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From: Steven Price <steven.price@arm.com>
To: linux-mm@kvack.org
Cc: "Steven Price" <steven.price@arm.com>,
	"Andy Lutomirski" <luto@kernel.org>,
	"Ard Biesheuvel" <ard.biesheuvel@linaro.org>,
	"Arnd Bergmann" <arnd@arndb.de>, "Borislav Petkov" <bp@alien8.de>,
	"Catalin Marinas" <catalin.marinas@arm.com>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	"Ingo Molnar" <mingo@redhat.com>,
	"James Morse" <james.morse@arm.com>,
	"Jérôme Glisse" <jglisse@redhat.com>,
	"Peter Zijlstra" <peterz@infradead.org>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Will Deacon" <will.deacon@arm.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org,
	"Mark Rutland" <Mark.Rutland@arm.com>,
	"Liang, Kan" <kan.liang@linux.intel.com>
Subject: [PATCH v3 34/34] x86: mm: Convert dump_pagetables to use walk_page_range
Date: Wed, 27 Feb 2019 17:06:08 +0000	[thread overview]
Message-ID: <20190227170608.27963-35-steven.price@arm.com> (raw)
In-Reply-To: <20190227170608.27963-1-steven.price@arm.com>

Make use of the new functionality in walk_page_range to remove the
arch page walking code and use the generic code to walk the page tables.

The effective permissions are passed down the chain using new fields
in struct pg_state.

The KASAN optimisation is implemented by including test_p?d callbacks
which can decide to skip an entire tree of entries

Signed-off-by: Steven Price <steven.price@arm.com>
---
 arch/x86/mm/dump_pagetables.c | 279 ++++++++++++++++++----------------
 1 file changed, 146 insertions(+), 133 deletions(-)

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 40a8b0da2170..64d1619493a4 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -33,6 +33,10 @@ struct pg_state {
 	int level;
 	pgprot_t current_prot;
 	pgprotval_t effective_prot;
+	pgprotval_t effective_prot_pgd;
+	pgprotval_t effective_prot_p4d;
+	pgprotval_t effective_prot_pud;
+	pgprotval_t effective_prot_pmd;
 	unsigned long start_address;
 	unsigned long current_address;
 	const struct addr_marker *marker;
@@ -355,22 +359,21 @@ static inline pgprotval_t effective_prot(pgprotval_t prot1, pgprotval_t prot2)
 	       ((prot1 | prot2) & _PAGE_NX);
 }
 
-static void walk_pte_level(struct pg_state *st, pmd_t addr, pgprotval_t eff_in,
-			   unsigned long P)
+static int ptdump_pte_entry(pte_t *pte, unsigned long addr,
+			    unsigned long next, struct mm_walk *walk)
 {
-	int i;
-	pte_t *pte;
-	pgprotval_t prot, eff;
-
-	for (i = 0; i < PTRS_PER_PTE; i++) {
-		st->current_address = normalize_addr(P + i * PTE_LEVEL_MULT);
-		pte = pte_offset_map(&addr, st->current_address);
-		prot = pte_flags(*pte);
-		eff = effective_prot(eff_in, prot);
-		note_page(st, __pgprot(prot), eff, 5);
-		pte_unmap(pte);
-	}
+	struct pg_state *st = walk->private;
+	pgprotval_t eff, prot;
+
+	st->current_address = normalize_addr(addr);
+
+	prot = pte_flags(*pte);
+	eff = effective_prot(st->effective_prot_pmd, prot);
+	note_page(st, __pgprot(prot), eff, 5);
+
+	return 0;
 }
+
 #ifdef CONFIG_KASAN
 
 /*
@@ -399,130 +402,152 @@ static inline bool kasan_page_table(struct pg_state *st, void *pt)
 }
 #endif
 
