powerpc/mm: convert coprocessor fault to lock_mm_and_find_vma()

commit 2cd76c50d0b41cec5c87abfcdf25b236a2793fb6 upstream.

This is one of the simple cases, except there's no pt_regs pointer.
Which is fine, as lock_mm_and_find_vma() is set up to work fine with a
NULL pt_regs.

Powerpc already enabled LOCK_MM_AND_FIND_VMA for the main CPU faulting,
so we can just use the helper without any extra work.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Samuel Mendoza-Jonas <samjonas@amazon.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/mm/copro_fault.c b/arch/powerpc/mm/copro_fault.c
index 7c507fb..f49fd87 100644 (file)
--- a/arch/powerpc/mm/copro_fault.c
+++ b/arch/powerpc/mm/copro_fault.c
@@ -33,19 +33,11 @@ int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
        if (mm->pgd == NULL)
                return -EFAULT;
 
-       mmap_read_lock(mm);
-       ret = -EFAULT;
-       vma = find_vma(mm, ea);
+       vma = lock_mm_and_find_vma(mm, ea, NULL);
        if (!vma)
-               goto out_unlock;
-
-       if (ea < vma->vm_start) {
-               if (!(vma->vm_flags & VM_GROWSDOWN))
-                       goto out_unlock;
-               if (expand_stack(vma, ea))
-                       goto out_unlock;
-       }
+               return -EFAULT;
 
+       ret = -EFAULT;
        is_write = dsisr & DSISR_ISSTORE;
        if (is_write) {
                if (!(vma->vm_flags & VM_WRITE))