mm/memory_hotplug: fix error handling in add_memory_resource()

[ Upstream commit f42ce5f ]

In add_memory_resource(), creation of memory block devices occurs after
successful call to arch_add_memory().  However, creation of memory block
devices could fail.  In that case, arch_remove_memory() is called to
perform necessary cleanup.

Currently with or without altmap support, arch_remove_memory() is always
passed with altmap set to NULL during error handling.  This leads to
freeing of struct pages using free_pages(), eventhough the allocation
might have been performed with altmap support via
altmap_alloc_block_buf().

Fix the error handling by passing altmap in arch_remove_memory(). This
ensures the following:
* When altmap is disabled, deallocation of the struct pages array occurs
  via free_pages().
* When altmap is enabled, deallocation occurs via vmem_altmap_free().

Link: https://lkml.kernel.org/r/20231120145354.308999-3-sumanthk@linux.ibm.com
Fixes: a08a2ae ("mm,memory_hotplug: allocate memmap from the added memory range")
Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: kernel test robot <lkp@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: <stable@vger.kernel.org>	[5.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

mm/memory_hotplug.c

@@ -1382,7 +1382,7 @@ int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags)
 	ret = create_memory_block_devices(start, size, mhp_altmap.alloc,
 					  group);
 	if (ret) {
-		arch_remove_memory(start, size, NULL);
+		arch_remove_memory(start, size, params.altmap);
 		goto error;
 	}