4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Williams <dan.j.williams@xxxxxxxxx> commit b03b99a329a14b7302f37c3ea6da3848db41c8c5 upstream. While reviewing the -stable patch for commit 86ef58a4e35e "nfit, libnvdimm: fix interleave set cookie calculation" Ben noted: "This is returning an int, thus it's effectively doing a 32-bit comparison and not the 64-bit comparison you say is needed." Update the compare operation to be immune to this integer demotion problem. Cc: Nicholas Moulin <nicholas.w.moulin@xxxxxxxxxxxxxxx> Fixes: 86ef58a4e35e ("nfit, libnvdimm: fix interleave set cookie calculation") Reported-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/nfit.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/drivers/acpi/nfit.c +++ b/drivers/acpi/nfit.c @@ -979,7 +979,11 @@ static int cmp_map(const void *m0, const const struct nfit_set_info_map *map0 = m0; const struct nfit_set_info_map *map1 = m1; - return map0->region_offset - map1->region_offset; + if (map0->region_offset < map1->region_offset) + return -1; + else if (map0->region_offset > map1->region_offset) + return 1; + return 0; } /* Retrieve the nth entry referencing this spa */