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| author | Christoph Hellwig <hch@lst.de> | 2021-07-23 15:50:17 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-07-28 14:37:40 +0200 |
| commit | ee791f0bba88799396463e38b6877e66bc160c52 (patch) | |
| tree | 2f070aa2b730e466f717973f4f47a1923b226582 /include | |
| parent | 5040926bc22d8cee69a494aad60278a27042adc6 (diff) | |
| download | linux-ee791f0bba88799396463e38b6877e66bc160c52.tar.gz linux-ee791f0bba88799396463e38b6877e66bc160c52.tar.bz2 linux-ee791f0bba88799396463e38b6877e66bc160c52.zip | |
mm: call flush_dcache_page() in memcpy_to_page() and memzero_page()
commit 8dad53a11f8d94dceb540a5f8f153484f42be84b upstream.
memcpy_to_page and memzero_page can write to arbitrary pages, which
could be in the page cache or in high memory, so call
flush_kernel_dcache_pages to flush the dcache.
This is a problem when using these helpers on dcache challeneged
architectures. Right now there are just a few users, chances are no one
used the PC floppy driver, the aha1542 driver for an ISA SCSI HBA, and a
few advanced and optional btrfs and ext4 features on those platforms yet
since the conversion.
Link: https://lkml.kernel.org/r/20210713055231.137602-2-hch@lst.de
Fixes: bb90d4bc7b6a ("mm/highmem: Lift memcpy_[to|from]_page to core")
Fixes: 28961998f858 ("iov_iter: lift memzero_page() to highmem.h")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/highmem.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 832b49b50c7b..fc80a40f5053 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -329,6 +329,7 @@ static inline void memcpy_to_page(struct page *page, size_t offset, VM_BUG_ON(offset + len > PAGE_SIZE); memcpy(to + offset, from, len); + flush_dcache_page(page); kunmap_local(to); } @@ -336,6 +337,7 @@ static inline void memzero_page(struct page *page, size_t offset, size_t len) { char *addr = kmap_atomic(page); memset(addr + offset, 0, len); + flush_dcache_page(page); kunmap_atomic(addr); } |