| /* 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/linkage.h> |
| #include <asm/thread_info.h> |
| #include <asm/errno.h> |
| #include <asm/asm.h> |
| #include <asm/smap.h> |
| #include <asm/export.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. |
| */ |
| |
| #ifdef CONFIG_X86_5LEVEL |
| #define LOAD_TASK_SIZE_MINUS_N(n) \ |
| ALTERNATIVE __stringify(mov $((1 << 47) - 4096 - (n)),%rbx), \ |
| __stringify(mov $((1 << 56) - 4096 - (n)),%rbx), X86_FEATURE_LA57 |
| #else |
| #define LOAD_TASK_SIZE_MINUS_N(n) \ |
| mov $(TASK_SIZE_MAX - (n)),%_ASM_BX |
| #endif |
| |
| .text |
| SYM_FUNC_START(__put_user_1) |
| LOAD_TASK_SIZE_MINUS_N(0) |
| cmp %_ASM_BX,%_ASM_CX |
| jae .Lbad_put_user |
| SYM_INNER_LABEL(__put_user_nocheck_1, SYM_L_GLOBAL) |
| ASM_STAC |
| 1: movb %al,(%_ASM_CX) |
| xor %ecx,%ecx |
| ASM_CLAC |
| ret |
| SYM_FUNC_END(__put_user_1) |
| EXPORT_SYMBOL(__put_user_1) |
| EXPORT_SYMBOL(__put_user_nocheck_1) |
| |
| SYM_FUNC_START(__put_user_2) |
| LOAD_TASK_SIZE_MINUS_N(1) |
| cmp %_ASM_BX,%_ASM_CX |
| jae .Lbad_put_user |
| SYM_INNER_LABEL(__put_user_nocheck_2, SYM_L_GLOBAL) |
| ASM_STAC |
| 2: movw %ax,(%_ASM_CX) |
| xor %ecx,%ecx |
| ASM_CLAC |
| ret |
| SYM_FUNC_END(__put_user_2) |
| EXPORT_SYMBOL(__put_user_2) |
| EXPORT_SYMBOL(__put_user_nocheck_2) |
| |
| SYM_FUNC_START(__put_user_4) |
| LOAD_TASK_SIZE_MINUS_N(3) |
| cmp %_ASM_BX,%_ASM_CX |
| jae .Lbad_put_user |
| SYM_INNER_LABEL(__put_user_nocheck_4, SYM_L_GLOBAL) |
| ASM_STAC |
| 3: movl %eax,(%_ASM_CX) |
| xor %ecx,%ecx |
| ASM_CLAC |
| ret |
| SYM_FUNC_END(__put_user_4) |
| EXPORT_SYMBOL(__put_user_4) |
| EXPORT_SYMBOL(__put_user_nocheck_4) |
| |
| SYM_FUNC_START(__put_user_8) |
| LOAD_TASK_SIZE_MINUS_N(7) |
| cmp %_ASM_BX,%_ASM_CX |
| jae .Lbad_put_user |
| SYM_INNER_LABEL(__put_user_nocheck_8, SYM_L_GLOBAL) |
| ASM_STAC |
| 4: mov %_ASM_AX,(%_ASM_CX) |
| #ifdef CONFIG_X86_32 |
| 5: movl %edx,4(%_ASM_CX) |
| #endif |
| xor %ecx,%ecx |
| ASM_CLAC |
| RET |
| SYM_FUNC_END(__put_user_8) |
| EXPORT_SYMBOL(__put_user_8) |
| EXPORT_SYMBOL(__put_user_nocheck_8) |
| |
| SYM_CODE_START_LOCAL(.Lbad_put_user_clac) |
| ASM_CLAC |
| .Lbad_put_user: |
| movl $-EFAULT,%ecx |
| RET |
| SYM_CODE_END(.Lbad_put_user_clac) |
| |
| _ASM_EXTABLE_UA(1b, .Lbad_put_user_clac) |
| _ASM_EXTABLE_UA(2b, .Lbad_put_user_clac) |
| _ASM_EXTABLE_UA(3b, .Lbad_put_user_clac) |
| _ASM_EXTABLE_UA(4b, .Lbad_put_user_clac) |
| #ifdef CONFIG_X86_32 |
| _ASM_EXTABLE_UA(5b, .Lbad_put_user_clac) |
| #endif |
