The patch titled
Subject: userfaultfd: remove WRITE_ONCE when setting folio->index during UFFDIO_MOVE
has been added to the -mm mm-unstable branch. Its filename is
userfaultfd-remove-write_once-when-setting-folio-index-during-uffdio_move.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/userfaultfd-remove-write_once-when-setting-folio-index-during-uffdio_move.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: userfaultfd: remove WRITE_ONCE when setting folio->index during UFFDIO_MOVE
Date: Sun, 14 Apr 2024 19:08:21 -0700
When folio is moved with UFFDIO_MOVE it gets locked before the rmap and
index are modified. Due to the folio lock being already held,
WRITE_ONCE() is not needed when setting the folio index. Remove it.
Link: https://lkml.kernel.org/r/20240415020821.1152951-1-surenb@xxxxxxxxxx
Reported-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Peter Xu <peterx@xxxxxxxxxx>
Cc: Lokesh Gidra <lokeshgidra@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 2 +-
mm/userfaultfd.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/mm/huge_memory.c~userfaultfd-remove-write_once-when-setting-folio-index-during-uffdio_move
+++ a/mm/huge_memory.c
@@ -2200,7 +2200,7 @@ int move_pages_huge_pmd(struct mm_struct
}
folio_move_anon_rmap(src_folio, dst_vma);
- WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr));
+ src_folio->index = linear_page_index(dst_vma, dst_addr);
_dst_pmd = mk_huge_pmd(&src_folio->page, dst_vma->vm_page_prot);
/* Follow mremap() behavior and treat the entry dirty after the move */
--- a/mm/userfaultfd.c~userfaultfd-remove-write_once-when-setting-folio-index-during-uffdio_move
+++ a/mm/userfaultfd.c
@@ -1026,7 +1026,7 @@ static int move_present_pte(struct mm_st
}
folio_move_anon_rmap(src_folio, dst_vma);
- WRITE_ONCE(src_folio->index, linear_page_index(dst_vma, dst_addr));
+ src_folio->index = linear_page_index(dst_vma, dst_addr);
orig_dst_pte = mk_pte(&src_folio->page, dst_vma->vm_page_prot);
/* Follow mremap() behavior and treat the entry dirty after the move */
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
fix-missing-vmalloch-includes-fix-2.patch
fix-missing-vmalloch-includes-fix-6.patch
mm-introduce-slabobj_ext-to-support-slab-object-extensions.patch
mm-introduce-__gfp_no_obj_ext-flag-to-selectively-prevent-slabobj_ext-creation.patch
mm-slab-introduce-slab_no_obj_ext-to-avoid-obj_ext-creation.patch
slab-objext-introduce-objext_flags-as-extension-to-page_memcg_data_flags.patch
lib-code-tagging-framework.patch
lib-code-tagging-module-support.patch
lib-prevent-module-unloading-if-memory-is-not-freed.patch
lib-add-allocation-tagging-support-for-memory-allocation-profiling.patch
lib-add-allocation-tagging-support-for-memory-allocation-profiling-fix.patch
lib-add-allocation-tagging-support-for-memory-allocation-profiling-fix-2.patch
lib-introduce-support-for-page-allocation-tagging.patch
lib-introduce-early-boot-parameter-to-avoid-page_ext-memory-overhead.patch
mm-percpu-increase-percpu_module_reserve-to-accommodate-allocation-tags.patch
mm-percpu-increase-percpu_module_reserve-to-accommodate-allocation-tags-fix.patch
change-alloc_pages-name-in-dma_map_ops-to-avoid-name-conflicts.patch
mm-enable-page-allocation-tagging.patch
mm-enable-page-allocation-tagging-fix.patch
mm-create-new-codetag-references-during-page-splitting.patch
mm-fix-non-compound-multi-order-memory-accounting-in-__free_pages.patch
mm-page_ext-enable-early_page_ext-when-config_mem_alloc_profiling_debug=y.patch
lib-add-codetag-reference-into-slabobj_ext.patch
mm-slab-add-allocation-accounting-into-slab-allocation-and-free-paths.patch
mm-slab-enable-slab-allocation-tagging-for-kmalloc-and-friends.patch
mm-slab-enable-slab-allocation-tagging-for-kmalloc-and-friends-fix.patch
mempool-hook-up-to-memory-allocation-profiling-fix.patch
mempool-hook-up-to-memory-allocation-profiling-fix-2.patch
mm-percpu-enable-per-cpu-allocation-tagging.patch
mm-percpu-enable-per-cpu-allocation-tagging-fix.patch
mm-vmalloc-enable-memory-allocation-profiling-fix.patch
mm-vmalloc-enable-memory-allocation-profiling-fix-2.patch
rhashtable-plumb-through-alloc-tag-fix.patch
lib-add-memory-allocations-report-in-show_mem.patch
codetag-debug-skip-objext-checking-when-its-for-objext-itself.patch
codetag-debug-mark-codetags-for-reserved-pages-as-empty.patch
codetag-debug-introduce-objexts_alloc_fail-to-mark-failed-slab_ext-allocations.patch
userfaultfd-remove-write_once-when-setting-folio-index-during-uffdio_move.patch
