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Patch "mm: fail get_vaddr_frames() for filesystem-dax mappings" has been added to the 4.14-stable tree

PATCH [email protected] 1 participant 1 message Dec 4, 2017

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This is a note to let you know that I've just added the patch titled

mm: fail get_vaddr_frames() for filesystem-dax mappings

to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
mm-fail-get_vaddr_frames-for-filesystem-dax-mappings.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From b7f0554a56f21fb3e636a627450a9add030889be Mon Sep 17 00:00:00 2001

From: Dan Williams <[email protected]>
Date: Wed, 29 Nov 2017 16:10:39 -0800
Subject: mm: fail get_vaddr_frames() for filesystem-dax mappings

From: Dan Williams <[email protected]>

commit b7f0554a56f21fb3e636a627450a9add030889be upstream.

Until there is a solution to the dma-to-dax vs truncate problem it is not safe to allow V4L2, Exynos, and other frame vector users to create long standing / irrevocable memory registrations against filesytem-dax vmas.

[[email protected]: add comment for vma_is_fsdax() check in get_vaddr_frames(), per Jan]
Link http://lkml.kernel.org/r/151197874035.26211.4061781453123083667.stgit@dwillia2-desk3.amr.corp.intel.com open here
Link http://lkml.kernel.org/r/151068939985.7446.15684639617389154187.stgit@dwillia2-desk3.amr.corp.intel.com open here
Fixes 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by Dan Williams <[email protected]>
Reviewed-by Jan Kara <[email protected]>
Cc Inki Dae <[email protected]>
Cc Seung-Woo Kim <[email protected]>
Cc Joonyoung Shim <[email protected]>
Cc Kyungmin Park <[email protected]>
Cc Mauro Carvalho Chehab <[email protected]>
Cc Mel Gorman <[email protected]>
Cc Vlastimil Babka <[email protected]>
Cc Christoph Hellwig <[email protected]>
Cc Doug Ledford <[email protected]>
Cc Hal Rosenstock <[email protected]>
Cc Jason Gunthorpe <[email protected]>
Cc Jeff Moyer <[email protected]>
Cc Ross Zwisler <[email protected]>
Cc Sean Hefty <[email protected]>
Signed-off-by Andrew Morton <[email protected]>
Signed-off-by Linus Torvalds <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 mm/frame_vector.c |   12 ++++++++++++
 1 file changed, 12 insertions(+)
mm/frame_vector.c +12 -0
@@ -53,6 +53,18 @@ int get_vaddr_frames(unsigned long start
 		ret = -EFAULT;
 		goto out;
 	}
+
+	/*
+	 * While get_vaddr_frames() could be used for transient (kernel
+	 * controlled lifetime) pinning of memory pages all current
+	 * users establish long term (userspace controlled lifetime)
+	 * page pinning. Treat get_vaddr_frames() like
+	 * get_user_pages_longterm() and disallow it for filesystem-dax
+	 * mappings.
+	 */
+	if (vma_is_fsdax(vma))
+		return -EOPNOTSUPP;
+
 	if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
 		vec->got_ref = true;
 		vec->is_pfns = false;

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/mm-hugetlbfs-introduce-split-to-vm_operations_struct.patch queue-4.14/ib-core-disable-memory-registration-of-filesystem-dax-vmas.patch queue-4.14/mm-introduce-get_user_pages_longterm.patch queue-4.14/mm-fail-get_vaddr_frames-for-filesystem-dax-mappings.patch queue-4.14/device-dax-implement-split-to-catch-invalid-munmap-attempts.patch queue-4.14/v4l2-disable-filesystem-dax-mapping-support.patch queue-4.14/mm-fix-device-dax-pud-write-faults-triggered-by-get_user_pages.patch queue-4.14/mm-madvise.c-fix-madvise-infinite-loop-under-special-circumstances.patch