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author | 2023-05-22 17:43:10 -0700 | |
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committer | 2023-08-18 10:12:02 -0700 | |
commit | 332c151c710ad404e6e67eba7ae899ad8333333f (patch) | |
tree | 3667e7a43f3380d29f24fb915b9225ea131532b1 /arch/arm64/include/asm/pgtable.h | |
parent | mm: call arch_swap_restore() from unuse_pte() (diff) | |
download | linux-332c151c710ad404e6e67eba7ae899ad8333333f.tar.gz linux-332c151c710ad404e6e67eba7ae899ad8333333f.tar.bz2 linux-332c151c710ad404e6e67eba7ae899ad8333333f.zip |
arm64: mte: simplify swap tag restoration logic
As a result of the patches "mm: Call arch_swap_restore() from
do_swap_page()" and "mm: Call arch_swap_restore() from unuse_pte()", there
are no circumstances in which a swapped-in page is installed in a page
table without first having arch_swap_restore() called on it. Therefore,
we no longer need the logic in set_pte_at() that restores the tags, so
remove it.
Link: https://lkml.kernel.org/r/20230523004312.1807357-4-pcc@google.com
Link: https://linux-review.googlesource.com/id/I8ad54476f3b2d0144ccd8ce0c1d7a2963e5ff6f3
Signed-off-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: kasan-dev@googlegroups.com
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: "Kuan-Ying Lee (李冠穎)" <Kuan-Ying.Lee@mediatek.com>
Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: "Huang, Ying" <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/arm64/include/asm/pgtable.h')
-rw-r--r-- | arch/arm64/include/asm/pgtable.h | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 0bd18de9fd97..e8a252e62b12 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -337,18 +337,8 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, * don't expose tags (instruction fetches don't check tags). */ if (system_supports_mte() && pte_access_permitted(pte, false) && - !pte_special(pte)) { - pte_t old_pte = READ_ONCE(*ptep); - /* - * We only need to synchronise if the new PTE has tags enabled - * or if swapping in (in which case another mapping may have - * set tags in the past even if this PTE isn't tagged). - * (!pte_none() && !pte_present()) is an open coded version of - * is_swap_pte() - */ - if (pte_tagged(pte) || (!pte_none(old_pte) && !pte_present(old_pte))) - mte_sync_tags(old_pte, pte); - } + !pte_special(pte) && pte_tagged(pte)) + mte_sync_tags(pte); __check_safe_pte_update(mm, ptep, pte); |