linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, anshuman.khandual@arm.com,
	benh@kernel.crashing.org, borntraeger@de.ibm.com, bp@alien8.de,
	cai@lca.pw, catalin.marinas@arm.com, christophe.leroy@c-s.fr,
	gerald.schaefer@de.ibm.com, gor@linux.ibm.com,
	heiko.carstens@de.ibm.com, hpa@zytor.com, kirill@shutemov.name,
	linux-mm@kvack.org, mingo@kernel.org, mingo@redhat.com,
	mm-commits@vger.kernel.org, mpe@ellerman.id.au,
	palmer@dabbelt.com, paul.walmsley@sifive.com, paulus@samba.org,
	rppt@linux.ibm.com, tglx@linutronix.de,
	torvalds@linux-foundation.org, vgupta@synopsys.com,
	will@kernel.org
Subject: [patch 024/127] mm/debug: add tests validating architecture page table helpers
Date: Thu, 04 Jun 2020 16:47:15 -0700	[thread overview]
Message-ID: <20200604234715.x-3eXwdwn%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200604164523.e15f3177f4b69dcb4f2534a1@linux-foundation.org>

From: Anshuman Khandual <anshuman.khandual@arm.com>
Subject: mm/debug: add tests validating architecture page table helpers

This adds tests which will validate architecture page table helpers and
other accessors in their compliance with expected generic MM semantics. 
This will help various architectures in validating changes to existing
page table helpers or addition of new ones.

This test covers basic page table entry transformations including but not
limited to old, young, dirty, clean, write, write protect etc at various
level along with populating intermediate entries with next page table page
and validating them.

Test page table pages are allocated from system memory with required size
and alignments.  The mapped pfns at page table levels are derived from a
real pfn representing a valid kernel text symbol.  This test gets called
via late_initcall().

This test gets built and run when CONFIG_DEBUG_VM_PGTABLE is selected. 
Any architecture, which is willing to subscribe this test will need to
select ARCH_HAS_DEBUG_VM_PGTABLE.  For now this is limited to arc, arm64,
x86, s390 and powerpc platforms where the test is known to build and run
successfully Going forward, other architectures too can subscribe the test
after fixing any build or runtime problems with their page table helpers.

Folks interested in making sure that a given platform's page table helpers
conform to expected generic MM semantics should enable the above config
which will just trigger this test during boot.  Any non conformity here
will be reported as an warning which would need to be fixed.  This test
will help catch any changes to the agreed upon semantics expected from
generic MM and enable platforms to accommodate it thereafter.

[anshuman.khandual@arm.com: v17]
  Link: http://lkml.kernel.org/r/1587436495-22033-3-git-send-email-anshuman.khandual@arm.com
[anshuman.khandual@arm.com: v18]
  Link: http://lkml.kernel.org/r/1588564865-31160-3-git-send-email-anshuman.khandual@arm.com
Link: http://lkml.kernel.org/r/1583919272-24178-1-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Qian Cai <cai@lca.pw>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>	[s390]
Tested-by: Christophe Leroy <christophe.leroy@c-s.fr>	[ppc32]
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/features/debug/debug-vm-pgtable/arch-support.txt |   34 
 arch/arc/Kconfig                                               |    1 
 arch/arm64/Kconfig                                             |    1 
 arch/powerpc/Kconfig                                           |    1 
 arch/s390/Kconfig                                              |    1 
 arch/x86/Kconfig                                               |    1 
 lib/Kconfig.debug                                              |   22 
 mm/Makefile                                                    |    1 
 mm/debug_vm_pgtable.c                                          |  382 ++++++++++
 9 files changed, 444 insertions(+)

