| /* 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 |
