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
>
> Fixes: e2b3d202d1db ("powerpc: Switch 16GB and 16MB explicit hugepages to a
> different page table format")
> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
> ---
> 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;
> }
>
