Re: [PATCH 02/13] mm/vma: update do_mmap() to use vma_flags_t
From: Lance Yang <lance.yang@linux.dev>
Date: 2026-07-02 15:09:16
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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
On 2026/7/2 22:16, Lorenzo Stoakes wrote:
On Thu, Jul 02, 2026 at 07:15:31PM +0800, Lance Yang wrote:
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diff --git a/mm/mmap.c b/mm/mmap.c index 46174e706bbe..547352183214 100644 --- a/mm/mmap.c +++ b/mm/mmap.c[...]quoted
@@ -488,23 +496,27 @@ unsigned long do_mmap(struct file *file, unsigned long addr,* Check to see if we are violating any seals and update VMA * flags if necessary to avoid future seal violations. */ - err = memfd_check_seals_mmap(file, &vm_flags); + err = memfd_check_seals_mmap(file, &vma_flags); if (err) return (unsigned long)err; } else { switch (flags & MAP_TYPE) { case MAP_SHARED: - if (vm_flags & (VM_GROWSDOWN|VM_GROWSUP)) + if (vma_flags_can_grow(&vma_flags)) return -EINVAL; /* * Ignore pgoff. */ pgoff = 0; - vm_flags |= VM_SHARED | VM_MAYSHARE; + vma_flags_set(&vma_flags, VMA_SHARED_BIT, VMA_MAYSHARE_BIT); break; - case MAP_DROPPABLE: - if (VM_DROPPABLE == VM_NONE) + case MAP_DROPPABLE: { + vma_flags_t droppable = VMA_DROPPABLE; + + if (vma_flags_empty(&droppable)) return -EOPNOTSUPP; + vma_flags_set_mask(&vma_flags, droppable); + /* * A locked or stack area makes no sense to be droppable. *@@ -515,23 +527,24 @@ unsigned long do_mmap(struct file *file, unsigned long addr,*/ if (flags & (MAP_LOCKED | MAP_HUGETLB)) return -EINVAL; - if (vm_flags & (VM_GROWSDOWN | VM_GROWSUP)) + if (vma_flags_can_grow(&vma_flags)) return -EINVAL; - vm_flags |= VM_DROPPABLE;Old code checked VM_GROWSDOWN|VM_GROWSUP before seting VM_DROPPABLE. New code flips that around. Hmm, shouldn't master, just made me look twice ;) Maybe keep old order?I guess I feared that defining droppable above then referencing it below would be less clear? Can move if you feel strongly about it, and sorry for making the move at the same time as the general vm_flags_t -> vma_flags_t refactor as it does make that less clear...
No need to churn just for me. Thanks :)