--- a/arch/arc/Kconfig~mm-debug-add-tests-validating-architecture-page-table-helpers
+++ a/arch/arc/Kconfig
@@ -6,6 +6,7 @@
 config ARC
 	def_bool y
 	select ARC_TIMERS
+	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SETUP_DMA_OPS
--- a/arch/arm64/Kconfig~mm-debug-add-tests-validating-architecture-page-table-helpers
+++ a/arch/arm64/Kconfig
@@ -12,6 +12,7 @@ config ARM64
 	select ARCH_HAS_DEBUG_WX
 	select ARCH_BINFMT_ELF_STATE
 	select ARCH_HAS_DEBUG_VIRTUAL
+	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI
--- a/arch/powerpc/Kconfig~mm-debug-add-tests-validating-architecture-page-table-helpers
+++ a/arch/powerpc/Kconfig
@@ -116,6 +116,7 @@ config PPC
 	#
 	select ARCH_32BIT_OFF_T if PPC32
 	select ARCH_HAS_DEBUG_VIRTUAL
+	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
--- a/arch/s390/Kconfig~mm-debug-add-tests-validating-architecture-page-table-helpers
+++ a/arch/s390/Kconfig
@@ -59,6 +59,7 @@ config KASAN_SHADOW_OFFSET
 config S390
 	def_bool y
 	select ARCH_BINFMT_ELF_STATE
+	select ARCH_HAS_DEBUG_VM_PGTABLE
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
--- a/arch/x86/Kconfig~mm-debug-add-tests-validating-architecture-page-table-helpers
+++ a/arch/x86/Kconfig
@@ -59,6 +59,7 @@ config X86
 	select ARCH_CLOCKSOURCE_INIT
 	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
 	select ARCH_HAS_DEBUG_VIRTUAL
+	select ARCH_HAS_DEBUG_VM_PGTABLE	if !X86_PAE
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_EARLY_DEBUG		if KGDB
 	select ARCH_HAS_ELF_RANDOMIZE
--- /dev/null
+++ a/Documentation/features/debug/debug-vm-pgtable/arch-support.txt
@@ -0,0 +1,34 @@
+#
+# Feature name:          debug-vm-pgtable
+#         Kconfig:       ARCH_HAS_DEBUG_VM_PGTABLE
+#         description:   arch supports pgtable tests for semantics compliance
+#
+    -----------------------
+    |         arch |status|
+    -----------------------
+    |       alpha: | TODO |
+    |         arc: |  ok  |
+    |         arm: | TODO |
+    |       arm64: |  ok  |
+    |         c6x: | TODO |
+    |        csky: | TODO |
+    |       h8300: | TODO |
+    |     hexagon: | TODO |
+    |        ia64: | TODO |
+    |        m68k: | TODO |
+    |  microblaze: | TODO |
+    |        mips: | TODO |
+    |       nds32: | TODO |
+    |       nios2: | TODO |
+    |    openrisc: | TODO |
+    |      parisc: | TODO |
+    |     powerpc: |  ok  |
+    |       riscv: | TODO |
+    |        s390: |  ok  |
+    |          sh: | TODO |
+    |       sparc: | TODO |
+    |          um: | TODO |
+    |   unicore32: | TODO |
+    |         x86: |  ok  |
+    |      xtensa: | TODO |
+    -----------------------
--- a/lib/Kconfig.debug~mm-debug-add-tests-validating-architecture-page-table-helpers
+++ a/lib/Kconfig.debug
@@ -658,6 +658,12 @@ config SCHED_STACK_END_CHECK
 	  data corruption or a sporadic crash at a later stage once the region
 	  is examined. The runtime overhead introduced is minimal.
 
+config ARCH_HAS_DEBUG_VM_PGTABLE
+	bool
+	help
+	  An architecture should select this when it can successfully
+	  build and run DEBUG_VM_PGTABLE.
+
 config DEBUG_VM
 	bool "Debug VM"
 	depends on DEBUG_KERNEL
@@ -693,6 +699,22 @@ config DEBUG_VM_PGFLAGS
 
 	  If unsure, say N.
 
+config DEBUG_VM_PGTABLE
+	bool "Debug arch page table for semantics compliance"
+	depends on MMU
+	depends on ARCH_HAS_DEBUG_VM_PGTABLE
+	default y if DEBUG_VM
+	help
+	  This option provides a debug method which can be used to test
+	  architecture page table helper functions on various platforms in
+	  verifying if they comply with expected generic MM semantics. This
+	  will help architecture code in making sure that any changes or
+	  new additions of these helpers still conform to expected
+	  semantics of the generic MM. Platforms will have to opt in for
+	  this through ARCH_HAS_DEBUG_VM_PGTABLE.
+
+	  If unsure, say N.
+
 config ARCH_HAS_DEBUG_VIRTUAL
 	bool
 
