[mirror_ubuntu-bionic-kernel.git] / fs / proc / task_nommu.c

// SPDX-License-Identifier: GPL-2.0

#include <linux/mm.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/fs_struct.h>
#include <linux/mount.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/sched/mm.h>

#include "internal.h"

/*
 * Logic: we've got two memory sums for each process, "shared", and
 * "non-shared". Shared memory may get counted more than 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_area_struct *vma;
	struct vm_region *region;
	struct rb_node *p;
	unsigned long bytes = 0, sbytes = 0, slack = 0, size;
        
	down_read(&mm->mmap_sem);
	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
		vma = rb_entry(p, struct vm_area_struct, vm_rb);

		bytes += kobjsize(vma);

		region = vma->vm_region;
		if (region) {
			size = kobjsize(region);
			size += region->vm_end - region->vm_start;
		} else {
			size = vma->vm_end - vma->vm_start;
		}

		if (atomic_read(&mm->mm_count) > 1 ||
		    vma->vm_flags & VM_MAYSHARE) {
			sbytes += size;
		} else {
			bytes += size;
			if (region)
				slack = region->vm_end - vma->vm_end;
		}
	}

	if (atomic_read(&mm->mm_count) > 1)
		sbytes += kobjsize(mm);
	else
		bytes += kobjsize(mm);
	
	if (current->fs && current->fs->users > 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_area_struct *vma;
	struct rb_node *p;
	unsigned long vsize = 0;

	down_read(&mm->mmap_sem);
	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
		vma = rb_entry(p, struct vm_area_struct, vm_rb);
		vsize += vma->vm_end - vma->vm_start;
	}
	up_read(&mm->mmap_sem);
	return vsize;
}

unsigned long task_statm(struct mm_struct *mm,
			 unsigned long *shared, unsigned long *text,
			 unsigned long *data, unsigned long *resident)
{
	struct vm_area_struct *vma;
	struct vm_region *region;
	struct rb_node *p;
	unsigned long size = kobjsize(mm);

	down_read(&mm->mmap_sem);
	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
		vma = rb_entry(p, struct vm_area_struct, vm_rb);
		size += kobjsize(vma);
		region = vma->vm_region;
		if (region) {
			size += kobjsize(region);
			size += region->vm_end - region->vm_start;
		}
	}

	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
		>> PAGE_SHIFT;
	*data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
		>> PAGE_SHIFT;
	up_read(&mm->mmap_sem);
	size >>= PAGE_SHIFT;
	size += *text + *data;
	*resident = size;
	return size;
}

static int is_stack(struct vm_area_struct *vma)
{
	struct mm_struct *mm = vma->vm_mm;

	/*
	 * We make no effort to guess what a given thread considers to be
	 * its "stack".  It's not even well-defined for programs written
	 * languages like Go.
	 */
	return vma->vm_start <= mm->start_stack &&
		vma->vm_end >= mm->start_stack;
}

/*
 * display a single VMA to a sequenced file
 */
static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
			  int is_pid)
{
	struct mm_struct *mm = vma->vm_mm;
	unsigned long ino = 0;
	struct file *file;
	dev_t dev = 0;
	int flags;
	unsigned long long pgoff = 0;

	flags = vma->vm_flags;
	file = vma->vm_file;

	if (file) {
		struct inode *inode = file_inode(vma->vm_file);
		dev = inode->i_sb->s_dev;
		ino = inode->i_ino;
		pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
	}

	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
	seq_printf(m,
		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
		   vma->vm_start,
		   vma->vm_end,
		   flags & VM_READ ? 'r' : '-',
		   flags & VM_WRITE ? 'w' : '-',
		   flags & VM_EXEC ? 'x' : '-',
		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
		   pgoff,
		   MAJOR(dev), MINOR(dev), ino);

	if (file) {
		seq_pad(m, ' ');
		seq_file_path(m, file, "");
	} else if (mm && is_stack(vma)) {
		seq_pad(m, ' ');
		seq_printf(m, "[stack]");
	}

