From 401035d5c456691f79fbcc08eb6ee5479c30b606 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Thu, 15 Oct 2020 20:05:06 -0700 Subject: mm/debug_vm_pgtable: avoid none pte in pte_clear_test pte_clear_tests operate on an existing pte entry. Make sure that is not a none pte entry. [aneesh.kumar@linux.ibm.com: avoid kernel crash with riscv] Link: https://lkml.kernel.org/r/20201015033206.140550-1-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V Signed-off-by: Andrew Morton Reviewed-by: Anshuman Khandual Cc: Christophe Leroy Cc: Michael Ellerman Cc: Nathan Chancellor Cc: Guenter Roeck Cc: Paul Walmsley Cc: Albert Ou Cc: Palmer Dabbelt Link: https://lkml.kernel.org/r/20200902114222.181353-14-aneesh.kumar@linux.ibm.com Signed-off-by: Linus Torvalds --- mm/debug_vm_pgtable.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'mm/debug_vm_pgtable.c') diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c index bfc9c6544adf..9a0a42a4f08d 100644 --- a/mm/debug_vm_pgtable.c +++ b/mm/debug_vm_pgtable.c @@ -540,12 +540,15 @@ static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp, #endif /* PAGETABLE_P4D_FOLDED */ static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, - unsigned long vaddr) + unsigned long pfn, unsigned long vaddr, + pgprot_t prot) { - pte_t pte = ptep_get(ptep); + pte_t pte = pfn_pte(pfn, prot); pr_debug("Validating PTE clear\n"); +#ifndef CONFIG_RISCV pte = __pte(pte_val(pte) | RANDOM_ORVALUE); +#endif set_pte_at(mm, vaddr, ptep, pte); barrier(); pte_clear(mm, vaddr, ptep); @@ -996,7 +999,7 @@ static int __init debug_vm_pgtable(void) ptl = pte_lockptr(mm, pmdp); spin_lock(ptl); - pte_clear_tests(mm, ptep, vaddr); + pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot); pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); pte_unmap_unlock(ptep, ptl); -- cgit