[PATCH 09/13] mm/vma: update create_init_stack_vma() to use vma_flags_t
From: Lorenzo Stoakes <ljs@kernel.org>
Date: 2026-06-29 19:26:28
Also in:
dri-devel, intel-gfx, intel-xe, linux-arm-msm, linux-fbdev, linux-fsdevel, linux-mips, linux-mm, linux-samsung-soc, linux-sound, linux-tegra, lkml, nouveau, virtualization, xen-devel
Subsystem:
exec & binfmt api, elf, memory management, memory management - core, memory mapping, the rest · Maintainers:
Kees Cook, Andrew Morton, David Hildenbrand, Liam R. Howlett, Lorenzo Stoakes, Linus Torvalds
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. Signed-off-by: Lorenzo Stoakes <ljs@kernel.org> --- include/linux/mm.h | 4 ++++ mm/vma_exec.c | 18 +++++++++++------- 2 files changed, 15 insertions(+), 7 deletions(-)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index b55790c75038..6e57d41677de 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h@@ -440,8 +440,10 @@ 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)
@@ -532,6 +534,8 @@ 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 b01c4964f2c9..48c783e73cf3 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);
--
2.54.0