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* [PATCH V3 0/2] mm/debug: Add tests for architecture exported page table helpers
@ 2019-09-20  6:33 anshuman.khandual
  2019-09-20  6:33 ` [PATCH V3 2/2] mm/pgtable/debug: Add test validating architecture " anshuman.khandual
  2019-09-24 11:51 ` [PATCH V3 0/2] mm/debug: Add tests for architecture exported " kirill
  0 siblings, 2 replies; 7+ messages in thread
From: anshuman.khandual @ 2019-09-20  6:33 UTC (permalink / raw)
  To: linux-snps-arc

This series adds a test validation for architecture exported page table
helpers. Patch in the series adds basic transformation tests at various
levels of the page table. Before that it exports gigantic page allocation
function from HugeTLB.

This test was originally suggested by Catalin during arm64 THP migration
RFC discussion earlier. Going forward it can include more specific tests
with respect to various generic MM functions like THP, HugeTLB etc and
platform specific tests.

https://lore.kernel.org/linux-mm/20190628102003.GA56463 at arrakis.emea.arm.com/

Testing:

Successfully build and boot tested on both arm64 and x86 platforms without
any test failing. Only build tested on some other platforms. Build failed
on some platforms (known) in pud_clear_tests() as there were no available
__pgd() definitions.

- ARM32
- IA64

But I would really appreciate if folks can help validate this test on other
architectures and report back problems. All suggestions, comments and inputs
welcome. Thank you.

Changes in V3:

- Changed test trigger from module format into late_initcall()
- Marked all functions with __init to be freed after completion
- Changed all __PGTABLE_PXX_FOLDED checks as mm_pxx_folded()
- Folded in PPC32 fixes from Christophe

Changes in V2:

https://lore.kernel.org/linux-mm/1568268173-31302-1-git-send-email-anshuman.khandual at arm.com/T/#t

- Fixed small typo error in MODULE_DESCRIPTION()
- Fixed m64k build problems for lvalue concerns in pmd_xxx_tests()
- Fixed dynamic page table level folding problems on x86 as per Kirril
- Fixed second pointers during pxx_populate_tests() per Kirill and Gerald
- Allocate and free pte table with pte_alloc_one/pte_free per Kirill
- Modified pxx_clear_tests() to accommodate s390 lower 12 bits situation
- Changed RANDOM_NZVALUE value from 0xbe to 0xff
- Changed allocation, usage, free sequence for saved_ptep
- Renamed VMA_FLAGS as VMFLAGS
- Implemented a new method for random vaddr generation
- Implemented some other cleanups
- Dropped extern reference to mm_alloc()
- Created and exported new alloc_gigantic_page_order()
- Dropped the custom allocator and used new alloc_gigantic_page_order()

Changes in V1:

https://lore.kernel.org/linux-mm/1567497706-8649-1-git-send-email-anshuman.khandual at arm.com/

- Added fallback mechanism for PMD aligned memory allocation failure

Changes in RFC V2:

https://lore.kernel.org/linux-mm/1565335998-22553-1-git-send-email-anshuman.khandual at arm.com/T/#u

- Moved test module and it's config from lib/ to mm/
- Renamed config TEST_ARCH_PGTABLE as DEBUG_ARCH_PGTABLE_TEST
- Renamed file from test_arch_pgtable.c to arch_pgtable_test.c
- Added relevant MODULE_DESCRIPTION() and MODULE_AUTHOR() details
- Dropped loadable module config option
- Basic tests now use memory blocks with required size and alignment
- PUD aligned memory block gets allocated with alloc_contig_range()
- If PUD aligned memory could not be allocated it falls back on PMD aligned
  memory block from page allocator and pud_* tests are skipped
- Clear and populate tests now operate on real in memory page table entries
- Dummy mm_struct gets allocated with mm_alloc()
- Dummy page table entries get allocated with [pud|pmd|pte]_alloc_[map]()
- Simplified [p4d|pgd]_basic_tests(), now has random values in the entries

Original RFC V1:

https://lore.kernel.org/linux-mm/1564037723-26676-1-git-send-email-anshuman.khandual at arm.com/

Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Vlastimil Babka <vbabka at suse.cz>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Mike Rapoport <rppt at linux.vnet.ibm.com>
Cc: Jason Gunthorpe <jgg at ziepe.ca>
Cc: Dan Williams <dan.j.williams at intel.com>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Michal Hocko <mhocko at kernel.org>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Mark Brown <broonie at kernel.org>
Cc: Steven Price <Steven.Price at arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel at linaro.org>
Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
Cc: Kees Cook <keescook at chromium.org>
Cc: Tetsuo Handa <penguin-kernel at i-love.sakura.ne.jp>
Cc: Matthew Wilcox <willy at infradead.org>
Cc: Sri Krishna chowdary <schowdary at nvidia.com>
Cc: Dave Hansen <dave.hansen at intel.com>
Cc: Russell King - ARM Linux <linux at armlinux.org.uk>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Martin Schwidefsky <schwidefsky at de.ibm.com>
Cc: Heiko Carstens <heiko.carstens at de.ibm.com>
Cc: "David S. Miller" <davem at davemloft.net>
Cc: Vineet Gupta <vgupta at synopsys.com>
Cc: James Hogan <jhogan at kernel.org>
Cc: Paul Burton <paul.burton at mips.com>
Cc: Ralf Baechle <ralf at linux-mips.org>
Cc: Kirill A. Shutemov <kirill at shutemov.name>
Cc: Gerald Schaefer <gerald.schaefer at de.ibm.com>
Cc: Christophe Leroy <christophe.leroy at c-s.fr>
Cc: Mike Kravetz <mike.kravetz at oracle.com>
Cc: linux-snps-arc at lists.infradead.org
Cc: linux-mips at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-ia64 at vger.kernel.org
Cc: linuxppc-dev at lists.ozlabs.org
Cc: linux-s390 at vger.kernel.org
Cc: linux-sh at vger.kernel.org
Cc: sparclinux at vger.kernel.org
Cc: x86 at kernel.org
Cc: linux-kernel at vger.kernel.org

Anshuman Khandual (2):
  mm/hugetlb: Make alloc_gigantic_page() available for general use
  mm/pgtable/debug: Add test validating architecture page table helpers

 arch/x86/include/asm/pgtable_64_types.h |   2 +
 include/linux/hugetlb.h                 |   9 +
 mm/Kconfig.debug                        |  14 +
 mm/Makefile                             |   1 +
 mm/arch_pgtable_test.c                  | 440 ++++++++++++++++++++++++++++++++
 mm/hugetlb.c                            |  24 +-
 6 files changed, 488 insertions(+), 2 deletions(-)
 create mode 100644 mm/arch_pgtable_test.c

-- 
2.7.4

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH V3 2/2] mm/pgtable/debug: Add test validating architecture page table helpers
  2019-09-20  6:33 [PATCH V3 0/2] mm/debug: Add tests for architecture exported page table helpers anshuman.khandual
@ 2019-09-20  6:33 ` " anshuman.khandual
  2019-09-21 16:00   ` lkp
  2019-09-24 11:51 ` [PATCH V3 0/2] mm/debug: Add tests for architecture exported " kirill
  1 sibling, 1 reply; 7+ messages in thread
From: anshuman.khandual @ 2019-09-20  6:33 UTC (permalink / raw)
  To: linux-snps-arc

This adds a test module which will validate architecture page table helpers
and accessors regarding compliance with generic MM semantics expectations.
This will help various architectures in validating changes to the existing
page table helpers or addition of new ones.

Test page table and memory pages creating it's entries at various level are
all allocated from system memory with required alignments. If memory pages
with required size and alignment could not be allocated, then all depending
individual tests are skipped.

