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- /* SPDX-License-Identifier: GPL-2.0 */
- /*
- * __put_user functions.
- *
- * (C) Copyright 2005 Linus Torvalds
- * (C) Copyright 2005 Andi Kleen
- * (C) Copyright 2008 Glauber Costa
- *
- * These functions have a non-standard call interface
- * to make them more efficient, especially as they
- * return an error value in addition to the "real"
- * return value.
- */
- #include <linux/export.h>
- #include <linux/linkage.h>
- #include <asm/thread_info.h>
- #include <asm/errno.h>
- #include <asm/asm.h>
- #include <asm/smap.h>
- /*
- * __put_user_X
- *
- * Inputs: %eax[:%edx] contains the data
- * %ecx contains the address
- *
- * Outputs: %ecx is error code (0 or -EFAULT)
- *
- * Clobbers: %ebx needed for task pointer
- *
- * These functions should not modify any other registers,
- * as they get called from within inline assembly.
- */
- .macro check_range size:req
- .if IS_ENABLED(CONFIG_X86_64)
- mov %rcx, %rbx
- sar $63, %rbx
- or %rbx, %rcx
- .else
- cmp $TASK_SIZE_MAX-\size+1, %ecx
- jae .Lbad_put_user
- .endif
- .endm
- .text
- SYM_FUNC_START(__put_user_1)
- check_range size=1
- ASM_STAC
- 1: movb %al,(%_ASM_CX)
- xor %ecx,%ecx
- ASM_CLAC
- RET
- SYM_FUNC_END(__put_user_1)
- EXPORT_SYMBOL(__put_user_1)
- SYM_FUNC_START(__put_user_nocheck_1)
- ASM_STAC
- 2: movb %al,(%_ASM_CX)
- xor %ecx,%ecx
- ASM_CLAC
- RET
- SYM_FUNC_END(__put_user_nocheck_1)
- EXPORT_SYMBOL(__put_user_nocheck_1)
- SYM_FUNC_START(__put_user_2)
- check_range size=2
- ASM_STAC
- 3: movw %ax,(%_ASM_CX)
- xor %ecx,%ecx
- ASM_CLAC
- RET
- SYM_FUNC_END(__put_user_2)
- EXPORT_SYMBOL(__put_user_2)
- SYM_FUNC_START(__put_user_nocheck_2)
- ASM_STAC
- 4: movw %ax,(%_ASM_CX)
- xor %ecx,%ecx
- ASM_CLAC
- RET
- SYM_FUNC_END(__put_user_nocheck_2)
- EXPORT_SYMBOL(__put_user_nocheck_2)
- SYM_FUNC_START(__put_user_4)
- check_range size=4
- ASM_STAC
- 5: movl %eax,(%_ASM_CX)
- xor %ecx,%ecx
- ASM_CLAC
- RET
- SYM_FUNC_END(__put_user_4)
- EXPORT_SYMBOL(__put_user_4)
- SYM_FUNC_START(__put_user_nocheck_4)
- ASM_STAC
- 6: movl %eax,(%_ASM_CX)
- xor %ecx,%ecx
- ASM_CLAC
- RET
- SYM_FUNC_END(__put_user_nocheck_4)
- EXPORT_SYMBOL(__put_user_nocheck_4)
- SYM_FUNC_START(__put_user_8)
- check_range size=8
- ASM_STAC
- 7: mov %_ASM_AX,(%_ASM_CX)
- #ifdef CONFIG_X86_32
- 8: movl %edx,4(%_ASM_CX)
- #endif
- xor %ecx,%ecx
- ASM_CLAC
- RET
- SYM_FUNC_END(__put_user_8)
- EXPORT_SYMBOL(__put_user_8)
- SYM_FUNC_START(__put_user_nocheck_8)
- ASM_STAC
- 9: mov %_ASM_AX,(%_ASM_CX)
- #ifdef CONFIG_X86_32
- 10: movl %edx,4(%_ASM_CX)
- #endif
- xor %ecx,%ecx
- ASM_CLAC
- RET
- SYM_FUNC_END(__put_user_nocheck_8)
- EXPORT_SYMBOL(__put_user_nocheck_8)
- SYM_CODE_START_LOCAL(__put_user_handle_exception)
- ASM_CLAC
- .Lbad_put_user:
- movl $-EFAULT,%ecx
- RET
- SYM_CODE_END(__put_user_handle_exception)
- _ASM_EXTABLE_UA(1b, __put_user_handle_exception)
- _ASM_EXTABLE_UA(2b, __put_user_handle_exception)
- _ASM_EXTABLE_UA(3b, __put_user_handle_exception)
- _ASM_EXTABLE_UA(4b, __put_user_handle_exception)
- _ASM_EXTABLE_UA(5b, __put_user_handle_exception)
- _ASM_EXTABLE_UA(6b, __put_user_handle_exception)
- _ASM_EXTABLE_UA(7b, __put_user_handle_exception)
- _ASM_EXTABLE_UA(9b, __put_user_handle_exception)
- #ifdef CONFIG_X86_32
- _ASM_EXTABLE_UA(8b, __put_user_handle_exception)
- _ASM_EXTABLE_UA(10b, __put_user_handle_exception)
- #endif
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