putuser.S

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * __put_user functions.
  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_nocheck_1)
 60	ANNOTATE_NOENDBR
 61	ASM_STAC
 622:	movb %al,(%_ASM_CX)
 63	xor %ecx,%ecx
 64	ASM_CLAC
 65	RET
 66SYM_FUNC_END(__put_user_nocheck_1)
 67EXPORT_SYMBOL(__put_user_nocheck_1)
 68
 69SYM_FUNC_START(__put_user_2)
 70	ANNOTATE_NOENDBR
 71	check_range size=2
 72	ASM_STAC
 733:	movw %ax,(%_ASM_CX)
 74	xor %ecx,%ecx
 75	ASM_CLAC
 76	RET
 77SYM_FUNC_END(__put_user_2)
 78EXPORT_SYMBOL(__put_user_2)
 79
 80SYM_FUNC_START(__put_user_nocheck_2)
 81	ANNOTATE_NOENDBR
 82	ASM_STAC
 834:	movw %ax,(%_ASM_CX)
 84	xor %ecx,%ecx
 85	ASM_CLAC
 86	RET
 87SYM_FUNC_END(__put_user_nocheck_2)
 88EXPORT_SYMBOL(__put_user_nocheck_2)
 89
 90SYM_FUNC_START(__put_user_4)
 91	ANNOTATE_NOENDBR
 92	check_range size=4
 93	ASM_STAC
 945:	movl %eax,(%_ASM_CX)
 95	xor %ecx,%ecx
 96	ASM_CLAC
 97	RET
 98SYM_FUNC_END(__put_user_4)
 99EXPORT_SYMBOL(__put_user_4)
100
101SYM_FUNC_START(__put_user_nocheck_4)
102	ANNOTATE_NOENDBR
103	ASM_STAC
1046:	movl %eax,(%_ASM_CX)
105	xor %ecx,%ecx
106	ASM_CLAC
107	RET
108SYM_FUNC_END(__put_user_nocheck_4)
109EXPORT_SYMBOL(__put_user_nocheck_4)
110
111SYM_FUNC_START(__put_user_8)
112	ANNOTATE_NOENDBR
113	check_range size=8
114	ASM_STAC
1157:	mov %_ASM_AX,(%_ASM_CX)
116#ifdef CONFIG_X86_32
1178:	movl %edx,4(%_ASM_CX)
118#endif
119	xor %ecx,%ecx
120	ASM_CLAC
121	RET
122SYM_FUNC_END(__put_user_8)
123EXPORT_SYMBOL(__put_user_8)
124
125SYM_FUNC_START(__put_user_nocheck_8)
126	ANNOTATE_NOENDBR
127	ASM_STAC
1289:	mov %_ASM_AX,(%_ASM_CX)
129#ifdef CONFIG_X86_32
13010:	movl %edx,4(%_ASM_CX)
131#endif
132	xor %ecx,%ecx
133	ASM_CLAC
134	RET
135SYM_FUNC_END(__put_user_nocheck_8)
136EXPORT_SYMBOL(__put_user_nocheck_8)
137
138SYM_CODE_START_LOCAL(__put_user_handle_exception)
139	ASM_CLAC
140.Lbad_put_user:
141	movl $-EFAULT,%ecx
142	RET
143SYM_CODE_END(__put_user_handle_exception)
144
145	_ASM_EXTABLE_UA(1b, __put_user_handle_exception)
146	_ASM_EXTABLE_UA(2b, __put_user_handle_exception)
147	_ASM_EXTABLE_UA(3b, __put_user_handle_exception)
148	_ASM_EXTABLE_UA(4b, __put_user_handle_exception)
149	_ASM_EXTABLE_UA(5b, __put_user_handle_exception)
150	_ASM_EXTABLE_UA(6b, __put_user_handle_exception)
151	_ASM_EXTABLE_UA(7b, __put_user_handle_exception)
152	_ASM_EXTABLE_UA(9b, __put_user_handle_exception)
153#ifdef CONFIG_X86_32
154	_ASM_EXTABLE_UA(8b, __put_user_handle_exception)
155	_ASM_EXTABLE_UA(10b, __put_user_handle_exception)
156#endif