fs/proc/task_mmu.c: simplify the vma_stop() logic

m_start() drops ->mmap_sem and does mmput() if it retuns vsyscall
vma. This is because in this case m_stop()->vma_stop() obviously
can't use gate_vma->vm_mm.

Now that we have proc_maps_private->mm we can simplify this logic:

  - Change m_start() to return with ->mmap_sem held unless it returns
    IS_ERR_OR_NULL().

  - Change vma_stop() to use priv->mm and avoid the ugly vma checks,
    this makes "vm_area_struct *vma" unnecessary.

  - This also allows m_start() to use vm_stop().

  - Cleanup m_next() to follow the new locking rule.

    Note: m_stop() looks very ugly, and this temporary uglifies it
    even more. Fixed by the next change.

[[email protected]: coding-style fixes]
Signed-off-by: Oleg Nesterov <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Cyrill Gorcunov <[email protected]>
Cc: "Eric W. Biederman" <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions