1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * The out-of-line helpers for put_user(). 4 * 5 * (C) Copyright 2005 Linus Torvalds 6 * (C) Copyright 2005 Andi Kleen 7 * (C) Copyright 2008 Glauber Costa 8 * 9 * These functions have a non-standard call interface 10 * to make them more efficient, especially as they 11 * return an error value in addition to the "real" 12 * return value. 13 */ 14#include <linux/export.h> 15#include <linux/linkage.h> 16#include <linux/objtool.h> 17#include <asm/thread_info.h> 18#include <asm/errno.h> 19#include <asm/asm.h> 20#include <asm/smap.h> 21 22/* 23 * __put_user_X 24 * 25 * Inputs: %eax[:%edx] contains the data 26 * %ecx contains the address 27 * 28 * Outputs: %ecx is error code (0 or -EFAULT) 29 * 30 * Clobbers: %ebx needed for task pointer 31 * 32 * These functions should not modify any other registers, 33 * as they get called from within inline assembly. 34 */ 35 36.macro check_range size:req 37.if IS_ENABLED(CONFIG_X86_64) 38 mov %rcx, %rbx 39 sar $63, %rbx 40 or %rbx, %rcx 41.else 42 cmp $TASK_SIZE_MAX-\size+1, %ecx 43 jae .Lbad_put_user 44.endif 45.endm 46 47.text 48SYM_FUNC_START(__put_user_1) 49 ANNOTATE_NOENDBR 50 check_range size=1 51 ASM_STAC 521: movb %al,(%_ASM_CX) 53 xor %ecx,%ecx 54 ASM_CLAC 55 RET 56SYM_FUNC_END(__put_user_1) 57EXPORT_SYMBOL(__put_user_1) 58 59SYM_FUNC_START(__put_user_2) 60 ANNOTATE_NOENDBR 61 check_range size=2 62 ASM_STAC 632: movw %ax,(%_ASM_CX) 64 xor %ecx,%ecx 65 ASM_CLAC 66 RET 67SYM_FUNC_END(__put_user_2) 68EXPORT_SYMBOL(__put_user_2) 69 70SYM_FUNC_START(__put_user_4) 71 ANNOTATE_NOENDBR 72 check_range size=4 73 ASM_STAC 743: movl %eax,(%_ASM_CX) 75 xor %ecx,%ecx 76 ASM_CLAC 77 RET 78SYM_FUNC_END(__put_user_4) 79EXPORT_SYMBOL(__put_user_4) 80 81SYM_FUNC_START(__put_user_8) 82 ANNOTATE_NOENDBR 83 check_range size=8 84 ASM_STAC 854: mov %_ASM_AX,(%_ASM_CX) 86#ifdef CONFIG_X86_32 875: movl %edx,4(%_ASM_CX) 88#endif 89 xor %ecx,%ecx 90 ASM_CLAC 91 RET 92SYM_FUNC_END(__put_user_8) 93EXPORT_SYMBOL(__put_user_8) 94 95SYM_CODE_START_LOCAL(__put_user_handle_exception) 96 ASM_CLAC 97.Lbad_put_user: 98 movl $-EFAULT,%ecx 99 RET 100SYM_CODE_END(__put_user_handle_exception) 101 102 _ASM_EXTABLE_UA(1b, __put_user_handle_exception) 103 _ASM_EXTABLE_UA(2b, __put_user_handle_exception) 104 _ASM_EXTABLE_UA(3b, __put_user_handle_exception) 105 _ASM_EXTABLE_UA(4b, __put_user_handle_exception) 106#ifdef CONFIG_X86_32 107 _ASM_EXTABLE_UA(5b, __put_user_handle_exception) 108#endif 109