From: zhanglianjie <zhanglianjie@xxxxxxxxxxxxx> [ Upstream commit 6817c944430d00f71ccaa9c99ff5b0096aeb7873 ] The cause of the problem is as follows: 1. when cat /sys/devices/system/memory/memory0/valid_zones, test_pages_in_a_zone() will be called. 2. test_pages_in_a_zone() finds the zone according to stat_pfn = 0. The smallest pfn of the numa node in the mips architecture is 128, and the page corresponding to the previous 0~127 pfn is not initialized (page->flags is 0xFFFFFFFF) 3. The nid and zonenum obtained using page_zone(pfn_to_page(0)) are out of bounds in the corresponding array, &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)], access to the out-of-bounds zone member variables appear abnormal, resulting in Oops. Therefore, it is necessary to keep the page between 0 and the minimum pfn to prevent Oops from appearing. Signed-off-by: zhanglianjie <zhanglianjie@xxxxxxxxxxxxx> Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/mips/loongson64/numa.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/mips/loongson64/numa.c b/arch/mips/loongson64/numa.c index cf9459f79f9b..e4c461df3ee6 100644 --- a/arch/mips/loongson64/numa.c +++ b/arch/mips/loongson64/numa.c @@ -182,6 +182,9 @@ static void __init node_mem_init(unsigned int node) if (node_end_pfn(0) >= (0xffffffff >> PAGE_SHIFT)) memblock_reserve((node_addrspace_offset | 0xfe000000), 32 << 20); + + /* Reserve pfn range 0~node[0]->node_start_pfn */ + memblock_reserve(0, PAGE_SIZE * start_pfn); } } -- 2.30.2
