From: Max Filippov jcmvbkbc@gmail.com
commit 03f889378f33aa9a9d8e5f49ba94134cf6158090 upstream.
MMU version of lock_mm_and_find_vma releases the mm lock before returning when VMA is not found. Do the same in noMMU version. This fixes hang on an attempt to handle protection fault.
Fixes: d85a143b69ab ("xtensa: fix NOMMU build with lock_mm_and_find_vma() conversion") Signed-off-by: Max Filippov jcmvbkbc@gmail.com Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/nommu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/mm/nommu.c +++ b/mm/nommu.c @@ -637,8 +637,13 @@ EXPORT_SYMBOL(find_vma); struct vm_area_struct *lock_mm_and_find_vma(struct mm_struct *mm, unsigned long addr, struct pt_regs *regs) { + struct vm_area_struct *vma; + mmap_read_lock(mm); - return vma_lookup(mm, addr); + vma = vma_lookup(mm, addr); + if (!vma) + mmap_read_unlock(mm); + return vma; }
/*