#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/mount.h>
#include <linux/seq_file.h>
#include <asm/elf.h>
#include <asm/uaccess.h>
#include "internal.h"

char *task_mem(struct mm_struct *mm, char *buffer)
{
	unsigned long data, text, lib;

	data = mm->total_vm - mm->shared_vm - mm->stack_vm;
	text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10;
	lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text;
	buffer += sprintf(buffer,
		"VmSize:\t%8lu kB\n"
		"VmLck:\t%8lu kB\n"
		"VmRSS:\t%8lu kB\n"
		"VmData:\t%8lu kB\n"
		"VmStk:\t%8lu kB\n"
		"VmExe:\t%8lu kB\n"
		"VmLib:\t%8lu kB\n"
		"VmPTE:\t%8lu kB\n",
		(mm->total_vm - mm->reserved_vm) << (PAGE_SHIFT-10),
		mm->locked_vm << (PAGE_SHIFT-10),
		get_mm_counter(mm, rss) << (PAGE_SHIFT-10),
		data << (PAGE_SHIFT-10),
		mm->stack_vm << (PAGE_SHIFT-10), text, lib,
		(PTRS_PER_PTE*sizeof(pte_t)*mm->nr_ptes) >> 10);
	return buffer;
}

unsigned long task_vsize(struct mm_struct *mm)
{
	return PAGE_SIZE * mm->total_vm;
}

int task_statm(struct mm_struct *mm, int *shared, int *text,
	       int *data, int *resident)
{
	int rss = get_mm_counter(mm, rss);

	*shared = rss - get_mm_counter(mm, anon_rss);
	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
								>> PAGE_SHIFT;
	*data = mm->total_vm - mm->shared_vm;
	*resident = rss;
	return mm->total_vm;
}

int proc_exe_link(struct inode *inode, struct dentry **dentry, struct vfsmount **mnt)
{
	struct vm_area_struct * vma;
	int result = -ENOENT;
	struct task_struct *task = proc_task(inode);
	struct mm_struct * mm = get_task_mm(task);

	if (!mm)
		goto out;
	down_read(&mm->mmap_sem);

	vma = mm->mmap;
	while (vma) {
		if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file)
			break;
		vma = vma->vm_next;
	}

	if (vma) {
		*mnt = mntget(vma->vm_file->f_vfsmnt);
		*dentry = dget(vma->vm_file->f_dentry);
		result = 0;
	}

	up_read(&mm->mmap_sem);
	mmput(mm);
out:
	return result;
}

static void pad_len_spaces(struct seq_file *m, int len)
{
	len = 25 + sizeof(void*) * 6 - len;
	if (len < 1)
		len = 1;
	seq_printf(m, "%*c", len, ' ');
}

static int show_map(struct seq_file *m, void *v)
{
	struct task_struct *task = m->private;
	struct vm_area_struct *map = v;
	struct mm_struct *mm = map->vm_mm;
	struct file *file = map->vm_file;
	int flags = map->vm_flags;
	unsigned long ino = 0;
	dev_t dev = 0;
	int len;

	if (file) {
		struct inode *inode = map->vm_file->f_dentry->d_inode;
		dev = inode->i_sb->s_dev;
		ino = inode->i_ino;
	}

	seq_printf(m, "%08lx-%08lx %c%c%c%c %08lx %02x:%02x %lu %n",
			map->vm_start,
			map->vm_end,
			flags & VM_READ ? 'r' : '-',
			flags & VM_WRITE ? 'w' : '-',
			flags & VM_EXEC ? 'x' : '-',
			flags & VM_MAYSHARE ? 's' : 'p',
			map->vm_pgoff << PAGE_SHIFT,
			MAJOR(dev), MINOR(dev), ino, &len);

	/*
	 * Print the dentry name for named mappings, and a
	 * special [heap] marker for the heap:
	 */
	if (map->vm_file) {
		pad_len_spaces(m, len);
		seq_path(m, file->f_vfsmnt, file->f_dentry, "");
	} else {
		if (mm) {
			if (map->vm_start <= mm->start_brk &&
						map->vm_end >= mm->brk) {
				pad_len_spaces(m, len);
				seq_puts(m, "[heap]");
			} else {
				if (map->vm_start <= mm->start_stack &&
					map->vm_end >= mm->start_stack) {

					pad_len_spaces(m, len);
					seq_puts(m, "[stack]");
				}
			}
		} else {
			pad_len_spaces(m, len);
			seq_puts(m, "[vdso]");
		}
	}
	seq_putc(m, '\n');
	if (m->count < m->size)  /* map is copied successfully */
		m->version = (map != get_gate_vma(task))? map->vm_start: 0;
	return 0;
}

static void *m_start(struct seq_file *m, loff_t *pos)
{
	struct task_struct *task = m->private;
	unsigned long last_addr = m->version;
	struct mm_struct *mm;
	struct vm_area_struct *map, *tail_map;
	loff_t l = *pos;

	/*
	 * We remember last_addr rather than next_addr to hit with
	 * mmap_cache most of the time. We have zero last_addr at
	 * the begining and also after lseek. We will have -1 last_addr
	 * after the end of the maps.
	 */

	if (last_addr == -1UL)
		return NULL;

	mm = get_task_mm(task);
	if (!mm)
		return NULL;

	tail_map = get_gate_vma(task);
	down_read(&mm->mmap_sem);

	/* Start with last addr hint */
	if (last_addr && (map = find_vma(mm, last_addr))) {
		map = map->vm_next;
		goto out;
	}

	/*
	 * Check the map index is within the range and do
	 * sequential scan until m_index.
	 */
	map = NULL;
	if ((unsigned long)l < mm->map_count) {
		map = mm->mmap;
		while (l-- && map)
			map = map->vm_next;
		goto out;
	}

	if (l != mm->map_count)
		tail_map = NULL; /* After gate map */

out:
	if (map)
		return map;

	/* End of maps has reached */
	m->version = (tail_map != NULL)? 0: -1UL;
	up_read(&mm->mmap_sem);
	mmput(mm);
	return tail_map;
}

static void m_stop(struct seq_file *m, void *v)
{
	struct task_struct *task = m->private;
	struct vm_area_struct *map = v;
	if (map && map != get_gate_vma(task)) {
		struct mm_struct *mm = map->vm_mm;
		up_read(&mm->mmap_sem);
		mmput(mm);
	}
}

static void *m_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct task_struct *task = m->private;
	struct vm_area_struct *map = v;
	struct vm_area_struct *tail_map = get_gate_vma(task);

	(*pos)++;
	if (map && (map != tail_map) && map->vm_next)
		return map->vm_next;
	m_stop(m, v);
	return (map != tail_map)? tail_map: NULL;
}

struct seq_operations proc_pid_maps_op = {
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= show_map
};