Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm fixes from Dan Williams:
 "1/ Two regression fixes since v4.6: one for the byte order of a sysfs
     attribute (bz121161) and another for QEMU 2.6's NVDIMM _DSM (ACPI
     Device Specific Method) implementation that gets tripped up by new
     auto-probing behavior in the NFIT driver.

  2/ A fix tagged for -stable that stops the kernel from
     clobbering/ignoring changes to the configuration of a 'pfn'
     instance ("struct page" driver).  For example changing the
     alignment from 2M to 1G may silently revert to 2M if that value is
     currently stored on media.

  3/ A fix from Eric for an xfstests failure in dax.  It is not
     currently tagged for -stable since it requires an 8-exabyte file
     system to trigger, and there appear to be no user visible side
     effects"

* 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  nfit: fix format interface code byte order
  dax: fix offset overflow in dax_io
  acpi, nfit: fix acpi_check_dsm() vs zero functions implemented
  libnvdimm, pfn, dax: fix initialization vs autodetect for mode + alignment

1 files changed, 6 insertions, 1 deletions

diff --git a/fs/dax.c b/fs/dax.c
index 761495bf5eb9..e207f8f9b700 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -208,7 +208,12 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter,
 				dax.addr += first;
 				size = map_len - first;
 			}
-			max = min(pos + size, end);
+			/*
+			 * pos + size is one past the last offset for IO,
+			 * so pos + size can overflow loff_t at extreme offsets.
+			 * Cast to u64 to catch this and get the true minimum.
+			 */
+			max = min_t(u64, pos + size, end);
 		}
 
 		if (iov_iter_rw(iter) == WRITE) {