On Thu, Jul 02, 2026 at 12:09:17AM +0800, Lance Yang wrote:

On Mon, Jun 29, 2026 at 08:25:35PM +0100, Lorenzo Stoakes wrote:

quoted

Replace use of the legacy vm_flags_t flags with vma_flags_t values
throughout the mprotect logic.

Note that we retain the legacy vm_flags_t bit shifting code in
do_mprotect_key(), deferring a vma_flags_t approach to this for the time
being.

Additionally update comments to reflect the changes to be consistent.

No functional change intended.

Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
---
mm/mprotect.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 9cbf932b028c..c9504b2a2525 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c

@@ -40,7 +40,7 @@

static bool maybe_change_pte_writable(struct vm_area_struct *vma, pte_t pte)
{
-	if (WARN_ON_ONCE(!(vma->vm_flags & VM_WRITE)))
+	if (WARN_ON_ONCE(!vma_test(vma, VMA_WRITE_BIT)))
		return false;

	/* Don't touch entries that are not even readable. */

@@ -97,7 +97,7 @@ static bool can_change_shared_pte_writable(struct vm_area_struct *vma,

bool can_change_pte_writable(struct vm_area_struct *vma, unsigned long addr,
			     pte_t pte)
{
-	if (!(vma->vm_flags & VM_SHARED))
+	if (!vma_test(vma, VMA_SHARED_BIT))
		return can_change_private_pte_writable(vma, addr, pte);

	return can_change_shared_pte_writable(vma, pte);

@@ -194,7 +194,7 @@ static __always_inline void set_write_prot_commit_flush_ptes(struct vm_area_stru

{
	bool set_write;

-	if (vma->vm_flags & VM_SHARED) {
+	if (vma_test(vma, VMA_SHARED_BIT)) {
		set_write = can_change_shared_pte_writable(vma, ptent);
		prot_commit_flush_ptes(vma, addr, ptep, oldpte, ptent, nr_ptes,
				       /* idx = */ 0, set_write, tlb);

@@ -811,8 +811,8 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,

		vm_unacct_memory(nrpages);

	/*
-	 * Private VM_LOCKED VMA becoming writable: trigger COW to avoid major
-	 * fault on access.
+	 * Private VMA_LOCKED_BIT VMA becoming writable: trigger COW to avoid
+	 * major fault on access.
	 */
	if (vma_flags_test(&new_vma_flags, VMA_WRITE_BIT) &&
	    vma_flags_test(&old_vma_flags, VMA_LOCKED_BIT) &&

@@ -886,7 +886,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,

			goto out;
		start = vma->vm_start;
		error = -EINVAL;
-		if (!(vma->vm_flags & VM_GROWSDOWN))
+		if (!vma_test(vma, VMA_GROWSDOWN_BIT))
			goto out;
	} else {
		if (vma->vm_start > start)

@@ -894,7 +894,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,

		if (unlikely(grows & PROT_GROWSUP)) {
			end = vma->vm_end;
			error = -EINVAL;
-			if (!(vma->vm_flags & VM_GROWSUP))
+			if (!vma_test(vma, VMA_GROWSUP_BIT))

IIUC, should this be

if (!vma_test_single_mask(vma, VMA_GROWSUP))

instead?

#elif defined(CONFIG_PARISC)
#define VM_GROWSUP	INIT_VM_FLAG(GROWSUP)
...
#ifndef VM_GROWSUP
#define VM_GROWSUP	VM_NONE
...

VM_GROWSUP is only defined as GROWSUP on parisc and becomes VM_NONE
elsewhere. But VMA_GROWSUP_BIT is the raw ARCH_1 bit, which is also used
for other arch-specific VMA flags:

	DECLARE_VMA_BIT_ALIAS(SAO, ARCH_1),		/* Strong Access Ordering (powerpc) */
	DECLARE_VMA_BIT_ALIAS(GROWSUP, ARCH_1),		/* parisc */
	DECLARE_VMA_BIT_ALIAS(SPARC_ADI, ARCH_1),	/* sparc64 */
	DECLARE_VMA_BIT_ALIAS(ARM64_BTI, ARCH_1),	/* arm64 */
	DECLARE_VMA_BIT_ALIAS(ARCH_CLEAR, ARCH_1),	/* sparc64, arm64 */
	DECLARE_VMA_BIT_ALIAS(MAPPED_COPY, ARCH_1),	/* !CONFIG_MMU */

Other vma_test() changes look fine to me: just fixed INIT_VM_FLAG()
masks matching their VMA_*_BIT :)

Thanks you're right, will fix!

Again I swear I ran claude on all of this so it's failing me here :)

Cheers, Lance

quoted

				goto out;
		}
	}

@@ -918,7 +918,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,

		}

		/* Does the application expect PROT_READ to imply PROT_EXEC */
-		if (rier && (vma->vm_flags & VM_MAYEXEC))
+		if (rier && vma_test(vma, VMA_MAYEXEC_BIT))
			prot |= PROT_EXEC;

		/*
--
2.54.0