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authorMuchun Song <songmuchun@bytedance.com>2022-03-22 22:41:59 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2022-03-22 23:57:04 +0100
commite763243cc6cb1fcc720ec58cfd6e7c35ae90a479 (patch)
treeb6de20f82fa7b03b38f434519f92fec965274580 /mm/memory.c
parentmm: fix missing cache flush for all tail pages of compound page (diff)
downloadlinux-e763243cc6cb1fcc720ec58cfd6e7c35ae90a479.tar.xz
linux-e763243cc6cb1fcc720ec58cfd6e7c35ae90a479.zip
mm: hugetlb: fix missing cache flush in copy_huge_page_from_user()
userfaultfd calls copy_huge_page_from_user() which does not do any cache flushing for the target page. Then the target page will be mapped to the user space with a different address (user address), which might have an alias issue with the kernel address used to copy the data from the user to. Fix this issue by flushing dcache in copy_huge_page_from_user(). Link: https://lkml.kernel.org/r/20220210123058.79206-4-songmuchun@bytedance.com Fixes: fa4d75c1de13 ("userfaultfd: hugetlbfs: add copy_huge_page_from_user for hugetlb userfaultfd support") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lars Persson <lars.persson@axis.com> Cc: Peter Xu <peterx@redhat.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
-rw-r--r--mm/memory.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/memory.c b/mm/memory.c
index c125c4969913..30e6d0248a3d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5444,6 +5444,8 @@ long copy_huge_page_from_user(struct page *dst_page,
if (rc)
break;
+ flush_dcache_page(subpage);
+
cond_resched();
}
return ret_val;