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authorThomas Zimmermann <tzimmermann@suse.de>2022-06-20 18:21:25 +0200
committerThomas Zimmermann <tzimmermann@suse.de>2022-06-20 18:21:25 +0200
commit2b1333b80885b896807ffb6ccf4bc21d29aa65e0 (patch)
tree51cc2d13d65603383db82c87f01a0aa93bd26010 /include/linux/mm_inline.h
parentcad564ca557f8d3bb3b1fa965d9a2b3f6490ec69 (diff)
parent0f95ee9a0c579ebed0309657f6918673927189f2 (diff)
Merge drm/drm-next into drm-misc-next
Backmerging to get new regmap APIs of v5.19-rc1. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Diffstat (limited to 'include/linux/mm_inline.h')
-rw-r--r--include/linux/mm_inline.h43
1 files changed, 43 insertions, 0 deletions
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index ac32125745ab..7b25b53c474a 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -6,6 +6,8 @@
#include <linux/huge_mm.h>
#include <linux/swap.h>
#include <linux/string.h>
+#include <linux/userfaultfd_k.h>
+#include <linux/swapops.h>
/**
* folio_is_file_lru - Should the folio be on a file LRU or anon LRU?
@@ -316,5 +318,46 @@ static inline bool mm_tlb_flush_nested(struct mm_struct *mm)
return atomic_read(&mm->tlb_flush_pending) > 1;
}
+/*
+ * If this pte is wr-protected by uffd-wp in any form, arm the special pte to
+ * replace a none pte. NOTE! This should only be called when *pte is already
+ * cleared so we will never accidentally replace something valuable. Meanwhile
+ * none pte also means we are not demoting the pte so tlb flushed is not needed.
+ * E.g., when pte cleared the caller should have taken care of the tlb flush.
+ *
+ * Must be called with pgtable lock held so that no thread will see the none
+ * pte, and if they see it, they'll fault and serialize at the pgtable lock.
+ *
+ * This function is a no-op if PTE_MARKER_UFFD_WP is not enabled.
+ */
+static inline void
+pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr,
+ pte_t *pte, pte_t pteval)
+{
+#ifdef CONFIG_PTE_MARKER_UFFD_WP
+ bool arm_uffd_pte = false;
+
+ /* The current status of the pte should be "cleared" before calling */
+ WARN_ON_ONCE(!pte_none(*pte));
+
+ if (vma_is_anonymous(vma) || !userfaultfd_wp(vma))
+ return;
+
+ /* A uffd-wp wr-protected normal pte */
+ if (unlikely(pte_present(pteval) && pte_uffd_wp(pteval)))
+ arm_uffd_pte = true;
+
+ /*
+ * A uffd-wp wr-protected swap pte. Note: this should even cover an
+ * existing pte marker with uffd-wp bit set.
+ */
+ if (unlikely(pte_swp_uffd_wp_any(pteval)))
+ arm_uffd_pte = true;
+
+ if (unlikely(arm_uffd_pte))
+ set_pte_at(vma->vm_mm, addr, pte,
+ make_pte_marker(PTE_MARKER_UFFD_WP));
+#endif
+}
#endif