Re: [PATCH 2/3] mm: update core kernel code to use vm_flags_t consistently
From: Harry Yoo <hidden>
Date: 2025-07-29 00:18:29
Also in:
kvm, linux-fsdevel, linux-mm, linuxppc-dev, lkml, nvdimm, sparclinux
On Wed, Jun 18, 2025 at 08:42:53PM +0100, Lorenzo Stoakes wrote:
The core kernel code is currently very inconsistent in its use of vm_flags_t vs. unsigned long. This prevents us from changing the type of vm_flags_t in the future and is simply not correct, so correct this. While this results in rather a lot of churn, it is a critical pre-requisite for a future planned change to VMA flag type. Additionally, update VMA userland tests to account for the changes. To make review easier and to break things into smaller parts, driver and architecture-specific changes is left for a subsequent commit. The code has been adjusted to cascade the changes across all calling code as far as is needed. We will adjust architecture-specific and driver code in a subsequent patch. Overall, this patch does not introduce any functional change. Signed-off-by: Lorenzo Stoakes <redacted> ---
[Adding Uladzislau to Cc] Hi Lorenzo, just wanted to clarify one thing. You know, many people acked and reviewed it, which makes me wonder if I'm misunderstanding something... but it wouldn't hurt to check, right?
quoted hunk ↗ jump to hunk
diff --git a/mm/execmem.c b/mm/execmem.c index 9720ac2dfa41..bd95ff6a1d03 100644 --- a/mm/execmem.c +++ b/mm/execmem.c@@ -26,7 +26,7 @@ static struct execmem_info default_execmem_info __ro_after_init; #ifdef CONFIG_MMU static void *execmem_vmalloc(struct execmem_range *range, size_t size, - pgprot_t pgprot, unsigned long vm_flags) + pgprot_t pgprot, vm_flags_t vm_flags) { bool kasan = range->flags & EXECMEM_KASAN_SHADOW; gfp_t gfp_flags = GFP_KERNEL | __GFP_NOWARN;
Is it intentional to use vm_flags_t for vm_struct flags, not vma flags? You didn't update the type of struct vm_struct.flags field and vm_flags parameter in __vmalloc_node_range_noprof() (of MMU version in mm/vmalloc.c) ...which makes me suspect it's not intentional?
quoted hunk ↗ jump to hunk
@@ -82,7 +82,7 @@ struct vm_struct *execmem_vmap(size_t size) } #else static void *execmem_vmalloc(struct execmem_range *range, size_t size, - pgprot_t pgprot, unsigned long vm_flags) + pgprot_t pgprot, vm_flags_t vm_flags) { return vmalloc(size); }
ditto.
quoted hunk ↗ jump to hunk
@@ -284,7 +284,7 @@ void execmem_cache_make_ro(void) static int execmem_cache_populate(struct execmem_range *range, size_t size) { - unsigned long vm_flags = VM_ALLOW_HUGE_VMAP; + vm_flags_t vm_flags = VM_ALLOW_HUGE_VMAP; struct vm_struct *vm; size_t alloc_size; int err = -ENOMEM;
ditto.
quoted hunk ↗ jump to hunk
@@ -407,7 +407,7 @@ void *execmem_alloc(enum execmem_type type, size_t size) { struct execmem_range *range = &execmem_info->ranges[type]; bool use_cache = range->flags & EXECMEM_ROX_CACHE; - unsigned long vm_flags = VM_FLUSH_RESET_PERMS; + vm_flags_t vm_flags = VM_FLUSH_RESET_PERMS; pgprot_t pgprot = range->pgprot; void *p;
ditto.
quoted hunk ↗ jump to hunk
diff --git a/mm/internal.h b/mm/internal.h index feda91c9b3f4..506c6fc8b6dc 100644 --- a/mm/internal.h +++ b/mm/internal.h@@ -1360,7 +1360,7 @@ int migrate_device_coherent_folio(struct folio *folio); struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long align, unsigned long shift, - unsigned long flags, unsigned long start, + vm_flags_t vm_flags, unsigned long start, unsigned long end, int node, gfp_t gfp_mask, const void *caller);
ditto.
quoted hunk ↗ jump to hunk
diff --git a/mm/nommu.c b/mm/nommu.c index b624acec6d2e..87e1acab0d64 100644 --- a/mm/nommu.c +++ b/mm/nommu.c@@ -126,7 +126,7 @@ void *vrealloc_noprof(const void *p, size_t size, gfp_t flags) void *__vmalloc_node_range_noprof(unsigned long size, unsigned long align, unsigned long start, unsigned long end, gfp_t gfp_mask, - pgprot_t prot, unsigned long vm_flags, int node, + pgprot_t prot, vm_flags_t vm_flags, int node, const void *caller) {
ditto.
return __vmalloc_noprof(size, gfp_mask);
-- Cheers, Harry / Hyeonggon