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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>
38 lines
1.8 KiB
C
38 lines
1.8 KiB
C
/**
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* Copyright (c) 2014, Raspberry Pi (Trading) Ltd.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions, and the following disclaimer,
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* without modification.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The names of the above-listed copyright holders may not be used
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* to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* ALTERNATIVELY, this software may be distributed under the terms of the
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* GNU General Public License ("GPL") version 2, as published by the Free
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* Software Foundation.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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EXPORT_SYMBOL(memcmp);
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