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40faf463e6
There are situations in which the architecture wants to use the register that represents its word-size, whatever it is. For those, introduce __ASM_REG in asm.h, along with the first users _ASM_AX and _ASM_DX. They have users waiting for it, namely the getuser functions. Signed-off-by: Glauber Costa <gcosta@redhat.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
80 lines
1.5 KiB
ArmAsm
80 lines
1.5 KiB
ArmAsm
/*
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* __get_user functions.
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*
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* (C) Copyright 1998 Linus Torvalds
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*
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* These functions have a non-standard call interface
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* to make them more efficient, especially as they
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* return an error value in addition to the "real"
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* return value.
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*/
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#include <linux/linkage.h>
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#include <asm/dwarf2.h>
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#include <asm/thread_info.h>
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#include <asm/asm.h>
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/*
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* __get_user_X
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*
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* Inputs: %eax contains the address
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*
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* Outputs: %eax is error code (0 or -EFAULT)
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* %edx contains zero-extended value
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*
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* These functions should not modify any other registers,
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* as they get called from within inline assembly.
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*/
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.text
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ENTRY(__get_user_1)
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CFI_STARTPROC
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GET_THREAD_INFO(%_ASM_DX)
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cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
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jae bad_get_user
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1: movzb (%_ASM_AX),%edx
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xor %eax,%eax
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ret
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CFI_ENDPROC
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ENDPROC(__get_user_1)
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ENTRY(__get_user_2)
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CFI_STARTPROC
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add $1,%_ASM_AX
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jc bad_get_user
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GET_THREAD_INFO(%_ASM_DX)
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cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
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jae bad_get_user
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2: movzwl -1(%_ASM_AX),%edx
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xor %eax,%eax
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ret
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CFI_ENDPROC
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ENDPROC(__get_user_2)
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ENTRY(__get_user_4)
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CFI_STARTPROC
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add $3,%_ASM_AX
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jc bad_get_user
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GET_THREAD_INFO(%_ASM_DX)
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cmp TI_addr_limit(%_ASM_DX),%_ASM_AX
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jae bad_get_user
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3: mov -3(%_ASM_AX),%edx
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xor %eax,%eax
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ret
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CFI_ENDPROC
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ENDPROC(__get_user_4)
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bad_get_user:
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CFI_STARTPROC
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xor %edx,%edx
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mov $-14,%_ASM_AX
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ret
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CFI_ENDPROC
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END(bad_get_user)
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.section __ex_table,"a"
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.long 1b,bad_get_user
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.long 2b,bad_get_user
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.long 3b,bad_get_user
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.previous
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