1
2#include <linux/mm.h>
3#include <linux/file.h>
4#include <linux/fdtable.h>
5#include <linux/fs_struct.h>
6#include <linux/mount.h>
7#include <linux/ptrace.h>
8#include <linux/slab.h>
9#include <linux/seq_file.h>
10#include "internal.h"
11
12/*
13 * Logic: we've got two memory sums for each process, "shared", and
14 * "non-shared". Shared memory may get counted more than once, for
15 * each process that owns it. Non-shared memory is counted
16 * accurately.
17 */
18void task_mem(struct seq_file *m, struct mm_struct *mm)
19{
20	struct vm_area_struct *vma;
21	struct vm_region *region;
22	struct rb_node *p;
23	unsigned long bytes = 0, sbytes = 0, slack = 0, size;
24
25	down_read(&mm->mmap_sem);
26	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
27		vma = rb_entry(p, struct vm_area_struct, vm_rb);
28
29		bytes += kobjsize(vma);
30
31		region = vma->vm_region;
32		if (region) {
33			size = kobjsize(region);
34			size += region->vm_end - region->vm_start;
35		} else {
36			size = vma->vm_end - vma->vm_start;
37		}
38
39		if (atomic_read(&mm->mm_count) > 1 ||
40		    vma->vm_flags & VM_MAYSHARE) {
41			sbytes += size;
42		} else {
43			bytes += size;
44			if (region)
45				slack = region->vm_end - vma->vm_end;
46		}
47	}
48
49	if (atomic_read(&mm->mm_count) > 1)
50		sbytes += kobjsize(mm);
51	else
52		bytes += kobjsize(mm);
53
54	if (current->fs && current->fs->users > 1)
55		sbytes += kobjsize(current->fs);
56	else
57		bytes += kobjsize(current->fs);
58
59	if (current->files && atomic_read(&current->files->count) > 1)
60		sbytes += kobjsize(current->files);
61	else
62		bytes += kobjsize(current->files);
63
64	if (current->sighand && atomic_read(&current->sighand->count) > 1)
65		sbytes += kobjsize(current->sighand);
66	else
67		bytes += kobjsize(current->sighand);
68
69	bytes += kobjsize(current); /* includes kernel stack */
70
71	seq_printf(m,
72		"Mem:\t%8lu bytes\n"
73		"Slack:\t%8lu bytes\n"
74		"Shared:\t%8lu bytes\n",
75		bytes, slack, sbytes);
76
77	up_read(&mm->mmap_sem);
78}
79
80unsigned long task_vsize(struct mm_struct *mm)
81{
82	struct vm_area_struct *vma;
83	struct rb_node *p;
84	unsigned long vsize = 0;
85
86	down_read(&mm->mmap_sem);
87	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
88		vma = rb_entry(p, struct vm_area_struct, vm_rb);
89		vsize += vma->vm_end - vma->vm_start;
90	}
91	up_read(&mm->mmap_sem);
92	return vsize;
93}
94
95unsigned long task_statm(struct mm_struct *mm,
96			 unsigned long *shared, unsigned long *text,
97			 unsigned long *data, unsigned long *resident)
98{
99	struct vm_area_struct *vma;
100	struct vm_region *region;
101	struct rb_node *p;
102	unsigned long size = kobjsize(mm);
103
104	down_read(&mm->mmap_sem);
105	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
106		vma = rb_entry(p, struct vm_area_struct, vm_rb);
107		size += kobjsize(vma);
108		region = vma->vm_region;
109		if (region) {
110			size += kobjsize(region);
111			size += region->vm_end - region->vm_start;
112		}
113	}
114
115	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
116		>> PAGE_SHIFT;
117	*data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
118		>> PAGE_SHIFT;
119	up_read(&mm->mmap_sem);
120	size >>= PAGE_SHIFT;
121	size += *text + *data;
122	*resident = size;
123	return size;
124}
125
126static pid_t pid_of_stack(struct proc_maps_private *priv,
127				struct vm_area_struct *vma, bool is_pid)
128{
129	struct inode *inode = priv->inode;
130	struct task_struct *task;
131	pid_t ret = 0;
132
133	rcu_read_lock();
134	task = pid_task(proc_pid(inode), PIDTYPE_PID);
135	if (task) {
136		task = task_of_stack(task, vma, is_pid);
137		if (task)
138			ret = task_pid_nr_ns(task, inode->i_sb->s_fs_info);
139	}
140	rcu_read_unlock();
141
142	return ret;
143}
144
145/*
146 * display a single VMA to a sequenced file
147 */
148static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
149			  int is_pid)
150{
151	struct mm_struct *mm = vma->vm_mm;
152	struct proc_maps_private *priv = m->private;
153	unsigned long ino = 0;
154	struct file *file;
155	dev_t dev = 0;
156	int flags;
157	unsigned long long pgoff = 0;
158
159	flags = vma->vm_flags;
160	file = vma->vm_file;
161
162	if (file) {
163		struct inode *inode = file_inode(vma->vm_file);
164		dev = inode->i_sb->s_dev;
165		ino = inode->i_ino;
166		pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
167	}
168
169	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
170	seq_printf(m,
171		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
172		   vma->vm_start,
173		   vma->vm_end,
174		   flags & VM_READ ? 'r' : '-',
175		   flags & VM_WRITE ? 'w' : '-',
176		   flags & VM_EXEC ? 'x' : '-',
177		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
178		   pgoff,
179		   MAJOR(dev), MINOR(dev), ino);
180
181	if (file) {
182		seq_pad(m, ' ');
183		seq_file_path(m, file, "");
184	} else if (mm) {
185		pid_t tid = pid_of_stack(priv, vma, is_pid);
186
187		if (tid != 0) {
188			seq_pad(m, ' ');
189			/*
190			 * Thread stack in /proc/PID/task/TID/maps or
191			 * the main process stack.
