mm/vma: update create_init_stack_vma() to use vma_flags_t

Replace use of the legacy vm_flags_t flags with vma_flags_t values in
create_init_stack_vma().

As part of this change we add VMA_STACK_EARLY and VMA_STACK_INCOMPLETE
vma_flags_t defines, and slightly rework create_init_stack_vma() for
clarity.

No functional change intended.

Link: https://lore.kernel.org/20260711-b4-vma-flags-mm-v2-9-0fa2357d5431@kernel.org
Signed-off-by: Lorenzo Stoakes <ljs@kernel.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jann Horn <jannh@google.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nico Pache <npache@redhat.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

3 files changed, 19 insertions, 7 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1209db1a4b92..550fb92957d1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -442,8 +442,10 @@ enum {
 #define VM_STACK	INIT_VM_FLAG(STACK)
 #ifdef CONFIG_STACK_GROWSUP
 #define VM_STACK_EARLY	INIT_VM_FLAG(STACK_EARLY)
+#define VMA_STACK_EARLY mk_vma_flags(VMA_STACK_EARLY_BIT)
 #else
 #define VM_STACK_EARLY	VM_NONE
+#define VMA_STACK_EARLY EMPTY_VMA_FLAGS
 #endif
 #ifdef CONFIG_ARCH_HAS_PKEYS
 #define VM_PKEY_SHIFT ((__force int)VMA_HIGH_ARCH_0_BIT)
@@ -544,6 +546,8 @@ enum {
 
 /* Bits set in the VMA until the stack is in its final location */
 #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY)
+#define VMA_STACK_INCOMPLETE_SETUP append_vma_flags(		\
+	VMA_STACK_EARLY, VMA_RAND_READ_BIT, VMA_SEQ_READ_BIT)
 
 #define TASK_EXEC_BIT ((current->personality & READ_IMPLIES_EXEC) ? \
 		       VMA_EXEC_BIT : VMA_READ_BIT)
diff --git a/mm/vma_exec.c b/mm/vma_exec.c
index a3c6b05c65fe..7af1260689b9 100644
--- a/mm/vma_exec.c
+++ b/mm/vma_exec.c
@@ -112,15 +112,17 @@ int relocate_vma_down(struct vm_area_struct *vma, unsigned long shift)
 int create_init_stack_vma(struct mm_struct *mm, struct vm_area_struct **vmap,
 			  unsigned long *top_mem_p)
 {
-	unsigned long flags = VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
+	vma_flags_t flags = VMA_STACK_INCOMPLETE_SETUP;
+	struct vm_area_struct *vma;
 	int err;
-	struct vm_area_struct *vma = vm_area_alloc(mm);
 
+	/* VMA_STACK_FLAGS and VMA_STACK_INCOMPLETE_SETUP must not overlap. */
+	VM_WARN_ON_ONCE(vma_flags_test_any_mask(&flags, VMA_STACK_FLAGS));
+
+	vma = vm_area_alloc(mm);
 	if (!vma)
 		return -ENOMEM;
 
-	vma_set_anonymous(vma);
-
 	if (mmap_write_lock_killable(mm)) {
 		err = -EINTR;
 		goto err_free;
@@ -134,18 +136,20 @@ int create_init_stack_vma(struct mm_struct *mm, struct vm_area_struct **vmap,
 	if (err)
 		goto err_ksm;
 
+	vma_flags_set_mask(&flags, VMA_STACK_FLAGS);
+	vma_set_anonymous(vma);
+
 	/*
 	 * Place the stack at the largest stack address the architecture
 	 * supports. Later, we'll move this to an appropriate place. We don't
 	 * use STACK_TOP because that can depend on attributes which aren't
 	 * configured yet.
 	 */
-	VM_WARN_ON_ONCE(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP);
 	vma->vm_end = STACK_TOP_MAX;
 	vma->vm_start = vma->vm_end - PAGE_SIZE;
 	if (pgtable_supports_soft_dirty())
-		flags |= VM_SOFTDIRTY;
-	vm_flags_init(vma, flags);
+		vma_flags_set(&flags, VMA_SOFTDIRTY_BIT);
+	vma->flags = flags;
 	vma->vm_page_prot = vma_get_page_prot(vma);
 
 	err = insert_vm_struct(mm, vma);
diff --git a/tools/testing/vma/include/dup.h b/tools/testing/vma/include/dup.h
index ba02017eca2e..cdeb53bbdd1b 100644
--- a/tools/testing/vma/include/dup.h
+++ b/tools/testing/vma/include/dup.h
@@ -245,8 +245,10 @@ enum {
 #define VM_STACK	INIT_VM_FLAG(STACK)
 #ifdef CONFIG_STACK_GROWS_UP
 #define VM_STACK_EARLY	INIT_VM_FLAG(STACK_EARLY)
+#define VMA_STACK_EARLY mk_vma_flags(VMA_STACK_EARLY_BIT)
 #else
 #define VM_STACK_EARLY	VM_NONE
+#define VMA_STACK_EARLY EMPTY_VMA_FLAGS
 #endif
 #ifdef CONFIG_ARCH_HAS_PKEYS
 #define VM_PKEY_SHIFT ((__force int)VMA_HIGH_ARCH_0_BIT)
@@ -315,6 +317,8 @@ enum {
 
 /* Bits set in the VMA until the stack is in its final location */
 #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ | VM_STACK_EARLY)
+#define VMA_STACK_INCOMPLETE_SETUP append_vma_flags(		\
+	VMA_STACK_EARLY, VMA_RAND_READ_BIT, VMA_SEQ_READ_BIT)
 
 #define TASK_EXEC_BIT ((current->personality & READ_IMPLIES_EXEC) ? \
 		       VM_EXEC_BIT : VM_READ_BIT)