Cc: Andrew Morton <akpm at linux-foundation.org>
Cc: Vlastimil Babka <vbabka at suse.cz>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Mike Rapoport <rppt at linux.vnet.ibm.com>
Cc: Jason Gunthorpe <jgg at ziepe.ca>
Cc: Dan Williams <dan.j.williams at intel.com>
Cc: Peter Zijlstra <peterz at infradead.org>
Cc: Michal Hocko <mhocko at kernel.org>
Cc: Mark Rutland <mark.rutland at arm.com>
Cc: Mark Brown <broonie at kernel.org>
Cc: Steven Price <Steven.Price at arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel at linaro.org>
Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
Cc: Kees Cook <keescook at chromium.org>
Cc: Tetsuo Handa <penguin-kernel at i-love.sakura.ne.jp>
Cc: Matthew Wilcox <willy at infradead.org>
Cc: Sri Krishna chowdary <schowdary at nvidia.com>
Cc: Dave Hansen <dave.hansen at intel.com>
Cc: Russell King - ARM Linux <linux at armlinux.org.uk>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Paul Mackerras <paulus at samba.org>
Cc: Martin Schwidefsky <schwidefsky at de.ibm.com>
Cc: Heiko Carstens <heiko.carstens at de.ibm.com>
Cc: "David S. Miller" <davem at davemloft.net>
Cc: Vineet Gupta <vgupta at synopsys.com>
Cc: James Hogan <jhogan at kernel.org>
Cc: Paul Burton <paul.burton at mips.com>
Cc: Ralf Baechle <ralf at linux-mips.org>
Cc: Kirill A. Shutemov <kirill at shutemov.name>
Cc: Gerald Schaefer <gerald.schaefer at de.ibm.com>
Cc: Christophe Leroy <christophe.leroy at c-s.fr>
Cc: linux-snps-arc at lists.infradead.org
Cc: linux-mips at vger.kernel.org
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-ia64 at vger.kernel.org
Cc: linuxppc-dev at lists.ozlabs.org
Cc: linux-s390 at vger.kernel.org
Cc: linux-sh at vger.kernel.org
Cc: sparclinux at vger.kernel.org
Cc: x86 at kernel.org
Cc: linux-kernel at vger.kernel.org

Suggested-by: Catalin Marinas <catalin.marinas at arm.com>
Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>
Tested-by: Christophe Leroy <christophe.leroy at c-s.fr>		(PPC32)
Signed-off-by: Anshuman Khandual <anshuman.khandual at arm.com>
---
 arch/x86/include/asm/pgtable_64_types.h |   2 +
 mm/Kconfig.debug                        |  14 +
 mm/Makefile                             |   1 +
 mm/arch_pgtable_test.c                  | 440 ++++++++++++++++++++++++++++++++
 4 files changed, 457 insertions(+)
 create mode 100644 mm/arch_pgtable_test.c

diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h
index 52e5f5f..b882792 100644
--- a/arch/x86/include/asm/pgtable_64_types.h
+++ b/arch/x86/include/asm/pgtable_64_types.h
@@ -40,6 +40,8 @@ static inline bool pgtable_l5_enabled(void)
 #define pgtable_l5_enabled() 0
 #endif /* CONFIG_X86_5LEVEL */
 
+#define mm_p4d_folded(mm) (!pgtable_l5_enabled())
+
 extern unsigned int pgdir_shift;
 extern unsigned int ptrs_per_p4d;
 
diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index 327b3eb..ce9c397 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -117,3 +117,17 @@ config DEBUG_RODATA_TEST
     depends on STRICT_KERNEL_RWX
     ---help---
       This option enables a testcase for the setting rodata read-only.
+
+config DEBUG_ARCH_PGTABLE_TEST
+	bool "Test arch page table helpers for semantics compliance"
+	depends on MMU
+	depends on DEBUG_KERNEL
+	help
+	  This options provides a kernel module which can be used to test
+	  architecture page table helper functions on various platform in
+	  verifying if they comply with expected generic MM semantics. This
+	  will help architectures code in making sure that any changes or
+	  new additions of these helpers will still conform to generic MM
+	  expected semantics.
+
+	  If unsure, say N.
diff --git a/mm/Makefile b/mm/Makefile
index d996846..bb572c5 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o
 obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o
 obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o
 obj-$(CONFIG_DEBUG_RODATA_TEST) += rodata_test.o
+obj-$(CONFIG_DEBUG_ARCH_PGTABLE_TEST) += arch_pgtable_test.o
 obj-$(CONFIG_PAGE_OWNER) += page_owner.o
 obj-$(CONFIG_CLEANCACHE) += cleancache.o
 obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
diff --git a/mm/arch_pgtable_test.c b/mm/arch_pgtable_test.c
new file mode 100644
index 0000000..2942a04
--- /dev/null
+++ b/mm/arch_pgtable_test.c
@@ -0,0 +1,440 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This kernel module validates architecture page table helpers &
+ * accessors and helps in verifying their continued compliance with
+ * generic MM semantics.
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ *
+ * Author: Anshuman Khandual <anshuman.khandual at arm.com>
+ */
+#define pr_fmt(fmt) "arch_pgtable_test: %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/sched/mm.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+
+/*
+ * Basic operations
+ *
+ * mkold(entry)			= An old and not a young entry
+ * mkyoung(entry)		= A young and not an old entry
+ * mkdirty(entry)		= A dirty and not a clean entry
+ * mkclean(entry)		= A clean and not a dirty entry
+ * mkwrite(entry)		= A write and not a write protected entry
+ * wrprotect(entry)		= A write protected and not a write entry
+ * pxx_bad(entry)		= A mapped and non-table entry
+ * pxx_same(entry1, entry2)	= Both entries hold the exact same value
+ */
+#define VMFLAGS	(VM_READ|VM_WRITE|VM_EXEC)
+
+/*
+ * On s390 platform, the lower 12 bits are used to identify given page table
+ * entry type and for other arch specific requirements. But these bits might
+ * affect the ability to clear entries with pxx_clear(). So while loading up
+ * the entries skip all lower 12 bits in order to accommodate s390 platform.
+ * It does not have affect any other platform.
+ */
+#define RANDOM_ORVALUE	(0xfffffffffffff000UL)
+#define RANDOM_NZVALUE	(0xff)
+
+static bool pud_aligned __initdata;
+static bool pmd_aligned __initdata;
+
+static void __init pte_basic_tests(struct page *page, pgprot_t prot)
+{
+	pte_t pte = mk_pte(page, prot);
+
+	WARN_ON(!pte_same(pte, pte));
+	WARN_ON(!pte_young(pte_mkyoung(pte)));
+	WARN_ON(!pte_dirty(pte_mkdirty(pte)));
+	WARN_ON(!pte_write(pte_mkwrite(pte)));
+	WARN_ON(pte_young(pte_mkold(pte)));
+	WARN_ON(pte_dirty(pte_mkclean(pte)));
+	WARN_ON(pte_write(pte_wrprotect(pte)));
+}
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE
+static void __init pmd_basic_tests(struct page *page, pgprot_t prot)
+{
+	pmd_t pmd;
+
+	/*
+	 * Memory block here must be PMD_SIZE aligned. Abort this
+	 * test in case we could not allocate such a memory block.
+	 */
+	if (!pmd_aligned) {
+		pr_warn("Could not proceed with PMD tests\n");
+		return;
+	}
+
+	pmd = mk_pmd(page, prot);
+	WARN_ON(!pmd_same(pmd, pmd));
+	WARN_ON(!pmd_young(pmd_mkyoung(pmd)));
+	WARN_ON(!pmd_dirty(pmd_mkdirty(pmd)));
