Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/mips/lib/strncpy_user.S
26439 views
1
/*

2
 * This file is subject to the terms and conditions of the GNU General Public

3
 * License.  See the file "COPYING" in the main directory of this archive

4
 * for more details.

5
 *

6
 * Copyright (C) 1996, 1999 by Ralf Baechle

7
 * Copyright (C) 2011 MIPS Technologies, Inc.

8
 */

9
#include <linux/errno.h>

10
#include <linux/export.h>

11
#include <asm/asm.h>

12
#include <asm/asm-offsets.h>

13
#include <asm/regdef.h>

14


15
#define EX(insn,reg,addr,handler)			\

16
9:	insn	reg, addr;				\

17
	.section __ex_table,"a";			\

18
	PTR_WD	9b, handler;				\

19
	.previous

20


21
/*

22
 * Returns: -EFAULT if exception before terminator, N if the entire

23
 * buffer filled, else strlen.

24
 */

25


26
/*

27
 * Ugly special case have to check: we might get passed a user space

28
 * pointer which wraps into the kernel space.  We don't deal with that.	 If

29
 * it happens at most some bytes of the exceptions handlers will be copied.

30
 */

31


32
LEAF(__strncpy_from_user_asm)

33
	move		t0, zero

34
	move		v1, a1

35
#ifdef CONFIG_EVA

36
	.set push

37
	.set eva

38
1:	EX(lbue, v0, (v1), .Lfault)

39
	.set pop

40
#else

41
1:	EX(lbu, v0, (v1), .Lfault)

42
#endif

43
	PTR_ADDIU	v1, 1

44
	R10KCBARRIER(0(ra))

45
	sb		v0, (a0)

46
	beqz		v0, 2f

47
	PTR_ADDIU	t0, 1

48
	PTR_ADDIU	a0, 1

49
	bne		t0, a2, 1b

50
2:	PTR_ADDU	v0, a1, t0

51
	xor		v0, a1

52
	bltz		v0, .Lfault

53
	move		v0, t0

54
	jr		ra			# return n

55
	END(__strncpy_from_user_asm)

56


57
.Lfault:

58
	li		v0, -EFAULT

59
	jr		ra

60


61
	.section	__ex_table,"a"

62
	PTR_WD		1b, .Lfault

63
	.previous

64


65
	EXPORT_SYMBOL(__strncpy_from_user_asm)

66


67