--- /dev/null
+++ a/mm/debug_vm_pgtable.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This kernel test validates architecture page table helpers and
+ * accessors and helps in verifying their continued compliance with
+ * expected generic MM semantics.
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ *
+ * Author: Anshuman Khandual <anshuman.khandual@arm.com>
+ */
+#define pr_fmt(fmt) "debug_vm_pgtable: %s: " fmt, __func__
+
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/hugetlb.h>
+#include <linux/kernel.h>
+#include <linux/kconfig.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/mm_types.h>
+#include <linux/module.h>
+#include <linux/pfn_t.h>
+#include <linux/printk.h>
+#include <linux/random.h>
+#include <linux/spinlock.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/start_kernel.h>
+#include <linux/sched/mm.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+#define VMFLAGS	(VM_READ|VM_WRITE|VM_EXEC)
+
+/*
+ * On s390 platform, the lower 4 bits are used to identify given page table
+ * entry type. But these bits might affect the ability to clear entries with
+ * pxx_clear() because of how dynamic page table folding works on s390. So
+ * while loading up the entries do not change the lower 4 bits. It does not
+ * have affect any other platform.
+ */
+#define S390_MASK_BITS	4
+#define RANDOM_ORVALUE	GENMASK(BITS_PER_LONG - 1, S390_MASK_BITS)
+#define RANDOM_NZVALUE	GENMASK(7, 0)
+
+static void __init pte_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	pte_t pte = pfn_pte(pfn, prot);
+
+	WARN_ON(!pte_same(pte, pte));
+	WARN_ON(!pte_young(pte_mkyoung(pte_mkold(pte))));
+	WARN_ON(!pte_dirty(pte_mkdirty(pte_mkclean(pte))));
+	WARN_ON(!pte_write(pte_mkwrite(pte_wrprotect(pte))));
+	WARN_ON(pte_young(pte_mkold(pte_mkyoung(pte))));
+	WARN_ON(pte_dirty(pte_mkclean(pte_mkdirty(pte))));
+	WARN_ON(pte_write(pte_wrprotect(pte_mkwrite(pte))));
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	pmd_t pmd = pfn_pmd(pfn, prot);
+
+	WARN_ON(!pmd_same(pmd, pmd));
+	WARN_ON(!pmd_young(pmd_mkyoung(pmd_mkold(pmd))));
+	WARN_ON(!pmd_dirty(pmd_mkdirty(pmd_mkclean(pmd))));
+	WARN_ON(!pmd_write(pmd_mkwrite(pmd_wrprotect(pmd))));
+	WARN_ON(pmd_young(pmd_mkold(pmd_mkyoung(pmd))));
+	WARN_ON(pmd_dirty(pmd_mkclean(pmd_mkdirty(pmd))));
+	WARN_ON(pmd_write(pmd_wrprotect(pmd_mkwrite(pmd))));
+	/*
+	 * A huge page does not point to next level page table
+	 * entry. Hence this must qualify as pmd_bad().
+	 */
+	WARN_ON(!pmd_bad(pmd_mkhuge(pmd)));
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	pud_t pud = pfn_pud(pfn, prot);
+
+	WARN_ON(!pud_same(pud, pud));
+	WARN_ON(!pud_young(pud_mkyoung(pud_mkold(pud))));
+	WARN_ON(!pud_write(pud_mkwrite(pud_wrprotect(pud))));
+	WARN_ON(pud_write(pud_wrprotect(pud_mkwrite(pud))));
+	WARN_ON(pud_young(pud_mkold(pud_mkyoung(pud))));
+
+	if (mm_pmd_folded(mm))
+		return;
+
+	/*
+	 * A huge page does not point to next level page table
+	 * entry. Hence this must qualify as pud_bad().
+	 */
+	WARN_ON(!pud_bad(pud_mkhuge(pud)));
+}
+#else  /* !CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+#else  /* !CONFIG_TRANSPARENT_HUGEPAGE */
+static void __init pmd_basic_tests(unsigned long pfn, pgprot_t prot) { }
+static void __init pud_basic_tests(unsigned long pfn, pgprot_t prot) { }
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+static void __init p4d_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	p4d_t p4d;
+
+	memset(&p4d, RANDOM_NZVALUE, sizeof(p4d_t));
+	WARN_ON(!p4d_same(p4d, p4d));
+}
+
+static void __init pgd_basic_tests(unsigned long pfn, pgprot_t prot)
