diff options
| author | Oleg Nesterov <oleg@redhat.com> | 2015-09-08 14:58:28 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-08 15:35:28 -0700 |
| commit | b5330628546616af14ff23075fbf8d4ad91f6e25 (patch) | |
| tree | e98ccd2ff6540fb05af8b9cd655adca197b42f21 /include/linux/mm.h | |
| parent | af8713b701a74c3784ce6683f64f474a94b1b643 (diff) | |
mm: introduce vma_is_anonymous(vma) helper
special_mapping_fault() is absolutely broken. It seems it was always
wrong, but this didn't matter until vdso/vvar started to use more than
one page.
And after this change vma_is_anonymous() becomes really trivial, it
simply checks vm_ops == NULL. However, I do think the helper makes
sense. There are a lot of ->vm_ops != NULL checks, the helper makes the
caller's code more understandable (self-documented) and this is more
grep-friendly.
This patch (of 3):
Preparation. Add the new simple helper, vma_is_anonymous(vma), and change
handle_pte_fault() to use it. It will have more users.
The name is not accurate, say a hpet_mmap()'ed vma is not anonymous.
Perhaps it should be named vma_has_fault() instead. But it matches the
logic in mmap.c/memory.c (see next changes). "True" just means that a
page fault will use do_anonymous_page().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/mm.h')
| -rw-r--r-- | include/linux/mm.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 8b257c43855b..dfb7ce05f1e3 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1260,6 +1260,11 @@ static inline int vma_growsdown(struct vm_area_struct *vma, unsigned long addr) return vma && (vma->vm_end == addr) && (vma->vm_flags & VM_GROWSDOWN); } +static inline bool vma_is_anonymous(struct vm_area_struct *vma) +{ + return !vma->vm_ops; +} + static inline int stack_guard_page_start(struct vm_area_struct *vma, unsigned long addr) { |