From 4d7672b46244abffea1953e55688c0ea143dd617 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 16 Dec 2005 10:21:23 -0800 Subject: Make sure we copy pages inserted with "vm_insert_page()" on fork The logic that decides that a fork() might be able to avoid copying a VM area when it can be re-created by page faults didn't know about the new vm_insert_page() case. Also make some things a bit more anal wrt VM_PFNMAP. Pointed out by Hugh Dickins Signed-off-by: Linus Torvalds --- mm/memory.c | 3 ++- mm/mmap.c | 2 +- mm/mremap.c | 2 +- 3 files changed, 4 insertions(+), 3 deletions(-) (limited to 'mm') diff --git a/mm/memory.c b/mm/memory.c index d22f78c8a381..d8dde07a3656 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -574,7 +574,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm, * readonly mappings. The tradeoff is that copy_page_range is more * efficient than faulting. */ - if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP))) { + if (!(vma->vm_flags & (VM_HUGETLB|VM_NONLINEAR|VM_PFNMAP|VM_INSERTPAGE))) { if (!vma->anon_vma) return 0; } @@ -1228,6 +1228,7 @@ int vm_insert_page(struct vm_area_struct *vma, unsigned long addr, struct page * return -EFAULT; if (!page_count(page)) return -EINVAL; + vma->vm_flags |= VM_INSERTPAGE; return insert_page(vma->vm_mm, addr, page, vma->vm_page_prot); } EXPORT_SYMBOL(vm_insert_page); diff --git a/mm/mmap.c b/mm/mmap.c index 11ca5927d5ff..64ba4dbcb7de 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -611,7 +611,7 @@ again: remove_next = 1 + (end > next->vm_end); * If the vma has a ->close operation then the driver probably needs to release * per-vma resources, so we don't attempt to merge those. */ -#define VM_SPECIAL (VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_RESERVED) +#define VM_SPECIAL (VM_IO | VM_DONTCOPY | VM_DONTEXPAND | VM_RESERVED | VM_PFNMAP) static inline int is_mergeable_vma(struct vm_area_struct *vma, struct file *file, unsigned long vm_flags) diff --git a/mm/mremap.c b/mm/mremap.c index b535438c363c..ddaeee9a0b69 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -323,7 +323,7 @@ unsigned long do_mremap(unsigned long addr, /* We can't remap across vm area boundaries */ if (old_len > vma->vm_end - addr) goto out; - if (vma->vm_flags & VM_DONTEXPAND) { + if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP)) { if (new_len > old_len) goto out; } -- cgit v1.2.2