+{
+	pgd_t pgd;
+
+	memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
+	WARN_ON(!pgd_same(pgd, pgd));
+}
+
+#ifndef __PAGETABLE_PUD_FOLDED
+static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp)
+{
+	pud_t pud = READ_ONCE(*pudp);
+
+	if (mm_pmd_folded(mm))
+		return;
+
+	pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
+	WRITE_ONCE(*pudp, pud);
+	pud_clear(pudp);
+	pud = READ_ONCE(*pudp);
+	WARN_ON(!pud_none(pud));
+}
+
+static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
+				      pmd_t *pmdp)
+{
+	pud_t pud;
+
+	if (mm_pmd_folded(mm))
+		return;
+	/*
+	 * This entry points to next level page table page.
+	 * Hence this must not qualify as pud_bad().
+	 */
+	pmd_clear(pmdp);
+	pud_clear(pudp);
+	pud_populate(mm, pudp, pmdp);
+	pud = READ_ONCE(*pudp);
+	WARN_ON(pud_bad(pud));
+}
+#else  /* !__PAGETABLE_PUD_FOLDED */
+static void __init pud_clear_tests(struct mm_struct *mm, pud_t *pudp) { }
+static void __init pud_populate_tests(struct mm_struct *mm, pud_t *pudp,
+				      pmd_t *pmdp)
+{
+}
+#endif /* PAGETABLE_PUD_FOLDED */
+
+#ifndef __PAGETABLE_P4D_FOLDED
+static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp)
+{
+	p4d_t p4d = READ_ONCE(*p4dp);
+
+	if (mm_pud_folded(mm))
+		return;
+
+	p4d = __p4d(p4d_val(p4d) | RANDOM_ORVALUE);
+	WRITE_ONCE(*p4dp, p4d);
+	p4d_clear(p4dp);
+	p4d = READ_ONCE(*p4dp);
+	WARN_ON(!p4d_none(p4d));
+}
+
+static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
+				      pud_t *pudp)
+{
+	p4d_t p4d;
+
+	if (mm_pud_folded(mm))
+		return;
+
+	/*
+	 * This entry points to next level page table page.
+	 * Hence this must not qualify as p4d_bad().
+	 */
+	pud_clear(pudp);
+	p4d_clear(p4dp);
+	p4d_populate(mm, p4dp, pudp);
+	p4d = READ_ONCE(*p4dp);
+	WARN_ON(p4d_bad(p4d));
+}
+
+static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp)
+{
+	pgd_t pgd = READ_ONCE(*pgdp);
+
+	if (mm_p4d_folded(mm))
+		return;
+
+	pgd = __pgd(pgd_val(pgd) | RANDOM_ORVALUE);
+	WRITE_ONCE(*pgdp, pgd);
+	pgd_clear(pgdp);
+	pgd = READ_ONCE(*pgdp);
+	WARN_ON(!pgd_none(pgd));
+}
+
+static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
+				      p4d_t *p4dp)
+{
+	pgd_t pgd;
+
+	if (mm_p4d_folded(mm))
+		return;
+
+	/*
+	 * This entry points to next level page table page.
+	 * Hence this must not qualify as pgd_bad().
+	 */
+	p4d_clear(p4dp);
+	pgd_clear(pgdp);
+	pgd_populate(mm, pgdp, p4dp);
+	pgd = READ_ONCE(*pgdp);
+	WARN_ON(pgd_bad(pgd));
+}
+#else  /* !__PAGETABLE_P4D_FOLDED */
+static void __init p4d_clear_tests(struct mm_struct *mm, p4d_t *p4dp) { }
+static void __init pgd_clear_tests(struct mm_struct *mm, pgd_t *pgdp) { }
+static void __init p4d_populate_tests(struct mm_struct *mm, p4d_t *p4dp,
+				      pud_t *pudp)
+{
+}
+static void __init pgd_populate_tests(struct mm_struct *mm, pgd_t *pgdp,
+				      p4d_t *p4dp)
+{
+}
+#endif /* PAGETABLE_P4D_FOLDED */
+
+static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep,
+				   unsigned long vaddr)
+{
+	pte_t pte = READ_ONCE(*ptep);
+
+	pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
+	set_pte_at(mm, vaddr, ptep, pte);
+	barrier();
+	pte_clear(mm, vaddr, ptep);
+	pte = READ_ONCE(*ptep);
+	WARN_ON(!pte_none(pte));
+}
+
+static void __init pmd_clear_tests(struct mm_struct *mm, pmd_t *pmdp)
+{
+	pmd_t pmd = READ_ONCE(*pmdp);
+
+	pmd = __pmd(pmd_val(pmd) | RANDOM_ORVALUE);
+	WRITE_ONCE(*pmdp, pmd);
+	pmd_clear(pmdp);
+	pmd = READ_ONCE(*pmdp);
+	WARN_ON(!pmd_none(pmd));
+}
+
+static void __init pmd_populate_tests(struct mm_struct *mm, pmd_t *pmdp,
+				      pgtable_t pgtable)
+{
+	pmd_t pmd;
+
+	/*
