-EFAULT) \
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: "memory"); \
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} while (0)
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extern int __get_user_bad(void);
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#define __copy_user(to, from, n) \
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do { \
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int w0, w1, w2, w3; \
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asm volatile( \
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"0: cmpnei %1, 0 \n" \
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" bf 8f \n" \
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" mov %3, %1 \n" \
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" or %3, %2 \n" \
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" andi %3, 3 \n" \
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" cmpnei %3, 0 \n" \
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" bf 1f \n" \
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" br 5f \n" \
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"1: cmplti %0, 16 \n" /* 4W */ \
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" bt 3f \n" \
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" ldw %3, (%2, 0) \n" \
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" ldw %4, (%2, 4) \n" \
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" ldw %5, (%2, 8) \n" \
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" ldw %6, (%2, 12) \n" \
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"2: stw %3, (%1, 0) \n" \
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"9: stw %4, (%1, 4) \n" \
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"10: stw %5, (%1, 8) \n" \
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"11: stw %6, (%1, 12) \n" \
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" addi %2, 16 \n" \
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" addi %1, 16 \n" \
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" subi %0, 16 \n" \
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" br 1b \n" \
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"3: cmplti %0, 4 \n" /* 1W */ \
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" bt 5f \n" \
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" ldw %3, (%2, 0) \n" \
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"4: stw %3, (%1, 0) \n" \
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" addi %2, 4 \n" \
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" addi %1, 4 \n" \
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" subi %0, 4 \n" \
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" br 3b \n" \
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"5: cmpnei %0, 0 \n" /* 1B */ \
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" bf 8f \n" \
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" ldb %3, (%2, 0) \n" \
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"6: stb %3, (%1, 0) \n" \
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" addi %2, 1 \n" \
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" addi %1, 1 \n" \
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" subi %0, 1 \n" \
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" br 5b \n" \
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"7: br 8f \n" \
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".section __ex_table, \"a\" \n" \
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".align 2 \n" \
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".long 2b, 7b \n" \
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".long 9b, 7b \n" \
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".long 10b, 7b \n" \
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".long 11b, 7b \n" \
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".long 4b, 7b \n" \
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".long 6b, 7b \n" \
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".previous \n" \
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"8: \n" \
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: "=r"(n), "=r"(to), "=r"(from), "=r"(w0), \
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"=r"(w1), "=r"(w2), "=r"(w3) \
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: "0"(n), "1"(to), "2"(from) \
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: "memory"); \
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} while (0)
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#define __copy_user_zeroing(to, from, n) \
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do { \
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int tmp; \
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int nsave; \
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asm volatile( \
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"0: cmpnei %1, 0 \n" \
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" bf 7f \n" \
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" mov %3, %1 \n" \
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" or %3, %2 \n" \
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" andi %3, 3 \n" \
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" cmpnei %3, 0 \n" \
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" bf 1f \n" \
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" br 5f \n" \
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"1: cmplti %0, 16 \n" \
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" bt 3f \n" \
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"2: ldw %3, (%2, 0) \n" \
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"10: ldw %4, (%2, 4) \n" \
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" stw %3, (%1, 0) \n" \
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" stw %4, (%1, 4) \n" \
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"11: ldw %3, (%2, 8) \n" \
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"12: ldw %4, (%2, 12) \n" \
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" stw %3, (%1, 8) \n" \
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" stw %4, (%1, 12) \n" \
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" addi %2, 16 \n" \
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" addi %1, 16 \n" \
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" subi %0, 16 \n" \
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" br 1b \n" \
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"3: cmplti %0, 4 \n" \
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" bt 5f \n" \
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"4: ldw %3, (%2, 0) \n" \
