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| author | Fabio M. De Francesco <fmdefrancesco@gmail.com> | 2022-06-06 16:15:33 +0200 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-06-16 19:48:29 -0700 |
| commit | 9384d79249d04b03572abb7e551a35d99c9268c0 (patch) | |
| tree | 02a003587fc361515b3d2df54a0d90c8b7d2de15 /include/linux/highmem.h | |
| parent | 673520f8da64f16077c1ecb190cbb38aa939fb41 (diff) | |
| download | linux-9384d79249d04b03572abb7e551a35d99c9268c0.tar.gz linux-9384d79249d04b03572abb7e551a35d99c9268c0.tar.bz2 linux-9384d79249d04b03572abb7e551a35d99c9268c0.zip | |
mm/highmem: delete memmove_page()
Matthew Wilcox reported that, while he was looking at memmove_page(), he
realized that it can't actually work.
The reasons are hidden in its implementation, which makes use of memmove()
on logical addresses provided by kmap_local_page(). memmove() does the
wrong thing when it tests "if (dest <= src)".
Therefore, delete memmove_page().
No need to change any other code because we have no call sites of
memmove_page() across the whole kernel.
Link: https://lkml.kernel.org/r/20220606141533.555-1-fmdefrancesco@gmail.com
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reported-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Baoquan He <bhe@redhat.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/highmem.h')
| -rw-r--r-- | include/linux/highmem.h | 13 |
1 files changed, 0 insertions, 13 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 3af34de54330..fee9835e3793 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -336,19 +336,6 @@ static inline void memcpy_page(struct page *dst_page, size_t dst_off, kunmap_local(dst); } -static inline void memmove_page(struct page *dst_page, size_t dst_off, - struct page *src_page, size_t src_off, - size_t len) -{ - char *dst = kmap_local_page(dst_page); - char *src = kmap_local_page(src_page); - - VM_BUG_ON(dst_off + len > PAGE_SIZE || src_off + len > PAGE_SIZE); - memmove(dst + dst_off, src + src_off, len); - kunmap_local(src); - kunmap_local(dst); -} - static inline void memset_page(struct page *page, size_t offset, int val, size_t len) { |