From: Gavin Shan <gshan@xxxxxxxxxx> Subject: mm/debug_vm_pgtable: use struct pgtable_debug_args in PTE modifying tests This uses struct pgtable_debug_args in PTE modifying tests. The allocated page is used as set_pte_at() is used there. The tests are skipped if the allocated page doesn't exist. It's notable that args->ptep need to be mapped before the tests. The reason why we don't map args->ptep at the beginning is PTE entry is only mapped and accessible in atomic context when CONFIG_HIGHPTE is enabled. So we avoid to do that so that atomic context is only enabled if needed. Besides, the unused variable @pte_aligned and @ptep in debug_vm_pgtable() are dropped. Link: https://lkml.kernel.org/r/20210809092631.1888748-8-gshan@xxxxxxxxxx Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx> Reviewed-by: Anshuman Khandual <anshuman.khandual@xxxxxxx> Tested-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx> [powerpc 8xx] Tested-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxxxxx> [s390] Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Chunyu Hu <chuhu@xxxxxxxxxx> Cc: Qian Cai <cai@xxxxxx> Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/debug_vm_pgtable.c | 67 +++++++++++++++++++--------------------- 1 file changed, 32 insertions(+), 35 deletions(-) --- a/mm/debug_vm_pgtable.c~mm-debug_vm_pgtable-use-struct-pgtable_debug_args-in-pte-modifying-tests +++ a/mm/debug_vm_pgtable.c @@ -117,10 +117,7 @@ static void __init pte_basic_tests(struc WARN_ON(!pte_dirty(pte_wrprotect(pte_mkdirty(pte)))); } -static void __init pte_advanced_tests(struct mm_struct *mm, - struct vm_area_struct *vma, pte_t *ptep, - unsigned long pfn, unsigned long vaddr, - pgprot_t prot) +static void __init pte_advanced_tests(struct pgtable_debug_args *args) { pte_t pte; @@ -129,35 +126,37 @@ static void __init pte_advanced_tests(st * This requires set_pte_at to be not used to update an * existing pte entry. Clear pte before we do set_pte_at */ + if (args->pte_pfn == ULONG_MAX) + return; pr_debug("Validating PTE advanced\n"); - pte = pfn_pte(pfn, prot); - set_pte_at(mm, vaddr, ptep, pte); - ptep_set_wrprotect(mm, vaddr, ptep); - pte = ptep_get(ptep); + pte = pfn_pte(args->pte_pfn, args->page_prot); + set_pte_at(args->mm, args->vaddr, args->ptep, pte); + ptep_set_wrprotect(args->mm, args->vaddr, args->ptep); + pte = ptep_get(args->ptep); WARN_ON(pte_write(pte)); - ptep_get_and_clear(mm, vaddr, ptep); - pte = ptep_get(ptep); + ptep_get_and_clear(args->mm, args->vaddr, args->ptep); + pte = ptep_get(args->ptep); WARN_ON(!pte_none(pte)); - pte = pfn_pte(pfn, prot); + pte = pfn_pte(args->pte_pfn, args->page_prot); pte = pte_wrprotect(pte); pte = pte_mkclean(pte); - set_pte_at(mm, vaddr, ptep, pte); + set_pte_at(args->mm, args->vaddr, args->ptep, pte); pte = pte_mkwrite(pte); pte = pte_mkdirty(pte); - ptep_set_access_flags(vma, vaddr, ptep, pte, 1); - pte = ptep_get(ptep); + ptep_set_access_flags(args->vma, args->vaddr, args->ptep, pte, 1); + pte = ptep_get(args->ptep); WARN_ON(!(pte_write(pte) && pte_dirty(pte))); - ptep_get_and_clear_full(mm, vaddr, ptep, 1); - pte = ptep_get(ptep); + ptep_get_and_clear_full(args->mm, args->vaddr, args->ptep, 1); + pte = ptep_get(args->ptep); WARN_ON(!pte_none(pte)); - pte = pfn_pte(pfn, prot); + pte = pfn_pte(args->pte_pfn, args->page_prot); pte = pte_mkyoung(pte); - set_pte_at(mm, vaddr, ptep, pte); - ptep_test_and_clear_young(vma, vaddr, ptep); - pte = ptep_get(ptep); + set_pte_at(args->mm, args->vaddr, args->ptep, pte); + ptep_test_and_clear_young(args->vma, args->vaddr, args->ptep); + pte = ptep_get(args->ptep); WARN_ON(pte_young(pte)); } @@ -618,20 +617,21 @@ static void __init pgd_populate_tests(st } #endif /* PAGETABLE_P4D_FOLDED */ -static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep, - unsigned long pfn, unsigned long vaddr, - pgprot_t prot) +static void __init pte_clear_tests(struct pgtable_debug_args *args) { - pte_t pte = pfn_pte(pfn, prot); + pte_t pte = pfn_pte(args->pte_pfn, args->page_prot); + + if (args->pte_pfn == ULONG_MAX) + return; pr_debug("Validating PTE clear\n"); #ifndef CONFIG_RISCV pte = __pte(pte_val(pte) | RANDOM_ORVALUE); #endif - set_pte_at(mm, vaddr, ptep, pte); + set_pte_at(args->mm, args->vaddr, args->ptep, pte); barrier(); - pte_clear(mm, vaddr, ptep); - pte = ptep_get(ptep); + pte_clear(args->mm, args->vaddr, args->ptep); + pte = ptep_get(args->ptep); WARN_ON(!pte_none(pte)); } @@ -1221,11 +1221,10 @@ static int __init debug_vm_pgtable(void) p4d_t *p4dp, *saved_p4dp; pud_t *pudp, *saved_pudp; pmd_t *pmdp, *saved_pmdp, pmd; - pte_t *ptep; pgtable_t saved_ptep; pgprot_t prot; phys_addr_t paddr; - unsigned long vaddr, pte_aligned, pmd_aligned; + unsigned long vaddr, pmd_aligned; unsigned long pud_aligned; spinlock_t *ptl = NULL; int idx, ret; @@ -1260,10 +1259,8 @@ static int __init debug_vm_pgtable(void) */ paddr = __pa_symbol(&start_kernel); - pte_aligned = (paddr & PAGE_MASK) >> PAGE_SHIFT; pmd_aligned = (paddr & PMD_MASK) >> PAGE_SHIFT; pud_aligned = (paddr & PUD_MASK) >> PAGE_SHIFT; - WARN_ON(!pfn_valid(pte_aligned)); pgdp = pgd_offset(mm, vaddr); p4dp = p4d_alloc(mm, pgdp, vaddr); @@ -1345,10 +1342,10 @@ static int __init debug_vm_pgtable(void) * proper page table lock. */ - ptep = pte_offset_map_lock(mm, pmdp, vaddr, &ptl); - pte_clear_tests(mm, ptep, pte_aligned, vaddr, prot); - pte_advanced_tests(mm, vma, ptep, pte_aligned, vaddr, prot); - pte_unmap_unlock(ptep, ptl); + args.ptep = pte_offset_map_lock(args.mm, args.pmdp, args.vaddr, &ptl); + pte_clear_tests(&args); + pte_advanced_tests(&args); + pte_unmap_unlock(args.ptep, ptl); ptl = pmd_lock(mm, pmdp); pmd_clear_tests(mm, pmdp); _
