Re: [PATCH v2 2/6] mm: replace VM_LOCKED_CLEAR_MASK with VM_LOCKED_MASK

[Mike Rapoport <rppt@xxxxxxxxxx>]

On Wed, Jan 25, 2023 at 12:38:47AM -0800, Suren Baghdasaryan wrote:
> To simplify the usage of VM_LOCKED_CLEAR_MASK in clear_vm_flags(),
> replace it with VM_LOCKED_MASK bitmask and convert all users.
> 
> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>

Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

> ---
>  include/linux/mm.h | 4 ++--
>  kernel/fork.c      | 2 +-
>  mm/hugetlb.c       | 4 ++--
>  mm/mlock.c         | 6 +++---
>  mm/mmap.c          | 6 +++---
>  mm/mremap.c        | 2 +-
>  6 files changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index b71f2809caac..da62bdd627bf 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -421,8 +421,8 @@ extern unsigned int kobjsize(const void *objp);
>  /* This mask defines which mm->def_flags a process can inherit its parent */
>  #define VM_INIT_DEF_MASK     VM_NOHUGEPAGE
>  
> -/* This mask is used to clear all the VMA flags used by mlock */
> -#define VM_LOCKED_CLEAR_MASK (~(VM_LOCKED | VM_LOCKONFAULT))
> +/* This mask represents all the VMA flag bits used by mlock */
> +#define VM_LOCKED_MASK       (VM_LOCKED | VM_LOCKONFAULT)
>  
>  /* Arch-specific flags to clear when updating VM flags on protection change 
> */
>  #ifndef VM_ARCH_CLEAR
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 6683c1b0f460..03d472051236 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -669,7 +669,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
>                       tmp->anon_vma = NULL;
>               } else if (anon_vma_fork(tmp, mpnt))
>                       goto fail_nomem_anon_vma_fork;
> -             tmp->vm_flags &= ~(VM_LOCKED | VM_LOCKONFAULT);
> +             clear_vm_flags(tmp, VM_LOCKED_MASK);
>               file = tmp->vm_file;
>               if (file) {
>                       struct address_space *mapping = file->f_mapping;
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index d20c8b09890e..4ecdbad9a451 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -6973,8 +6973,8 @@ static unsigned long page_table_shareable(struct 
> vm_area_struct *svma,
>       unsigned long s_end = sbase + PUD_SIZE;
>  
>       /* Allow segments to share if only one is marked locked */
> -     unsigned long vm_flags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
> -     unsigned long svm_flags = svma->vm_flags & VM_LOCKED_CLEAR_MASK;
> +     unsigned long vm_flags = vma->vm_flags & ~VM_LOCKED_MASK;
> +     unsigned long svm_flags = svma->vm_flags & ~VM_LOCKED_MASK;
>  
>       /*
>        * match the virtual addresses, permission and the alignment of the
> diff --git a/mm/mlock.c b/mm/mlock.c
> index 0336f52e03d7..5c4fff93cd6b 100644
> --- a/mm/mlock.c
> +++ b/mm/mlock.c
> @@ -497,7 +497,7 @@ static int apply_vma_lock_flags(unsigned long start, 
> size_t len,
>               if (vma->vm_start != tmp)
>                       return -ENOMEM;
>  
> -             newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
> +             newflags = vma->vm_flags & ~VM_LOCKED_MASK;
>               newflags |= flags;
>               /* Here we know that  vma->vm_start <= nstart < vma->vm_end. */
>               tmp = vma->vm_end;
> @@ -661,7 +661,7 @@ static int apply_mlockall_flags(int flags)
>       struct vm_area_struct *vma, *prev = NULL;
>       vm_flags_t to_add = 0;
>  
> -     current->mm->def_flags &= VM_LOCKED_CLEAR_MASK;
> +     current->mm->def_flags &= ~VM_LOCKED_MASK;
>       if (flags & MCL_FUTURE) {
>               current->mm->def_flags |= VM_LOCKED;
>  
> @@ -681,7 +681,7 @@ static int apply_mlockall_flags(int flags)
>       for_each_vma(vmi, vma) {
>               vm_flags_t newflags;
>  
> -             newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK;
> +             newflags = vma->vm_flags & ~VM_LOCKED_MASK;
>               newflags |= to_add;
>  
>               /* Ignore errors */
> diff --git a/mm/mmap.c b/mm/mmap.c
> index d4abc6feced1..323bd253b25a 100644
> --- a/mm/mmap.c
> +++ b/mm/mmap.c
> @@ -2671,7 +2671,7 @@ unsigned long mmap_region(struct file *file, unsigned 
> long addr,
>               if ((vm_flags & VM_SPECIAL) || vma_is_dax(vma) ||
>                                       is_vm_hugetlb_page(vma) ||
>                                       vma == get_gate_vma(current->mm))
> -                     vma->vm_flags &= VM_LOCKED_CLEAR_MASK;
> +                     clear_vm_flags(vma, VM_LOCKED_MASK);
>               else
>                       mm->locked_vm += (len >> PAGE_SHIFT);
>       }
> @@ -3340,8 +3340,8 @@ static struct vm_area_struct *__install_special_mapping(
>       vma->vm_start = addr;
>       vma->vm_end = addr + len;
>  
> -     vma->vm_flags = vm_flags | mm->def_flags | VM_DONTEXPAND | VM_SOFTDIRTY;
> -     vma->vm_flags &= VM_LOCKED_CLEAR_MASK;
> +     init_vm_flags(vma, (vm_flags | mm->def_flags |
> +                   VM_DONTEXPAND | VM_SOFTDIRTY) & ~VM_LOCKED_MASK);
>       vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
>  
>       vma->vm_ops = ops;
> diff --git a/mm/mremap.c b/mm/mremap.c
> index 1b3ee02bead7..35db9752cb6a 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -687,7 +687,7 @@ static unsigned long move_vma(struct vm_area_struct *vma,
>  
>       if (unlikely(!err && (flags & MREMAP_DONTUNMAP))) {
>               /* We always clear VM_LOCKED[ONFAULT] on the old vma */
> -             vma->vm_flags &= VM_LOCKED_CLEAR_MASK;
> +             clear_vm_flags(vma, VM_LOCKED_MASK);
>  
>               /*
>                * anon_vma links of the old vma is no longer needed after its 
> page
> -- 
> 2.39.1
> 
>