192			 */
193			if (!is_pid || (vma->vm_start <= mm->start_stack &&
194			    vma->vm_end >= mm->start_stack))
195				seq_printf(m, "[stack]");
196			else
197				seq_printf(m, "[stack:%d]", tid);
198		}
199	}
200
201	seq_putc(m, '\n');
202	return 0;
203}
204
205/*
206 * display mapping lines for a particular process's /proc/pid/maps
207 */
208static int show_map(struct seq_file *m, void *_p, int is_pid)
209{
210	struct rb_node *p = _p;
211
212	return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb),
213			      is_pid);
214}
215
216static int show_pid_map(struct seq_file *m, void *_p)
217{
218	return show_map(m, _p, 1);
219}
220
221static int show_tid_map(struct seq_file *m, void *_p)
222{
223	return show_map(m, _p, 0);
224}
225
226static void *m_start(struct seq_file *m, loff_t *pos)
227{
228	struct proc_maps_private *priv = m->private;
229	struct mm_struct *mm;
230	struct rb_node *p;
231	loff_t n = *pos;
232
233	/* pin the task and mm whilst we play with them */
234	priv->task = get_proc_task(priv->inode);
235	if (!priv->task)
236		return ERR_PTR(-ESRCH);
237
238	mm = priv->mm;
239	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
240		return NULL;
241
242	down_read(&mm->mmap_sem);
243	/* start from the Nth VMA */
244	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
245		if (n-- == 0)
246			return p;
247
248	up_read(&mm->mmap_sem);
249	mmput(mm);
250	return NULL;
251}
252
253static void m_stop(struct seq_file *m, void *_vml)
254{
255	struct proc_maps_private *priv = m->private;
256
257	if (!IS_ERR_OR_NULL(_vml)) {
258		up_read(&priv->mm->mmap_sem);
259		mmput(priv->mm);
260	}
261	if (priv->task) {
262		put_task_struct(priv->task);
263		priv->task = NULL;
264	}
265}
266
267static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
268{
269	struct rb_node *p = _p;
270
271	(*pos)++;
272	return p ? rb_next(p) : NULL;
273}
274
275static const struct seq_operations proc_pid_maps_ops = {
276	.start	= m_start,
277	.next	= m_next,
278	.stop	= m_stop,
279	.show	= show_pid_map
280};
281
282static const struct seq_operations proc_tid_maps_ops = {
283	.start	= m_start,
284	.next	= m_next,
285	.stop	= m_stop,
286	.show	= show_tid_map
287};
288
289static int maps_open(struct inode *inode, struct file *file,
290		     const struct seq_operations *ops)
291{
292	struct proc_maps_private *priv;
293
294	priv = __seq_open_private(file, ops, sizeof(*priv));
295	if (!priv)
296		return -ENOMEM;
297
298	priv->inode = inode;
299	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
300	if (IS_ERR(priv->mm)) {
301		int err = PTR_ERR(priv->mm);
302
303		seq_release_private(inode, file);
304		return err;
305	}
306
307	return 0;
308}
309
310
311static int map_release(struct inode *inode, struct file *file)
312{
313	struct seq_file *seq = file->private_data;
314	struct proc_maps_private *priv = seq->private;
315
316	if (priv->mm)
317		mmdrop(priv->mm);
318
319	return seq_release_private(inode, file);
320}
321
322static int pid_maps_open(struct inode *inode, struct file *file)
323{
324	return maps_open(inode, file, &proc_pid_maps_ops);
325}
326
327static int tid_maps_open(struct inode *inode, struct file *file)
328{
329	return maps_open(inode, file, &proc_tid_maps_ops);
330}
331
332const struct file_operations proc_pid_maps_operations = {
333	.open		= pid_maps_open,
334	.read		= seq_read,
335	.llseek		= seq_lseek,
336	.release	= map_release,
337};
338
339const struct file_operations proc_tid_maps_operations = {
340	.open		= tid_maps_open,
341	.read		= seq_read,
342	.llseek		= seq_lseek,
343	.release	= map_release,
344};
345
346