52eb053b71
This was found by make randconfig If the kernel .text is very large, the .fixup section branches are too far away to be relocated correctly. Use "sethi %hi(label), reg; jmpl reg + %lo(label); %g0" sequence instead of the branch to fix this. There is another case in switch_to() involving a branch, which is fixed similarly. Signed-off-by: David S. Miller <davem@davemloft.net>
276 lines
8.6 KiB
C
276 lines
8.6 KiB
C
/* $Id: uaccess.h,v 1.35 2002/02/09 19:49:31 davem Exp $ */
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#ifndef _ASM_UACCESS_H
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#define _ASM_UACCESS_H
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/*
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* User space memory access functions
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*/
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#ifdef __KERNEL__
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#include <linux/compiler.h>
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#include <linux/sched.h>
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#include <linux/string.h>
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#include <asm/a.out.h>
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#include <asm/asi.h>
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#include <asm/system.h>
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#include <asm/spitfire.h>
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#include <asm-generic/uaccess.h>
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#endif
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#ifndef __ASSEMBLY__
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/*
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* Sparc64 is segmented, though more like the M68K than the I386.
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* We use the secondary ASI to address user memory, which references a
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* completely different VM map, thus there is zero chance of the user
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* doing something queer and tricking us into poking kernel memory.
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*
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* What is left here is basically what is needed for the other parts of
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* the kernel that expect to be able to manipulate, erum, "segments".
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* Or perhaps more properly, permissions.
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*
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* "For historical reasons, these macros are grossly misnamed." -Linus
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*/
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#define KERNEL_DS ((mm_segment_t) { ASI_P })
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#define USER_DS ((mm_segment_t) { ASI_AIUS }) /* har har har */
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#define VERIFY_READ 0
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#define VERIFY_WRITE 1
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#define get_fs() ((mm_segment_t) { get_thread_current_ds() })
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#define get_ds() (KERNEL_DS)
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#define segment_eq(a,b) ((a).seg == (b).seg)
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#define set_fs(val) \
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do { \
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set_thread_current_ds((val).seg); \
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__asm__ __volatile__ ("wr %%g0, %0, %%asi" : : "r" ((val).seg)); \
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} while(0)
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static inline int __access_ok(const void __user * addr, unsigned long size)
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{
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return 1;
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}
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static inline int access_ok(int type, const void __user * addr, unsigned long size)
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{
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return 1;
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}
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/*
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* The exception table consists of pairs of addresses: the first is the
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* address of an instruction that is allowed to fault, and the second is
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* the address at which the program should continue. No registers are
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* modified, so it is entirely up to the continuation code to figure out
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* what to do.
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*
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* All the routines below use bits of fixup code that are out of line
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* with the main instruction path. This means when everything is well,
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* we don't even have to jump over them. Further, they do not intrude
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* on our cache or tlb entries.
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*/
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struct exception_table_entry {
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unsigned int insn, fixup;
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};
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extern void __ret_efault(void);
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extern void __retl_efault(void);
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/* Uh, these should become the main single-value transfer routines..
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* They automatically use the right size if we just have the right
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* 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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#define put_user(x,ptr) ({ \
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unsigned long __pu_addr = (unsigned long)(ptr); \
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__chk_user_ptr(ptr); \
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__put_user_nocheck((__typeof__(*(ptr)))(x),__pu_addr,sizeof(*(ptr))); })
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#define get_user(x,ptr) ({ \
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unsigned long __gu_addr = (unsigned long)(ptr); \
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__chk_user_ptr(ptr); \
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__get_user_nocheck((x),__gu_addr,sizeof(*(ptr)),__typeof__(*(ptr))); })
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#define __put_user(x,ptr) put_user(x,ptr)
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#define __get_user(x,ptr) get_user(x,ptr)
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struct __large_struct { unsigned long buf[100]; };
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#define __m(x) ((struct __large_struct *)(x))
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#define __put_user_nocheck(data,addr,size) ({ \
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register int __pu_ret; \
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switch (size) { \
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case 1: __put_user_asm(data,b,addr,__pu_ret); break; \
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case 2: __put_user_asm(data,h,addr,__pu_ret); break; \
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case 4: __put_user_asm(data,w,addr,__pu_ret); break; \
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case 8: __put_user_asm(data,x,addr,__pu_ret); break; \
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default: __pu_ret = __put_user_bad(); break; \
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} __pu_ret; })
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#define __put_user_asm(x,size,addr,ret) \
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__asm__ __volatile__( \
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"/* Put user asm, inline. */\n" \
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"1:\t" "st"#size "a %1, [%2] %%asi\n\t" \
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"clr %0\n" \
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"2:\n\n\t" \
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".section .fixup,#alloc,#execinstr\n\t" \
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".align 4\n" \
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"3:\n\t" \
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"sethi %%hi(2b), %0\n\t" \
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"jmpl %0 + %%lo(2b), %%g0\n\t" \
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" mov %3, %0\n\n\t" \
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".previous\n\t" \
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".section __ex_table,\"a\"\n\t" \
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".align 4\n\t" \
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".word 1b, 3b\n\t" \
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".previous\n\n\t" \
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: "=r" (ret) : "r" (x), "r" (__m(addr)), \
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"i" (-EFAULT))
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extern int __put_user_bad(void);
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#define __get_user_nocheck(data,addr,size,type) ({ \
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register int __gu_ret; \