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" stw %3, (%1, 0) \n" \
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" addi %2, 4 \n" \
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" addi %1, 4 \n" \
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" subi %0, 4 \n" \
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" br 3b \n" \
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"5: cmpnei %0, 0 \n" \
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" bf 7f \n" \
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"6: ldb %3, (%2, 0) \n" \
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" stb %3, (%1, 0) \n" \
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" addi %2, 1 \n" \
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" addi %1, 1 \n" \
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" subi %0, 1 \n" \
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" br 5b \n" \
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"8: mov %3, %0 \n" \
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" movi %4, 0 \n" \
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"9: stb %4, (%1, 0) \n" \
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" addi %1, 1 \n" \
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" subi %3, 1 \n" \
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" cmpnei %3, 0 \n" \
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" bt 9b \n" \
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" br 7f \n" \
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".section __ex_table, \"a\" \n" \
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".align 2 \n" \
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".long 2b, 8b \n" \
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".long 10b, 8b \n" \
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".long 11b, 8b \n" \
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".long 12b, 8b \n" \
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".long 4b, 8b \n" \
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".long 6b, 8b \n" \
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".previous \n" \
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"7: \n" \
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: "=r"(n), "=r"(to), "=r"(from), "=r"(nsave), \
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"=r"(tmp) \
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: "0"(n), "1"(to), "2"(from) \
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: "memory"); \
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} while (0)
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unsigned long raw_copy_from_user(void *to, const void *from, unsigned long n);
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unsigned long raw_copy_to_user(void *to, const void *from, unsigned long n);
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unsigned long clear_user(void *to, unsigned long n);
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unsigned long __clear_user(void __user *to, unsigned long n);
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long strncpy_from_user(char *dst, const char *src, long count);
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long __strncpy_from_user(char *dst, const char *src, long count);
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/*
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* Return the size of a string (including the ending 0)
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*
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* Return 0 on exception, a value greater than N if too long
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*/
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long strnlen_user(const char *src, long n);
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#define strlen_user(str) strnlen_user(str, 32767)
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struct exception_table_entry {
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unsigned long insn;
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unsigned long nextinsn;
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};
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extern int fixup_exception(struct pt_regs *regs);
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#endif /* __ASM_CSKY_UACCESS_H */
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262
arch/csky/lib/usercopy.c
Normal file
262
arch/csky/lib/usercopy.c
Normal file
@ -0,0 +1,262 @@
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// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
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#include <linux/uaccess.h>
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#include <linux/types.h>
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unsigned long raw_copy_from_user(void *to, const void *from,
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unsigned long n)
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{
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if (access_ok(VERIFY_READ, from, n))
|
||||
__copy_user_zeroing(to, from, n);
|
||||
else
|
||||
memset(to, 0, n);
|
||||
return n;
|
||||
}
|
||||
EXPORT_SYMBOL(raw_copy_from_user);
|
||||
|
||||
unsigned long raw_copy_to_user(void *to, const void *from,
|
||||
unsigned long n)
|
||||
{
|
||||
if (access_ok(VERIFY_WRITE, to, n))
|
||||
__copy_user(to, from, n);
|
||||
return n;
|
||||
}
|
||||
EXPORT_SYMBOL(raw_copy_to_user);
|
||||
|
||||
|
||||
/*
|
||||
* copy a null terminated string from userspace.
|
||||
*/
|
||||
#define __do_strncpy_from_user(dst, src, count, res) \
|
||||
do { \
|
||||
int tmp; \
|
||||
long faultres; \
|
||||
asm volatile( \
|
||||
" cmpnei %3, 0 \n" \
|
||||
" bf 4f \n" \
|
||||
"1: cmpnei %1, 0 \n" \
|
||||
" bf 5f \n" \
|
||||
"2: ldb %4, (%3, 0) \n" \
|
||||
" stb %4, (%2, 0) \n" \
|
||||
" cmpnei %4, 0 \n" \
|
||||
" bf 3f \n" \
|
||||
" addi %3, 1 \n" \
|
||||
" addi %2, 1 \n" \
|
||||
" subi %1, 1 \n" \
|
||||
" br 1b \n" \
|
||||
"3: subu %0, %1 \n" \
|
||||
" br 5f \n" \
|
||||
"4: mov %0, %5 \n" \
|
||||
" br 5f \n" \
|
||||
".section __ex_table, \"a\" \n" \
|
||||
".align 2 \n" \
|
||||
".long 2b, 4b \n" \
|
||||
".previous \n" \
|
||||
"5: \n" \
|
||||
: "=r"(res), "=r"(count), "=r"(dst), \
|
||||
"=r"(src), "=r"(tmp), "=r"(faultres) \
|
||||
: "5"(-EFAULT), "0"(count), "1"(count), \
|
||||
"2"(dst), "3"(src) \
|
||||
: "memory", "cc"); \
|
||||
} while (0)
|
||||
|
||||
/*
|
||||
* __strncpy_from_user: - Copy a NUL terminated string from userspace,
|
||||
* with less checking.