+	 * This entry points to next level page table page.
+	 * Hence this must not qualify as pmd_bad().
+	 */
+	pmd_clear(pmdp);
+	pmd_populate(mm, pmdp, pgtable);
+	pmd = READ_ONCE(*pmdp);
+	WARN_ON(pmd_bad(pmd));
+}
+
+static unsigned long __init get_random_vaddr(void)
+{
+	unsigned long random_vaddr, random_pages, total_user_pages;
+
+	total_user_pages = (TASK_SIZE - FIRST_USER_ADDRESS) / PAGE_SIZE;
+
+	random_pages = get_random_long() % total_user_pages;
+	random_vaddr = FIRST_USER_ADDRESS + random_pages * PAGE_SIZE;
+
+	return random_vaddr;
+}
+
+static int __init debug_vm_pgtable(void)
+{
+	struct mm_struct *mm;
+	pgd_t *pgdp;
+	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 pud_aligned, p4d_aligned, pgd_aligned;
+	spinlock_t *uninitialized_var(ptl);
+
+	pr_info("Validating architecture page table helpers\n");
+	prot = vm_get_page_prot(VMFLAGS);
+	vaddr = get_random_vaddr();
+	mm = mm_alloc();
+	if (!mm) {
+		pr_err("mm_struct allocation failed\n");
+		return 1;
+	}
+
+	/*
+	 * PFN for mapping at PTE level is determined from a standard kernel
+	 * text symbol. But pfns for higher page table levels are derived by
+	 * masking lower bits of this real pfn. These derived pfns might not
+	 * exist on the platform but that does not really matter as pfn_pxx()
+	 * helpers will still create appropriate entries for the test. This
+	 * helps avoid large memory block allocations to be used for mapping
+	 * at higher page table levels.
+	 */
+	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;
+	p4d_aligned = (paddr & P4D_MASK) >> PAGE_SHIFT;
+	pgd_aligned = (paddr & PGDIR_MASK) >> PAGE_SHIFT;
+	WARN_ON(!pfn_valid(pte_aligned));
+
+	pgdp = pgd_offset(mm, vaddr);
+	p4dp = p4d_alloc(mm, pgdp, vaddr);
+	pudp = pud_alloc(mm, p4dp, vaddr);
+	pmdp = pmd_alloc(mm, pudp, vaddr);
+	ptep = pte_alloc_map_lock(mm, pmdp, vaddr, &ptl);
+
+	/*
+	 * Save all the page table page addresses as the page table
+	 * entries will be used for testing with random or garbage
+	 * values. These saved addresses will be used for freeing
+	 * page table pages.
+	 */
+	pmd = READ_ONCE(*pmdp);
+	saved_p4dp = p4d_offset(pgdp, 0UL);
+	saved_pudp = pud_offset(p4dp, 0UL);
+	saved_pmdp = pmd_offset(pudp, 0UL);
+	saved_ptep = pmd_pgtable(pmd);
+
+	pte_basic_tests(pte_aligned, prot);
+	pmd_basic_tests(pmd_aligned, prot);
+	pud_basic_tests(pud_aligned, prot);
+	p4d_basic_tests(p4d_aligned, prot);
+	pgd_basic_tests(pgd_aligned, prot);
+
+	pte_clear_tests(mm, ptep, vaddr);
+	pmd_clear_tests(mm, pmdp);
+	pud_clear_tests(mm, pudp);
+	p4d_clear_tests(mm, p4dp);
+	pgd_clear_tests(mm, pgdp);
+
+	pte_unmap_unlock(ptep, ptl);
+
+	pmd_populate_tests(mm, pmdp, saved_ptep);
+	pud_populate_tests(mm, pudp, saved_pmdp);
+	p4d_populate_tests(mm, p4dp, saved_pudp);
+	pgd_populate_tests(mm, pgdp, saved_p4dp);
+
+	p4d_free(mm, saved_p4dp);
+	pud_free(mm, saved_pudp);
+	pmd_free(mm, saved_pmdp);
+	pte_free(mm, saved_ptep);
+
+	mm_dec_nr_puds(mm);
+	mm_dec_nr_pmds(mm);
+	mm_dec_nr_ptes(mm);
+	mmdrop(mm);
+	return 0;
+}
+late_initcall(debug_vm_pgtable);
--- a/mm/Makefile~mm-debug-add-tests-validating-architecture-page-table-helpers
+++ a/mm/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_HWPOISON_INJECT) += hwpoiso
 obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
 obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
 obj-$(CONFIG_DEBUG_RODATA_TEST) += rodata_test.o
+obj-$(CONFIG_DEBUG_VM_PGTABLE) += debug_vm_pgtable.o
 obj-$(CONFIG_PAGE_OWNER) += page_owner.o
 obj-$(CONFIG_CLEANCACHE) += cleancache.o
 obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
_


