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CC:     <linuxppc-dev@lists.ozlabs.org>,
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        Kefeng Wang <wangkefeng.wang@huawei.com>,
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        Tong Tiangen <tongtiangen@huawei.com>
Subject: [PATCH -next v4 2/7] arm64: fix types in copy_highpage()
Date:   Wed, 20 Apr 2022 03:04:13 +0000
Message-ID: <20220420030418.3189040-3-tongtiangen@huawei.com>
In-Reply-To: <20220420030418.3189040-1-tongtiangen@huawei.com>
References: <20220420030418.3189040-1-tongtiangen@huawei.com>
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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>
---
 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);
 
-- 
2.25.1