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 v4 19/19] x86: mm: Convert dump_pagetables to use walk_page_range
Date: Wed, 6 Mar 2019 15:50:31 +0000 [thread overview]
Message-ID: <20190306155031.4291-20-steven.price@arm.com> (raw)
In-Reply-To: <20190306155031.4291-1-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 | 282 ++++++++++++++++++----------------
1 file changed, 146 insertions(+), 136 deletions(-)
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index b1c04ecc18cc..f6b814aaddf7 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;
@@ -356,22 +360,21 @@ 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
/*
@@ -400,133 +403,152 @@ 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)
-#undef pud_large
-#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)
-#undef p4d_large
-#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;
}
-#undef pgd_large
-#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,
+ struct mm_walk *walk)
+{
+ struct pg_state *st = walk->private;
+
+ st->current_address = normalize_addr(addr);
+
+ note_page(st, __pgprot(0), 0, -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;
@@ -534,27 +556,15 @@ 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
prev parent reply other threads:[~2019-03-06 15:52 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-06 15:50 [PATCH v4 00/19] Convert x86 & arm64 to use generic page walk Steven Price
2019-03-06 15:50 ` [PATCH v4 01/19] arc: mm: Add p?d_large() definitions Steven Price
2019-03-06 15:50 ` [PATCH v4 02/19] arm64: " Steven Price
2019-03-06 15:50 ` [PATCH v4 03/19] mips: " Steven Price
2019-03-06 17:12 ` Paul Burton
2019-03-06 15:50 ` [PATCH v4 04/19] powerpc: " Steven Price
2019-03-08 8:37 ` Mike Rapoport
2019-03-08 10:50 ` Steven Price
2019-03-06 15:50 ` [PATCH v4 05/19] riscv: " Steven Price
2019-03-06 15:50 ` [PATCH v4 06/19] s390: " Steven Price
2019-03-06 15:50 ` [PATCH v4 07/19] sparc: " Steven Price
2019-03-06 19:02 ` David Miller
2019-03-06 15:50 ` [PATCH v4 08/19] x86: " Steven Price
2019-03-06 15:50 ` [PATCH v4 09/19] mm: Add generic p?d_large() macros Steven Price
2019-03-06 15:50 ` [PATCH v4 10/19] mm: pagewalk: Add p4d_entry() and pgd_entry() Steven Price
2019-03-06 15:50 ` [PATCH v4 11/19] mm: pagewalk: Allow walking without vma Steven Price
2019-03-06 15:50 ` [PATCH v4 12/19] mm: pagewalk: Add test_p?d callbacks Steven Price
2019-03-06 15:50 ` [PATCH v4 13/19] arm64: mm: Convert mm/dump.c to use walk_page_range() Steven Price
2019-03-06 15:50 ` [PATCH v4 14/19] x86: mm: Don't display pages which aren't present in debugfs Steven Price
2019-03-06 15:50 ` [PATCH v4 15/19] x86: mm: Point to struct seq_file from struct pg_state Steven Price
2019-03-06 15:50 ` [PATCH v4 16/19] x86: mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct Steven Price
2019-03-06 15:50 ` [PATCH v4 17/19] x86: mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct Steven Price
2019-03-06 15:50 ` [PATCH v4 18/19] x86: mm: Convert ptdump_walk_pgd_level_core() " Steven Price
2019-03-06 15:50 ` Steven Price [this message]
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