	seq_putc(m, '\n');
	return 0;
}

/*
 * display mapping lines for a particular process's /proc/pid/maps
 */
static int show_map(struct seq_file *m, void *_p, int is_pid)
{
	struct rb_node *p = _p;

	return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb),
			      is_pid);
}

static int show_pid_map(struct seq_file *m, void *_p)
{
	return show_map(m, _p, 1);
}

static int show_tid_map(struct seq_file *m, void *_p)
{
	return show_map(m, _p, 0);
}

static void *m_start(struct seq_file *m, loff_t *pos)
{
	struct proc_maps_private *priv = m->private;
	struct mm_struct *mm;
	struct rb_node *p;
	loff_t n = *pos;

	/* pin the task and mm whilst we play with them */
	priv->task = get_proc_task(priv->inode);
	if (!priv->task)
		return ERR_PTR(-ESRCH);

	mm = priv->mm;
	if (!mm || !mmget_not_zero(mm))
		return NULL;

	down_read(&mm->mmap_sem);
	/* start from the Nth VMA */
	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
		if (n-- == 0)
			return p;

	up_read(&mm->mmap_sem);
	mmput(mm);
	return NULL;
}

static void m_stop(struct seq_file *m, void *_vml)
{
	struct proc_maps_private *priv = m->private;

	if (!IS_ERR_OR_NULL(_vml)) {
		up_read(&priv->mm->mmap_sem);
		mmput(priv->mm);
	}
	if (priv->task) {
		put_task_struct(priv->task);
		priv->task = NULL;
	}
}

static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
{
	struct rb_node *p = _p;

	(*pos)++;
	return p ? rb_next(p) : NULL;
}

static const struct seq_operations proc_pid_maps_ops = {
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= show_pid_map
};

static const struct seq_operations proc_tid_maps_ops = {
	.start	= m_start,
	.next	= m_next,
	.stop	= m_stop,
	.show	= show_tid_map
};

static int maps_open(struct inode *inode, struct file *file,
		     const struct seq_operations *ops)
{
	struct proc_maps_private *priv;

	priv = __seq_open_private(file, ops, sizeof(*priv));
	if (!priv)
		return -ENOMEM;

	priv->inode = inode;
	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
	if (IS_ERR(priv->mm)) {
		int err = PTR_ERR(priv->mm);

		seq_release_private(inode, file);
		return err;
	}

	return 0;
}


static int map_release(struct inode *inode, struct file *file)
{
	struct seq_file *seq = file->private_data;
	struct proc_maps_private *priv = seq->private;

	if (priv->mm)
		mmdrop(priv->mm);

	return seq_release_private(inode, file);
}

static int pid_maps_open(struct inode *inode, struct file *file)
{
	return maps_open(inode, file, &proc_pid_maps_ops);
}

static int tid_maps_open(struct inode *inode, struct file *file)
{
	return maps_open(inode, file, &proc_tid_maps_ops);
}

const struct file_operations proc_pid_maps_operations = {
	.open		= pid_maps_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= map_release,
};

