Re: [PATCH 09/13] fs/proc/task_mmu: convert VMA flag tests to use vma_flags_t

Replace use of the legacy vm_flags_t flags with vma_flags_t values where
VMA flags are tested directly in /proc/$pid/[s]maps, pagemap, clear_refs
and PROCMAP_QUERY.

In replacing vm_flags_clear() (which takes the VMA write lock) with
vma_clear_flags() (which does not) in clear_refs_write(), we explicitly
write lock the VMA. The mmap write lock is already held at this point.

The show_vma_header_prefix() and show_smap_vma_flags() output functions and
the thp_vma_allowable_orders() call continue to use legacy flags for the
time being.

No functional change intended.

Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
---
fs/proc/task_mmu.c | 43 ++++++++++++++++++++++---------------------
1 file changed, 22 insertions(+), 21 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 22361607020d..b6e8ef15e40e 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c

@@ -569,18 +569,18 @@ static struct vm_area_struct *query_matching_vma(struct proc_maps_locking_ctx *l

	/* VMA permissions should satisfy query flags */
	if (flags & PROCMAP_QUERY_VMA_FLAGS) {
-		u32 perm = 0;
+		vma_flags_t perm = EMPTY_VMA_FLAGS;

		if (flags & PROCMAP_QUERY_VMA_READABLE)
-			perm |= VM_READ;
+			vma_flags_set(&perm, VMA_READ_BIT);
		if (flags & PROCMAP_QUERY_VMA_WRITABLE)
-			perm |= VM_WRITE;
+			vma_flags_set(&perm, VMA_WRITE_BIT);
		if (flags & PROCMAP_QUERY_VMA_EXECUTABLE)
-			perm |= VM_EXEC;
+			vma_flags_set(&perm, VMA_EXEC_BIT);
		if (flags & PROCMAP_QUERY_VMA_SHARED)
-			perm |= VM_MAYSHARE;
+			vma_flags_set(&perm, VMA_MAYSHARE_BIT);

-		if ((vma->vm_flags & perm) != perm)
+		if (!vma_test_all_mask(vma, perm))
			goto skip_vma;
	}

@@ -647,13 +647,13 @@ static int do_procmap_query(struct mm_struct *mm, void __user *uarg)

	karg.vma_end = vma->vm_end;

	karg.vma_flags = 0;
-	if (vma->vm_flags & VM_READ)
+	if (vma_test(vma, VMA_READ_BIT))
		karg.vma_flags |= PROCMAP_QUERY_VMA_READABLE;
-	if (vma->vm_flags & VM_WRITE)
+	if (vma_test(vma, VMA_WRITE_BIT))
		karg.vma_flags |= PROCMAP_QUERY_VMA_WRITABLE;
-	if (vma->vm_flags & VM_EXEC)
+	if (vma_test(vma, VMA_EXEC_BIT))
		karg.vma_flags |= PROCMAP_QUERY_VMA_EXECUTABLE;
-	if (vma->vm_flags & VM_MAYSHARE)
+	if (vma_test(vma, VMA_MAYSHARE_BIT))
		karg.vma_flags |= PROCMAP_QUERY_VMA_SHARED;

	karg.vma_page_size = vma_kernel_pagesize(vma);

@@ -970,7 +970,7 @@ static void smaps_pte_entry(pte_t *pte, unsigned long addr,

{
	struct mem_size_stats *mss = walk->private;
	struct vm_area_struct *vma = walk->vma;
-	bool locked = !!(vma->vm_flags & VM_LOCKED);
+	bool locked = vma_test(vma, VMA_LOCKED_BIT);
	struct page *page = NULL;
	bool present = false, young = false, dirty = false;
	pte_t ptent = ptep_get(pte);

@@ -1017,7 +1017,7 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr,

{
	struct mem_size_stats *mss = walk->private;
	struct vm_area_struct *vma = walk->vma;
-	bool locked = !!(vma->vm_flags & VM_LOCKED);
+	bool locked = vma_test(vma, VMA_LOCKED_BIT);
	struct page *page = NULL;
	bool present = false;
	struct folio *folio;

@@ -1728,7 +1728,7 @@ static int clear_refs_test_walk(unsigned long start, unsigned long end,

	struct clear_refs_private *cp = walk->private;
	struct vm_area_struct *vma = walk->vma;

-	if (vma->vm_flags & VM_PFNMAP)
+	if (vma_test(vma, VMA_PFNMAP_BIT))
		return 1;

	/*

@@ -1798,9 +1798,10 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,

		if (type == CLEAR_REFS_SOFT_DIRTY) {
			for_each_vma(vmi, vma) {
-				if (!(vma->vm_flags & VM_SOFTDIRTY))
+				if (!vma_test(vma, VMA_SOFTDIRTY_BIT))
					continue;
-				vm_flags_clear(vma, VM_SOFTDIRTY);