From 3a0060d2ba7c30dafee30a178643507f5b1f5b19 Mon Sep 17 00:00:00 2001 From: Alison Schofield Date: Fri, 12 Jan 2024 12:09:51 -0800 Subject: [PATCH] x86/numa: Fix the sort compare func used in numa_fill_memblks() [ Upstream commit b626070ffc14acca5b87a2aa5f581db98617584c ] The compare function used to sort memblks into starting address order fails when the result of its u64 address subtraction gets truncated to an int upon return. The impact of the bad sort is that memblks will be filled out incorrectly. Depending on the set of memblks, a user may see no errors at all but still have a bad fill, or see messages reporting a node overlap that leads to numa init failure: [] node 0 [mem: ] overlaps with node 1 [mem: ] [] No NUMA configuration found Replace with a comparison that can only result in: 1, 0, -1. Fixes: 8f012db27c95 ("x86/numa: Introduce numa_fill_memblks()") Signed-off-by: Alison Schofield Acked-by: Dave Hansen Reviewed-by: Dan Williams Link: https://lore.kernel.org/r/99dcb3ae87e04995e9f293f6158dc8fa0749a487.1705085543.git.alison.schofield@intel.com Signed-off-by: Dan Williams Signed-off-by: Sasha Levin --- arch/x86/mm/numa.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index e60c61b8bbc6..dae5c952735c 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -961,7 +961,7 @@ static int __init cmp_memblk(const void *a, const void *b) const struct numa_memblk *ma = *(const struct numa_memblk **)a; const struct numa_memblk *mb = *(const struct numa_memblk **)b; - return ma->start - mb->start; + return (ma->start > mb->start) - (ma->start < mb->start); } static struct numa_memblk *numa_memblk_list[NR_NODE_MEMBLKS] __initdata;