xref: /linux/fs/proc/task_nommu.c (revision f7511d5f66f01fc451747b24e79f3ada7a3af9af)
1 
2 #include <linux/mm.h>
3 #include <linux/file.h>
4 #include <linux/mount.h>
5 #include <linux/ptrace.h>
6 #include <linux/seq_file.h>
7 #include "internal.h"
8 
9 /*
10  * Logic: we've got two memory sums for each process, "shared", and
11  * "non-shared". Shared memory may get counted more then once, for
12  * each process that owns it. Non-shared memory is counted
13  * accurately.
14  */
15 void task_mem(struct seq_file *m, struct mm_struct *mm)
16 {
17 	struct vm_list_struct *vml;
18 	unsigned long bytes = 0, sbytes = 0, slack = 0;
19 
20 	down_read(&mm->mmap_sem);
21 	for (vml = mm->context.vmlist; vml; vml = vml->next) {
22 		if (!vml->vma)
23 			continue;
24 
25 		bytes += kobjsize(vml);
26 		if (atomic_read(&mm->mm_count) > 1 ||
27 		    atomic_read(&vml->vma->vm_usage) > 1
28 		    ) {
29 			sbytes += kobjsize((void *) vml->vma->vm_start);
30 			sbytes += kobjsize(vml->vma);
31 		} else {
32 			bytes += kobjsize((void *) vml->vma->vm_start);
33 			bytes += kobjsize(vml->vma);
34 			slack += kobjsize((void *) vml->vma->vm_start) -
35 				(vml->vma->vm_end - vml->vma->vm_start);
36 		}
37 	}
38 
39 	if (atomic_read(&mm->mm_count) > 1)
40 		sbytes += kobjsize(mm);
41 	else
42 		bytes += kobjsize(mm);
43 
44 	if (current->fs && atomic_read(&current->fs->count) > 1)
45 		sbytes += kobjsize(current->fs);
46 	else
47 		bytes += kobjsize(current->fs);
48 
49 	if (current->files && atomic_read(&current->files->count) > 1)
50 		sbytes += kobjsize(current->files);
51 	else
52 		bytes += kobjsize(current->files);
53 
54 	if (current->sighand && atomic_read(&current->sighand->count) > 1)
55 		sbytes += kobjsize(current->sighand);
56 	else
57 		bytes += kobjsize(current->sighand);
58 
59 	bytes += kobjsize(current); /* includes kernel stack */
60 
61 	seq_printf(m,
62 		"Mem:\t%8lu bytes\n"
63 		"Slack:\t%8lu bytes\n"
64 		"Shared:\t%8lu bytes\n",
65 		bytes, slack, sbytes);
66 
67 	up_read(&mm->mmap_sem);
68 }
69 
70 unsigned long task_vsize(struct mm_struct *mm)
71 {
72 	struct vm_list_struct *tbp;
73 	unsigned long vsize = 0;
74 
75 	down_read(&mm->mmap_sem);
76 	for (tbp = mm->context.vmlist; tbp; tbp = tbp->next) {
77 		if (tbp->vma)
78 			vsize += kobjsize((void *) tbp->vma->vm_start);
79 	}
80 	up_read(&mm->mmap_sem);
81 	return vsize;
82 }
83 
84 int task_statm(struct mm_struct *mm, int *shared, int *text,
85 	       int *data, int *resident)
86 {
87 	struct vm_list_struct *tbp;
88 	int size = kobjsize(mm);
89 
90 	down_read(&mm->mmap_sem);
91 	for (tbp = mm->context.vmlist; tbp; tbp = tbp->next) {
92 		size += kobjsize(tbp);
93 		if (tbp->vma) {
94 			size += kobjsize(tbp->vma);
95 			size += kobjsize((void *) tbp->vma->vm_start);
96 		}
97 	}
98 
99 	size += (*text = mm->end_code - mm->start_code);
100 	size += (*data = mm->start_stack - mm->start_data);
101 	up_read(&mm->mmap_sem);
102 	*resident = size;
103 	return size;
104 }
105 
106 /*
107  * display mapping lines for a particular process's /proc/pid/maps
108  */
109 static int show_map(struct seq_file *m, void *_vml)
110 {
111 	struct vm_list_struct *vml = _vml;
112 	struct proc_maps_private *priv = m->private;
113 	struct task_struct *task = priv->task;
114 
115 	if (maps_protect && !ptrace_may_attach(task))
116 		return -EACCES;
117 
118 	return nommu_vma_show(m, vml->vma);
119 }
120 
121 static void *m_start(struct seq_file *m, loff_t *pos)
122 {
123 	struct proc_maps_private *priv = m->private;
124 	struct vm_list_struct *vml;
125 	struct mm_struct *mm;
126 	loff_t n = *pos;
127 
128 	/* pin the task and mm whilst we play with them */
129 	priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
130 	if (!priv->task)
131 		return NULL;
132 
133 	mm = mm_for_maps(priv->task);
134 	if (!mm) {
135 		put_task_struct(priv->task);
136 		priv->task = NULL;
137 		return NULL;
138 	}
139 
140 	/* start from the Nth VMA */
141 	for (vml = mm->context.vmlist; vml; vml = vml->next)
142 		if (n-- == 0)
143 			return vml;
144 	return NULL;
145 }
146 
147 static void m_stop(struct seq_file *m, void *_vml)
148 {
149 	struct proc_maps_private *priv = m->private;
150 
151 	if (priv->task) {
152 		struct mm_struct *mm = priv->task->mm;
153 		up_read(&mm->mmap_sem);
154 		mmput(mm);
155 		put_task_struct(priv->task);
156 	}
157 }
158 
159 static void *m_next(struct seq_file *m, void *_vml, loff_t *pos)
160 {
161 	struct vm_list_struct *vml = _vml;
162 
163 	(*pos)++;
164 	return vml ? vml->next : NULL;
165 }
166 
167 static const struct seq_operations proc_pid_maps_ops = {
168 	.start	= m_start,
169 	.next	= m_next,
170 	.stop	= m_stop,
171 	.show	= show_map
172 };
173 
174 static int maps_open(struct inode *inode, struct file *file)
175 {
176 	struct proc_maps_private *priv;
177 	int ret = -ENOMEM;
178 
179 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
180 	if (priv) {
181 		priv->pid = proc_pid(inode);
182 		ret = seq_open(file, &proc_pid_maps_ops);
183 		if (!ret) {
184 			struct seq_file *m = file->private_data;
185 			m->private = priv;
186 		} else {
187 			kfree(priv);
188 		}
189 	}
190 	return ret;
191 }
192 
193 const struct file_operations proc_maps_operations = {
194 	.open		= maps_open,
195 	.read		= seq_read,
196 	.llseek		= seq_lseek,
197 	.release	= seq_release_private,
198 };
199 
200