The patch titled
Subject: mm/uffd: fix warning without PTE_MARKER_UFFD_WP compiled in
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
mm-uffd-fix-warning-without-pte_marker_uffd_wp-compiled-in.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-uffd-fix-warning-without-pte_marker_uffd_wp-compiled-in.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Peter Xu <peterx@xxxxxxxxxx>
Subject: mm/uffd: fix warning without PTE_MARKER_UFFD_WP compiled in
Date: Fri, 30 Sep 2022 20:25:55 -0400
When PTE_MARKER_UFFD_WP not configured, it's still possible to reach pte
marker code and trigger an warning. Add a few CONFIG_PTE_MARKER_UFFD_WP
ifdefs to make sure the code won't be reached when not compiled in.
Link: https://lkml.kernel.org/r/YzeR+R6b4bwBlBHh@x1n
Fixes: 679d10331910180 ("mm: introduce PTE_MARKER swap entry")
Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
Reported-by: <syzbot+2b9b4f0895be09a6dec3@xxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: Brian Geffon <bgeffon@xxxxxxxxxx>
Cc: Edward Liaw <edliaw@xxxxxxxxxx>
Cc: Liu Shixin <liushixin2@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 4 ++++
mm/memory.c | 2 ++
mm/mprotect.c | 2 ++
3 files changed, 8 insertions(+)
--- a/mm/hugetlb.c~mm-uffd-fix-warning-without-pte_marker_uffd_wp-compiled-in
+++ a/mm/hugetlb.c
@@ -5059,6 +5059,7 @@ static void __unmap_hugepage_range(struc
* unmapped and its refcount is dropped, so just clear pte here.
*/
if (unlikely(!pte_present(pte))) {
+#ifdef CONFIG_PTE_MARKER_UFFD_WP
/*
* If the pte was wr-protected by uffd-wp in any of the
* swap forms, meanwhile the caller does not want to
@@ -5070,6 +5071,7 @@ static void __unmap_hugepage_range(struc
set_huge_pte_at(mm, address, ptep,
make_pte_marker(PTE_MARKER_UFFD_WP));
else
+#endif
huge_pte_clear(mm, address, ptep, sz);
spin_unlock(ptl);
continue;
@@ -5098,11 +5100,13 @@ static void __unmap_hugepage_range(struc
tlb_remove_huge_tlb_entry(h, tlb, ptep, address);
if (huge_pte_dirty(pte))
set_page_dirty(page);
+#ifdef CONFIG_PTE_MARKER_UFFD_WP
/* Leave a uffd-wp pte marker if needed */
if (huge_pte_uffd_wp(pte) &&
!(zap_flags & ZAP_FLAG_DROP_MARKER))
set_huge_pte_at(mm, address, ptep,
make_pte_marker(PTE_MARKER_UFFD_WP));
+#endif
hugetlb_count_sub(pages_per_huge_page(h), mm);
page_remove_rmap(page, vma, true);
--- a/mm/memory.c~mm-uffd-fix-warning-without-pte_marker_uffd_wp-compiled-in
+++ a/mm/memory.c
@@ -1393,10 +1393,12 @@ zap_install_uffd_wp_if_needed(struct vm_
unsigned long addr, pte_t *pte,
struct zap_details *details, pte_t pteval)
{
+#ifdef CONFIG_PTE_MARKER_UFFD_WP
if (zap_drop_file_uffd_wp(details))
return;
pte_install_uffd_wp_if_needed(vma, addr, pte, pteval);
+#endif
}
static unsigned long zap_pte_range(struct mmu_gather *tlb,
--- a/mm/mprotect.c~mm-uffd-fix-warning-without-pte_marker_uffd_wp-compiled-in
+++ a/mm/mprotect.c
@@ -260,6 +260,7 @@ static unsigned long change_pte_range(st
} else {
/* It must be an none page, or what else?.. */
WARN_ON_ONCE(!pte_none(oldpte));
+#ifdef CONFIG_PTE_MARKER_UFFD_WP
if (unlikely(uffd_wp && !vma_is_anonymous(vma))) {
/*
* For file-backed mem, we need to be able to
@@ -271,6 +272,7 @@ static unsigned long change_pte_range(st
make_pte_marker(PTE_MARKER_UFFD_WP));
pages++;
}
+#endif
}
} while (pte++, addr += PAGE_SIZE, addr != end);
arch_leave_lazy_mmu_mode();
_
Patches currently in -mm which might be from peterx@xxxxxxxxxx are
mm-uffd-fix-warning-without-pte_marker_uffd_wp-compiled-in.patch
