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From:   Su Hui <suhui@nfschina.com>
To:     nathan@kernel.org, ndesaulniers@google.com, trix@redhat.com
Cc:     Su Hui <suhui@nfschina.com>, akpm@linux-foundation.org,
        willy@infradead.org, fmdefrancesco@gmail.com, ira.weiny@intel.com,
        tony.luck@intel.com, jiaqiyan@google.com, pcc@google.com,
        linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
        kernel-janitors@vger.kernel.org
Subject: [PATCH] highmem: fix a memory copy problem in memcpy_from_folio
Date:   Thu, 30 Nov 2023 11:40:18 +0800
Message-Id: <20231130034017.1210429-1-suhui@nfschina.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Clang static checker complains that value stored to 'from' is never read.
And memcpy_from_folio() only copy the last chunk memory from folio to
destination.
Using 'to += chunk' to replace 'from += chunk' to fix this typo problem.

Fixes: b23d03ef7af5 ("highmem: add memcpy_to_folio() and memcpy_from_folio()")
Signed-off-by: Su Hui <suhui@nfschina.com>
---
 include/linux/highmem.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 4cacc0e43b51..be20cff4ba73 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -454,7 +454,7 @@ static inline void memcpy_from_folio(char *to, struct folio *folio,
 		memcpy(to, from, chunk);
 		kunmap_local(from);
 
-		from += chunk;
+		to += chunk;
 		offset += chunk;
 		len -= chunk;
 	} while (len > 0);
-- 
2.30.2