The patch titled
Subject: kernel/fork: convert vma assignment to a memcpy
has been added to the -mm mm-unstable branch. Its filename is
kernel-fork-convert-vma-assignment-to-a-memcpy.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kernel-fork-convert-vma-assignment-to-a-memcpy.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Subject: kernel/fork: convert vma assignment to a memcpy
Date: Thu, 26 Jan 2023 11:37:46 -0800
Patch series "introduce vm_flags modifier functions", v4.
This patchset was originally published as a part of per-VMA locking [1]
and was split after suggestion that it's viable on its own and to
facilitate the review process. It is now a preprequisite for the next
version of per-VMA lock patchset, which reuses vm_flags modifier functions
to lock the VMA when vm_flags are being updated.
VMA vm_flags modifications are usually done under exclusive mmap_lock
protection because this attrubute affects other decisions like VMA merging
or splitting and races should be prevented. Introduce vm_flags modifier
functions to enforce correct locking.
This patch (of 7):
Convert vma assignment in vm_area_dup() to a memcpy() to prevent compiler
errors when we add a const modifier to vma->vm_flags.
Link: https://lkml.kernel.org/r/20230126193752.297968-1-surenb@xxxxxxxxxx
Link: https://lkml.kernel.org/r/20230126193752.297968-2-surenb@xxxxxxxxxx
Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arjun Roy <arjunroy@xxxxxxxxxx>
Cc: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Greg Thelen <gthelen@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Joel Fernandes <joelaf@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Laurent Dufour <ldufour@xxxxxxxxxxxxx>
Cc: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Cc: Peter Oskolkov <posk@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Punit Agrawal <punit.agrawal@xxxxxxxxxxxxx>
Cc: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Soheil Hassas Yeganeh <soheil@xxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/fork.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/fork.c~kernel-fork-convert-vma-assignment-to-a-memcpy
+++ a/kernel/fork.c
@@ -472,7 +472,7 @@ struct vm_area_struct *vm_area_dup(struc
* orig->shared.rb may be modified concurrently, but the clone
* will be reinitialized.
*/
- *new = data_race(*orig);
+ data_race(memcpy(new, orig, sizeof(*new)));
INIT_LIST_HEAD(&new->anon_vma_chain);
dup_anon_vma_name(orig, new);
}
_
Patches currently in -mm which might be from surenb@xxxxxxxxxx are
kernel-fork-convert-vma-assignment-to-a-memcpy.patch
mm-introduce-vma-vm_flags-wrapper-functions.patch
mm-replace-vm_locked_clear_mask-with-vm_locked_mask.patch
mm-replace-vma-vm_flags-direct-modifications-with-modifier-calls.patch
mm-replace-vma-vm_flags-indirect-modification-in-ksm_madvise.patch
mm-introduce-__vm_flags_mod-and-use-it-in-untrack_pfn.patch
mm-export-dump_mm.patch