+	WARN_ON(!pmd_write(pmd_mkwrite(pmd)));
+	WARN_ON(pmd_young(pmd_mkold(pmd)));
+	WARN_ON(pmd_dirty(pmd_mkclean(pmd)));
+	WARN_ON(pmd_write(pmd_wrprotect(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)));
+}
+#else
+static void __init pmd_basic_tests(struct page *page, pgprot_t prot) { }
+#endif
+
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static void __init pud_basic_tests(struct page *page, pgprot_t prot)
+{
+	pud_t pud;
+
+	/*
+	 * Memory block here must be PUD_SIZE aligned. Abort this
+	 * test in case we could not allocate such a memory block.
+	 */
+	if (!pud_aligned) {
+		pr_warn("Could not proceed with PUD tests\n");
+		return;
+	}
+
+	pud = pfn_pud(page_to_pfn(page), prot);
+	WARN_ON(!pud_same(pud, pud));
+	WARN_ON(!pud_young(pud_mkyoung(pud)));
+	WARN_ON(!pud_write(pud_mkwrite(pud)));
+	WARN_ON(pud_write(pud_wrprotect(pud)));
+	WARN_ON(pud_young(pud_mkold(pud)));
+
+	if (mm_pmd_folded(mm) || __is_defined(ARCH_HAS_4LEVEL_HACK))
+		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
+static void __init pud_basic_tests(struct page *page, pgprot_t prot) { }
+#endif
+
+static void __init p4d_basic_tests(struct page *page, 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(struct page *page, pgprot_t prot)
+{
+	pgd_t pgd;
+
+	memset(&pgd, RANDOM_NZVALUE, sizeof(pgd_t));
+	WARN_ON(!pgd_same(pgd, pgd));
+}
+
+#ifndef __ARCH_HAS_4LEVEL_HACK
+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
+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
+
+#ifndef __ARCH_HAS_5LEVEL_HACK
+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
+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
+
+static void __init pte_clear_tests(struct mm_struct *mm, pte_t *ptep)
+{
+	pte_t pte = READ_ONCE(*ptep);
+
+	pte = __pte(pte_val(pte) | RANDOM_ORVALUE);
+	WRITE_ONCE(*ptep, pte);
+	pte_clear(mm, 0, 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 struct page * __init alloc_mapped_page(void)
+{
+	struct page *page;
+	gfp_t gfp_mask = GFP_KERNEL | __GFP_ZERO;
+
+	page = alloc_gigantic_page_order(get_order(PUD_SIZE), gfp_mask,
+				first_memory_node, &node_states[N_MEMORY]);
+	if (page) {
+		pud_aligned = true;
+		pmd_aligned = true;
+		return page;
+	}
+
+	page = alloc_pages(gfp_mask, get_order(PMD_SIZE));
+	if (page) {
+		pmd_aligned = true;
+		return page;
+	}
+	return alloc_page(gfp_mask);
+}
+
+static void __init free_mapped_page(struct page *page)
+{
+	if (pud_aligned) {
+		unsigned long pfn = page_to_pfn(page);
+
+		free_contig_range(pfn, 1ULL << get_order(PUD_SIZE));
+		return;
+	}
+
+	if (pmd_aligned) {
+		int order = get_order(PMD_SIZE);
+
+		free_pages((unsigned long)page_address(page), order);
+		return;
+	}
+	free_page((unsigned long)page_address(page));
+}
+
+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;
+
+	WARN_ON(random_vaddr > TASK_SIZE);
+	WARN_ON(random_vaddr < FIRST_USER_ADDRESS);
+	return random_vaddr;
+}
+
+static int __init arch_pgtable_tests_init(void)
+{
+	struct mm_struct *mm;
+	struct page *page;
+	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;
+	unsigned long vaddr;
+
+	prot = vm_get_page_prot(VMFLAGS);
+	vaddr = get_random_vaddr();
+	mm = mm_alloc();
+	if (!mm) {
+		pr_err("mm_struct allocation failed\n");
+		return 1;
+	}
+
+	page = alloc_mapped_page();
+	if (!page) {
+		pr_err("memory allocation failed\n");
+		return 1;
+	}
+
+	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(mm, pmdp, vaddr);
+
+	/*
+	 * 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(page, prot);
+	pmd_basic_tests(page, prot);
+	pud_basic_tests(page, prot);
+	p4d_basic_tests(page, prot);
+	pgd_basic_tests(page, prot);
+
+	pte_clear_tests(mm, ptep);
+	pmd_clear_tests(mm, pmdp);
+	pud_clear_tests(mm, pudp);
+	p4d_clear_tests(mm, p4dp);
+	pgd_clear_tests(mm, pgdp);
+
+	pte_unmap(ptep);
+
+	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);
+
+	free_mapped_page(page);
+	return 0;
+}
+late_initcall(arch_pgtable_tests_init);
-- 
2.7.4

