From b626070ffc14acca5b87a2aa5f581db98617584c 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() 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 --- 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 8ada9bbfad583..65e9a6e391c04 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -934,7 +934,7 @@ 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; -- 2.30.2