From 4674fdb9f1493f12a15c5f2158f260060b58953e Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 31 May 2016 14:49:01 +0100 Subject: [PATCH] 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 Signed-off-by: Ard Biesheuvel Cc: Laura Abbott Cc: Will Deacon Signed-off-by: Catalin Marinas --- arch/arm64/include/asm/ptdump.h | 44 +++++++++++++++++++++++++++++++++ arch/arm64/mm/dump.c | 32 +++++++++++++++--------- 2 files changed, 64 insertions(+), 12 deletions(-) create mode 100644 arch/arm64/include/asm/ptdump.h diff --git a/arch/arm64/include/asm/ptdump.h b/arch/arm64/include/asm/ptdump.h new file mode 100644 index 000000000000..07b8ed037dee --- /dev/null +++ b/arch/arm64/include/asm/ptdump.h @@ -0,0 +1,44 @@ +/* + * Copyright (C) 2014 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ +#ifndef __ASM_PTDUMP_H +#define __ASM_PTDUMP_H + +#ifdef CONFIG_ARM64_PTDUMP + +#include + +struct addr_marker { + unsigned long start_address; + char *name; +}; + +struct ptdump_info { + struct mm_struct *mm; + const struct addr_marker *markers; + unsigned long base_addr; + unsigned long max_addr; +}; + +int ptdump_register(struct ptdump_info *info, const char *name); + +#else +static inline int ptdump_register(struct ptdump_info *info, const char *name) +{ + return 0; +} +#endif /* CONFIG_ARM64_PTDUMP */ + +#endif /* __ASM_PTDUMP_H */ diff --git a/arch/arm64/mm/dump.c b/arch/arm64/mm/dump.c index ccfde237d6e6..f94b80eb295d 100644 --- a/arch/arm64/mm/dump.c +++ b/arch/arm64/mm/dump.c @@ -27,11 +27,7 @@ #include #include #include - -struct addr_marker { - unsigned long start_address; - const char *name; -}; +#include static const struct addr_marker address_markers[] = { #ifdef CONFIG_KASAN @@ -290,7 +286,8 @@ static void walk_pud(struct pg_state *st, pgd_t *pgd, unsigned long start) } } -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 void walk_pgd(struct pg_state *st, struct mm_struct *mm, unsigned long st 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_show(struct seq_file *m, void *v) 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 @@ static const struct file_operations ptdump_fops = { .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 @@ static int ptdump_init(void) 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); -- 2.39.5