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x86/mm/dump_pagetables: Add the EFI pagetable to the debugfs 'page_tables' directory

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EFI is complicated enough that being able to view its pagetables is
quite helpful.  Rather than requiring users to fish it out of dmesg
on an appropriately configured kernel, let users view it in debugfs
as well.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/ba158a93f3250e6fca752cff2cfb1fcdd9f2b50c.1517414050.git.luto@kernel.org
[ Fixed trivial whitespace damage and fixed missing export. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2018-01-31 07:56:22 -08:00 committed by Ingo Molnar
parent 1070730c1a
commit 116fef6408
2 changed files with 35 additions and 1 deletions
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32
arch/x86/mm/debug_pagetables.c
View File

@ -72,6 +72,31 @@ static const struct file_operations ptdump_curusr_fops = {
};
#endif
#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
extern pgd_t *efi_pgd;
static struct dentry *pe_efi;
static int ptdump_show_efi(struct seq_file *m, void *v)
{
if (efi_pgd)
ptdump_walk_pgd_level_debugfs(m, efi_pgd, false);
return 0;
}
static int ptdump_open_efi(struct inode *inode, struct file *filp)
{
return single_open(filp, ptdump_show_efi, NULL);
}
static const struct file_operations ptdump_efi_fops = {
.owner = THIS_MODULE,
.open = ptdump_open_efi,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif
static struct dentry *dir, *pe_knl, *pe_curknl;
static int __init pt_dump_debug_init(void)
@ -96,6 +121,13 @@ static int __init pt_dump_debug_init(void)
if (!pe_curusr)
goto err;
#endif
#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
pe_efi = debugfs_create_file("efi", 0400, dir, NULL, &ptdump_efi_fops);
if (!pe_efi)
goto err;
#endif
return 0;
err:
debugfs_remove_recursive(dir);

4
arch/x86/platform/efi/efi_64.c
View File

@ -27,6 +27,7 @@
#include <linux/ioport.h>
#include <linux/mc146818rtc.h>
#include <linux/efi.h>
#include <linux/export.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/reboot.h>
@ -190,7 +191,8 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd)
early_code_mapping_set_exec(0);
}
static pgd_t *efi_pgd;
pgd_t *efi_pgd;
EXPORT_SYMBOL_GPL(efi_pgd);
/*
* We need our own copy of the higher levels of the page tables