From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, chaitanya.kulkarni@wdc.com,
hch@lst.de, ira.weiny@intel.com, linux-mm@kvack.org,
mm-commits@vger.kernel.org, stable@vger.kernel.org,
torvalds@linux-foundation.org
Subject: [patch 06/15] mm: call flush_dcache_page() in memcpy_to_page() and memzero_page()
Date: Fri, 23 Jul 2021 15:50:17 -0700 [thread overview]
Message-ID: <20210723225017.xFO0jZesP%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210723154926.c6cda0f262b1990b950a5886@linux-foundation.org>
From: Christoph Hellwig <hch@lst.de>
Subject: mm: call flush_dcache_page() in memcpy_to_page() and memzero_page()
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 dr\u0456ver, 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>
---
include/linux/highmem.h | 2 ++
1 file changed, 2 insertions(+)
--- a/include/linux/highmem.h~mm-call-flush_dcache_page-in-memcpy_to_page-and-memzero_page
+++ a/include/linux/highmem.h
@@ -318,6 +318,7 @@ static inline void memcpy_to_page(struct
VM_BUG_ON(offset + len > PAGE_SIZE);
memcpy(to + offset, from, len);
+ flush_dcache_page(page);
kunmap_local(to);
}
@@ -325,6 +326,7 @@ static inline void memzero_page(struct p
{
char *addr = kmap_atomic(page);
memset(addr + offset, 0, len);
+ flush_dcache_page(page);
kunmap_atomic(addr);
}
_
next prev parent reply other threads:[~2021-07-23 22:50 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-23 22:49 incoming Andrew Morton
2021-07-23 22:50 ` [patch 01/15] userfaultfd: do not untag user pointers Andrew Morton
2021-07-23 22:50 ` [patch 02/15] selftest: use mmap instead of posix_memalign to allocate memory Andrew Morton
2021-07-23 22:50 ` [patch 03/15] kfence: defer kfence_test_init to ensure that kunit debugfs is created Andrew Morton
2021-07-23 22:50 ` [patch 04/15] kfence: move the size check to the beginning of __kfence_alloc() Andrew Morton
2021-07-23 22:50 ` [patch 05/15] kfence: skip all GFP_ZONEMASK allocations Andrew Morton
2021-07-23 22:50 ` Andrew Morton [this message]
2021-07-24 6:59 ` [patch 06/15] mm: call flush_dcache_page() in memcpy_to_page() and memzero_page() Christoph Hellwig
2021-07-24 16:23 ` Matthew Wilcox
2021-07-23 22:50 ` [patch 07/15] mm: use kmap_local_page in memzero_page Andrew Morton
2021-07-23 22:50 ` [patch 08/15] mm: page_alloc: fix page_poison=1 / INIT_ON_ALLOC_DEFAULT_ON interaction Andrew Morton
2021-07-23 22:50 ` [patch 09/15] memblock: make for_each_mem_range() traverse MEMBLOCK_HOTPLUG regions Andrew Morton
2021-07-23 22:50 ` [patch 10/15] writeback, cgroup: remove wb from offline list before releasing refcnt Andrew Morton
2021-07-23 22:50 ` [patch 11/15] writeback, cgroup: do not reparent dax inodes Andrew Morton
2021-07-23 22:50 ` [patch 12/15] mm/secretmem: wire up ->set_page_dirty Andrew Morton
2021-07-23 22:50 ` [patch 13/15] mm: mmap_lock: fix disabling preemption directly Andrew Morton
2021-07-23 22:50 ` [patch 14/15] mm: fix the deadlock in finish_fault() Andrew Morton
2021-07-23 22:50 ` [patch 15/15] hugetlbfs: fix mount mode command line processing Andrew Morton
2021-07-24 1:41 ` Al Viro
2021-07-26 5:22 ` Andrew Morton
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