  parent reply	other threads:[~2020-06-04 23:47 UTC|newest]

Thread overview: 129+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-06-04 23:45 incoming Andrew Morton
2020-06-04 23:45 ` [patch 001/127] kcov: cleanup debug messages Andrew Morton
2020-06-04 23:45 ` [patch 002/127] kcov: fix potential use-after-free in kcov_remote_start Andrew Morton
2020-06-04 23:45 ` [patch 003/127] kcov: move t->kcov assignments into kcov_start/stop Andrew Morton
2020-06-04 23:45 ` [patch 004/127] kcov: move t->kcov_sequence assignment Andrew Morton
2020-06-04 23:46 ` [patch 005/127] kcov: use t->kcov_mode as enabled indicator Andrew Morton
2020-06-04 23:46 ` [patch 006/127] kcov: collect coverage from interrupts Andrew Morton
2020-06-04 23:46 ` [patch 007/127] usb: core: kcov: collect coverage from usb complete callback Andrew Morton
2020-06-04 23:46 ` [patch 008/127] mm/util.c: remove the VM_WARN_ONCE for vm_committed_as underflow check Andrew Morton
2020-06-04 23:46 ` [patch 009/127] h8300: remove usage of __ARCH_USE_5LEVEL_HACK Andrew Morton
2020-06-04 23:46 ` [patch 010/127] arm: add support for folded p4d page tables Andrew Morton
2020-06-04 23:46 ` [patch 011/127] arm64: " Andrew Morton
2020-06-04 23:46 ` [patch 012/127] hexagon: remove __ARCH_USE_5LEVEL_HACK Andrew Morton
2020-06-04 23:46 ` [patch 013/127] ia64: add support for folded p4d page tables Andrew Morton
2020-06-04 23:46 ` [patch 014/127] nios2: " Andrew Morton
2020-06-04 23:46 ` [patch 015/127] openrisc: " Andrew Morton
2020-06-04 23:46 ` [patch 016/127] powerpc: " Andrew Morton
2020-06-04 23:46 ` [patch 017/127] sh: fault: modernize printing of kernel messages Andrew Morton
2020-06-04 23:46 ` [patch 018/127] sh: drop __pXd_offset() macros that duplicate pXd_index() ones Andrew Morton
2020-06-04 23:46 ` [patch 019/127] sh: add support for folded p4d page tables Andrew Morton
2020-06-04 23:47 ` [patch 020/127] unicore32: remove __ARCH_USE_5LEVEL_HACK Andrew Morton
2020-06-04 23:47 ` [patch 021/127] asm-generic: remove pgtable-nop4d-hack.h Andrew Morton
2020-06-04 23:47 ` [patch 022/127] mm: remove __ARCH_HAS_5LEVEL_HACK and include/asm-generic/5level-fixup.h Andrew Morton
2020-06-04 23:47 ` [patch 023/127] x86/mm: define mm_p4d_folded() Andrew Morton
2020-06-04 23:47 ` Andrew Morton [this message]
2020-06-04 23:47 ` [patch 025/127] mm/vmalloc: fix a typo in comment Andrew Morton
2020-06-04 23:47 ` [patch 026/127] arch/kmap: remove BUG_ON() Andrew Morton
2020-06-04 23:47 ` [patch 027/127] arch/xtensa: move kmap build bug out of the way Andrew Morton
2020-06-04 23:47 ` [patch 028/127] arch/kmap: remove redundant arch specific kmaps Andrew Morton
2020-06-04 23:47 ` [patch 029/127] arch/kunmap: remove duplicate kunmap implementations Andrew Morton
2020-06-04 23:47 ` [patch 030/127] {x86,powerpc,microblaze}/kmap: move preempt disable Andrew Morton
2020-06-04 23:47 ` [patch 031/127] arch/kmap_atomic: consolidate duplicate code Andrew Morton
2020-06-04 23:47 ` [patch 032/127] arch/kunmap_atomic: " Andrew Morton
2020-06-04 23:47 ` [patch 033/127] arch/kmap: ensure kmap_prot visibility Andrew Morton
2020-06-04 23:47 ` [patch 034/127] arch/kmap: don't hard code kmap_prot values Andrew Morton
2020-06-04 23:47 ` [patch 035/127] arch/kmap: define kmap_atomic_prot() for all arch's Andrew Morton
2020-06-04 23:48 ` [patch 036/127] drm: remove drm specific kmap_atomic code Andrew Morton
2020-06-04 23:48 ` [patch 037/127] kmap: remove kmap_atomic_to_page() Andrew Morton
2020-06-04 23:48 ` [patch 038/127] parisc/kmap: remove duplicate kmap code Andrew Morton
2020-06-04 23:48 ` [patch 039/127] sparc: remove unnecessary includes Andrew Morton
2020-06-04 23:48 ` [patch 040/127] kmap: consolidate kmap_prot definitions Andrew Morton
2020-06-04 23:48 ` [patch 041/127] mm: add kvfree_sensitive() for freeing sensitive data objects Andrew Morton
2020-06-16 20:59   ` Jarkko Sakkinen
2020-06-04 23:48 ` [patch 042/127] mm/memory_hotplug: refrain from adding memory into an impossible node Andrew Morton
2020-06-04 23:48 ` [patch 043/127] powerpc/pseries/hotplug-memory: stop checking is_mem_section_removable() Andrew Morton
2020-06-04 23:48 ` [patch 044/127] mm/memory_hotplug: remove is_mem_section_removable() Andrew Morton
2020-06-04 23:48 ` [patch 045/127] mm/memory_hotplug: set node_start_pfn of hotadded pgdat to 0 Andrew Morton
2020-06-04 23:48 ` [patch 046/127] mm/memory_hotplug: handle memblocks only with CONFIG_ARCH_KEEP_MEMBLOCK Andrew Morton
2020-06-04 23:48 ` [patch 047/127] mm/memory_hotplug: introduce add_memory_driver_managed() Andrew Morton
2020-06-04 23:48 ` [patch 048/127] kexec_file: don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGED Andrew Morton