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH V3 2/2] mm/pgtable/debug: Add test validating architecture page table helpers
  2019-09-20  6:33 ` [PATCH V3 2/2] mm/pgtable/debug: Add test validating architecture " anshuman.khandual
@ 2019-09-21 16:00   ` lkp
  2019-09-23  6:27     ` anshuman.khandual
  0 siblings, 1 reply; 7+ messages in thread
From: lkp @ 2019-09-21 16:00 UTC (permalink / raw)
  To: linux-snps-arc

Hi Anshuman,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on linus/master]
[cannot apply to v5.3 next-20190919]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Anshuman-Khandual/mm-debug-Add-tests-for-architecture-exported-page-table-helpers/20190920-143746
config: ia64-allmodconfig (attached as .config)
compiler: ia64-linux-gcc (GCC) 7.4.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.4.0 make.cross ARCH=ia64 
:::::: branch date: 3 hours ago
:::::: commit date: 3 hours ago

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp at intel.com>

All error/warnings (new ones prefixed by >>):

   In file included from include/asm-generic/pgtable-nopud.h:8:0,
                    from arch/ia64/include/asm/pgtable.h:591,
                    from include/linux/mm.h:99,
                    from include/linux/highmem.h:8,
                    from mm/arch_pgtable_test.c:14:
   mm/arch_pgtable_test.c: In function 'pud_clear_tests':
>> include/asm-generic/pgtable-nop4d-hack.h:47:32: error: implicit declaration of function '__pgd'; did you mean '__p4d'? [-Werror=implicit-function-declaration]
    #define __pud(x)    ((pud_t) { __pgd(x) })
                                   ^
>> mm/arch_pgtable_test.c:162:8: note: in expansion of macro '__pud'
     pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
           ^~~~~
>> include/asm-generic/pgtable-nop4d-hack.h:47:22: warning: missing braces around initializer [-Wmissing-braces]
    #define __pud(x)    ((pud_t) { __pgd(x) })
                         ^
>> mm/arch_pgtable_test.c:162:8: note: in expansion of macro '__pud'
     pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
           ^~~~~
   cc1: some warnings being treated as errors

# https://github.com/0day-ci/linux/commit/49047f93b076974eefa5b019311bd3b734d61f8c
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 49047f93b076974eefa5b019311bd3b734d61f8c
vim +47 include/asm-generic/pgtable-nop4d-hack.h

30ec842660bd0d Kirill A. Shutemov 2017-03-09  45  
30ec842660bd0d Kirill A. Shutemov 2017-03-09  46  #define pud_val(x)				(pgd_val((x).pgd))
30ec842660bd0d Kirill A. Shutemov 2017-03-09 @47  #define __pud(x)				((pud_t) { __pgd(x) })
30ec842660bd0d Kirill A. Shutemov 2017-03-09  48  

:::::: The code at line 47 was first introduced by commit
:::::: 30ec842660bd0d056d4a7028ac5bd4a82b113d4f asm-generic: introduce __ARCH_USE_5LEVEL_HACK

:::::: TO: Kirill A. Shutemov <kirill.shutemov at linux.intel.com>
:::::: CC: Linus Torvalds <torvalds at linux-foundation.org>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
-------------- next part --------------
A non-text attachment was scrubbed...
Name: .config.gz
Type: application/gzip
Size: 54827 bytes
Desc: .config.gz
URL: <http://lists.infradead.org/pipermail/linux-snps-arc/attachments/20190922/c39652f5/attachment-0001.gz>

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH V3 2/2] mm/pgtable/debug: Add test validating architecture page table helpers
  2019-09-21 16:00   ` lkp
@ 2019-09-23  6:27     ` anshuman.khandual
  0 siblings, 0 replies; 7+ messages in thread
From: anshuman.khandual @ 2019-09-23  6:27 UTC (permalink / raw)
  To: linux-snps-arc



