/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* __put_user functions.
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*
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* (C) Copyright 2005 Linus Torvalds
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* (C) Copyright 2005 Andi Kleen
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* (C) Copyright 2008 Glauber Costa
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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/thread_info.h>
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#include <asm/errno.h>
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#include <asm/asm.h>
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#include <asm/smap.h>
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#include <asm/export.h>
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/*
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* __put_user_X
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*
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* Inputs: %eax[:%edx] contains the data
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* %ecx contains the address
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*
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* Outputs: %ecx is error code (0 or -EFAULT)
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*
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* Clobbers: %ebx needed for task pointer
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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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#ifdef CONFIG_X86_5LEVEL
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#define LOAD_TASK_SIZE_MINUS_N(n) \
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ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rbx), \
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__stringify(mov $((1 << 56) - 4096 - (n)),%rbx), X86_FEATURE_LA57
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#else
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#define LOAD_TASK_SIZE_MINUS_N(n) \
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mov $(TASK_SIZE_MAX - (n)),%_ASM_BX
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#endif
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.text
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SYM_FUNC_START(__put_user_1)
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LOAD_TASK_SIZE_MINUS_N(0)
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cmp %_ASM_BX,%_ASM_CX
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jae .Lbad_put_user
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SYM_INNER_LABEL(__put_user_nocheck_1, SYM_L_GLOBAL)
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ASM_STAC
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1: movb %al,(%_ASM_CX)
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xor %ecx,%ecx
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ASM_CLAC
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RET
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SYM_FUNC_END(__put_user_1)
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EXPORT_SYMBOL(__put_user_1)
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EXPORT_SYMBOL(__put_user_nocheck_1)
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SYM_FUNC_START(__put_user_2)
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LOAD_TASK_SIZE_MINUS_N(1)
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cmp %_ASM_BX,%_ASM_CX
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jae .Lbad_put_user
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SYM_INNER_LABEL(__put_user_nocheck_2, SYM_L_GLOBAL)
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ASM_STAC
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2: movw %ax,(%_ASM_CX)
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xor %ecx,%ecx
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ASM_CLAC
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RET
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SYM_FUNC_END(__put_user_2)
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EXPORT_SYMBOL(__put_user_2)
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EXPORT_SYMBOL(__put_user_nocheck_2)
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SYM_FUNC_START(__put_user_4)
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LOAD_TASK_SIZE_MINUS_N(3)
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cmp %_ASM_BX,%_ASM_CX
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jae .Lbad_put_user
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SYM_INNER_LABEL(__put_user_nocheck_4, SYM_L_GLOBAL)
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ASM_STAC
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3: movl %eax,(%_ASM_CX)
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xor %ecx,%ecx
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ASM_CLAC
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RET
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SYM_FUNC_END(__put_user_4)
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EXPORT_SYMBOL(__put_user_4)
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EXPORT_SYMBOL(__put_user_nocheck_4)
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SYM_FUNC_START(__put_user_8)
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LOAD_TASK_SIZE_MINUS_N(7)
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cmp %_ASM_BX,%_ASM_CX
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jae .Lbad_put_user
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SYM_INNER_LABEL(__put_user_nocheck_8, SYM_L_GLOBAL)
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ASM_STAC
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4: mov %_ASM_AX,(%_ASM_CX)
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#ifdef CONFIG_X86_32
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5: movl %edx,4(%_ASM_CX)
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#endif
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xor %ecx,%ecx
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ASM_CLAC
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RET
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SYM_FUNC_END(__put_user_8)
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EXPORT_SYMBOL(__put_user_8)
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EXPORT_SYMBOL(__put_user_nocheck_8)
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SYM_CODE_START_LOCAL(.Lbad_put_user_clac)
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ASM_CLAC
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.Lbad_put_user:
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movl $-EFAULT,%ecx
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RET
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SYM_CODE_END(.Lbad_put_user_clac)
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_ASM_EXTABLE_UA(1b, .Lbad_put_user_clac)
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_ASM_EXTABLE_UA(2b, .Lbad_put_user_clac)
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_ASM_EXTABLE_UA(3b, .Lbad_put_user_clac)
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_ASM_EXTABLE_UA(4b, .Lbad_put_user_clac)
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#ifdef CONFIG_X86_32
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_ASM_EXTABLE_UA(5b, .Lbad_put_user_clac)
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#endif
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