2020-06-04 23:48 ` [patch 049/127] device-dax: add memory via add_memory_driver_managed() Andrew Morton
2020-06-04 23:48 ` [patch 050/127] mm/memory_hotplug: disable the functionality for 32b Andrew Morton
2020-06-04 23:48 ` [patch 051/127] mm: replace zero-length array with flexible-array member Andrew Morton
2020-06-04 23:48 ` [patch 052/127] mm/memory_hotplug: fix a typo in comment "recoreded"->"recorded" Andrew Morton
2020-06-04 23:49 ` [patch 053/127] mm: ksm: fix a typo in comment "alreaady"->"already" Andrew Morton
2020-06-04 23:49 ` [patch 054/127] mm: mmap: fix a typo in comment "compatbility"->"compatibility" Andrew Morton
2020-06-04 23:49 ` [patch 055/127] mm/hugetlb: fix a typos in comments Andrew Morton
2020-06-04 23:49 ` [patch 056/127] mm/vmsan: fix some typos in comment Andrew Morton
2020-06-04 23:49 ` [patch 057/127] mm/compaction: fix a typo in comment "pessemistic"->"pessimistic" Andrew Morton
2020-06-04 23:49 ` [patch 058/127] mm/memblock: fix a typo in comment "implict"->"implicit" Andrew Morton
2020-06-04 23:49 ` [patch 059/127] mm/list_lru: fix a typo in comment "numbesr"->"numbers" Andrew Morton
2020-06-04 23:49 ` [patch 060/127] mm/filemap: fix a typo in comment "unneccssary"->"unnecessary" Andrew Morton
2020-06-04 23:49 ` [patch 061/127] mm/frontswap: fix some typos in frontswap.c Andrew Morton
2020-06-04 23:49 ` [patch 062/127] mm, memcg: fix some typos in memcontrol.c Andrew Morton
2020-06-04 23:49 ` [patch 063/127] mm: fix a typo in comment "strucure"->"structure" Andrew Morton
2020-06-04 23:49 ` [patch 064/127] mm/slub: fix a typo in comment "disambiguiation"->"disambiguation" Andrew Morton
2020-06-04 23:49 ` [patch 065/127] mm/sparse: fix a typo in comment "convienence"->"convenience" Andrew Morton
2020-06-04 23:49 ` [patch 066/127] mm/page-writeback: fix a typo in comment "effictive"->"effective" Andrew Morton
2020-06-04 23:49 ` [patch 067/127] mm/memory: fix a typo in comment "attampt"->"attempt" Andrew Morton
2020-06-04 23:49 ` [patch 068/127] mm: use false for bool variable Andrew Morton
2020-06-04 23:49 ` [patch 069/127] include/linux/mm.h: return true in cpupid_pid_unset() Andrew Morton
2020-06-04 23:49 ` [patch 070/127] zcomp: Use ARRAY_SIZE() for backends list Andrew Morton
2020-06-04 23:49 ` [patch 071/127] proc: rename "catch" function argument Andrew Morton
2020-06-04 23:49 ` [patch 072/127] user.c: make uidhash_table static Andrew Morton
2020-06-04 23:50 ` [patch 073/127] get_maintainer: add email addresses from .yaml files Andrew Morton
2020-06-04 23:50 ` [patch 074/127] get_maintainer: fix unexpected behavior for path/to//file (double slashes) Andrew Morton
2020-06-04 23:50 ` [patch 075/127] lib/math: avoid trailing newline hidden in pr_fmt() Andrew Morton
2020-06-04 23:50 ` [patch 076/127] lib: Add might_fault() to strncpy_from_user Andrew Morton
2020-06-04 23:50 ` [patch 077/127] lib/test_lockup.c: make test_inode static Andrew Morton
2020-06-04 23:50 ` [patch 078/127] lib/zlib: remove outdated and incorrect pre-increment optimization Andrew Morton
2020-06-04 23:50 ` [patch 079/127] lib/percpu-refcount.c: use a more common logging style Andrew Morton
2020-06-04 23:50 ` [patch 080/127] lib/flex_proportions.c: cleanup __fprop_inc_percpu_max Andrew Morton
2020-06-04 23:50 ` [patch 081/127] lib: make a test module with set/clear bit Andrew Morton
2020-06-04 23:50 ` [patch 082/127] include/linux/bitops.h: avoid clang shift-count-overflow warnings Andrew Morton
2020-06-04 23:50 ` [patch 083/127] checkpatch: additional MAINTAINER section entry ordering checks Andrew Morton
2020-06-04 23:50 ` [patch 084/127] checkpatch: look for c99 comments in ctx_locate_comment Andrew Morton
2020-06-04 23:50 ` [patch 085/127] checkpatch: disallow --git and --file/--fix Andrew Morton
2020-06-04 23:50 ` [patch 086/127] checkpatch: use patch subject when reading from stdin Andrew Morton
2020-06-04 23:50 ` [patch 087/127] fs/binfmt_elf: remove redundant elf_map ifndef Andrew Morton
2020-06-04 23:50 ` [patch 088/127] elfnote: mark all .note sections SHF_ALLOC Andrew Morton
2020-06-04 23:50 ` [patch 089/127] init: allow distribution configuration of default init Andrew Morton
2020-06-04 23:50 ` [patch 090/127] fat: don't allow to mount if the FAT length == 0 Andrew Morton
2020-06-04 23:50 ` [patch 091/127] fat: improve the readahead for FAT entries Andrew Morton
2020-06-04 23:51 ` [patch 092/127] fs/seq_file.c: seq_read: Update pr_info_ratelimited Andrew Morton
2020-06-04 23:51 ` [patch 093/127] include/linux/seq_file.h: introduce DEFINE_SEQ_ATTRIBUTE() helper macro Andrew Morton
