Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/arm/lib/putuser.S
26292 views
1
/* SPDX-License-Identifier: GPL-2.0-only */

2
/*

3
 *  linux/arch/arm/lib/putuser.S

4
 *

5
 *  Copyright (C) 2001 Russell King

6
 *

7
 *  Idea from x86 version, (C) Copyright 1998 Linus Torvalds

8
 *

9
 * These functions have a non-standard call interface to make

10
 * them more efficient, especially as they return an error

11
 * value in addition to the "real" return value.

12
 *

13
 * __put_user_X

14
 *

15
 * Inputs:	r0 contains the address

16
 *		r1 contains the address limit, which must be preserved

17
 *		r2, r3 contains the value

18
 * Outputs:	r0 is the error code

19
 *		lr corrupted

20
 *

21
 * No other registers must be altered.  (see <asm/uaccess.h>

22
 * for specific ASM register usage).

23
 *

24
 * Note that ADDR_LIMIT is either 0 or 0xc0000000

25
 * Note also that it is intended that __put_user_bad is not global.

26
 */

27
#include <linux/linkage.h>

28
#include <asm/assembler.h>

29
#include <asm/errno.h>

30
#include <asm/domain.h>

31


32
ENTRY(__put_user_1)

33
	check_uaccess r0, 1, r1, ip, __put_user_bad

34
1: TUSER(strb)	r2, [r0]

35
	mov	r0, #0

36
	ret	lr

37
ENDPROC(__put_user_1)

38


39
ENTRY(__put_user_2)

40
	check_uaccess r0, 2, r1, ip, __put_user_bad

41
#if __LINUX_ARM_ARCH__ >= 6

42


43
2: TUSER(strh)	r2, [r0]

44


45
#else

46


47
	mov	ip, r2, lsr #8

48
#ifndef __ARMEB__

49
2: TUSER(strb)	r2, [r0], #1

50
3: TUSER(strb)	ip, [r0]

51
#else

52
2: TUSER(strb)	ip, [r0], #1

53
3: TUSER(strb)	r2, [r0]

54
#endif

55


56
#endif /* __LINUX_ARM_ARCH__ >= 6 */

57
	mov	r0, #0

58
	ret	lr

59
ENDPROC(__put_user_2)

60


61
ENTRY(__put_user_4)

62
	check_uaccess r0, 4, r1, ip, __put_user_bad

63
4: TUSER(str)	r2, [r0]

64
	mov	r0, #0

65
	ret	lr

66
ENDPROC(__put_user_4)

67


68
ENTRY(__put_user_8)

69
	check_uaccess r0, 8, r1, ip, __put_user_bad

70
#ifdef CONFIG_THUMB2_KERNEL

71
5: TUSER(str)	r2, [r0]

72
6: TUSER(str)	r3, [r0, #4]

73
#else

74
5: TUSER(str)	r2, [r0], #4

75
6: TUSER(str)	r3, [r0]

76
#endif

77
	mov	r0, #0

78
	ret	lr

79
ENDPROC(__put_user_8)

80


81
__put_user_bad:

82
	mov	r0, #-EFAULT

83
	ret	lr

84
ENDPROC(__put_user_bad)

85


86
.pushsection __ex_table, "a"

87
	.long	1b, __put_user_bad

88
	.long	2b, __put_user_bad

89
#if __LINUX_ARM_ARCH__ < 6

90
	.long	3b, __put_user_bad

91
#endif

92
	.long	4b, __put_user_bad

93
	.long	5b, __put_user_bad

94
	.long	6b, __put_user_bad

95
.popsection

96


97