acrn-kernel/arch/sparc/lib/strncpy_from_user.S

48 lines
707 B
ArmAsm

/* strncpy_from_user.S: Sparc strncpy from userspace.
*
* Copyright(C) 1996 David S. Miller
*/
#include <asm/ptrace.h>
#include <asm/errno.h>
.text
.align 4
/* Must return:
*
* -EFAULT for an exception
* count if we hit the buffer limit
* bytes copied if we hit a null byte
*/
.globl __strncpy_from_user
__strncpy_from_user:
/* %o0=dest, %o1=src, %o2=count */
mov %o2, %o3
1:
subcc %o2, 1, %o2
bneg 2f
nop
10:
ldub [%o1], %o4
add %o0, 1, %o0
cmp %o4, 0
add %o1, 1, %o1
bne 1b
stb %o4, [%o0 - 1]
2:
add %o2, 1, %o0
retl
sub %o3, %o0, %o0
.section .fixup,#alloc,#execinstr
.align 4
4:
retl
mov -EFAULT, %o0
.section __ex_table,#alloc
.align 4
.word 10b, 4b