Files
android_kernel_xiaomi_sm8450/arch/arm64/mm/copypage.c
Tong Tiangen 018ebe4c18 arm64: fix types in copy_highpage()
[ Upstream commit 921d161f15d6b090599f6a8c23f131969edbd1fa ]

In copy_highpage() the `kto` and `kfrom` local variables are pointers to
struct page, but these are used to hold arbitrary pointers to kernel memory
. Each call to page_address() returns a void pointer to memory associated
with the relevant page, and copy_page() expects void pointers to this
memory.

This inconsistency was introduced in commit 2563776b41 ("arm64: mte:
Tags-aware copy_{user_,}highpage() implementations") and while this
doesn't appear to be harmful in practice it is clearly wrong.

Correct this by making `kto` and `kfrom` void pointers.

Fixes: 2563776b41 ("arm64: mte: Tags-aware copy_{user_,}highpage() implementations")
Signed-off-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lore.kernel.org/r/20220420030418.3189040-3-tongtiangen@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-06-09 10:21:06 +02:00

38 lines
868 B
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Based on arch/arm/mm/copypage.c
*
* Copyright (C) 2002 Deep Blue Solutions Ltd, All Rights Reserved.
* Copyright (C) 2012 ARM Ltd.
*/
#include <linux/bitops.h>
#include <linux/mm.h>
#include <asm/page.h>
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
#include <asm/mte.h>
void copy_highpage(struct page *to, struct page *from)
{
void *kto = page_address(to);
void *kfrom = page_address(from);
copy_page(kto, kfrom);
if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) {
set_bit(PG_mte_tagged, &to->flags);
mte_copy_page_tags(kto, kfrom);
}
}
EXPORT_SYMBOL(copy_highpage);
void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma)
{
copy_highpage(to, from);
flush_dcache_page(to);
}
EXPORT_SYMBOL_GPL(copy_user_highpage);