|
||||
* @dst: Destination address, in kernel space. This buffer must be at
|
||||
* least @count bytes long.
|
||||
* @src: Source address, in user space.
|
||||
* @count: Maximum number of bytes to copy, including the trailing NUL.
|
||||
*
|
||||
* Copies a NUL-terminated string from userspace to kernel space.
|
||||
* Caller must check the specified block with access_ok() before calling
|
||||
* this function.
|
||||
*
|
||||
* On success, returns the length of the string (not including the trailing
|
||||
* NUL).
|
||||
*
|
||||
* If access to userspace fails, returns -EFAULT (some data may have been
|
||||
* copied).
|
||||
*
|
||||
* If @count is smaller than the length of the string, copies @count bytes
|
||||
* and returns @count.
|
||||
*/
|
||||
long __strncpy_from_user(char *dst, const char *src, long count)
|
||||
{
|
||||
long res;
|
||||
|
||||
__do_strncpy_from_user(dst, src, count, res);
|
||||
return res;
|
||||
}
|
||||
EXPORT_SYMBOL(__strncpy_from_user);
|
||||
|
||||
/*
|
||||
* strncpy_from_user: - Copy a NUL terminated string from userspace.
|
||||
* @dst: Destination address, in kernel space. This buffer must be at
|
||||
* least @count bytes long.
|
||||
* @src: Source address, in user space.
|
||||
* @count: Maximum number of bytes to copy, including the trailing NUL.
|
||||
*
|
||||
* Copies a NUL-terminated string from userspace to kernel space.
|
||||
*
|
||||
* On success, returns the length of the string (not including the trailing
|
||||
* NUL).
|
||||
*
|
||||
* If access to userspace fails, returns -EFAULT (some data may have been
|
||||
* copied).
|
||||
*
|
||||
* If @count is smaller than the length of the string, copies @count bytes
|
||||
* and returns @count.
|
||||
*/
|
||||
long strncpy_from_user(char *dst, const char *src, long count)
|
||||
{
|
||||
long res = -EFAULT;
|
||||
|
||||
if (access_ok(VERIFY_READ, src, 1))
|
||||
__do_strncpy_from_user(dst, src, count, res);
|
||||
return res;
|
||||
}
|
||||
EXPORT_SYMBOL(strncpy_from_user);
|
||||
|
||||
/*
|
||||
* strlen_user: - Get the size of a string in user space.
|
||||
* @str: The string to measure.
|
||||
* @n: The maximum valid length
|
||||
*
|
||||
* Get the size of a NUL-terminated string in user space.
|
||||
*
|
||||
* Returns the size of the string INCLUDING the terminating NUL.
|
||||
* On exception, returns 0.
|
||||
* If the string is too long, returns a value greater than @n.
|
||||
*/
|
||||
long strnlen_user(const char *s, long n)
|
||||
{
|
||||
unsigned long res, tmp;
|
||||
|
||||
if (s == NULL)
|
||||
return 0;
|
||||
|
||||
asm volatile(
|
||||
" cmpnei %1, 0 \n"
|
||||
" bf 3f \n"
|
||||
"1: cmpnei %0, 0 \n"
|
||||
" bf 3f \n"
|
||||
"2: ldb %3, (%1, 0) \n"
|
||||
" cmpnei %3, 0 \n"
|
||||
" bf 3f \n"
|
||||
" subi %0, 1 \n"
|
||||
" addi %1, 1 \n"
|
||||
" br 1b \n"
|
||||
"3: subu %2, %0 \n"
|
||||
" addi %2, 1 \n"
|
||||
" br 5f \n"
|
||||
"4: movi %0, 0 \n"
|
||||
" br 5f \n"
|
||||
