memblock: fix crash when reserved memory is not added to memory

JIRA: https://issues.redhat.com/browse/RHEL-36126
Conflicts: backport out-of-order before
    commit 77e6c43 ("memblock: introduce MEMBLOCK_RSRV_NOINIT flag")
    where MEMBLOCK_RSRV_NOINIT is added and checked in the loop.

commit 6a9531c
Author: Yajun Deng <yajun.deng@linux.dev>
Date:   Thu Jan 18 14:18:53 2024 +0800

    memblock: fix crash when reserved memory is not added to memory

    After commit 61167ad ("mm: pass nid to reserve_bootmem_region()")
    nid of a reserved region is used by init_reserved_page() (with
    CONFIG_DEFERRED_STRUCT_PAGE_INIT=y) to access node strucure.
    In many cases the nid of the reserved memory is not set and this causes
    a crash.

    When the nid of a reserved region is not set, fall back to
    early_pfn_to_nid(), so that nid of the first_online_node will be passed
    to init_reserved_page().

    Fixes: 61167ad ("mm: pass nid to reserve_bootmem_region()")
    Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
    Link: https://lore.kernel.org/r/20240118061853.2652295-1-yajun.deng@linux.dev
    [rppt: massaged the commit message]
    Signed-off-by: Mike Rapoport (IBM) <rppt@kernel.org>

Signed-off-by: Eric Chanudet <echanude@redhat.com>

Author: eric-ch

mm/memblock.c

@@ -2115,6 +2115,9 @@ static void __init memmap_init_reserved_pages(void)
 		start = region->base;
 		end = start + region->size;
 
+		if (nid == NUMA_NO_NODE || nid >= MAX_NUMNODES)
+			nid = early_pfn_to_nid(PFN_DOWN(start));
+
 		reserve_bootmem_region(start, end, nid);
 	}
 }