Merge tag 'fixes-2025-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock

Pull memblock fixes from Mike Rapoport:
 "Fixes for nid setting in memmap_init_reserved_pages():

   - pass 'size' rather than 'end' to memblock_set_node() as that
     function expects

   - fix a corner case when memblock.reserved is doubled at
     memmap_init_reserved_pages() and the newly reserved block
     won't have nid assigned"

* tag 'fixes-2025-04-29' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
  memblock tests: add test for memblock_set_node
  mm/memblock: repeat setting reserved region nid if array is doubled
  mm/memblock: pass size instead of end to memblock_set_node()

2 files changed, 113 insertions, 1 deletions

diff --git a/mm/memblock.c b/mm/memblock.c
index 0a53db4d9f7b..d3509414b8c3 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -2183,11 +2183,14 @@ static void __init memmap_init_reserved_pages(void)
 	struct memblock_region *region;
 	phys_addr_t start, end;
 	int nid;
+	unsigned long max_reserved;
 
 	/*
 	 * set nid on all reserved pages and also treat struct
 	 * pages for the NOMAP regions as PageReserved
 	 */
+repeat:
+	max_reserved = memblock.reserved.max;
 	for_each_mem_region(region) {
 		nid = memblock_get_region_node(region);
 		start = region->base;
@@ -2196,8 +2199,15 @@ static void __init memmap_init_reserved_pages(void)
 		if (memblock_is_nomap(region))
 			reserve_bootmem_region(start, end, nid);
 
-		memblock_set_node(start, end, &memblock.reserved, nid);
+		memblock_set_node(start, region->size, &memblock.reserved, nid);
 	}
+	/*
+	 * 'max' is changed means memblock.reserved has been doubled its
+	 * array, which may result a new reserved region before current
+	 * 'start'. Now we should repeat the procedure to set its node id.
+	 */
+	if (max_reserved != memblock.reserved.max)
+		goto repeat;
 
 	/*
 	 * initialize struct pages for reserved regions that don't have
diff --git a/tools/testing/memblock/tests/basic_api.c b/tools/testing/memblock/tests/basic_api.c
index 67503089e6a0..01e836fba488 100644
--- a/tools/testing/memblock/tests/basic_api.c
+++ b/tools/testing/memblock/tests/basic_api.c
@@ -2434,6 +2434,107 @@ static int memblock_overlaps_region_checks(void)
 	return 0;
 }
 
+#ifdef CONFIG_NUMA
+static int memblock_set_node_check(void)
+{
+	unsigned long i, max_reserved;
+	struct memblock_region *rgn;
+	void *orig_region;
+
+	PREFIX_PUSH();
+
+	reset_memblock_regions();
+	memblock_allow_resize();
+
+	dummy_physical_memory_init();
+	memblock_add(dummy_physical_memory_base(), MEM_SIZE);
+	orig_region = memblock.reserved.regions;
+
+	/* Equally Split range to node 0 and 1*/
+	memblock_set_node(memblock_start_of_DRAM(),
+			memblock_phys_mem_size() / 2, &memblock.memory, 0);
+	memblock_set_node(memblock_start_of_DRAM() + memblock_phys_mem_size() / 2,
+			memblock_phys_mem_size() / 2, &memblock.memory, 1);
+
+	ASSERT_EQ(memblock.memory.cnt, 2);
+	rgn = &memblock.memory.regions[0];
+	ASSERT_EQ(rgn->base, memblock_start_of_DRAM());
+	ASSERT_EQ(rgn->size, memblock_phys_mem_size() / 2);
+	ASSERT_EQ(memblock_get_region_node(rgn), 0);
+	rgn = &memblock.memory.regions[1];
+	ASSERT_EQ(rgn->base, memblock_start_of_DRAM() + memblock_phys_mem_size() / 2);
+	ASSERT_EQ(rgn->size, memblock_phys_mem_size() / 2);
+	ASSERT_EQ(memblock_get_region_node(rgn), 1);
+
+	/* Reserve 126 regions with the last one across node boundary */
+	for (i = 0; i < 125; i++)
+		memblock_reserve(memblock_start_of_DRAM() + SZ_16 * i, SZ_8);
+
+	memblock_reserve(memblock_start_of_DRAM() + memblock_phys_mem_size() / 2 - SZ_8,
+			SZ_16);
+
+	/*
+	 * Commit 61167ad5fecd ("mm: pass nid to reserve_bootmem_region()")
+	 * do following process to set nid to each memblock.reserved region.
+	 * But it may miss some region if memblock_set_node() double the
+	 * array.
+	 *
+	 * By checking 'max', we make sure all region nid is set properly.
+	 */
+repeat:
+	max_reserved = memblock.reserved.max;
+	for_each_mem_region(rgn) {
+		int nid = memblock_get_region_node(rgn);
+
+		memblock_set_node(rgn->base, rgn->size, &memblock.reserved, nid);
+	}
+	if (max_reserved != memblock.reserved.max)
+		goto repeat;
+
+	/* Confirm each region has valid node set */
+	for_each_reserved_mem_region(rgn) {
+		ASSERT_TRUE(numa_valid_node(memblock_get_region_node(rgn)));
+		if (rgn == (memblock.reserved.regions + memblock.reserved.cnt - 1))
+			ASSERT_EQ(1, memblock_get_region_node(rgn));
+		else
+			ASSERT_EQ(0, memblock_get_region_node(rgn));
+	}
+
+	dummy_physical_memory_cleanup();
+
+	/*
+	 * The current reserved.regions is occupying a range of memory that
+	 * allocated from dummy_physical_memory_init(). After free the memory,
+	 * we must not use it. So restore the origin memory region to make sure
+	 * the tests can run as normal and not affected by the double array.
+	 */
+	memblock.reserved.regions = orig_region;
+	memblock.reserved.cnt = INIT_MEMBLOCK_RESERVED_REGIONS;
+
+	test_pass_pop();
+
+	return 0;
+}
+
+static int memblock_set_node_checks(void)
+{
+	prefix_reset();
+	prefix_push("memblock_set_node");
+	test_print("Running memblock_set_node tests...\n");
+
+	memblock_set_node_check();
+
+	prefix_pop();
+
+	return 0;
+}
+#else
+static int memblock_set_node_checks(void)
+{
+	return 0;
+}
+#endif
+
 int memblock_basic_checks(void)
 {
 	memblock_initialization_check();
@@ -2444,6 +2545,7 @@ int memblock_basic_checks(void)
 	memblock_bottom_up_checks();
 	memblock_trim_memory_checks();
 	memblock_overlaps_region_checks();
+	memblock_set_node_checks();
 
 	return 0;
 }