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
Subject: [PATCH 12/13] x86/mm: Convert ptdump_walk_pgd_level_core() to take an mm_struct
Date: Fri, 15 Feb 2019 17:02:33 +0000 [thread overview]
Message-ID: <20190215170235.23360-13-steven.price@arm.com> (raw)
In-Reply-To: <20190215170235.23360-1-steven.price@arm.com>
An mm_struct is needed to enable x86 to use of the generic
walk_page_range() function.
In the case of walking the user page tables (when
CONFIG_PAGE_TABLE_ISOLATION is enabled), it is necessary to create a
fake_mm structure because there isn't an mm_struct with a pointer
to the pgd of the user page tables. This fake_mm structure is
initialised with the minimum necessary for the generic page walk code.
Signed-off-by: Steven Price <steven.price@arm.com>
---
arch/x86/mm/dump_pagetables.c | 36 ++++++++++++++++++++---------------
1 file changed, 21 insertions(+), 15 deletions(-)
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 18fb6193311f..ddb22e7f81b3 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -111,8 +111,6 @@ static struct addr_marker address_markers[] = {
[END_OF_SPACE_NR] = { -1, NULL }
};
-#define INIT_PGD ((pgd_t *) &init_top_pgt)
-
#else /* CONFIG_X86_64 */
enum address_markers_idx {
@@ -147,8 +145,6 @@ static struct addr_marker address_markers[] = {
[END_OF_SPACE_NR] = { -1, NULL }
};
-#define INIT_PGD (swapper_pg_dir)
-
#endif /* !CONFIG_X86_64 */
/* Multipliers for offsets within the PTEs */
@@ -522,10 +518,10 @@ static inline bool is_hypervisor_range(int idx)
#endif
}
-static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
+static void ptdump_walk_pgd_level_core(struct seq_file *m, struct mm_struct *mm,
bool checkwx, bool dmesg)
{
- pgd_t *start = pgd;
+ pgd_t *start = mm->pgd;
pgprotval_t prot, eff;
int i;
struct pg_state st = {};
@@ -572,39 +568,49 @@ static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm)
{
- ptdump_walk_pgd_level_core(m, mm->pgd, false, true);
+ ptdump_walk_pgd_level_core(m, mm, false, true);
}
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+static void ptdump_walk_pgd_level_user_core(struct seq_file *m,
+ struct mm_struct *mm,
+ bool checkwx, bool dmesg)
+{
+ struct mm_struct fake_mm = {
+ .pgd = kernel_to_user_pgdp(mm->pgd)
+ };
+ init_rwsem(&fake_mm.mmap_sem);
+ ptdump_walk_pgd_level_core(m, &fake_mm, checkwx, dmesg);
+}
+#endif
+
void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm,
bool user)
{
- pgd_t *pgd = mm->pgd;
#ifdef CONFIG_PAGE_TABLE_ISOLATION
if (user && static_cpu_has(X86_FEATURE_PTI))
- pgd = kernel_to_user_pgdp(pgd);
+ ptdump_walk_pgd_level_user_core(m, mm, false, false);
+ else
#endif
- ptdump_walk_pgd_level_core(m, pgd, false, false);
+ ptdump_walk_pgd_level_core(m, mm, false, false);
}
EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level_debugfs);
void ptdump_walk_user_pgd_level_checkwx(void)
{
#ifdef CONFIG_PAGE_TABLE_ISOLATION
- pgd_t *pgd = INIT_PGD;
-
if (!(__supported_pte_mask & _PAGE_NX) ||
!static_cpu_has(X86_FEATURE_PTI))
return;
pr_info("x86/mm: Checking user space page tables\n");
- pgd = kernel_to_user_pgdp(pgd);
- ptdump_walk_pgd_level_core(NULL, pgd, true, false);
+ ptdump_walk_pgd_level_user_core(NULL, &init_mm, true, false);
#endif
}
void ptdump_walk_pgd_level_checkwx(void)
{
- ptdump_walk_pgd_level_core(NULL, INIT_PGD, true, false);
+ ptdump_walk_pgd_level_core(NULL, &init_mm, true, false);
}
static int __init pt_dump_init(void)
--
2.20.1
next prev parent reply other threads:[~2019-02-15 17:03 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-15 17:02 [PATCH 00/13] Convert x86 & arm64 to use generic page walk Steven Price
2019-02-15 17:02 ` [PATCH 01/13] arm64: mm: Add p?d_large() definitions Steven Price
2019-02-18 11:16 ` Mark Rutland
2019-02-18 11:29 ` Peter Zijlstra
2019-02-18 13:45 ` Mark Rutland
2019-02-18 14:11 ` Steven Price
2019-02-18 14:29 ` Mark Rutland
2019-02-18 15:06 ` Peter Zijlstra
2019-02-18 15:30 ` Steven Price
2019-02-18 17:04 ` Mark Rutland
2019-02-18 17:22 ` Steven Price
2019-02-15 17:02 ` [PATCH 02/13] x86/mm: " Steven Price
2019-02-15 17:02 ` [PATCH 03/13] mm: Add generic p?d_large() macros Steven Price
2019-02-18 11:14 ` Mark Rutland
2019-02-18 12:53 ` Peter Zijlstra
2019-02-18 14:20 ` Steven Price
2019-02-18 11:31 ` Peter Zijlstra
2019-02-18 14:19 ` Steven Price
2019-02-19 3:44 ` Liang, Kan
2019-02-20 13:56 ` Steven Price
2019-02-15 17:02 ` [PATCH 04/13] mm: pagewalk: Add p4d_entry() and pgd_entry() Steven Price
2019-02-15 17:02 ` [PATCH 05/13] mm: pagewalk: Allow walking without vma Steven Price
2019-02-15 17:02 ` [PATCH 06/13] mm: pagewalk: Add 'depth' parameter to pte_hole Steven Price
2019-02-18 11:23 ` Mark Rutland
2019-02-18 15:23 ` Steven Price
2019-02-20 11:35 ` William Kucharski
2019-02-20 14:10 ` Steven Price
2019-02-15 17:02 ` [PATCH 07/13] mm: pagewalk: Add test_p?d callbacks Steven Price
2019-02-15 17:02 ` [PATCH 08/13] arm64: mm: Convert mm/dump.c to use walk_page_range() Steven Price
2019-02-15 17:02 ` [PATCH 09/13] x86/mm: Point to struct seq_file from struct pg_state Steven Price
2019-02-15 17:02 ` [PATCH 10/13] x86/mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct Steven Price
2019-02-15 17:02 ` [PATCH 11/13] x86/mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct Steven Price
2019-02-15 17:02 ` Steven Price [this message]
2019-02-15 17:02 ` [PATCH 13/13] x86: mm: Convert dump_pagetables to use walk_page_range Steven Price
2019-02-15 17:16 ` Dave Hansen
2019-02-15 17:32 ` Steven Price
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