[PATCH AUTOSEL 6.13 24/31] LoongArch: Fix kernel_page_present() for KPRANGE/XKPRANGE

Sasha Levin
2025-02-18T20:25:48Z

From: Huacai Chen <chenhuacai@loongson.cn>

[ Upstream commit 619b52777a4972bdb6ddf86ac54c6f68a47b51c4 ]

Now kernel_page_present() always return true for KPRANGE/XKPRANGE
addresses, this isn't correct because hibernation (ACPI S4) use it
to distinguish whether a page is saveable. If all KPRANGE/XKPRANGE
addresses are considered as saveable, then reserved memory such as
EFI_RUNTIME_SERVICES_CODE / EFI_RUNTIME_SERVICES_DATA will also be
saved and restored.

Fix this by returning true only if the KPRANGE/XKPRANGE address is in
memblock.memory.

Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/loongarch/mm/pageattr.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/loongarch/mm/pageattr.c b/arch/loongarch/mm/pageattr.c
index bf86782484440..99165903908a4 100644
--- a/arch/loongarch/mm/pageattr.c
+++ b/arch/loongarch/mm/pageattr.c
@@ -3,6 +3,7 @@
* Copyright (C) 2024 Loongson Technology Corporation Limited
*/

+#include <linux/memblock.h>
#include <linux/pagewalk.h>
#include <linux/pgtable.h>
#include <asm/set_memory.h>
@@ -167,7 +168,7 @@ bool kernel_page_present(struct page *page)
unsigned long addr = (unsigned long)page_address(page);

if (addr < vm_map_base)
- return true;
+ return memblock_is_memory(__pa(addr));

pgd = pgd_offset_k(addr);
if (pgd_none(pgdp_get(pgd)))
--
2.39.5