arm64: mm: dump: make page table dumping reusable
For debugging purposes, it would be nice if we could export page tables
other than the swapper_pg_dir to userspace. To enable this, this patch
refactors the arm64 page table dumping code such that multiple tables
may be registered with the framework, and exported under debugfs.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Laura Abbott <labbott@fedoraproject.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c
index ccfde23..f94b80e 100644
--- a/arch/arm64/mm/dump.c
+++ b/arch/arm64/mm/dump.c
@@ -27,11 +27,7 @@
#include <asm/memory.h>
#include <asm/pgtable.h>
#include <asm/pgtable-hwdef.h>
-
-struct addr_marker {
- unsigned long start_address;
- const char *name;
-};
+#include <asm/ptdump.h>
static const struct addr_marker address_markers[] = {
#ifdef CONFIG_KASAN
@@ -290,7 +286,8 @@
}
}
-static void walk_pgd(struct pg_state *st, struct mm_struct *mm, unsigned long start)
+static void walk_pgd(struct pg_state *st, struct mm_struct *mm,
+ unsigned long start)
{
pgd_t *pgd = pgd_offset(mm, 0UL);
unsigned i;
@@ -309,12 +306,13 @@
static int ptdump_show(struct seq_file *m, void *v)
{
+ struct ptdump_info *info = m->private;
struct pg_state st = {
.seq = m,
- .marker = address_markers,
+ .marker = info->markers,
};
- walk_pgd(&st, &init_mm, VA_START);
+ walk_pgd(&st, info->mm, info->base_addr);
note_page(&st, 0, 0, 0);
return 0;
@@ -322,7 +320,7 @@
static int ptdump_open(struct inode *inode, struct file *file)
{
- return single_open(file, ptdump_show, NULL);
+ return single_open(file, ptdump_show, inode->i_private);
}
static const struct file_operations ptdump_fops = {
@@ -332,7 +330,7 @@
.release = single_release,
};
-static int ptdump_init(void)
+int ptdump_register(struct ptdump_info *info, const char *name)
{
struct dentry *pe;
unsigned i, j;
@@ -342,8 +340,18 @@
for (j = 0; j < pg_level[i].num; j++)
pg_level[i].mask |= pg_level[i].bits[j].mask;
- pe = debugfs_create_file("kernel_page_tables", 0400, NULL, NULL,
- &ptdump_fops);
+ pe = debugfs_create_file(name, 0400, NULL, info, &ptdump_fops);
return pe ? 0 : -ENOMEM;
}
+
+static struct ptdump_info kernel_ptdump_info = {
+ .mm = &init_mm,
+ .markers = address_markers,
+ .base_addr = VA_START,
+};
+
+static int ptdump_init(void)
+{
+ return ptdump_register(&kernel_ptdump_info, "kernel_page_tables");
+}
device_initcall(ptdump_init);