On 09/21/2019 09:30 PM, kbuild test robot wrote:
> Hi Anshuman,
> 
> Thank you for the patch! Yet something to improve:
> 
> [auto build test ERROR on linus/master]
> [cannot apply to v5.3 next-20190919]
> [if your patch is applied to the wrong git tree, please drop us a note to help
> improve the system. BTW, we also suggest to use '--base' option to specify the
> base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
> 
> url:    https://github.com/0day-ci/linux/commits/Anshuman-Khandual/mm-debug-Add-tests-for-architecture-exported-page-table-helpers/20190920-143746
> config: ia64-allmodconfig (attached as .config)
> compiler: ia64-linux-gcc (GCC) 7.4.0
> reproduce:
>         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         GCC_VERSION=7.4.0 make.cross ARCH=ia64 
> :::::: branch date: 3 hours ago
> :::::: commit date: 3 hours ago
> 
> If you fix the issue, kindly add following tag
> Reported-by: kbuild test robot <lkp at intel.com>
> 
> All error/warnings (new ones prefixed by >>):
> 
>    In file included from include/asm-generic/pgtable-nopud.h:8:0,
>                     from arch/ia64/include/asm/pgtable.h:591,
>                     from include/linux/mm.h:99,
>                     from include/linux/highmem.h:8,
>                     from mm/arch_pgtable_test.c:14:
>    mm/arch_pgtable_test.c: In function 'pud_clear_tests':
>>> include/asm-generic/pgtable-nop4d-hack.h:47:32: error: implicit declaration of function '__pgd'; did you mean '__p4d'? [-Werror=implicit-function-declaration]
>     #define __pud(x)    ((pud_t) { __pgd(x) })
>                                    ^
>>> mm/arch_pgtable_test.c:162:8: note: in expansion of macro '__pud'
>      pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
>            ^~~~~
>>> include/asm-generic/pgtable-nop4d-hack.h:47:22: warning: missing braces around initializer [-Wmissing-braces]
>     #define __pud(x)    ((pud_t) { __pgd(x) })
>                          ^
>>> mm/arch_pgtable_test.c:162:8: note: in expansion of macro '__pud'
>      pud = __pud(pud_val(pud) | RANDOM_ORVALUE);
>            ^~~~~
>    cc1: some warnings being treated as errors
> 
> # https://github.com/0day-ci/linux/commit/49047f93b076974eefa5b019311bd3b734d61f8c
> git remote add linux-review https://github.com/0day-ci/linux
> git remote update linux-review
> git checkout 49047f93b076974eefa5b019311bd3b734d61f8c
> vim +47 include/asm-generic/pgtable-nop4d-hack.h
> 
> 30ec842660bd0d Kirill A. Shutemov 2017-03-09  45  
> 30ec842660bd0d Kirill A. Shutemov 2017-03-09  46  #define pud_val(x)				(pgd_val((x).pgd))
> 30ec842660bd0d Kirill A. Shutemov 2017-03-09 @47  #define __pud(x)				((pud_t) { __pgd(x) })

I had mentioned about this build failure in the cover letter. The same
problem also exists on arm32 platform.

- Anshuman

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH V3 0/2] mm/debug: Add tests for architecture exported page table helpers
  2019-09-20  6:33 [PATCH V3 0/2] mm/debug: Add tests for architecture exported page table helpers anshuman.khandual
  2019-09-20  6:33 ` [PATCH V3 2/2] mm/pgtable/debug: Add test validating architecture " anshuman.khandual
@ 2019-09-24 11:51 ` " kirill
  2019-09-24 12:31   ` rppt
  1 sibling, 1 reply; 7+ messages in thread
From: kirill @ 2019-09-24 11:51 UTC (permalink / raw)
  To: linux-snps-arc

On Fri, Sep 20, 2019@12:03:21PM +0530, Anshuman Khandual wrote:
> This series adds a test validation for architecture exported page table
> helpers. Patch in the series adds basic transformation tests at various
> levels of the page table. Before that it exports gigantic page allocation
> function from HugeTLB.
> 
> This test was originally suggested by Catalin during arm64 THP migration
> RFC discussion earlier. Going forward it can include more specific tests
> with respect to various generic MM functions like THP, HugeTLB etc and
> platform specific tests.
> 
> https://lore.kernel.org/linux-mm/20190628102003.GA56463 at arrakis.emea.arm.com/
> 
> Testing:
> 
> Successfully build and boot tested on both arm64 and x86 platforms without
> any test failing. Only build tested on some other platforms. Build failed
> on some platforms (known) in pud_clear_tests() as there were no available
> __pgd() definitions.
> 
> - ARM32
> - IA64

Hm. Grep shows __pgd() definitions for both of them. Is it for specific
config?


-- 
 Kirill A. Shutemov

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH V3 0/2] mm/debug: Add tests for architecture exported page table helpers
  2019-09-24 11:51 ` [PATCH V3 0/2] mm/debug: Add tests for architecture exported " kirill
@ 2019-09-24 12:31   ` rppt
  2019-09-25  3:36     ` anshuman.khandual
  0 siblings, 1 reply; 7+ messages in thread
From: rppt @ 2019-09-24 12:31 UTC (permalink / raw)
  To: linux-snps-arc