-#if PTRS_PER_PMD > 1
-
-static void walk_pmd_level(struct pg_state *st, pud_t addr,
-			   pgprotval_t eff_in, unsigned long P)
+static int ptdump_test_pmd(unsigned long addr, unsigned long next,
+			   pmd_t *pmd, struct mm_walk *walk)
 {
-	int i;
-	pmd_t *start, *pmd_start;
-	pgprotval_t prot, eff;
-
-	pmd_start = start = (pmd_t *)pud_page_vaddr(addr);
-	for (i = 0; i < PTRS_PER_PMD; i++) {
-		st->current_address = normalize_addr(P + i * PMD_LEVEL_MULT);
-		if (!pmd_none(*start)) {
-			prot = pmd_flags(*start);
-			eff = effective_prot(eff_in, prot);
-			if (pmd_large(*start) || !pmd_present(*start)) {
-				note_page(st, __pgprot(prot), eff, 4);
-			} else if (!kasan_page_table(st, pmd_start)) {
-				walk_pte_level(st, *start, eff,
-					       P + i * PMD_LEVEL_MULT);
-			}
-		} else
-			note_page(st, __pgprot(0), 0, 4);
-		start++;
-	}
+	struct pg_state *st = walk->private;
+
+	st->current_address = normalize_addr(addr);
+
+	if (kasan_page_table(st, pmd))
+		return 1;
+	return 0;
 }
 
-#else
-#define walk_pmd_level(s,a,e,p) walk_pte_level(s,__pmd(pud_val(a)),e,p)
-#define pud_large(a) pmd_large(__pmd(pud_val(a)))
-#define pud_none(a)  pmd_none(__pmd(pud_val(a)))
-#endif
+static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,
+			    unsigned long next, struct mm_walk *walk)
+{
+	struct pg_state *st = walk->private;
+	pgprotval_t eff, prot;
+
+	prot = pmd_flags(*pmd);
+	eff = effective_prot(st->effective_prot_pud, prot);
+
+	st->current_address = normalize_addr(addr);
+
+	if (pmd_large(*pmd))
+		note_page(st, __pgprot(prot), eff, 4);
 
-#if PTRS_PER_PUD > 1
+	st->effective_prot_pmd = eff;
 
-static void walk_pud_level(struct pg_state *st, p4d_t addr, pgprotval_t eff_in,
-			   unsigned long P)
+	return 0;
+}
+
+static int ptdump_test_pud(unsigned long addr, unsigned long next,
+			   pud_t *pud, struct mm_walk *walk)
 {
-	int i;
-	pud_t *start, *pud_start;
-	pgprotval_t prot, eff;
-	pud_t *prev_pud = NULL;
-
-	pud_start = start = (pud_t *)p4d_page_vaddr(addr);
-
-	for (i = 0; i < PTRS_PER_PUD; i++) {
-		st->current_address = normalize_addr(P + i * PUD_LEVEL_MULT);
-		if (!pud_none(*start)) {
-			prot = pud_flags(*start);
-			eff = effective_prot(eff_in, prot);
-			if (pud_large(*start) || !pud_present(*start)) {
-				note_page(st, __pgprot(prot), eff, 3);
-			} else if (!kasan_page_table(st, pud_start)) {
-				walk_pmd_level(st, *start, eff,
-					       P + i * PUD_LEVEL_MULT);
-			}
-		} else
-			note_page(st, __pgprot(0), 0, 3);
+	struct pg_state *st = walk->private;
 
-		prev_pud = start;
-		start++;
-	}
+	st->current_address = normalize_addr(addr);
+
+	if (kasan_page_table(st, pud))
+		return 1;
+	return 0;
 }
 
-#else
-#define walk_pud_level(s,a,e,p) walk_pmd_level(s,__pud(p4d_val(a)),e,p)
-#define p4d_large(a) pud_large(__pud(p4d_val(a)))
-#define p4d_none(a)  pud_none(__pud(p4d_val(a)))
-#endif
+static int ptdump_pud_entry(pud_t *pud, unsigned long addr,
+			    unsigned long next, struct mm_walk *walk)
+{
+	struct pg_state *st = walk->private;
+	pgprotval_t eff, prot;
+
+	prot = pud_flags(*pud);
+	eff = effective_prot(st->effective_prot_p4d, prot);
+
+	st->current_address = normalize_addr(addr);
+
+	if (pud_large(*pud))
+		note_page(st, __pgprot(prot), eff, 3);
+
+	st->effective_prot_pud = eff;
 
