xref: /openbmc/linux/fs/proc/task_nommu.c (revision a09d2831)
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/seq_file.h>
9 #include "internal.h"
10 
11 /*
12  * Logic: we've got two memory sums for each process, "shared", and
13  * "non-shared". Shared memory may get counted more than once, for
14  * each process that owns it. Non-shared memory is counted
15  * accurately.
16  */
17 void task_mem(struct seq_file *m, struct mm_struct *mm)
18 {
19 	struct vm_area_struct *vma;
20 	struct vm_region *region;
21 	struct rb_node *p;
22 	unsigned long bytes = 0, sbytes = 0, slack = 0, size;
23 
24 	down_read(&mm->mmap_sem);
25 	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
26 		vma = rb_entry(p, struct vm_area_struct, vm_rb);
27 
28 		bytes += kobjsize(vma);
29 
30 		region = vma->vm_region;
31 		if (region) {
32 			size = kobjsize(region);
33 			size += region->vm_end - region->vm_start;
34 		} else {
35 			size = vma->vm_end - vma->vm_start;
36 		}
37 
38 		if (atomic_read(&mm->mm_count) > 1 ||
39 		    vma->vm_flags & VM_MAYSHARE) {
40 			sbytes += size;
41 		} else {
42 			bytes += size;
43 			if (region)
44 				slack = region->vm_end - vma->vm_end;
45 		}
46 	}
47 
48 	if (atomic_read(&mm->mm_count) > 1)
49 		sbytes += kobjsize(mm);
50 	else
51 		bytes += kobjsize(mm);
52 
53 	if (current->fs && current->fs->users > 1)
54 		sbytes += kobjsize(current->fs);
55 	else
56 		bytes += kobjsize(current->fs);
57 
58 	if (current->files && atomic_read(&current->files->count) > 1)
59 		sbytes += kobjsize(current->files);
60 	else
61 		bytes += kobjsize(current->files);
62 
63 	if (current->sighand && atomic_read(&current->sighand->count) > 1)
64 		sbytes += kobjsize(current->sighand);
65 	else
66 		bytes += kobjsize(current->sighand);
67 
68 	bytes += kobjsize(current); /* includes kernel stack */
69 
70 	seq_printf(m,
71 		"Mem:\t%8lu bytes\n"
72 		"Slack:\t%8lu bytes\n"
73 		"Shared:\t%8lu bytes\n",
74 		bytes, slack, sbytes);
75 
76 	up_read(&mm->mmap_sem);
77 }
78 
79 unsigned long task_vsize(struct mm_struct *mm)
80 {
81 	struct vm_area_struct *vma;
82 	struct rb_node *p;
83 	unsigned long vsize = 0;
84 
85 	down_read(&mm->mmap_sem);
86 	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
87 		vma = rb_entry(p, struct vm_area_struct, vm_rb);
88 		vsize += vma->vm_end - vma->vm_start;
89 	}
90 	up_read(&mm->mmap_sem);
91 	return vsize;
92 }
93 
94 int task_statm(struct mm_struct *mm, int *shared, int *text,
95 	       int *data, int *resident)
96 {
97 	struct vm_area_struct *vma;
98 	struct vm_region *region;
99 	struct rb_node *p;
100 	int size = kobjsize(mm);
101 
102 	down_read(&mm->mmap_sem);
103 	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
104 		vma = rb_entry(p, struct vm_area_struct, vm_rb);
105 		size += kobjsize(vma);
106 		region = vma->vm_region;
107 		if (region) {
108 			size += kobjsize(region);
109 			size += region->vm_end - region->vm_start;
110 		}
111 	}
112 
113 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
114 		>> PAGE_SHIFT;
115 	*data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
116 		>> PAGE_SHIFT;
117 	up_read(&mm->mmap_sem);
118 	size >>= PAGE_SHIFT;
119 	size += *text + *data;
120 	*resident = size;
121 	return size;
122 }
123 
124 /*
125  * display a single VMA to a sequenced file
126  */
127 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
128 {
129 	unsigned long ino = 0;
130 	struct file *file;
131 	dev_t dev = 0;
132 	int flags, len;
133 	unsigned long long pgoff = 0;
134 
135 	flags = vma->vm_flags;
136 	file = vma->vm_file;
137 
138 	if (file) {
139 		struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
140 		dev = inode->i_sb->s_dev;
141 		ino = inode->i_ino;
142 		pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
143 	}
144 
145 	seq_printf(m,
146 		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
147 		   vma->vm_start,
148 		   vma->vm_end,
149 		   flags & VM_READ ? 'r' : '-',
150 		   flags & VM_WRITE ? 'w' : '-',
151 		   flags & VM_EXEC ? 'x' : '-',
152 		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
153 		   pgoff,
154 		   MAJOR(dev), MINOR(dev), ino, &len);
155 
156 	if (file) {
157 		len = 25 + sizeof(void *) * 6 - len;
158 		if (len < 1)
159 			len = 1;
160 		seq_printf(m, "%*c", len, ' ');
161 		seq_path(m, &file->f_path, "");
162 	}
163 
164 	seq_putc(m, '\n');
165 	return 0;
166 }
167 
168 /*
169  * display mapping lines for a particular process's /proc/pid/maps
170  */
171 static int show_map(struct seq_file *m, void *_p)
172 {
173 	struct rb_node *p = _p;
174 
175 	return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
176 }
177 
178 static void *m_start(struct seq_file *m, loff_t *pos)
179 {
180 	struct proc_maps_private *priv = m->private;
181 	struct mm_struct *mm;
182 	struct rb_node *p;
183 	loff_t n = *pos;
184 
185 	/* pin the task and mm whilst we play with them */
186 	priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
187 	if (!priv->task)
188 		return NULL;
189 
190 	mm = mm_for_maps(priv->task);
191 	if (!mm) {
192 		put_task_struct(priv->task);
193 		priv->task = NULL;
194 		return NULL;
195 	}
196 	down_read(&mm->mmap_sem);
197 
198 	/* start from the Nth VMA */
199 	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
200 		if (n-- == 0)
201 			return p;
202 	return NULL;
203 }
204 
205 static void m_stop(struct seq_file *m, void *_vml)
206 {
207 	struct proc_maps_private *priv = m->private;
208 
209 	if (priv->task) {
210 		struct mm_struct *mm = priv->task->mm;
211 		up_read(&mm->mmap_sem);
212 		mmput(mm);
213 		put_task_struct(priv->task);
214 	}
215 }
216 
217 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
218 {
219 	struct rb_node *p = _p;
220 
221 	(*pos)++;
222 	return p ? rb_next(p) : NULL;
223 }
224 
225 static const struct seq_operations proc_pid_maps_ops = {
226 	.start	= m_start,
227 	.next	= m_next,
228 	.stop	= m_stop,
229 	.show	= show_map
230 };
231 
232 static int maps_open(struct inode *inode, struct file *file)
233 {
234 	struct proc_maps_private *priv;
235 	int ret = -ENOMEM;
236 
237 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
238 	if (priv) {
239 		priv->pid = proc_pid(inode);
240 		ret = seq_open(file, &proc_pid_maps_ops);
241 		if (!ret) {
242 			struct seq_file *m = file->private_data;
243 			m->private = priv;
244 		} else {
245 			kfree(priv);
246 		}
247 	}
248 	return ret;
249 }
250 
251 const struct file_operations proc_maps_operations = {
252 	.open		= maps_open,
253 	.read		= seq_read,
254 	.llseek		= seq_lseek,
255 	.release	= seq_release_private,
256 };
257 
258