From b03b99a329a14b7302f37c3ea6da3848db41c8c5 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 27 Mar 2017 21:53:38 -0700 Subject: [PATCH] acpi, nfit, libnvdimm: fix interleave set cookie calculation (64-bit comparison) 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: Cc: Nicholas Moulin Fixes: 86ef58a4e35e ("nfit, libnvdimm: fix interleave set cookie calculation") Reported-by: Ben Hutchings Signed-off-by: Dan Williams --- drivers/acpi/nfit/core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 662036bdc65e..c8ea9d698cd0 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1617,7 +1617,11 @@ static int cmp_map(const void *m0, const void *m1) 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 */