xref: /openbmc/linux/fs/proc/task_nommu.c (revision a1e58bbd)
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 int proc_exe_link(struct inode *inode, struct path *path)
107 {
108 	struct vm_list_struct *vml;
109 	struct vm_area_struct *vma;
110 	struct task_struct *task = get_proc_task(inode);
111 	struct mm_struct *mm = get_task_mm(task);
112 	int result = -ENOENT;
113 
114 	if (!mm)
115 		goto out;
116 	down_read(&mm->mmap_sem);
117 
118 	vml = mm->context.vmlist;
119 	vma = NULL;
120 	while (vml) {
121 		if ((vml->vma->vm_flags & VM_EXECUTABLE) && vml->vma->vm_file) {
122 			vma = vml->vma;
123 			break;
124 		}
125 		vml = vml->next;
126 	}
127 
128 	if (vma) {
129 		*path = vma->vm_file->f_path;
130 		path_get(&vma->vm_file->f_path);
131 		result = 0;
132 	}
133 
134 	up_read(&mm->mmap_sem);
135 	mmput(mm);
136 out:
137 	return result;
138 }
139 
140 /*
141  * display mapping lines for a particular process's /proc/pid/maps
142  */
143 static int show_map(struct seq_file *m, void *_vml)
144 {
145 	struct vm_list_struct *vml = _vml;
146 	struct proc_maps_private *priv = m->private;
147 	struct task_struct *task = priv->task;
148 
149 	if (maps_protect && !ptrace_may_attach(task))
150 		return -EACCES;
151 
152 	return nommu_vma_show(m, vml->vma);
153 }
154 
155 static void *m_start(struct seq_file *m, loff_t *pos)
156 {
157 	struct proc_maps_private *priv = m->private;
158 	struct vm_list_struct *vml;
159 	struct mm_struct *mm;
160 	loff_t n = *pos;
161 
162 	/* pin the task and mm whilst we play with them */
163 	priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
164 	if (!priv->task)
165 		return NULL;
166 
167 	mm = mm_for_maps(priv->task);
168 	if (!mm) {
169 		put_task_struct(priv->task);
170 		priv->task = NULL;
171 		return NULL;
172 	}
173 
174 	/* start from the Nth VMA */
175 	for (vml = mm->context.vmlist; vml; vml = vml->next)
176 		if (n-- == 0)
177 			return vml;
178 	return NULL;
179 }
180 
181 static void m_stop(struct seq_file *m, void *_vml)
182 {
183 	struct proc_maps_private *priv = m->private;
184 
185 	if (priv->task) {
186 		struct mm_struct *mm = priv->task->mm;
187 		up_read(&mm->mmap_sem);
188 		mmput(mm);
189 		put_task_struct(priv->task);
190 	}
191 }
192 
193 static void *m_next(struct seq_file *m, void *_vml, loff_t *pos)
194 {
195 	struct vm_list_struct *vml = _vml;
196 
197 	(*pos)++;
198 	return vml ? vml->next : NULL;
199 }
200 
201 static const struct seq_operations proc_pid_maps_ops = {
202 	.start	= m_start,
203 	.next	= m_next,
204 	.stop	= m_stop,
205 	.show	= show_map
206 };
207 
208 static int maps_open(struct inode *inode, struct file *file)
209 {
210 	struct proc_maps_private *priv;
211 	int ret = -ENOMEM;
212 
213 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
214 	if (priv) {
215 		priv->pid = proc_pid(inode);
216 		ret = seq_open(file, &proc_pid_maps_ops);
217 		if (!ret) {
218 			struct seq_file *m = file->private_data;
219 			m->private = priv;
220 		} else {
221 			kfree(priv);
222 		}
223 	}
224 	return ret;
225 }
226 
227 const struct file_operations proc_maps_operations = {
228 	.open		= maps_open,
229 	.read		= seq_read,
230 	.llseek		= seq_lseek,
231 	.release	= seq_release_private,
232 };
233 
234