linux/arch/x86/mm/debug_pagetables.c

115 lines
2.6 KiB
C

#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_debugfs(m, NULL, false);
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 int ptdump_show_curknl(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);
up_read(&current->mm->mmap_sem);
}
return 0;
}
static int ptdump_open_curknl(struct inode *inode, struct file *filp)
{
return single_open(filp, ptdump_show_curknl, NULL);
}
static const struct file_operations ptdump_curknl_fops = {
.owner = THIS_MODULE,
.open = ptdump_open_curknl,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#ifdef CONFIG_PAGE_TABLE_ISOLATION
static struct dentry *pe_curusr;
static int ptdump_show_curusr(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);
up_read(&current->mm->mmap_sem);
}
return 0;
}
static int ptdump_open_curusr(struct inode *inode, struct file *filp)
{
return single_open(filp, ptdump_show_curusr, NULL);
}
static const struct file_operations ptdump_curusr_fops = {
.owner = THIS_MODULE,
.open = ptdump_open_curusr,
.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)
{
dir = debugfs_create_dir("page_tables", NULL);
if (!dir)
return -ENOMEM;
pe_knl = debugfs_create_file("kernel", 0400, dir, NULL,
&ptdump_fops);
if (!pe_knl)
goto err;
pe_curknl = debugfs_create_file("current_kernel", 0400,
dir, NULL, &ptdump_curknl_fops);
if (!pe_curknl)
goto err;
#ifdef CONFIG_PAGE_TABLE_ISOLATION
pe_curusr = debugfs_create_file("current_user", 0400,
dir, NULL, &ptdump_curusr_fops);
if (!pe_curusr)
goto err;
#endif
return 0;
err:
debugfs_remove_recursive(dir);
return -ENOMEM;
}
static void __exit pt_dump_debug_exit(void)
{
debugfs_remove_recursive(dir);
}
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");