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copyinout.S
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copyinout.S
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/*-
* Copyright (c) 2015 The FreeBSD Foundation
* All rights reserved.
*
* This software was developed by Andrew Turner under
* sponsorship from the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <machine/asm.h>
__FBSDID("$FreeBSD$");
#include <sys/errno.h>
#include "assym.s"
/*
* Fault handler for the copy{in,out} functions below.
*/
ENTRY(copyio_fault)
SET_FAULT_HANDLER(xzr, x1) /* Clear the handler */
mov x0, #EFAULT
ret
END(copyio_fault)
/*
* Copies from a kernel to user address
*
* int copyout(const void *kaddr, void *udaddr, size_t len)
*/
ENTRY(copyout)
cbz x2, 2f /* If len == 0 then skip loop */
adr x6, copyio_fault /* Get the handler address */
SET_FAULT_HANDLER(x6, x7) /* Set the handler */
1: ldrb w4, [x0], #1 /* Load from kaddr */
strb w4, [x1], #1 /* Store in uaddr */
sub x2, x2, #1 /* len-- */
cbnz x2, 1b
SET_FAULT_HANDLER(xzr, x7) /* Clear the handler */
2: mov x0, xzr /* return 0 */
ret
END(copyout)
/*
* Copies from a user to kernel address
*
* int copyin(const void *uaddr, void *kdaddr, size_t len)
*/
ENTRY(copyin)
cbz x2, 2f /* If len == 0 then skip loop */
adr x6, copyio_fault /* Get the handler address */
SET_FAULT_HANDLER(x6, x7) /* Set the handler */
1: ldrb w4, [x0], #1 /* Load from uaddr */
strb w4, [x1], #1 /* Store in kaddr */
sub x2, x2, #1 /* len-- */
cbnz x2, 1b
SET_FAULT_HANDLER(xzr, x7) /* Clear the handler */
2: mov x0, xzr /* return 0 */
ret
END(copyin)
/*
* Copies a string from a user to kernel address
*
* int copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *done)
*/
ENTRY(copyinstr)
mov x5, xzr /* count = 0 */
cbz x2, 3f /* If len == 0 then skip loop */
adr x6, copyio_fault /* Get the handler address */
SET_FAULT_HANDLER(x6, x7) /* Set the handler */
1: ldrb w4, [x0], #1 /* Load from uaddr */
strb w4, [x1], #1 /* Store in kaddr */
cbz w4, 2f /* If == 0 then break */
sub x2, x2, #1 /* len-- */
add x5, x5, #1 /* count++ */
cbnz x2, 1b
2: SET_FAULT_HANDLER(xzr, x7) /* Clear the handler */
3: cbz x3, 4f /* Check if done != NULL */
add x5, x5, #1 /* count++ */
str x5, [x3] /* done = count */
4: mov x0, xzr /* return 0 */
ret
END(copyinstr)