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 <[email protected]>
---
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 fa9b4a487a47..e8e3e48c5333 100644
--- a/arch/mips/loongson64/numa.c
+++ b/arch/mips/loongson64/numa.c
@@ -129,6 +129,9 @@ 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);
}
}
--
2.20.1
On Mon, Jun 28, 2021 at 05:11:05PM +0800, zhanglianjie wrote:
> 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 <[email protected]>
> ---
> arch/mips/loongson64/numa.c | 3 +++
> 1 file changed, 3 insertions(+)
applied to mips-next (with subject changed to reflect what patch does).
Thomas.
--
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea. [ RFC1925, 2.3 ]