On Wed, 09 Sep 2020 11:38:39 +0530 "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> wrote: > Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx> writes: > > > On Fri, 4 Sep 2020 18:01:15 +0200 > > Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx> wrote: > > > > [...] > >> > >> BTW2, a quick test with this change (so far) made the issues on s390 > >> go away: > >> > >> @@ -1069,7 +1074,7 @@ static int __init debug_vm_pgtable(void) > >> spin_unlock(ptl); > >> > >> #ifndef CONFIG_PPC_BOOK3S_64 > >> - hugetlb_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); > >> + hugetlb_advanced_tests(mm, vma, (pte_t *) pmdp, pmd_aligned, vaddr, prot); > >> #endif > >> > >> spin_lock(&mm->page_table_lock); > >> > >> That would more match the "pte_t pointer" usage for hugetlb code, > >> i.e. just cast a pmd_t pointer to it. Also changed to pmd_aligned, > >> but I think the root cause is the pte_t pointer. > >> > >> Not entirely sure though if that would really be the correct fix. > >> I somehow lost whatever little track I had about what these tests > >> really want to check, and if that would still be valid with that > >> change. > > > > Uh oh, wasn't aware that this (or some predecessor) already went > > upstream, and broke our debug kernel today. > > Not sure i followed the above. Are you finding that s390 kernel crash > after this patch series or the original patchset? As noted in my patch > the hugetlb test is broken and we should fix that. A quick fix is to > comment out that test for s390 too as i have done for PPC64. We see it with both, it basically is broken since there is a hugetlb test using real pte pointers. It doesn't always show, depending on random vaddr, so it slipped through earlier testing. I guess we also would have had one or the other chance to notice that earlier, through better review, or better reading of previous mails. I must admit that I neglected this a bit.