-static void walk_p4d_level(struct pg_state *st, pgd_t addr, pgprotval_t eff_in,
-			   unsigned long P)
+	return 0;
+}
+
+static int ptdump_test_p4d(unsigned long addr, unsigned long next,
+			   p4d_t *p4d, struct mm_walk *walk)
 {
-	int i;
-	p4d_t *start, *p4d_start;
-	pgprotval_t prot, eff;
-
-	if (PTRS_PER_P4D == 1)
-		return walk_pud_level(st, __p4d(pgd_val(addr)), eff_in, P);
-
-	p4d_start = start = (p4d_t *)pgd_page_vaddr(addr);
-
-	for (i = 0; i < PTRS_PER_P4D; i++) {
-		st->current_address = normalize_addr(P + i * P4D_LEVEL_MULT);
-		if (!p4d_none(*start)) {
-			prot = p4d_flags(*start);
-			eff = effective_prot(eff_in, prot);
-			if (p4d_large(*start) || !p4d_present(*start)) {
-				note_page(st, __pgprot(prot), eff, 2);
-			} else if (!kasan_page_table(st, p4d_start)) {
-				walk_pud_level(st, *start, eff,
-					       P + i * P4D_LEVEL_MULT);
-			}
-		} else
-			note_page(st, __pgprot(0), 0, 2);
+	struct pg_state *st = walk->private;
 
-		start++;
-	}
+	st->current_address = normalize_addr(addr);
+
+	if (kasan_page_table(st, p4d))
+		return 1;
+	return 0;
 }
 
-#define pgd_large(a) (pgtable_l5_enabled() ? pgd_large(a) : p4d_large(__p4d(pgd_val(a))))
-#define pgd_none(a)  (pgtable_l5_enabled() ? pgd_none(a) : p4d_none(__p4d(pgd_val(a))))
+static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,
+			    unsigned long next, struct mm_walk *walk)
+{
+	struct pg_state *st = walk->private;
+	pgprotval_t eff, prot;
+
+	prot = p4d_flags(*p4d);
+	eff = effective_prot(st->effective_prot_pgd, prot);
+
+	st->current_address = normalize_addr(addr);
+
+	if (p4d_large(*p4d))
+		note_page(st, __pgprot(prot), eff, 2);
+
+	st->effective_prot_p4d = eff;
+
+	return 0;
+}
 
-static inline bool is_hypervisor_range(int idx)
+static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,
+			    unsigned long next, struct mm_walk *walk)
 {
-#ifdef CONFIG_X86_64
-	/*
-	 * A hole in the beginning of kernel address space reserved
-	 * for a hypervisor.
-	 */
-	return	(idx >= pgd_index(GUARD_HOLE_BASE_ADDR)) &&
-		(idx <  pgd_index(GUARD_HOLE_END_ADDR));
+	struct pg_state *st = walk->private;
+	pgprotval_t eff, prot;
+
+	prot = pgd_flags(*pgd);
+
+#ifdef CONFIG_X86_PAE
+	eff = _PAGE_USER | _PAGE_RW;
 #else
-	return false;
+	eff = prot;
 #endif
+
+	st->current_address = normalize_addr(addr);
+
+	if (pgd_large(*pgd))
+		note_page(st, __pgprot(prot), eff, 1);
+
+	st->effective_prot_pgd = eff;
+
+	return 0;
+}
+
+static int ptdump_hole(unsigned long addr, unsigned long next, int depth,
+		       struct mm_walk *walk)
+{
+	struct pg_state *st = walk->private;
+
+	st->current_address = normalize_addr(addr);
+
+	note_page(st, __pgprot(0), 0, depth + 1);
+
+	return 0;
 }
 