const struct file_operations proc_tid_maps_operations = {
	.open		= tid_maps_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= map_release,
};
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2
	3	#include <linux/mm.h>
	4	#include <linux/file.h>
eb28062f	5	#include <linux/fdtable.h>
5ad4e53b	6	#include <linux/fs_struct.h>
1da177e4	7	#include <linux/mount.h>
5096add8	8	#include <linux/ptrace.h>
5a0e3ad6	9	#include <linux/slab.h>
1da177e4	10	#include <linux/seq_file.h>
6e84f315 IM	11	#include <linux/sched/mm.h>
6e84f315 IM	12
1da177e4 LT	13	#include "internal.h"
	14
	15	/*
	16	* Logic: we've got two memory sums for each process, "shared", and
025dfdaf	17	* "non-shared". Shared memory may get counted more than once, for
1da177e4 LT	18	* each process that owns it. Non-shared memory is counted
	19	* accurately.
	20	*/
df5f8314	21	void task_mem(struct seq_file m, struct mm_struct mm)
1da177e4	22	{
8feae131	23	struct vm_area_struct *vma;
38f71479	24	struct vm_region *region;
8feae131	25	struct rb_node *p;
38f71479	26	unsigned long bytes = 0, sbytes = 0, slack = 0, size;
1da177e4 LT	27
1da177e4 LT	28	down_read(&mm->mmap_sem);
8feae131 DH	29	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
8feae131 DH	30	vma = rb_entry(p, struct vm_area_struct, vm_rb);
1da177e4	31
8feae131	32	bytes += kobjsize(vma);
38f71479 DH	33
	34	region = vma->vm_region;
	35	if (region) {
	36	size = kobjsize(region);
	37	size += region->vm_end - region->vm_start;
	38	} else {
	39	size = vma->vm_end - vma->vm_start;
	40	}
	41
1da177e4	42	if (atomic_read(&mm->mm_count) > 1 \|\|
8feae131	43	vma->vm_flags & VM_MAYSHARE) {
38f71479	44	sbytes += size;
1da177e4	45	} else {
38f71479 DH	46	bytes += size;
	47	if (region)
	48	slack = region->vm_end - vma->vm_end;
1da177e4 LT	49	}
	50	}
	51
	52	if (atomic_read(&mm->mm_count) > 1)
	53	sbytes += kobjsize(mm);
	54	else
	55	bytes += kobjsize(mm);
	56
498052bb	57	if (current->fs && current->fs->users > 1)
1da177e4 LT	58	sbytes += kobjsize(current->fs);
	59	else
	60	bytes += kobjsize(current->fs);
	61
	62	if (current->files && atomic_read(&current->files->count) > 1)
	63	sbytes += kobjsize(current->files);
	64	else
	65	bytes += kobjsize(current->files);
	66
	67	if (current->sighand && atomic_read(&current->sighand->count) > 1)
	68	sbytes += kobjsize(current->sighand);
	69	else
	70	bytes += kobjsize(current->sighand);
	71
	72	bytes += kobjsize(current); /* includes kernel stack */
	73
df5f8314	74	seq_printf(m,
1da177e4 LT	75	"Mem:\t%8lu bytes\n"
	76	"Slack:\t%8lu bytes\n"
	77	"Shared:\t%8lu bytes\n",
	78	bytes, slack, sbytes);
	79
	80	up_read(&mm->mmap_sem);
1da177e4 LT	81	}
	82
	83	unsigned long task_vsize(struct mm_struct *mm)
	84	{
8feae131 DH	85	struct vm_area_struct *vma;
8feae131 DH	86	struct rb_node *p;
1da177e4 LT	87	unsigned long vsize = 0;
	88
	89	down_read(&mm->mmap_sem);
8feae131 DH	90	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
8feae131 DH	91	vma = rb_entry(p, struct vm_area_struct, vm_rb);
38f71479	92	vsize += vma->vm_end - vma->vm_start;
1da177e4 LT	93	}
	94	up_read(&mm->mmap_sem);
	95	return vsize;
	96	}
	97
a2ade7b6 AD	98	unsigned long task_statm(struct mm_struct *mm,
	99	unsigned long shared, unsigned long text,
	100	unsigned long data, unsigned long resident)
1da177e4	101	{
8feae131	102	struct vm_area_struct *vma;
38f71479	103	struct vm_region *region;
8feae131	104	struct rb_node *p;
