The patch titled
Subject: x86: mm: convert ptdump_walk_pgd_level_core() to take an mm_struct
has been added to the -mm tree. Its filename is
x86-mm-convert-ptdump_walk_pgd_level_core-to-take-an-mm_struct.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/x86-mm-convert-ptdump_walk_pgd_level_core-to-take-an-mm_struct.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/x86-mm-convert-ptdump_walk_pgd_level_core-to-take-an-mm_struct.patch
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------------------------------------------------------
From: Steven Price <steven.price@xxxxxxx>
Subject: x86: mm: convert ptdump_walk_pgd_level_core() to take an mm_struct
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.
Link: http://lkml.kernel.org/r/20190722154210.42799-19-steven.price@xxxxxxx
Signed-off-by: Steven Price <steven.price@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/mm/dump_pagetables.c | 36 ++++++++++++++++++--------------
1 file changed, 21 insertions(+), 15 deletions(-)
--- a/arch/x86/mm/dump_pagetables.c~x86-mm-convert-ptdump_walk_pgd_level_core-to-take-an-mm_struct
+++ a/arch/x86/mm/dump_pagetables.c
@@ -107,8 +107,6 @@ static struct addr_marker address_marker
[END_OF_SPACE_NR] = { -1, NULL }
};
-#define INIT_PGD ((pgd_t *) &init_top_pgt)
-
#else /* CONFIG_X86_64 */
enum address_markers_idx {
@@ -143,8 +141,6 @@ static struct addr_marker address_marker
[END_OF_SPACE_NR] = { -1, NULL }
};
-#define INIT_PGD (swapper_pg_dir)
-
#endif /* !CONFIG_X86_64 */
/* Multipliers for offsets within the PTEs */
@@ -516,10 +512,10 @@ static inline bool is_hypervisor_range(i
#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 = {};
@@ -566,39 +562,49 @@ static void ptdump_walk_pgd_level_core(s
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 && boot_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) ||
!boot_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)
_
Patches currently in -mm which might be from steven.price@xxxxxxx are
arc-mm-add-pd_leaf-definitions.patch
arm-mm-add-pd_leaf-definitions.patch
arm64-mm-add-pd_leaf-definitions.patch
mips-mm-add-pd_leaf-definitions.patch
powerpc-mm-add-pd_leaf-definitions.patch
riscv-mm-add-pd_leaf-definitions.patch
s390-mm-add-pd_leaf-definitions.patch
sparc-mm-add-pd_leaf-definitions.patch
x86-mm-add-pd_leaf-definitions.patch
mm-add-generic-pd_leaf-macros.patch
mm-pagewalk-add-p4d_entry-and-pgd_entry.patch
mm-pagewalk-allow-walking-without-vma.patch
mm-pagewalk-add-test_pd-callbacks.patch
x86-mm-dont-display-pages-which-arent-present-in-debugfs.patch
x86-mm-point-to-struct-seq_file-from-struct-pg_state.patch
x86-mmefi-convert-ptdump_walk_pgd_level-to-take-a-mm_struct.patch
x86-mm-convert-ptdump_walk_pgd_level_debugfs-to-take-an-mm_struct.patch
x86-mm-convert-ptdump_walk_pgd_level_core-to-take-an-mm_struct.patch
mm-add-generic-ptdump.patch
x86-mm-convert-dump_pagetables-to-use-walk_page_range.patch
arm64-mm-convert-mm-dumpc-to-use-walk_page_range.patch
