| From 7262fe1d52e70ac76496befa5c3be57f79426b53 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Mon, 28 Jun 2021 19:35:10 -0700 |
| Subject: mm/debug_vm_pgtable: ensure THP availability via |
| has_transparent_hugepage() |
| |
| From: Anshuman Khandual <anshuman.khandual@arm.com> |
| |
| [ Upstream commit 65ac1a60a57e2c55f2ac37f27095f6b012295e81 ] |
| |
| On certain platforms, THP support could not just be validated via the |
| build option CONFIG_TRANSPARENT_HUGEPAGE. Instead |
| has_transparent_hugepage() also needs to be called upon to verify THP |
| runtime support. Otherwise the debug test will just run into unusable THP |
| helpers like in the case of a 4K hash config on powerpc platform [1]. |
| This just moves all pfn_pmd() and pfn_pud() after THP runtime validation |
| with has_transparent_hugepage() which prevents the mentioned problem. |
| |
| [1] https://bugzilla.kernel.org/show_bug.cgi?id=213069 |
| |
| Link: https://lkml.kernel.org/r/1621397588-19211-1-git-send-email-anshuman.khandual@arm.com |
| Fixes: 787d563b8642 ("mm/debug_vm_pgtable: fix kernel crash by checking for THP support") |
| Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> |
| Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> |
| Cc: Christophe Leroy <christophe.leroy@csgroup.eu> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| mm/debug_vm_pgtable.c | 63 ++++++++++++++++++++++++++++++++++--------- |
| 1 file changed, 51 insertions(+), 12 deletions(-) |
| |
| diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c |
| index 726fd2030f64..12ebc97e8b43 100644 |
| --- a/mm/debug_vm_pgtable.c |
| +++ b/mm/debug_vm_pgtable.c |
| @@ -146,13 +146,14 @@ static void __init pte_savedwrite_tests(unsigned long pfn, pgprot_t prot) |
| static void __init pmd_basic_tests(unsigned long pfn, int idx) |
| { |
| pgprot_t prot = protection_map[idx]; |
| - pmd_t pmd = pfn_pmd(pfn, prot); |
| unsigned long val = idx, *ptr = &val; |
| + pmd_t pmd; |
| |
| if (!has_transparent_hugepage()) |
| return; |
| |
| pr_debug("Validating PMD basic (%pGv)\n", ptr); |
| + pmd = pfn_pmd(pfn, prot); |
| |
| /* |
| * This test needs to be executed after the given page table entry |
| @@ -185,7 +186,7 @@ static void __init pmd_advanced_tests(struct mm_struct *mm, |
| unsigned long pfn, unsigned long vaddr, |
| pgprot_t prot, pgtable_t pgtable) |
| { |
| - pmd_t pmd = pfn_pmd(pfn, prot); |
| + pmd_t pmd; |
| |
| if (!has_transparent_hugepage()) |
| return; |
| @@ -232,9 +233,14 @@ static void __init pmd_advanced_tests(struct mm_struct *mm, |
| |
| static void __init pmd_leaf_tests(unsigned long pfn, pgprot_t prot) |
| { |
| - pmd_t pmd = pfn_pmd(pfn, prot); |
| + pmd_t pmd; |
| + |
| + if (!has_transparent_hugepage()) |
| + return; |
| |
| pr_debug("Validating PMD leaf\n"); |
| + pmd = pfn_pmd(pfn, prot); |
| + |
| /* |
| * PMD based THP is a leaf entry. |
| */ |
| @@ -267,12 +273,16 @@ static void __init pmd_huge_tests(pmd_t *pmdp, unsigned long pfn, pgprot_t prot) |
| |
| static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) |
| { |
| - pmd_t pmd = pfn_pmd(pfn, prot); |
| + pmd_t pmd; |
| |
| if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) |
| return; |
| |
| + if (!has_transparent_hugepage()) |
| + return; |
| + |
| pr_debug("Validating PMD saved write\n"); |
| + pmd = pfn_pmd(pfn, prot); |
| WARN_ON(!pmd_savedwrite(pmd_mk_savedwrite(pmd_clear_savedwrite(pmd)))); |
| WARN_ON(pmd_savedwrite(pmd_clear_savedwrite(pmd_mk_savedwrite(pmd)))); |
| } |
| @@ -281,13 +291,14 @@ static void __init pmd_savedwrite_tests(unsigned long pfn, pgprot_t prot) |
| static void __init pud_basic_tests(struct mm_struct *mm, unsigned long pfn, int idx) |
| { |
| pgprot_t prot = protection_map[idx]; |
| - pud_t pud = pfn_pud(pfn, prot); |
| unsigned long val = idx, *ptr = &val; |
| + pud_t pud; |
| |
| if (!has_transparent_hugepage()) |
| return; |
| |
| pr_debug("Validating PUD basic (%pGv)\n", ptr); |
| + pud = pfn_pud(pfn, prot); |
| |
| /* |
| * This test needs to be executed after the given page table entry |
