Commit 8609d1b5 authored by Kees Cook's avatar Kees Cook Committed by Ingo Molnar

x86/mm: Turn CONFIG_X86_PTDUMP into a module

Being able to examine page tables is handy, so make this a
module that can be loaded as needed.
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: http://lkml.kernel.org/r/20151120010755.GA9060@www.outflux.netSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 1ec21837
......@@ -69,7 +69,7 @@ config X86_PTDUMP_CORE
def_bool n
config X86_PTDUMP
bool "Export kernel pagetable layout to userspace via debugfs"
tristate "Export kernel pagetable layout to userspace via debugfs"
depends on DEBUG_KERNEL
select DEBUG_FS
select X86_PTDUMP_CORE
......
......@@ -15,6 +15,7 @@ obj-$(CONFIG_X86_32) += pgtable_32.o iomap_32.o
obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
obj-$(CONFIG_X86_PTDUMP_CORE) += dump_pagetables.o
obj-$(CONFIG_X86_PTDUMP) += debug_pagetables.o
obj-$(CONFIG_HIGHMEM) += highmem_32.o
......
#include <linux/debugfs.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <asm/pgtable.h>
static int ptdump_show(struct seq_file *m, void *v)
{
ptdump_walk_pgd_level(m, NULL);
return 0;
}
static int ptdump_open(struct inode *inode, struct file *filp)
{
return single_open(filp, ptdump_show, NULL);
}
static const struct file_operations ptdump_fops = {
.owner = THIS_MODULE,
.open = ptdump_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static struct dentry *pe;
static int __init pt_dump_debug_init(void)
{
pe = debugfs_create_file("kernel_page_tables", 0600, NULL, NULL,
&ptdump_fops);
if (!pe)
return -ENOMEM;
return 0;
}
static void __exit pt_dump_debug_exit(void)
{
debugfs_remove_recursive(pe);
}
module_init(pt_dump_debug_init);
module_exit(pt_dump_debug_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");
......@@ -426,38 +426,15 @@ void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd)
{
ptdump_walk_pgd_level_core(m, pgd, false);
}
EXPORT_SYMBOL_GPL(ptdump_walk_pgd_level);
void ptdump_walk_pgd_level_checkwx(void)
{
ptdump_walk_pgd_level_core(NULL, NULL, true);
}
#ifdef CONFIG_X86_PTDUMP
static int ptdump_show(struct seq_file *m, void *v)
static int __init pt_dump_init(void)
{
ptdump_walk_pgd_level(m, NULL);
return 0;
}
static int ptdump_open(struct inode *inode, struct file *filp)
{
return single_open(filp, ptdump_show, NULL);
}
static const struct file_operations ptdump_fops = {
.open = ptdump_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif
static int pt_dump_init(void)
{
#ifdef CONFIG_X86_PTDUMP
struct dentry *pe;
#endif
#ifdef CONFIG_X86_32
/* Not a compile-time constant on x86-32 */
address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
......@@ -468,13 +445,6 @@ static int pt_dump_init(void)
address_markers[FIXADDR_START_NR].start_address = FIXADDR_START;
#endif
#ifdef CONFIG_X86_PTDUMP
pe = debugfs_create_file("kernel_page_tables", 0600, NULL, NULL,
&ptdump_fops);
if (!pe)
return -ENOMEM;
#endif
return 0;
}
......
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