Thread (34 messages) 34 messages, 6 authors, 2023-01-26
STALE1219d
Revisions (3)
  1. v2 current
  2. v3 [diff vs current]
  3. v4 [diff vs current]

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

From: Suren Baghdasaryan <surenb@google.com>
Date: 2023-01-25 08:42:58
Also in: alsa-devel, amd-gfx, bpf, dmaengine, dri-devel, intel-gfx, kexec, kvm, linux-acpi, linux-arch, linux-arm-msm, linux-crypto, linux-ext4, linux-fsdevel, linux-media, linux-mediatek, linux-mm, linux-perf-users, linux-rdma, linux-s390, linux-samsung-soc, linux-scsi, linux-staging, linux-tegra, linux-um, linux-usb, linux-xfs, linuxppc-dev, lkml, loongarch, netdev, nvdimm, selinux, sparclinux, target-devel, xen-devel
Subsystem: exec & binfmt api, elf, hugetlb subsystem, memory management, memory management - core, memory mapping, scheduler, the rest · Maintainers: Kees Cook, Muchun Song, Oscar Salvador, Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds

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>
---
 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
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