c0f0601060
In strncpy_from_user_asm, when the destination buffer length was the same as the actual string length, we were returning the size of the destination buffer. But since it's a NUL terminated string, we should return the length of the string instead. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
135 lines
4.1 KiB
ArmAsm
135 lines
4.1 KiB
ArmAsm
/*
|
|
* Copyright 2010 Tilera Corporation. All Rights Reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation, version 2.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
|
|
* NON INFRINGEMENT. See the GNU General Public License for
|
|
* more details.
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/errno.h>
|
|
#include <asm/cache.h>
|
|
#include <arch/chip.h>
|
|
|
|
/* Access user memory, but use MMU to avoid propagating kernel exceptions. */
|
|
|
|
/*
|
|
* strnlen_user_asm takes the pointer in r0, and the length bound in r1.
|
|
* It returns the length, including the terminating NUL, or zero on exception.
|
|
* If length is greater than the bound, returns one plus the bound.
|
|
*/
|
|
STD_ENTRY(strnlen_user_asm)
|
|
{ bz r1, 2f; addi r3, r0, -1 } /* bias down to include NUL */
|
|
1: { lb_u r4, r0; addi r1, r1, -1 }
|
|
bz r4, 2f
|
|
{ bnzt r1, 1b; addi r0, r0, 1 }
|
|
2: { sub r0, r0, r3; jrp lr }
|
|
STD_ENDPROC(strnlen_user_asm)
|
|
.pushsection .fixup,"ax"
|
|
strnlen_user_fault:
|
|
{ move r0, zero; jrp lr }
|
|
ENDPROC(strnlen_user_fault)
|
|
.section __ex_table,"a"
|
|
.align 4
|
|
.word 1b, strnlen_user_fault
|
|
.popsection
|
|
|
|
/*
|
|
* strncpy_from_user_asm takes the kernel target pointer in r0,
|
|
* the userspace source pointer in r1, and the length bound (including
|
|
* the trailing NUL) in r2. On success, it returns the string length
|
|
* (not including the trailing NUL), or -EFAULT on failure.
|
|
*/
|
|
STD_ENTRY(strncpy_from_user_asm)
|
|
{ bz r2, 2f; move r3, r0 }
|
|
1: { lb_u r4, r1; addi r1, r1, 1; addi r2, r2, -1 }
|
|
{ sb r0, r4; addi r0, r0, 1 }
|
|
bz r4, 2f
|
|
bnzt r2, 1b
|
|
{ sub r0, r0, r3; jrp lr }
|
|
2: addi r0, r0, -1 /* don't count the trailing NUL */
|
|
{ sub r0, r0, r3; jrp lr }
|
|
STD_ENDPROC(strncpy_from_user_asm)
|
|
.pushsection .fixup,"ax"
|
|
strncpy_from_user_fault:
|
|
{ movei r0, -EFAULT; jrp lr }
|
|
ENDPROC(strncpy_from_user_fault)
|
|
.section __ex_table,"a"
|
|
.align 4
|
|
.word 1b, strncpy_from_user_fault
|
|
.popsection
|
|
|
|
/*
|
|
* clear_user_asm takes the user target address in r0 and the
|
|
* number of bytes to zero in r1.
|
|
* It returns the number of uncopiable bytes (hopefully zero) in r0.
|
|
* Note that we don't use a separate .fixup section here since we fall
|
|
* through into the "fixup" code as the last straight-line bundle anyway.
|
|
*/
|
|
STD_ENTRY(clear_user_asm)
|
|
{ bz r1, 2f; or r2, r0, r1 }
|
|
andi r2, r2, 3
|
|
bzt r2, .Lclear_aligned_user_asm
|
|
1: { sb r0, zero; addi r0, r0, 1; addi r1, r1, -1 }
|
|
bnzt r1, 1b
|
|
2: { move r0, r1; jrp lr }
|
|
.pushsection __ex_table,"a"
|
|
.align 4
|
|
.word 1b, 2b
|
|
.popsection
|
|
|
|
.Lclear_aligned_user_asm:
|
|
1: { sw r0, zero; addi r0, r0, 4; addi r1, r1, -4 }
|
|
bnzt r1, 1b
|
|
2: { move r0, r1; jrp lr }
|
|
STD_ENDPROC(clear_user_asm)
|
|
.pushsection __ex_table,"a"
|
|
.align 4
|
|
.word 1b, 2b
|
|
.popsection
|
|
|
|
/*
|
|
* flush_user_asm takes the user target address in r0 and the
|
|
* number of bytes to flush in r1.
|
|
* It returns the number of unflushable bytes (hopefully zero) in r0.
|
|
*/
|
|
STD_ENTRY(flush_user_asm)
|
|
bz r1, 2f
|
|
{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
|
|
{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
|
|
{ and r0, r0, r2; and r1, r1, r2 }
|
|
{ sub r1, r1, r0 }
|
|
1: { flush r0; addi r1, r1, -CHIP_FLUSH_STRIDE() }
|
|
{ addi r0, r0, CHIP_FLUSH_STRIDE(); bnzt r1, 1b }
|
|
2: { move r0, r1; jrp lr }
|
|
STD_ENDPROC(flush_user_asm)
|
|
.pushsection __ex_table,"a"
|
|
.align 4
|
|
.word 1b, 2b
|
|
.popsection
|
|
|
|
/*
|
|
* finv_user_asm takes the user target address in r0 and the
|
|
* number of bytes to flush-invalidate in r1.
|
|
* It returns the number of not finv'able bytes (hopefully zero) in r0.
|
|
*/
|
|
STD_ENTRY(finv_user_asm)
|
|
bz r1, 2f
|
|
{ movei r2, L2_CACHE_BYTES; add r1, r0, r1 }
|
|
{ sub r2, zero, r2; addi r1, r1, L2_CACHE_BYTES-1 }
|
|
{ and r0, r0, r2; and r1, r1, r2 }
|
|
{ sub r1, r1, r0 }
|
|
1: { finv r0; addi r1, r1, -CHIP_FINV_STRIDE() }
|
|
{ addi r0, r0, CHIP_FINV_STRIDE(); bnzt r1, 1b }
|
|
2: { move r0, r1; jrp lr }
|
|
STD_ENDPROC(finv_user_asm)
|
|
.pushsection __ex_table,"a"
|
|
.align 4
|
|
.word 1b, 2b
|
|
.popsection
|