This is a note to let you know that I've just added the patch titled
memblock: make memblock_set_node() also warn about use of MAX_NUMNODES
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
memblock-make-memblock_set_node-also-warn-about-use-.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 270445a91055004fc3c93507fb72aa18bc500622
Author: Jan Beulich <jbeulich@xxxxxxxx>
Date: Wed May 29 09:39:10 2024 +0200
memblock: make memblock_set_node() also warn about use of MAX_NUMNODES
[ Upstream commit e0eec24e2e199873f43df99ec39773ad3af2bff7 ]
On an (old) x86 system with SRAT just covering space above 4Gb:
ACPI: SRAT: Node 0 PXM 0 [mem 0x100000000-0xfffffffff] hotplug
the commit referenced below leads to this NUMA configuration no longer
being refused by a CONFIG_NUMA=y kernel (previously
NUMA: nodes only cover 6144MB of your 8185MB e820 RAM. Not used.
No NUMA configuration found
Faking a node at [mem 0x0000000000000000-0x000000027fffffff]
was seen in the log directly after the message quoted above), because of
memblock_validate_numa_coverage() checking for NUMA_NO_NODE (only). This
in turn led to memblock_alloc_range_nid()'s warning about MAX_NUMNODES
triggering, followed by a NULL deref in memmap_init() when trying to
access node 64's (NODE_SHIFT=6) node data.
To compensate said change, make memblock_set_node() warn on and adjust
a passed in value of MAX_NUMNODES, just like various other functions
already do.
Fixes: ff6c3d81f2e8 ("NUMA: optimize detection of memory with no node id assigned by firmware")
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/1c8a058c-5365-4f27-a9f1-3aeb7fb3e7b2@xxxxxxxx
Signed-off-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/mm/memblock.c b/mm/memblock.c
index 87a2b4340ce4..ba64b47b7c3b 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1321,6 +1321,10 @@ int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
int start_rgn, end_rgn;
int i, ret;
+ if (WARN_ONCE(nid == MAX_NUMNODES,
+ "Usage of MAX_NUMNODES is deprecated. Use NUMA_NO_NODE instead\n"))
+ nid = NUMA_NO_NODE;
+
ret = memblock_isolate_range(type, base, size, &start_rgn, &end_rgn);
if (ret)
return ret;