a2ade7b6	105	unsigned long size = kobjsize(mm);
1da177e4 LT	106
1da177e4 LT	107	down_read(&mm->mmap_sem);
8feae131 DH	108	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
	109	vma = rb_entry(p, struct vm_area_struct, vm_rb);
	110	size += kobjsize(vma);
38f71479 DH	111	region = vma->vm_region;
	112	if (region) {
	113	size += kobjsize(region);
	114	size += region->vm_end - region->vm_start;
	115	}
1da177e4 LT	116	}
1da177e4 LT	117
7e1e0ef2 SM	118	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
	119	>> PAGE_SHIFT;
	120	*data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
	121	>> PAGE_SHIFT;
1da177e4	122	up_read(&mm->mmap_sem);
7e1e0ef2 SM	123	size >>= PAGE_SHIFT;
7e1e0ef2 SM	124	size += text + data;
1da177e4 LT	125	*resident = size;
	126	return size;
	127	}
	128
1240ea0d	129	static int is_stack(struct vm_area_struct *vma)
58cb6548	130	{
65376df5	131	struct mm_struct *mm = vma->vm_mm;
b18cb64e AL	132
	133	/*
	134	* We make no effort to guess what a given thread considers to be
	135	* its "stack". It's not even well-defined for programs written
	136	* languages like Go.
	137	*/
	138	return vma->vm_start <= mm->start_stack &&
	139	vma->vm_end >= mm->start_stack;
58cb6548 ON	140	}
58cb6548 ON	141
8feae131 DH	142	/*
	143	* display a single VMA to a sequenced file
	144	*/
b7643757 SP	145	static int nommu_vma_show(struct seq_file m, struct vm_area_struct vma,
b7643757 SP	146	int is_pid)
8feae131	147	{
3c26c9d9	148	struct mm_struct *mm = vma->vm_mm;
8feae131 DH	149	unsigned long ino = 0;
	150	struct file *file;
	151	dev_t dev = 0;
652586df	152	int flags;
6260a4b0	153	unsigned long long pgoff = 0;
8feae131 DH	154
	155	flags = vma->vm_flags;
	156	file = vma->vm_file;
	157
	158	if (file) {
496ad9aa	159	struct inode *inode = file_inode(vma->vm_file);
8feae131 DH	160	dev = inode->i_sb->s_dev;
8feae131 DH	161	ino = inode->i_ino;
4c967291	162	pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
8feae131 DH	163	}
8feae131 DH	164
652586df	165	seq_setwidth(m, 25 + sizeof(void ) 6 - 1);
8feae131	166	seq_printf(m,
652586df	167	"%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
8feae131 DH	168	vma->vm_start,
	169	vma->vm_end,
	170	flags & VM_READ ? 'r' : '-',
	171	flags & VM_WRITE ? 'w' : '-',
	172	flags & VM_EXEC ? 'x' : '-',
	173	flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
6260a4b0	174	pgoff,
652586df	175	MAJOR(dev), MINOR(dev), ino);
8feae131 DH	176
8feae131 DH	177	if (file) {
652586df	178	seq_pad(m, ' ');
2726d566	179	seq_file_path(m, file, "");
1240ea0d	180	} else if (mm && is_stack(vma)) {
65376df5 JW	181	seq_pad(m, ' ');
65376df5 JW	182	seq_printf(m, "[stack]");
8feae131 DH	183	}
	184
	185	seq_putc(m, '\n');
	186	return 0;
	187	}
	188
1da177e4	189	/*
dbf8685c	190	* display mapping lines for a particular process's /proc/pid/maps
1da177e4	191	*/
b7643757	192	static int show_map(struct seq_file m, void _p, int is_pid)
1da177e4	193	{
8feae131	194	struct rb_node *p = _p;
5096add8	195
b7643757 SP	196	return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb),
	197	is_pid);
	198	}
	199
	200	static int show_pid_map(struct seq_file m, void _p)
	201	{
	202	return show_map(m, _p, 1);
	203	}
	204
	205	static int show_tid_map(struct seq_file m, void _p)
	206	{
	207	return show_map(m, _p, 0);
1da177e4	208	}
dbf8685c	209
1da177e4 LT	210	static void m_start(struct seq_file m, loff_t *pos)
1da177e4 LT	211	{
dbf8685c	212	struct proc_maps_private *priv = m->private;