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register unsigned long __gu_val; \
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switch (size) { \
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case 1: __get_user_asm(__gu_val,ub,addr,__gu_ret); break; \
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case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
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case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
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case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
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default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
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} data = (type) __gu_val; __gu_ret; })
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#define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
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register unsigned long __gu_val __asm__ ("l1"); \
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switch (size) { \
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case 1: __get_user_asm_ret(__gu_val,ub,addr,retval); break; \
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case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
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case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
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case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
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default: if (__get_user_bad()) return retval; \
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} data = (type) __gu_val; })
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#define __get_user_asm(x,size,addr,ret) \
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__asm__ __volatile__( \
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"/* Get user asm, inline. */\n" \
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"1:\t" "ld"#size "a [%2] %%asi, %1\n\t" \
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"clr %0\n" \
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"2:\n\n\t" \
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".section .fixup,#alloc,#execinstr\n\t" \
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".align 4\n" \
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"3:\n\t" \
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"sethi %%hi(2b), %0\n\t" \
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"clr %1\n\t" \
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"jmpl %0 + %%lo(2b), %%g0\n\t" \
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" mov %3, %0\n\n\t" \
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".previous\n\t" \
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".section __ex_table,\"a\"\n\t" \
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".align 4\n\t" \
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".word 1b, 3b\n\n\t" \
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".previous\n\t" \
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: "=r" (ret), "=r" (x) : "r" (__m(addr)), \
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"i" (-EFAULT))
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#define __get_user_asm_ret(x,size,addr,retval) \
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if (__builtin_constant_p(retval) && retval == -EFAULT) \
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__asm__ __volatile__( \
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"/* Get user asm ret, inline. */\n" \
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"1:\t" "ld"#size "a [%1] %%asi, %0\n\n\t" \
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".section __ex_table,\"a\"\n\t" \
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".align 4\n\t" \
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".word 1b,__ret_efault\n\n\t" \
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".previous\n\t" \
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: "=r" (x) : "r" (__m(addr))); \
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else \
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__asm__ __volatile__( \
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"/* Get user asm ret, inline. */\n" \
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"1:\t" "ld"#size "a [%1] %%asi, %0\n\n\t" \
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".section .fixup,#alloc,#execinstr\n\t" \
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".align 4\n" \
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"3:\n\t" \
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"ret\n\t" \
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" restore %%g0, %2, %%o0\n\n\t" \
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".previous\n\t" \
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".section __ex_table,\"a\"\n\t" \
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".align 4\n\t" \
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".word 1b, 3b\n\n\t" \
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".previous\n\t" \
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: "=r" (x) : "r" (__m(addr)), "i" (retval))
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extern int __get_user_bad(void);
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extern unsigned long __must_check ___copy_from_user(void *to,
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const void __user *from,
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unsigned long size);
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extern unsigned long copy_from_user_fixup(void *to, const void __user *from,
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unsigned long size);
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static inline unsigned long __must_check
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copy_from_user(void *to, const void __user *from, unsigned long size)
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{
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unsigned long ret = ___copy_from_user(to, from, size);
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if (unlikely(ret))
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ret = copy_from_user_fixup(to, from, size);
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return ret;
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}
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#define __copy_from_user copy_from_user
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extern unsigned long __must_check ___copy_to_user(void __user *to,
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const void *from,
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unsigned long size);
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extern unsigned long copy_to_user_fixup(void __user *to, const void *from,
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unsigned long size);
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static inline unsigned long __must_check
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copy_to_user(void __user *to, const void *from, unsigned long size)
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{
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unsigned long ret = ___copy_to_user(to, from, size);
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if (unlikely(ret))
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ret = copy_to_user_fixup(to, from, size);
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return ret;
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}
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#define __copy_to_user copy_to_user
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extern unsigned long __must_check ___copy_in_user(void __user *to,
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const void __user *from,
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unsigned long size);
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extern unsigned long copy_in_user_fixup(void __user *to, void __user *from,
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unsigned long size);
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static inline unsigned long __must_check
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copy_in_user(void __user *to, void __user *from, unsigned long size)
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{
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unsigned long ret = ___copy_in_user(to, from, size);
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if (unlikely(ret))
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ret = copy_in_user_fixup(to, from, size);
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return ret;
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}
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#define __copy_in_user copy_in_user
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extern unsigned long __must_check __clear_user(void __user *, unsigned long);
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#define clear_user __clear_user
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extern long __must_check __strncpy_from_user(char *dest, const char __user *src, long count);
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#define strncpy_from_user __strncpy_from_user
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extern long __strlen_user(const char __user *);
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extern long __strnlen_user(const char __user *, long len);
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#define strlen_user __strlen_user
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#define strnlen_user __strnlen_user
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#define __copy_to_user_inatomic __copy_to_user
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#define __copy_from_user_inatomic __copy_from_user
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_UACCESS_H */
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