[PATCH AUTOSEL 5.1 086/141] powerpc/mm: Handle page table allocation failures
flat view
STALE2634d
From: Sasha Levin <sashal@kernel.org>
Date: 2019-07-19 04:05:32
Also in:
lkml, stable
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
From: "Aneesh Kumar K.V" <redacted>
[ Upstream commit 2230ebf6e6dd0b7751e2921b40f6cfe34f09bb16 ]
This fixes kernel crash that arises due to not handling page table allocation
failures while allocating hugetlb page table.
Fixes: e2b3d202d1db ("powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format")
Signed-off-by: Aneesh Kumar K.V <redacted>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/mm/hugetlbpage.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 9e732bb2c84a..88888e098a08 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c@@ -154,6 +154,8 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz } else { pdshift = PUD_SHIFT; pu = pud_alloc(mm, pg, addr); + if (!pu) + return NULL; if (pshift == PUD_SHIFT) return (pte_t *)pu; else if (pshift > PMD_SHIFT) {
@@ -162,6 +164,8 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz } else { pdshift = PMD_SHIFT; pm = pmd_alloc(mm, pu, addr); + if (!pm) + return NULL; if (pshift == PMD_SHIFT) /* 16MB hugepage */ return (pte_t *)pm;
@@ -178,12 +182,16 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr, unsigned long sz } else { pdshift = PUD_SHIFT; pu = pud_alloc(mm, pg, addr); + if (!pu) + return NULL; if (pshift >= PUD_SHIFT) { ptl = pud_lockptr(mm, pu); hpdp = (hugepd_t *)pu; } else { pdshift = PMD_SHIFT; pm = pmd_alloc(mm, pu, addr); + if (!pm) + return NULL; ptl = pmd_lockptr(mm, pm); hpdp = (hugepd_t *)pm; }
--
2.20.1