x86/numa: Fix the address overlap check in numa_fill_memblks()
authorAlison Schofield <alison.schofield@intel.com>
Fri, 12 Jan 2024 20:09:50 +0000 (12:09 -0800)
committerDan Williams <dan.j.williams@intel.com>
Sat, 17 Feb 2024 07:20:34 +0000 (23:20 -0800)
commit9b99c17f7510bed2adbe17751fb8abddba5620bc
tree90d494a50adbfa815882e03241ecb32a5a764b3a
parenteef5c7b28dbecd6b141987a96db6c54e49828102
x86/numa: Fix the address overlap check in numa_fill_memblks()

numa_fill_memblks() fills in the gaps in numa_meminfo memblks over a
physical address range. To do so, it first creates a list of existing
memblks that overlap that address range. The issue is that it is off
by one when comparing to the end of the address range, so memblks
that do not overlap are selected.

The impact of selecting a memblk that does not actually overlap is
that an existing memblk may be filled when the expected action is to
do nothing and return NUMA_NO_MEMBLK to the caller. The caller can
then add a new NUMA node and memblk.

Replace the broken open-coded search for address overlap with the
memblock helper memblock_addrs_overlap(). Update the kernel doc
and in code comments.

Suggested by: "Huang, Ying" <ying.huang@intel.com>

Fixes: 8f012db27c95 ("x86/numa: Introduce numa_fill_memblks()")
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Link: https://lore.kernel.org/r/10a3e6109c34c21a8dd4c513cf63df63481a2b07.1705085543.git.alison.schofield@intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
arch/x86/mm/numa.c
include/linux/memblock.h
mm/memblock.c