Re: [RFC PATCH 1/3] powerpc/mm: Handle page table allocation failures
From: Tyrel Datwyler <hidden>
Date: 2019-05-14 22:37:05
On 05/14/2019 07:50 AM, Aneesh Kumar K.V wrote:
This fixes the below crash that arises due to not handling page table allocation failures while allocating hugetlb page table.
Was there supposed to be a oops stack trace attached here in the commit log? -Tyrel
quoted hunk ↗ jump to hunk
Fixes: e2b3d202d1db ("powerpc: Switch 16GB and 16MB explicit hugepages to a different page table format") Signed-off-by: Aneesh Kumar K.V <redacted> --- 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 c5c9ff2d7afc..ae9d71da5219 100644 --- a/arch/powerpc/mm/hugetlbpage.c +++ b/arch/powerpc/mm/hugetlbpage.c@@ -130,6 +130,8 @@ 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) {@@ -138,6 +140,8 @@ 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;@@ -154,12 +158,16 @@ 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; }