| @@ -323,7 +334,7 @@ static void __init pud_advanced_tests(struct mm_struct *mm, |
| unsigned long pfn, unsigned long vaddr, |
| pgprot_t prot) |
| { |
| - pud_t pud = pfn_pud(pfn, prot); |
| + pud_t pud; |
| |
| if (!has_transparent_hugepage()) |
| return; |
| @@ -332,6 +343,7 @@ static void __init pud_advanced_tests(struct mm_struct *mm, |
| /* Align the address wrt HPAGE_PUD_SIZE */ |
| vaddr &= HPAGE_PUD_MASK; |
| |
| + pud = pfn_pud(pfn, prot); |
| set_pud_at(mm, vaddr, pudp, pud); |
| pudp_set_wrprotect(mm, vaddr, pudp); |
| pud = READ_ONCE(*pudp); |
| @@ -370,9 +382,13 @@ static void __init pud_advanced_tests(struct mm_struct *mm, |
| |
| static void __init pud_leaf_tests(unsigned long pfn, pgprot_t prot) |
| { |
| - pud_t pud = pfn_pud(pfn, prot); |
| + pud_t pud; |
| + |
| + if (!has_transparent_hugepage()) |
| + return; |
| |
| pr_debug("Validating PUD leaf\n"); |
| + pud = pfn_pud(pfn, prot); |
| /* |
| * PUD based THP is a leaf entry. |
| */ |
| @@ -654,12 +670,16 @@ static void __init pte_protnone_tests(unsigned long pfn, pgprot_t prot) |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| static void __init pmd_protnone_tests(unsigned long pfn, pgprot_t prot) |
| { |
| - pmd_t pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); |
| + pmd_t pmd; |
| |
| if (!IS_ENABLED(CONFIG_NUMA_BALANCING)) |
| return; |
| |
| + if (!has_transparent_hugepage()) |
| + return; |
| + |
| pr_debug("Validating PMD protnone\n"); |
| + pmd = pmd_mkhuge(pfn_pmd(pfn, prot)); |
| WARN_ON(!pmd_protnone(pmd)); |
| WARN_ON(!pmd_present(pmd)); |
| } |
| @@ -679,18 +699,26 @@ static void __init pte_devmap_tests(unsigned long pfn, pgprot_t prot) |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| static void __init pmd_devmap_tests(unsigned long pfn, pgprot_t prot) |
| { |
| - pmd_t pmd = pfn_pmd(pfn, prot); |
| + pmd_t pmd; |
| + |
| + if (!has_transparent_hugepage()) |
| + return; |
| |
| pr_debug("Validating PMD devmap\n"); |
| + pmd = pfn_pmd(pfn, prot); |
| WARN_ON(!pmd_devmap(pmd_mkdevmap(pmd))); |
| } |
| |
| #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD |
| static void __init pud_devmap_tests(unsigned long pfn, pgprot_t prot) |
| { |
| - pud_t pud = pfn_pud(pfn, prot); |
| + pud_t pud; |
| + |
| + if (!has_transparent_hugepage()) |
| + return; |
| |
| pr_debug("Validating PUD devmap\n"); |
| + pud = pfn_pud(pfn, prot); |
| WARN_ON(!pud_devmap(pud_mkdevmap(pud))); |
| } |
| #else /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */ |
| @@ -733,25 +761,33 @@ static void __init pte_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot) |
| #ifdef CONFIG_TRANSPARENT_HUGEPAGE |
| static void __init pmd_soft_dirty_tests(unsigned long pfn, pgprot_t prot) |
| { |
| - pmd_t pmd = pfn_pmd(pfn, prot); |
| + pmd_t pmd; |
| |
| if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY)) |
| return; |
| |
| + if (!has_transparent_hugepage()) |
| + return; |
| + |
| pr_debug("Validating PMD soft dirty\n"); |
| + pmd = pfn_pmd(pfn, prot); |
| WARN_ON(!pmd_soft_dirty(pmd_mksoft_dirty(pmd))); |
| WARN_ON(pmd_soft_dirty(pmd_clear_soft_dirty(pmd))); |
| } |
| |
| static void __init pmd_swap_soft_dirty_tests(unsigned long pfn, pgprot_t prot) |
| { |
| - pmd_t pmd = pfn_pmd(pfn, prot); |
| + pmd_t pmd; |
| |
| if (!IS_ENABLED(CONFIG_MEM_SOFT_DIRTY) || |
| !IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION)) |
| return; |
| |
| + if (!has_transparent_hugepage()) |
| + return; |
| + |
| pr_debug("Validating PMD swap soft dirty\n"); |
| + pmd = pfn_pmd(pfn, prot); |
| WARN_ON(!pmd_swp_soft_dirty(pmd_swp_mksoft_dirty(pmd))); |
| WARN_ON(pmd_swp_soft_dirty(pmd_swp_clear_soft_dirty(pmd))); |
| } |
| @@ -780,6 +816,9 @@ static void __init pmd_swap_tests(unsigned long pfn, pgprot_t prot) |
| swp_entry_t swp; |
| pmd_t pmd; |
| |
| + if (!has_transparent_hugepage()) |
| + return; |
| + |
| pr_debug("Validating PMD swap\n"); |
| pmd = pfn_pmd(pfn, prot); |
| swp = __pmd_to_swp_entry(pmd); |
| -- |
| 2.30.2 |
| |