dbf8685c	213	struct mm_struct *mm;
8feae131	214	struct rb_node *p;
dbf8685c DH	215	loff_t n = *pos;
	216
	217	/* pin the task and mm whilst we play with them */
2c03376d	218	priv->task = get_proc_task(priv->inode);
dbf8685c	219	if (!priv->task)
ec6fd8a4	220	return ERR_PTR(-ESRCH);
dbf8685c	221
27692cd5	222	mm = priv->mm;
388f7934	223	if (!mm \|\| !mmget_not_zero(mm))
27692cd5	224	return NULL;
dbf8685c	225
47fecca1	226	down_read(&mm->mmap_sem);
dbf8685c	227	/* start from the Nth VMA */
8feae131	228	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
dbf8685c	229	if (n-- == 0)
8feae131	230	return p;
47fecca1 ON	231
	232	up_read(&mm->mmap_sem);
	233	mmput(mm);
1da177e4 LT	234	return NULL;
1da177e4 LT	235	}
dbf8685c DH	236
dbf8685c DH	237	static void m_stop(struct seq_file m, void _vml)
1da177e4	238	{
dbf8685c DH	239	struct proc_maps_private *priv = m->private;
dbf8685c DH	240
47fecca1 ON	241	if (!IS_ERR_OR_NULL(_vml)) {
	242	up_read(&priv->mm->mmap_sem);
	243	mmput(priv->mm);
	244	}
dbf8685c	245	if (priv->task) {
dbf8685c	246	put_task_struct(priv->task);
47fecca1	247	priv->task = NULL;
dbf8685c	248	}
1da177e4	249	}
dbf8685c	250
8feae131	251	static void m_next(struct seq_file m, void _p, loff_t pos)
1da177e4	252	{
8feae131	253	struct rb_node *p = _p;
dbf8685c DH	254
dbf8685c DH	255	(*pos)++;
8feae131	256	return p ? rb_next(p) : NULL;
1da177e4	257	}
dbf8685c	258
03a44825	259	static const struct seq_operations proc_pid_maps_ops = {
1da177e4 LT	260	.start = m_start,
	261	.next = m_next,
	262	.stop = m_stop,
b7643757 SP	263	.show = show_pid_map
	264	};
	265
	266	static const struct seq_operations proc_tid_maps_ops = {
	267	.start = m_start,
	268	.next = m_next,
	269	.stop = m_stop,
	270	.show = show_tid_map
1da177e4	271	};
662795de	272
b7643757 SP	273	static int maps_open(struct inode inode, struct file file,
b7643757 SP	274	const struct seq_operations *ops)
662795de	275	{
dbf8685c	276	struct proc_maps_private *priv;
ce34fddb	277
27692cd5	278	priv = __seq_open_private(file, ops, sizeof(*priv));
ce34fddb ON	279	if (!priv)
	280	return -ENOMEM;
	281
2c03376d	282	priv->inode = inode;
27692cd5 ON	283	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
	284	if (IS_ERR(priv->mm)) {
	285	int err = PTR_ERR(priv->mm);
	286
	287	seq_release_private(inode, file);
	288	return err;
	289	}
	290
ce34fddb	291	return 0;
662795de EB	292	}
662795de EB	293
27692cd5 ON	294
	295	static int map_release(struct inode inode, struct file file)
	296	{
	297	struct seq_file *seq = file->private_data;
	298	struct proc_maps_private *priv = seq->private;
	299
	300	if (priv->mm)
	301	mmdrop(priv->mm);
	302
	303	return seq_release_private(inode, file);
	304	}
	305
b7643757 SP	306	static int pid_maps_open(struct inode inode, struct file file)
	307	{
	308	return maps_open(inode, file, &proc_pid_maps_ops);
	309	}
	310
	311	static int tid_maps_open(struct inode inode, struct file file)
	312	{
	313	return maps_open(inode, file, &proc_tid_maps_ops);
	314	}
	315
	316	const struct file_operations proc_pid_maps_operations = {
	317	.open = pid_maps_open,
	318	.read = seq_read,
	319	.llseek = seq_lseek,
27692cd5	320	.release = map_release,
b7643757 SP	321	};
	322
	323	const struct file_operations proc_tid_maps_operations = {
	324	.open = tid_maps_open,
662795de EB	325	.read = seq_read,
662795de EB	326	.llseek = seq_lseek,
27692cd5	327	.release = map_release,
662795de EB	328	};
662795de EB	329