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    Subject[PATCH 5.18 391/879] arm64: fix types in copy_highpage()
    Date
    From: Tong Tiangen <tongtiangen@huawei.com>

    [ 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 2563776b41c3 ("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: 2563776b41c3 ("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>
    ---
    arch/arm64/mm/copypage.c | 4 ++--
    1 file changed, 2 insertions(+), 2 deletions(-)

    diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
    index b5447e53cd73..0dea80bf6de4 100644
    --- a/arch/arm64/mm/copypage.c
    +++ b/arch/arm64/mm/copypage.c
    @@ -16,8 +16,8 @@

    void copy_highpage(struct page *to, struct page *from)
    {
    - struct page *kto = page_address(to);
    - struct page *kfrom = page_address(from);
    + void *kto = page_address(to);
    + void *kfrom = page_address(from);

    copy_page(kto, kfrom);

    --
    2.35.1


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