mirror of
https://github.com/raspberrypi/linux.git
synced 2025-12-06 10:00:17 +00:00
a4f87dea2d
Provide a __copy_from_user that uses memcpy. On BCM2708, use optimised memcpy/memmove/memcmp/memset implementations. arch/arm: Add mmiocpy/set aliases for memcpy/set See: https://github.com/raspberrypi/linux/issues/1082 copy_from_user: CPU_SW_DOMAIN_PAN compatibility The downstream copy_from_user acceleration must also play nice with CONFIG_CPU_SW_DOMAIN_PAN. See: https://github.com/raspberrypi/linux/issues/1381 Signed-off-by: Phil Elwell <phil@raspberrypi.org> Fix copy_from_user if BCM2835_FAST_MEMCPY=n The change which introduced CONFIG_BCM2835_FAST_MEMCPY unconditionally changed the behaviour of arm_copy_from_user. The page pinning code is not safe on ARMv7 if LPAE & high memory is enabled and causes crashes which look like PTE corruption. Make __copy_from_user_memcpy conditional on CONFIG_2835_FAST_MEMCPY=y which is really an ARMv6 / Pi1 optimization and not necessary on newer ARM processors. arm: fix mmap unlocks in uaccess_with_memcpy.c This is a regression that was added with the commit192a4e923eas of rpi-5.8.y, since that is when the move to the mmap locking API was introduced -d8ed45c5dcThe issue is that when the patch to improve performance for the __copy_to_user and __copy_from_user functions were added for the Raspberry Pi, some of the mmaps were incorrectly mapped to write instead of read. This would cause a verity of issues, and in my case, prevent the booting of a squashfs filesystem on rpi-5.8-y and above. An example of the panic you would see from this can be seen at https://pastebin.com/raw/jBz5xCzL Signed-off-by: Christian Lamparter <chunkeey@gmail.com> Signed-off-by: Christopher Blake <chrisrblake93@gmail.com>
62 lines
2.1 KiB
ArmAsm
62 lines
2.1 KiB
ArmAsm
/*
|
|
Copyright (c) 2013, Raspberry Pi Foundation
|
|
Copyright (c) 2013, RISC OS Open Ltd
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* 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.
|
|
* Neither the name of the copyright holder nor the
|
|
names of its contributors may be used to endorse or promote products
|
|
derived from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT HOLDER 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 <linux/linkage.h>
|
|
#include "arm-mem.h"
|
|
#include "memcpymove.h"
|
|
|
|
/* Prevent the stack from becoming executable */
|
|
#if defined(__linux__) && defined(__ELF__)
|
|
.section .note.GNU-stack,"",%progbits
|
|
#endif
|
|
|
|
.text
|
|
.arch armv6
|
|
.object_arch armv4
|
|
.arm
|
|
.altmacro
|
|
.p2align 2
|
|
|
|
/*
|
|
* void *memcpy(void * restrict s1, const void * restrict s2, size_t n);
|
|
* On entry:
|
|
* a1 = pointer to destination
|
|
* a2 = pointer to source
|
|
* a3 = number of bytes to copy
|
|
* On exit:
|
|
* a1 preserved
|
|
*/
|
|
|
|
.set prefetch_distance, 3
|
|
|
|
ENTRY(mmiocpy)
|
|
ENTRY(memcpy)
|
|
memcpy 0
|
|
ENDPROC(memcpy)
|
|
ENDPROC(mmiocpy)
|