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

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@google.com

Acked-by: Mike Rapoport (IBM) rppt@kernel.org

---

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