[PATCH 11/13] x86/mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct

Steven Price
2019-02-15T17:03:46Z

To enable x86 to use the generic walk_page_range() function, the
callers of ptdump_walk_pgd_level_debugfs() need to pass in the mm_struct.

This means that ptdump_walk_pgd_level_core() is now always passed a
valid pgd, so drop the support for pgd==NULL.

Signed-off-by: Steven Price <steven.price@arm.com>
---
arch/x86/include/asm/pgtable.h | 3 ++-
arch/x86/mm/debug_pagetables.c | 8 ++++----
arch/x86/mm/dump_pagetables.c | 14 ++++++--------
3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 371901283d5f..ab2aa3eb05e9 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -28,7 +28,8 @@ extern pgd_t early_top_pgt[PTRS_PER_PGD];
int __init __early_make_pgtable(unsigned long address, pmdval_t pmd);

void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm);
-void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd, bool user);
+void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm,
+ bool user);
void ptdump_walk_pgd_level_checkwx(void);
void ptdump_walk_user_pgd_level_checkwx(void);

diff --git a/arch/x86/mm/debug_pagetables.c b/arch/x86/mm/debug_pagetables.c
index cd84f067e41d..824131052574 100644
--- a/arch/x86/mm/debug_pagetables.c
+++ b/arch/x86/mm/debug_pagetables.c
@@ -6,7 +6,7 @@

static int ptdump_show(struct seq_file *m, void *v)
{
- ptdump_walk_pgd_level_debugfs(m, NULL, false);
+ ptdump_walk_pgd_level_debugfs(m, &init_mm, false);
return 0;
}

@@ -16,7 +16,7 @@ static int ptdump_curknl_show(struct seq_file *m, void *v)
{
if (current->mm->pgd) {
down_read(&current->mm->mmap_sem);
- ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, false);
+ ptdump_walk_pgd_level_debugfs(m, current->mm, false);
up_read(&current->mm->mmap_sem);
}
return 0;
@@ -31,7 +31,7 @@ static int ptdump_curusr_show(struct seq_file *m, void *v)
{
if (current->mm->pgd) {
down_read(&current->mm->mmap_sem);
- ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, true);
+ ptdump_walk_pgd_level_debugfs(m, current->mm, true);
up_read(&current->mm->mmap_sem);
}
return 0;
@@ -46,7 +46,7 @@ static struct dentry *pe_efi;
static int ptdump_efi_show(struct seq_file *m, void *v)
{
if (efi_mm.pgd)
- ptdump_walk_pgd_level_debugfs(m, efi_mm.pgd, false);
+ ptdump_walk_pgd_level_debugfs(m, &efi_mm, false);
return 0;
}

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 1a4a03e3a6bd..18fb6193311f 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -525,16 +525,12 @@ static inline bool is_hypervisor_range(int idx)
static void ptdump_walk_pgd_level_core(struct seq_file *m, pgd_t *pgd,
bool checkwx, bool dmesg)
{
- pgd_t *start = INIT_PGD;
+ pgd_t *start = pgd;
pgprotval_t prot, eff;
int i;
struct pg_state st = {};

- if (pgd) {
- start = pgd;
- st.to_dmesg = dmesg;
- }
-
+ st.to_dmesg = dmesg;
st.check_wx = checkwx;
st.seq = m;
if (checkwx)
@@ -579,8 +575,10 @@ void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm)
ptdump_walk_pgd_level_core(m, mm->pgd, false, true);
}

-void ptdump_walk_pgd_level_debugfs(struct seq_file *m, pgd_t *pgd, bool user)
+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);
@@ -606,7 +604,7 @@ void ptdump_walk_user_pgd_level_checkwx(void)

void ptdump_walk_pgd_level_checkwx(void)
{
- ptdump_walk_pgd_level_core(NULL, NULL, true, false);
+ ptdump_walk_pgd_level_core(NULL, INIT_PGD, true, false);
}

static int __init pt_dump_init(void)
--
2.20.1