2020-06-04 23:51 ` [patch 094/127] mm/vmstat.c: convert to use DEFINE_SEQ_ATTRIBUTE macro Andrew Morton
2020-06-04 23:51 ` [patch 095/127] kernel/kprobes.c: " Andrew Morton
2020-06-04 23:51 ` [patch 096/127] exec: simplify the copy_strings_kernel calling convention Andrew Morton
2020-06-04 23:51 ` [patch 097/127] exec: open code copy_string_kernel Andrew Morton
2020-06-04 23:51 ` [patch 098/127] rapidio: avoid data race between file operation callbacks and mport_cdev_add() Andrew Morton
2020-06-04 23:51 ` [patch 099/127] rapidio: convert get_user_pages() --> pin_user_pages() Andrew Morton
2020-06-04 23:51 ` [patch 100/127] kernel/relay.c: handle alloc_percpu returning NULL in relay_open Andrew Morton
2020-06-04 23:51 ` [patch 101/127] kernel/relay.c: fix read_pos error when multiple readers Andrew Morton
2020-06-04 23:51 ` [patch 102/127] selftests/x86/pkeys: move selftests to arch-neutral directory Andrew Morton
2020-06-04 23:51 ` [patch 103/127] selftests/vm/pkeys: rename all references to pkru to a generic name Andrew Morton
2020-06-04 23:51 ` [patch 104/127] selftests/vm/pkeys: move generic definitions to header file Andrew Morton
2020-06-04 23:51 ` [patch 105/127] selftests/vm/pkeys: move some definitions to arch-specific header Andrew Morton
2020-06-04 23:51 ` [patch 106/127] selftests/vm/pkeys: make gcc check arguments of sigsafe_printf() Andrew Morton
2020-06-04 23:51 ` [patch 107/127] selftests: vm: pkeys: Use sane types for pkey register Andrew Morton
2020-06-04 23:51 ` [patch 108/127] selftests: vm: pkeys: add helpers for pkey bits Andrew Morton
2020-06-04 23:51 ` [patch 109/127] selftests/vm/pkeys: fix pkey_disable_clear() Andrew Morton
2020-06-04 23:52 ` [patch 110/127] selftests/vm/pkeys: fix assertion in pkey_disable_set/clear() Andrew Morton
2020-06-04 23:52 ` [patch 111/127] selftests/vm/pkeys: fix alloc_random_pkey() to make it really random Andrew Morton
2020-06-04 23:52 ` [patch 112/127] selftests: vm: pkeys: use the correct huge page size Andrew Morton
2020-06-04 23:52 ` [patch 113/127] selftests/vm/pkeys: introduce generic pkey abstractions Andrew Morton
2020-06-04 23:52 ` [patch 114/127] selftests/vm/pkeys: introduce powerpc support Andrew Morton
2020-06-04 23:52 ` [patch 115/127] selftests/vm/pkeys: fix number of reserved powerpc pkeys Andrew Morton
2020-06-04 23:52 ` [patch 116/127] selftests/vm/pkeys: fix assertion in test_pkey_alloc_exhaust() Andrew Morton
2020-06-04 23:52 ` [patch 117/127] selftests/vm/pkeys: improve checks to determine pkey support Andrew Morton
2020-06-04 23:52 ` [patch 118/127] selftests/vm/pkeys: associate key on a mapped page and detect access violation Andrew Morton
2020-06-04 23:52 ` [patch 119/127] selftests/vm/pkeys: associate key on a mapped page and detect write violation Andrew Morton
2020-06-04 23:52 ` [patch 120/127] selftests/vm/pkeys: detect write violation on a mapped access-denied-key page Andrew Morton
2020-06-04 23:52 ` [patch 121/127] selftests/vm/pkeys: introduce a sub-page allocator Andrew Morton
2020-06-04 23:52 ` [patch 122/127] selftests/vm/pkeys: test correct behaviour of pkey-0 Andrew Morton
2020-06-04 23:52 ` [patch 123/127] selftests/vm/pkeys: override access right definitions on powerpc Andrew Morton
2020-06-04 23:52 ` [patch 124/127] selftests: vm: pkeys: use the correct page size " Andrew Morton
2020-06-04 23:52 ` [patch 125/127] selftests: vm: pkeys: fix multilib builds for x86 Andrew Morton
2020-06-04 23:52 ` [patch 126/127] tools/testing/selftests/vm: remove duplicate headers Andrew Morton
2020-06-04 23:53 ` [patch 127/127] lib/ubsan.c: fix gcc-10 warnings Andrew Morton

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200604234715.x-3eXwdwn%akpm@linux-foundation.org \
    --to=akpm@linux-foundation.org \
    --cc=anshuman.khandual@arm.com \
    --cc=benh@kernel.crashing.org \
    --cc=borntraeger@de.ibm.com \
    --cc=bp@alien8.de \
    --cc=cai@lca.pw \
    --cc=catalin.marinas@arm.com \
    --cc=christophe.leroy@c-s.fr \
    --cc=gerald.schaefer@de.ibm.com \
    --cc=gor@linux.ibm.com \
    --cc=heiko.carstens@de.ibm.com \
    --cc=hpa@zytor.com \
    --cc=kirill@shutemov.name \
    --cc=linux-mm@kvack.org \
    --cc=mingo@kernel.org \
    --cc=mingo@redhat.com \
    --cc=mm-commits@vger.kernel.org \
    --cc=mpe@ellerman.id.au \
    --cc=palmer@dabbelt.com \
    --cc=paul.walmsley@sifive.com \
    --cc=paulus@samba.org \
    --cc=rppt@linux.ibm.com \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=vgupta@synopsys.com \
    --cc=will@kernel.org \
    --subject='Re: [patch 024/127] mm/debug: add tests validating architecture page table helpers' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox