Commit daa28075 authored Jun 07, 2018 by Kirill A. Shutemov Committed by Linus Torvalds Jun 07, 2018

mm/shmem.c: zero out unused vma fields in shmem_pseudo_vma_init()

shmem/tmpfs uses pseudo vma to allocate page with correct NUMA policy.

The pseudo vma doesn't have vm_page_prot set. We are going to encode
encryption KeyID in vm_page_prot. Having garbage there causes problems.

Zero out all unused fields in the pseudo vma.

Link: http://lkml.kernel.org/r/20180531135602.20321-1-kirill.shutemov@linux.intel.com

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 7810e678

mm/shmem.c

+1 −2

Original line number	Original line	Diff line number	Diff line
	@@ -1420,10 +1420,9 @@ static void shmem_pseudo_vma_init(struct vm_area_struct *vma,
	struct shmem_inode_info *info, pgoff_t index)		struct shmem_inode_info *info, pgoff_t index)
	{		{
	/* Create a pseudo vma that just contains the policy */		/* Create a pseudo vma that just contains the policy */
	vma->vm_start = 0;		memset(vma, 0, sizeof(*vma));
	/* Bias interleave by inode number to distribute better across nodes */		/* Bias interleave by inode number to distribute better across nodes */
	vma->vm_pgoff = index + info->vfs_inode.i_ino;		vma->vm_pgoff = index + info->vfs_inode.i_ino;
	vma->vm_ops = NULL;
	vma->vm_policy = mpol_shared_policy_lookup(&info->policy, index);		vma->vm_policy = mpol_shared_policy_lookup(&info->policy, index);
	}		}