xref: /openbmc/linux/fs/proc/task_nommu.c (revision 2c03376d)
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  */
18 void 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 
80 unsigned 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 
95 unsigned 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 
126 /*
127  * display a single VMA to a sequenced file
128  */
129 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma,
130 			  int is_pid)
131 {
132 	struct mm_struct *mm = vma->vm_mm;
133 	struct proc_maps_private *priv = m->private;
134 	unsigned long ino = 0;
135 	struct file *file;
136 	dev_t dev = 0;
137 	int flags;
138 	unsigned long long pgoff = 0;
139 
140 	flags = vma->vm_flags;
141 	file = vma->vm_file;
142 
143 	if (file) {
144 		struct inode *inode = file_inode(vma->vm_file);
145 		dev = inode->i_sb->s_dev;
146 		ino = inode->i_ino;
147 		pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
148 	}
149 
150 	seq_setwidth(m, 25 + sizeof(void *) * 6 - 1);
151 	seq_printf(m,
152 		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ",
153 		   vma->vm_start,
154 		   vma->vm_end,
155 		   flags & VM_READ ? 'r' : '-',
156 		   flags & VM_WRITE ? 'w' : '-',
157 		   flags & VM_EXEC ? 'x' : '-',
158 		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
159 		   pgoff,
160 		   MAJOR(dev), MINOR(dev), ino);
161 
162 	if (file) {
163 		seq_pad(m, ' ');
164 		seq_path(m, &file->f_path, "");
165 	} else if (mm) {
166 		pid_t tid = vm_is_stack(priv->task, vma, is_pid);
167 
168 		if (tid != 0) {
169 			seq_pad(m, ' ');
170 			/*
171 			 * Thread stack in /proc/PID/task/TID/maps or
172 			 * the main process stack.
173 			 */
174 			if (!is_pid || (vma->vm_start <= mm->start_stack &&
175 			    vma->vm_end >= mm->start_stack))
176 				seq_printf(m, "[stack]");
177 			else
178 				seq_printf(m, "[stack:%d]", tid);
179 		}
180 	}
181 
182 	seq_putc(m, '\n');
183 	return 0;
184 }
185 
186 /*
187  * display mapping lines for a particular process's /proc/pid/maps
188  */
189 static int show_map(struct seq_file *m, void *_p, int is_pid)
190 {
191 	struct rb_node *p = _p;
192 
193 	return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb),
194 			      is_pid);
195 }
196 
197 static int show_pid_map(struct seq_file *m, void *_p)
198 {
199 	return show_map(m, _p, 1);
200 }
201 
202 static int show_tid_map(struct seq_file *m, void *_p)
203 {
204 	return show_map(m, _p, 0);
205 }
206 
207 static void *m_start(struct seq_file *m, loff_t *pos)
208 {
209 	struct proc_maps_private *priv = m->private;
210 	struct mm_struct *mm;
211 	struct rb_node *p;
212 	loff_t n = *pos;
213 
214 	/* pin the task and mm whilst we play with them */
215 	priv->task = get_proc_task(priv->inode);
216 	if (!priv->task)
217 		return ERR_PTR(-ESRCH);
218 
219 	mm = priv->mm;
220 	if (!mm || !atomic_inc_not_zero(&mm->mm_users))
221 		return NULL;
222 
223 	down_read(&mm->mmap_sem);
224 	/* start from the Nth VMA */
225 	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
226 		if (n-- == 0)
227 			return p;
228 
229 	up_read(&mm->mmap_sem);
230 	mmput(mm);
231 	return NULL;
232 }
233 
234 static void m_stop(struct seq_file *m, void *_vml)
235 {
236 	struct proc_maps_private *priv = m->private;
237 
238 	if (!IS_ERR_OR_NULL(_vml)) {
239 		up_read(&priv->mm->mmap_sem);
240 		mmput(priv->mm);
241 	}
242 	if (priv->task) {
243 		put_task_struct(priv->task);
244 		priv->task = NULL;
245 	}
246 }
247 
248 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
249 {
250 	struct rb_node *p = _p;
251 
252 	(*pos)++;
253 	return p ? rb_next(p) : NULL;
254 }
255 
256 static const struct seq_operations proc_pid_maps_ops = {
257 	.start	= m_start,
258 	.next	= m_next,
259 	.stop	= m_stop,
260 	.show	= show_pid_map
261 };
262 
263 static const struct seq_operations proc_tid_maps_ops = {
264 	.start	= m_start,
265 	.next	= m_next,
266 	.stop	= m_stop,
267 	.show	= show_tid_map
268 };
269 
270 static int maps_open(struct inode *inode, struct file *file,
271 		     const struct seq_operations *ops)
272 {
273 	struct proc_maps_private *priv;
274 
275 	priv = __seq_open_private(file, ops, sizeof(*priv));
276 	if (!priv)
277 		return -ENOMEM;
278 
279 	priv->inode = inode;
280 	priv->mm = proc_mem_open(inode, PTRACE_MODE_READ);
281 	if (IS_ERR(priv->mm)) {
282 		int err = PTR_ERR(priv->mm);
283 
284 		seq_release_private(inode, file);
285 		return err;
286 	}
287 
288 	return 0;
289 }
290 
291 
292 static int map_release(struct inode *inode, struct file *file)
293 {
294 	struct seq_file *seq = file->private_data;
295 	struct proc_maps_private *priv = seq->private;
296 
297 	if (priv->mm)
298 		mmdrop(priv->mm);
299 
300 	return seq_release_private(inode, file);
301 }
302 
303 static int pid_maps_open(struct inode *inode, struct file *file)
304 {
305 	return maps_open(inode, file, &proc_pid_maps_ops);
306 }
307 
308 static int tid_maps_open(struct inode *inode, struct file *file)
309 {
310 	return maps_open(inode, file, &proc_tid_maps_ops);
311 }
312 
313 const struct file_operations proc_pid_maps_operations = {
314 	.open		= pid_maps_open,
315 	.read		= seq_read,
316 	.llseek		= seq_lseek,
317 	.release	= map_release,
318 };
319 
320 const struct file_operations proc_tid_maps_operations = {
321 	.open		= tid_maps_open,
322 	.read		= seq_read,
323 	.llseek		= seq_lseek,
324 	.release	= map_release,
325 };
326 
327