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author | Zi Yan <ziy@nvidia.com> | 2024-12-09 13:23:26 -0500 |
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committer | Andrew Morton <akpm@linux-foundation.org> | 2024-12-18 19:04:43 -0800 |
commit | c51a4f11e6d8246590b5e64908c1ed84b33e8ba2 (patch) | |
tree | 3f0b6782610111332ef3da61cfcdbf90a248ebac /drivers | |
parent | 5c0541e11c16bd2f162e23a22d07c09d58017e5a (diff) | |
download | lwn-c51a4f11e6d8246590b5e64908c1ed84b33e8ba2.tar.gz lwn-c51a4f11e6d8246590b5e64908c1ed84b33e8ba2.zip |
mm: use clear_user_(high)page() for arch with special user folio handling
Some architectures have special handling after clearing user folios:
architectures, which set cpu_dcache_is_aliasing() to true, require
flushing dcache; arc, which sets cpu_icache_is_aliasing() to true, changes
folio->flags to make icache coherent to dcache. So __GFP_ZERO using only
clear_page() is not enough to zero user folios and clear_user_(high)page()
must be used. Otherwise, user data will be corrupted.
Fix it by always clearing user folios with clear_user_(high)page() when
cpu_dcache_is_aliasing() is true or cpu_icache_is_aliasing() is true.
Rename alloc_zeroed() to user_alloc_needs_zeroing() and invert the logic
to clarify its intend.
Link: https://lkml.kernel.org/r/20241209182326.2955963-2-ziy@nvidia.com
Fixes: 5708d96da20b ("mm: avoid zeroing user movable page twice with init_on_alloc=1")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Closes: https://lore.kernel.org/linux-mm/CAMuHMdV1hRp_NtR5YnJo=HsfgKQeH91J537Gh4gKk3PFZhSkbA@mail.gmail.com/
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Potapenko <glider@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers')
0 files changed, 0 insertions, 0 deletions