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-rw-r--r--arch/arm64/kernel/mte.c18
1 files changed, 13 insertions, 5 deletions
diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
index 125a10e413e9..69b3fde8759e 100644
--- a/arch/arm64/kernel/mte.c
+++ b/arch/arm64/kernel/mte.c
@@ -32,10 +32,9 @@ DEFINE_STATIC_KEY_FALSE(mte_async_mode);
EXPORT_SYMBOL_GPL(mte_async_mode);
#endif
-static void mte_sync_page_tags(struct page *page, pte_t *ptep, bool check_swap)
+static void mte_sync_page_tags(struct page *page, pte_t old_pte,
+ bool check_swap, bool pte_is_tagged)
{
- pte_t old_pte = READ_ONCE(*ptep);
-
if (check_swap && is_swap_pte(old_pte)) {
swp_entry_t entry = pte_to_swp_entry(old_pte);
@@ -43,6 +42,9 @@ static void mte_sync_page_tags(struct page *page, pte_t *ptep, bool check_swap)
return;
}
+ if (!pte_is_tagged)
+ return;
+
page_kasan_tag_reset(page);
/*
* We need smp_wmb() in between setting the flags and clearing the
@@ -55,16 +57,22 @@ static void mte_sync_page_tags(struct page *page, pte_t *ptep, bool check_swap)
mte_clear_page_tags(page_address(page));
}
-void mte_sync_tags(pte_t *ptep, pte_t pte)
+void mte_sync_tags(pte_t old_pte, pte_t pte)
{
struct page *page = pte_page(pte);
long i, nr_pages = compound_nr(page);
bool check_swap = nr_pages == 1;
+ bool pte_is_tagged = pte_tagged(pte);
+
+ /* Early out if there's nothing to do */
+ if (!check_swap && !pte_is_tagged)
+ return;
/* if PG_mte_tagged is set, tags have already been initialised */
for (i = 0; i < nr_pages; i++, page++) {
if (!test_and_set_bit(PG_mte_tagged, &page->flags))
- mte_sync_page_tags(page, ptep, check_swap);
+ mte_sync_page_tags(page, old_pte, check_swap,
+ pte_is_tagged);
}
}