[PATCH 4.19 260/421] MIPS: add PMD table accounting into MIPSpmd_alloc_one

Greg Kroah-Hartman
2021-07-19T16:23:01Z

From: Huang Pei <huangpei@loongson.cn>

[ Upstream commit ed914d48b6a1040d1039d371b56273d422c0081e ]

This fixes Page Table accounting bug.

MIPS is the ONLY arch just defining __HAVE_ARCH_PMD_ALLOC_ONE alone.
Since commit b2b29d6d011944 (mm: account PMD tables like PTE tables),
"pmd_free" in asm-generic with PMD table accounting and "pmd_alloc_one"
in MIPS without PMD table accounting causes PageTable accounting number
negative, which read by global_zone_page_state(), always returns 0.

Signed-off-by: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/mips/include/asm/pgalloc.h | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h
index 39b9f311c4ef..f800872f867b 100644
--- a/arch/mips/include/asm/pgalloc.h
+++ b/arch/mips/include/asm/pgalloc.h
@@ -93,11 +93,15 @@ do { \

static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long address)
{
- pmd_t *pmd;
+ pmd_t *pmd = NULL;
+ struct page *pg;

- pmd = (pmd_t *) __get_free_pages(GFP_KERNEL, PMD_ORDER);
- if (pmd)
+ pg = alloc_pages(GFP_KERNEL | __GFP_ACCOUNT, PMD_ORDER);
+ if (pg) {
+ pgtable_pmd_page_ctor(pg);
+ pmd = (pmd_t *)page_address(pg);
pmd_init((unsigned long)pmd, (unsigned long)invalid_pte_table);
+ }
return pmd;
}

--
2.30.2