linux/fs/proc/task_nommu.c
Alexey Dobriyan 3bbfe05967 proc: remove kernel.maps_protect
After commit 831830b5a2 aka
"restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace"
sysctl stopped being relevant because commit moved security checks from ->show
time to ->start time (mm_for_maps()).

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
2008-10-10 04:24:51 +04:00

196 lines
4.3 KiB
C

#include <linux/mm.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/mount.h>
#include <linux/ptrace.h>
#include <linux/seq_file.h>
#include "internal.h"
/*
* Logic: we've got two memory sums for each process, "shared", and
* "non-shared". Shared memory may get counted more then once, for
* each process that owns it. Non-shared memory is counted
* accurately.
*/
void task_mem(struct seq_file *m, struct mm_struct *mm)
{
struct vm_list_struct *vml;
unsigned long bytes = 0, sbytes = 0, slack = 0;
down_read(&mm->mmap_sem);
for (vml = mm->context.vmlist; vml; vml = vml->next) {
if (!vml->vma)
continue;
bytes += kobjsize(vml);
if (atomic_read(&mm->mm_count) > 1 ||
atomic_read(&vml->vma->vm_usage) > 1
) {
sbytes += kobjsize((void *) vml->vma->vm_start);
sbytes += kobjsize(vml->vma);
} else {
bytes += kobjsize((void *) vml->vma->vm_start);
bytes += kobjsize(vml->vma);
slack += kobjsize((void *) vml->vma->vm_start) -
(vml->vma->vm_end - vml->vma->vm_start);
}
}
if (atomic_read(&mm->mm_count) > 1)
sbytes += kobjsize(mm);
else
bytes += kobjsize(mm);
if (current->fs && atomic_read(&current->fs->count) > 1)
sbytes += kobjsize(current->fs);
else
bytes += kobjsize(current->fs);
if (current->files && atomic_read(&current->files->count) > 1)
sbytes += kobjsize(current->files);
else
bytes += kobjsize(current->files);
if (current->sighand && atomic_read(&current->sighand->count) > 1)
sbytes += kobjsize(current->sighand);
else
bytes += kobjsize(current->sighand);
bytes += kobjsize(current); /* includes kernel stack */
seq_printf(m,
"Mem:\t%8lu bytes\n"
"Slack:\t%8lu bytes\n"
"Shared:\t%8lu bytes\n",
bytes, slack, sbytes);
up_read(&mm->mmap_sem);
}
unsigned long task_vsize(struct mm_struct *mm)
{
struct vm_list_struct *tbp;
unsigned long vsize = 0;
down_read(&mm->mmap_sem);
for (tbp = mm->context.vmlist; tbp; tbp = tbp->next) {
if (tbp->vma)
vsize += kobjsize((void *) tbp->vma->vm_start);
}
up_read(&mm->mmap_sem);
return vsize;
}
int task_statm(struct mm_struct *mm, int *shared, int *text,
int *data, int *resident)
{
struct vm_list_struct *tbp;
int size = kobjsize(mm);
down_read(&mm->mmap_sem);
for (tbp = mm->context.vmlist; tbp; tbp = tbp->next) {
size += kobjsize(tbp);
if (tbp->vma) {
size += kobjsize(tbp->vma);
size += kobjsize((void *) tbp->vma->vm_start);
}
}
size += (*text = mm->end_code - mm->start_code);
size += (*data = mm->start_stack - mm->start_data);
up_read(&mm->mmap_sem);
*resident = size;
return size;
}
/*
* display mapping lines for a particular process's /proc/pid/maps
*/
static int show_map(struct seq_file *m, void *_vml)
{
struct vm_list_struct *vml = _vml;
return nommu_vma_show(m, vml->vma);
}
static void *m_start(struct seq_file *m, loff_t *pos)
{
struct proc_maps_private *priv = m->private;
struct vm_list_struct *vml;
struct mm_struct *mm;
loff_t n = *pos;
/* pin the task and mm whilst we play with them */
priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
if (!priv->task)
return NULL;
mm = mm_for_maps(priv->task);
if (!mm) {
put_task_struct(priv->task);
priv->task = NULL;
return NULL;
}
/* start from the Nth VMA */
for (vml = mm->context.vmlist; vml; vml = vml->next)
if (n-- == 0)
return vml;
return NULL;
}
static void m_stop(struct seq_file *m, void *_vml)
{
struct proc_maps_private *priv = m->private;
if (priv->task) {
struct mm_struct *mm = priv->task->mm;
up_read(&mm->mmap_sem);
mmput(mm);
put_task_struct(priv->task);
}
}
static void *m_next(struct seq_file *m, void *_vml, loff_t *pos)
{
struct vm_list_struct *vml = _vml;
(*pos)++;
return vml ? vml->next : NULL;
}
static const struct seq_operations proc_pid_maps_ops = {
.start = m_start,
.next = m_next,
.stop = m_stop,
.show = show_map
};
static int maps_open(struct inode *inode, struct file *file)
{
struct proc_maps_private *priv;
int ret = -ENOMEM;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (priv) {
priv->pid = proc_pid(inode);
ret = seq_open(file, &proc_pid_maps_ops);
if (!ret) {
struct seq_file *m = file->private_data;
m->private = priv;
} else {
kfree(priv);
}
}
return ret;
}
const struct file_operations proc_maps_operations = {
.open = maps_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release_private,
};