".section __ex_table, \"a\" \n"
|
||||
".align 2 \n"
|
||||
".long 2b, 4b \n"
|
||||
".previous \n"
|
||||
"5: \n"
|
||||
: "=r"(n), "=r"(s), "=r"(res), "=r"(tmp)
|
||||
: "0"(n), "1"(s), "2"(n)
|
||||
: "memory", "cc");
|
||||
|
||||
return res;
|
||||
}
|
||||
EXPORT_SYMBOL(strnlen_user);
|
||||
|
||||
#define __do_clear_user(addr, size) \
|
||||
do { \
|
||||
int __d0, zvalue, tmp; \
|
||||
\
|
||||
asm volatile( \
|
||||
"0: cmpnei %1, 0 \n" \
|
||||
" bf 7f \n" \
|
||||
" mov %3, %1 \n" \
|
||||
" andi %3, 3 \n" \
|
||||
" cmpnei %3, 0 \n" \
|
||||
" bf 1f \n" \
|
||||
" br 5f \n" \
|
||||
"1: cmplti %0, 32 \n" /* 4W */ \
|
||||
" bt 3f \n" \
|
||||
"8: stw %2, (%1, 0) \n" \
|
||||
"10: stw %2, (%1, 4) \n" \
|
||||
"11: stw %2, (%1, 8) \n" \
|
||||
"12: stw %2, (%1, 12) \n" \
|
||||
"13: stw %2, (%1, 16) \n" \
|
||||
"14: stw %2, (%1, 20) \n" \
|
||||
"15: stw %2, (%1, 24) \n" \
|
||||
"16: stw %2, (%1, 28) \n" \
|
||||
" addi %1, 32 \n" \
|
||||
" subi %0, 32 \n" \
|
||||
" br 1b \n" \
|
||||
"3: cmplti %0, 4 \n" /* 1W */ \
|
||||
" bt 5f \n" \
|
||||
"4: stw %2, (%1, 0) \n" \
|
||||
" addi %1, 4 \n" \
|
||||
" subi %0, 4 \n" \
|
||||
" br 3b \n" \
|
||||
"5: cmpnei %0, 0 \n" /* 1B */ \
|
||||
"9: bf 7f \n" \
|
||||
"6: stb %2, (%1, 0) \n" \
|
||||
" addi %1, 1 \n" \
|
||||
" subi %0, 1 \n" \
|
||||
" br 5b \n" \
|
||||
".section __ex_table,\"a\" \n" \
|
||||
".align 2 \n" \
|
||||
".long 8b, 9b \n" \
|
||||
".long 10b, 9b \n" \
|
||||
".long 11b, 9b \n" \
|
||||
".long 12b, 9b \n" \
|
||||
".long 13b, 9b \n" \
|
||||
".long 14b, 9b \n" \
|
||||
".long 15b, 9b \n" \
|
||||
".long 16b, 9b \n" \
|
||||
".long 4b, 9b \n" \
|
||||
".long 6b, 9b \n" \
|
||||
".previous \n" \
|
||||
"7: \n" \
|
||||
: "=r"(size), "=r" (__d0), \
|
||||
"=r"(zvalue), "=r"(tmp) \
|
||||
: "0"(size), "1"(addr), "2"(0) \
|
||||
: "memory", "cc"); \
|
||||
} while (0)
|
||||
|
||||
/*
|
||||
* clear_user: - Zero a block of memory in user space.
|
||||
* @to: Destination address, in user space.
|
||||
* @n: 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.
|
||||
*/
|
||||
unsigned long
|
||||
clear_user(void __user *to, unsigned long n)
|
||||
{
|
||||
if (access_ok(VERIFY_WRITE, to, n))
|
||||
__do_clear_user(to, n);
|
||||
return n;
|
||||
}
|
||||
EXPORT_SYMBOL(clear_user);
|
||||
|
||||
/*
|
||||
* __clear_user: - Zero a block of memory in user space, with less checking.
|
||||
* @to: Destination address, in user space.
|
||||
* @n: Number of bytes to zero.
|
||||
*
|
||||
* Zero a block of memory in user space. Caller must check
|
||||
* the specified block with access_ok() before calling this function.
|
||||
*
|
||||
* Returns number of bytes that could not be cleared.
|
||||
* On success, this will be zero.
|
||||
*/
|
||||
unsigned long
|
||||
__clear_user(void __user *to, unsigned long n)
|
||||
{
|
||||
__do_clear_user(to, n);
|
||||
return n;
|
||||
}
|
||||
EXPORT_SYMBOL(__clear_user);
|
||||
Loading…
Reference in New Issue
Block a user