 static void ptdump_walk_pgd_level_core(struct seq_file *m, struct mm_struct *mm,
 				       bool checkwx, bool dmesg)
 {
-	pgd_t *start = mm->pgd;
-	pgprotval_t prot, eff;
-	int i;
 	struct pg_state st = {};
+	struct mm_walk walk = {
+		.mm		= mm,
+		.pgd_entry	= ptdump_pgd_entry,
+		.p4d_entry	= ptdump_p4d_entry,
+		.pud_entry	= ptdump_pud_entry,
+		.pmd_entry	= ptdump_pmd_entry,
+		.pte_entry	= ptdump_pte_entry,
+		.test_p4d	= ptdump_test_p4d,
+		.test_pud	= ptdump_test_pud,
+		.test_pmd	= ptdump_test_pmd,
+		.pte_hole	= ptdump_hole,
+		.private	= &st
+	};
 
 	st.to_dmesg = dmesg;
 	st.check_wx = checkwx;
@@ -530,27 +555,15 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m, struct mm_struct *mm,
 	if (checkwx)
 		st.wx_pages = 0;
 
-	for (i = 0; i < PTRS_PER_PGD; i++) {
-		st.current_address = normalize_addr(i * PGD_LEVEL_MULT);
-		if (!pgd_none(*start) && !is_hypervisor_range(i)) {
-			prot = pgd_flags(*start);
-#ifdef CONFIG_X86_PAE
-			eff = _PAGE_USER | _PAGE_RW;
+	down_read(&mm->mmap_sem);
+#ifdef CONFIG_X86_64
+	walk_page_range(0, PTRS_PER_PGD*PGD_LEVEL_MULT/2, &walk);
+	walk_page_range(normalize_addr(PTRS_PER_PGD*PGD_LEVEL_MULT/2), ~0,
+			&walk);
 #else
-			eff = prot;
+	walk_page_range(0, ~0, &walk);
 #endif
-			if (pgd_large(*start) || !pgd_present(*start)) {
-				note_page(&st, __pgprot(prot), eff, 1);
-			} else {
-				walk_p4d_level(&st, *start, eff,
-					       i * PGD_LEVEL_MULT);
-			}
-		} else
-			note_page(&st, __pgprot(0), 0, 1);
-
-		cond_resched();
-		start++;
-	}
+	up_read(&mm->mmap_sem);
 
 	/* Flush out the last page */
 	st.current_address = normalize_addr(PTRS_PER_PGD*PGD_LEVEL_MULT);
-- 
2.20.1


      parent reply	other threads:[~2019-02-27 17:08 UTC|newest]

