+ mm-mark-vma-as-being-written-when-changing-vm_flags.patch added to mm-unstable branch

+ mm-mark-vma-as-being-written-when-changing-vm_flags.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: mark VMA as being written when changing vm_flags
has been added to the -mm mm-unstable branch.  Its filename is
     mm-mark-vma-as-being-written-when-changing-vm_flags.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-mark-vma-as-being-written-when-changing-vm_flags.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@google.com>
Subject: mm: mark VMA as being written when changing vm_flags
Date: Mon, 27 Feb 2023 09:36:12 -0800

Updates to vm_flags have to be done with VMA marked as being written for
preventing concurrent page faults or other modifications.

Link: https://lkml.kernel.org/r/20230227173632.3292573-14-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


--- a/include/linux/mm.h~mm-mark-vma-as-being-written-when-changing-vm_flags
+++ a/include/linux/mm.h
@@ -726,28 +726,28 @@ static inline void vm_flags_init(struct
 static inline void vm_flags_reset(struct vm_area_struct *vma,
 				  vm_flags_t flags)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	vm_flags_init(vma, flags);
 }
 
 static inline void vm_flags_reset_once(struct vm_area_struct *vma,
 				       vm_flags_t flags)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	WRITE_ONCE(ACCESS_PRIVATE(vma, __vm_flags), flags);
 }
 
 static inline void vm_flags_set(struct vm_area_struct *vma,
 				vm_flags_t flags)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	ACCESS_PRIVATE(vma, __vm_flags) |= flags;
 }
 
 static inline void vm_flags_clear(struct vm_area_struct *vma,
 				  vm_flags_t flags)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	ACCESS_PRIVATE(vma, __vm_flags) &= ~flags;
 }
 
@@ -768,7 +768,7 @@ static inline void __vm_flags_mod(struct
 static inline void vm_flags_mod(struct vm_area_struct *vma,
 				vm_flags_t set, vm_flags_t clear)
 {
-	mmap_assert_write_locked(vma->vm_mm);
+	vma_start_write(vma);
 	__vm_flags_mod(vma, set, clear);
 }
 
_

Patches currently in -mm which might be from surenb@google.com are

mm-introduce-config_per_vma_lock.patch
mm-move-mmap_lock-assert-function-definitions.patch
mm-add-per-vma-lock-and-helper-functions-to-control-it.patch
mm-mark-vma-as-being-written-when-changing-vm_flags.patch
mm-mmap-move-vma_prepare-before-vma_adjust_trans_huge.patch
mm-khugepaged-write-lock-vma-while-collapsing-a-huge-page.patch
mm-mmap-write-lock-vmas-in-vma_prepare-before-modifying-them.patch
mm-mremap-write-lock-vma-while-remapping-it-to-a-new-address-range.patch
mm-write-lock-vmas-before-removing-them-from-vma-tree.patch
mm-conditionally-write-lock-vma-in-free_pgtables.patch
kernel-fork-assert-no-vma-readers-during-its-destruction.patch
mm-mmap-prevent-pagefault-handler-from-racing-with-mmu_notifier-registration.patch
mm-introduce-vma-detached-flag.patch
mm-introduce-lock_vma_under_rcu-to-be-used-from-arch-specific-code.patch
mm-fall-back-to-mmap_lock-if-vma-anon_vma-is-not-yet-set.patch
mm-add-fault_flag_vma_lock-flag.patch
mm-prevent-do_swap_page-from-handling-page-faults-under-vma-lock.patch
mm-prevent-userfaults-to-be-handled-under-per-vma-lock.patch
mm-introduce-per-vma-lock-statistics.patch
x86-mm-try-vma-lock-based-page-fault-handling-first.patch
arm64-mm-try-vma-lock-based-page-fault-handling-first.patch
mm-mmap-free-vm_area_struct-without-call_rcu-in-exit_mmap.patch
mm-separate-vma-lock-from-vm_area_struct.patch
per-vma-locks.patch