On Tue, Sep 24, 2019@02:51:01PM +0300, Kirill A. Shutemov wrote:
> On Fri, Sep 20, 2019@12:03:21PM +0530, Anshuman Khandual wrote:
> > This series adds a test validation for architecture exported page table
> > helpers. Patch in the series adds basic transformation tests at various
> > levels of the page table. Before that it exports gigantic page allocation
> > function from HugeTLB.
> > 
> > This test was originally suggested by Catalin during arm64 THP migration
> > RFC discussion earlier. Going forward it can include more specific tests
> > with respect to various generic MM functions like THP, HugeTLB etc and
> > platform specific tests.
> > 
> > https://lore.kernel.org/linux-mm/20190628102003.GA56463 at arrakis.emea.arm.com/
> > 
> > Testing:
> > 
> > Successfully build and boot tested on both arm64 and x86 platforms without
> > any test failing. Only build tested on some other platforms. Build failed
> > on some platforms (known) in pud_clear_tests() as there were no available
> > __pgd() definitions.
> > 
> > - ARM32
> > - IA64
> 
> Hm. Grep shows __pgd() definitions for both of them. Is it for specific
> config?
 
For ARM32 it's defined only for 3-lelel page tables, i.e with LPAE on.
For IA64 it's defined for !STRICT_MM_TYPECHECKS which is even not a config
option, but a define in arch/ia64/include/asm/page.h
 
> -- 
>  Kirill A. Shutemov

-- 
Sincerely yours,
Mike.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH V3 0/2] mm/debug: Add tests for architecture exported page table helpers
  2019-09-24 12:31   ` rppt
@ 2019-09-25  3:36     ` anshuman.khandual
  0 siblings, 0 replies; 7+ messages in thread
From: anshuman.khandual @ 2019-09-25  3:36 UTC (permalink / raw)
  To: linux-snps-arc



On 09/24/2019 06:01 PM, Mike Rapoport wrote:
> On Tue, Sep 24, 2019@02:51:01PM +0300, Kirill A. Shutemov wrote:
>> On Fri, Sep 20, 2019@12:03:21PM +0530, Anshuman Khandual wrote:
>>> This series adds a test validation for architecture exported page table
>>> helpers. Patch in the series adds basic transformation tests at various
>>> levels of the page table. Before that it exports gigantic page allocation
>>> function from HugeTLB.
>>>
>>> This test was originally suggested by Catalin during arm64 THP migration
>>> RFC discussion earlier. Going forward it can include more specific tests
>>> with respect to various generic MM functions like THP, HugeTLB etc and
>>> platform specific tests.
>>>
>>> https://lore.kernel.org/linux-mm/20190628102003.GA56463 at arrakis.emea.arm.com/
>>>
>>> Testing:
>>>
>>> Successfully build and boot tested on both arm64 and x86 platforms without
>>> any test failing. Only build tested on some other platforms. Build failed
>>> on some platforms (known) in pud_clear_tests() as there were no available
>>> __pgd() definitions.
>>>
>>> - ARM32
>>> - IA64
>>
>> Hm. Grep shows __pgd() definitions for both of them. Is it for specific
>> config?
>  
> For ARM32 it's defined only for 3-lelel page tables, i.e with LPAE on.
> For IA64 it's defined for !STRICT_MM_TYPECHECKS which is even not a config
> option, but a define in arch/ia64/include/asm/page.h

Right. So now where we go from here ! We will need help from platform folks to
fix this unless its trivial. I did propose this on last thread (v2), wondering if
it will be a better idea to restrict DEBUG_ARCH_PGTABLE_TEST among architectures
which have fixed all pending issues whether build or run time. Though enabling all
platforms where the test builds at the least might make more sense, we might have
to just exclude arm32 and ia64 for now. Then run time problems can be fixed later
platform by platform. Any thoughts ?

BTW the test is known to run successfully on arm64, x86, ppc32 platforms. Gerald
has been trying to get it working on s390. in the meantime., if there are other
volunteers to test this on ppc64, sparc, riscv, mips, m68k etc platforms, it will
be really helpful.

- Anshuman

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, back to index

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-09-20  6:33 [PATCH V3 0/2] mm/debug: Add tests for architecture exported page table helpers anshuman.khandual
2019-09-20  6:33 ` [PATCH V3 2/2] mm/pgtable/debug: Add test validating architecture " anshuman.khandual
2019-09-21 16:00   ` lkp
2019-09-23  6:27     ` anshuman.khandual
2019-09-24 11:51 ` [PATCH V3 0/2] mm/debug: Add tests for architecture exported " kirill
2019-09-24 12:31   ` rppt
2019-09-25  3:36     ` anshuman.khandual

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