Thread overview: 68+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-27 17:05 [PATCH v3 00/34] Convert x86 & arm64 to use generic page walk Steven Price
2019-02-27 17:05 ` [PATCH v3 01/34] alpha: mm: Add p?d_large() definitions Steven Price
2019-02-27 17:05 ` [PATCH v3 02/34] arc: " Steven Price
2019-02-27 18:18   ` Vineet Gupta
2019-02-27 17:05 ` [PATCH v3 03/34] arm: " Steven Price
2019-03-01 21:47   ` Kirill A. Shutemov
2019-03-04 11:56     ` Steven Price
2019-03-04 13:10       ` Kirill A. Shutemov
2019-02-27 17:05 ` [PATCH v3 04/34] arm64: " Steven Price
2019-02-27 17:05 ` [PATCH v3 05/34] c6x: " Steven Price
2019-03-01 21:48   ` Kirill A. Shutemov
2019-03-04 12:01     ` Steven Price
2019-03-04 13:11       ` Kirill A. Shutemov
2019-02-27 17:05 ` [PATCH v3 06/34] csky: " Steven Price
2019-03-01 21:51   ` Kirill A. Shutemov
2019-02-27 17:05 ` [PATCH v3 07/34] hexagon: " Steven Price
2019-02-27 17:05 ` [PATCH v3 08/34] ia64: " Steven Price
2019-03-01 21:57   ` Kirill A. Shutemov
2019-03-04 13:16     ` Steven Price
2019-03-04 19:06       ` Luck, Tony
2019-03-06 13:45         ` Steven Price
2019-02-27 17:05 ` [PATCH v3 09/34] m68k: " Steven Price
2019-02-27 19:27   ` Geert Uytterhoeven
2019-02-28 11:36     ` Mike Rapoport
2019-02-28 11:53       ` Geert Uytterhoeven
2019-02-28 12:04         ` Steven Price
2019-03-01 11:45           ` Mike Rapoport
2019-02-27 17:05 ` [PATCH v3 10/34] microblaze: " Steven Price
2019-02-27 17:05 ` [PATCH v3 11/34] mips: " Steven Price
2019-02-28  2:15   ` Paul Burton
2019-02-28 12:11     ` Steven Price
2019-02-28 18:55       ` Paul Burton
2019-03-01 11:02         ` Steven Price
2019-02-27 17:05 ` [PATCH v3 12/34] nds32: " Steven Price
2019-02-27 17:05 ` [PATCH v3 13/34] nios2: " Steven Price
2019-02-27 17:05 ` [PATCH v3 14/34] openrisc: " Steven Price
2019-02-27 17:05 ` [PATCH v3 15/34] parisc: " Steven Price
2019-02-27 18:54   ` Helge Deller
2019-03-01 22:12     ` Kirill A. Shutemov
2019-03-05 21:45       ` Helge Deller
2019-02-27 17:05 ` [PATCH v3 16/34] powerpc: " Steven Price
2019-02-27 17:05 ` [PATCH v3 17/34] riscv: " Steven Price
2019-02-27 17:05 ` [PATCH v3 18/34] s390: " Steven Price
2019-02-27 17:40   ` Martin Schwidefsky
2019-02-28 11:43     ` Steven Price
2019-02-27 17:05 ` [PATCH v3 19/34] sh: " Steven Price
2019-02-27 17:05 ` [PATCH v3 20/34] sparc: " Steven Price
2019-02-27 18:38   ` David Miller
2019-02-28 11:49     ` Steven Price
2019-02-27 17:05 ` [PATCH v3 21/34] um: " Steven Price
2019-02-27 17:05 ` [PATCH v3 22/34] unicore32: " Steven Price
2019-02-27 17:05 ` [PATCH v3 23/34] xtensa: " Steven Price
2019-02-27 17:29   ` Max Filippov
2019-02-27 17:05 ` [PATCH v3 24/34] mm: Add generic p?d_large() macros Steven Price
2019-02-27 17:05 ` [PATCH v3 25/34] mm: pagewalk: Add p4d_entry() and pgd_entry() Steven Price
2019-02-27 17:06 ` [PATCH v3 26/34] mm: pagewalk: Allow walking without vma Steven Price
2019-02-27 17:06 ` [PATCH v3 27/34] mm: pagewalk: Add 'depth' parameter to pte_hole Steven Price
2019-02-27 17:38   ` Dave Hansen
2019-02-28 11:28     ` Steven Price
2019-02-28 19:00       ` Dave Hansen
2019-03-01 11:24         ` Steven Price
2019-02-27 17:06 ` [PATCH v3 28/34] mm: pagewalk: Add test_p?d callbacks Steven Price
2019-02-27 17:06 ` [PATCH v3 29/34] arm64: mm: Convert mm/dump.c to use walk_page_range() Steven Price
2019-02-27 17:06 ` [PATCH v3 30/34] x86/mm: Point to struct seq_file from struct pg_state Steven Price
2019-02-27 17:06 ` [PATCH v3 31/34] x86/mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct Steven Price
2019-02-27 17:06 ` [PATCH v3 32/34] x86/mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct Steven Price
2019-02-27 17:06 ` [PATCH v3 33/34] x86/mm: Convert ptdump_walk_pgd_level_core() " Steven Price
2019-02-27 17:06 ` Steven Price [this message]

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