xref: /openbmc/linux/fs/proc/task_nommu.c (revision 275876e2)
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_pid_task(priv->pid, PIDTYPE_PID);
216 	if (!priv->task)
217 		return ERR_PTR(-ESRCH);
218 
219 	mm = mm_access(priv->task, PTRACE_MODE_READ);
220 	if (!mm || IS_ERR(mm)) {
221 		put_task_struct(priv->task);
222 		priv->task = NULL;
223 		return mm;
224 	}
225 	down_read(&mm->mmap_sem);
226 
227 	/* start from the Nth VMA */
228 	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
229 		if (n-- == 0)
230 			return p;
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 (priv->task) {
239 		struct mm_struct *mm = priv->task->mm;
240 		up_read(&mm->mmap_sem);
241 		mmput(mm);
242 		put_task_struct(priv->task);
243 	}
244 }
245 
246 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
247 {
248 	struct rb_node *p = _p;
249 
250 	(*pos)++;
251 	return p ? rb_next(p) : NULL;
252 }
253 
254 static const struct seq_operations proc_pid_maps_ops = {
255 	.start	= m_start,
256 	.next	= m_next,
257 	.stop	= m_stop,
258 	.show	= show_pid_map
259 };
260 
261 static const struct seq_operations proc_tid_maps_ops = {
262 	.start	= m_start,
263 	.next	= m_next,
264 	.stop	= m_stop,
265 	.show	= show_tid_map
266 };
267 
268 static int maps_open(struct inode *inode, struct file *file,
269 		     const struct seq_operations *ops)
270 {
271 	struct proc_maps_private *priv;
272 	int ret = -ENOMEM;
273 
274 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
275 	if (priv) {
276 		priv->pid = proc_pid(inode);
277 		ret = seq_open(file, ops);
278 		if (!ret) {
279 			struct seq_file *m = file->private_data;
280 			m->private = priv;
281 		} else {
282 			kfree(priv);
283 		}
284 	}
285 	return ret;
286 }
287 
288 static int pid_maps_open(struct inode *inode, struct file *file)
289 {
290 	return maps_open(inode, file, &proc_pid_maps_ops);
291 }
292 
293 static int tid_maps_open(struct inode *inode, struct file *file)
294 {
295 	return maps_open(inode, file, &proc_tid_maps_ops);
296 }
297 
298 const struct file_operations proc_pid_maps_operations = {
299 	.open		= pid_maps_open,
300 	.read		= seq_read,
301 	.llseek		= seq_lseek,
302 	.release	= seq_release_private,
303 };
304 
305 const struct file_operations proc_tid_maps_operations = {
306 	.open		= tid_maps_open,
307 	.read		= seq_read,
308 	.llseek		= seq_lseek,
309 	.release	= seq_release_private,
310 };
311 
312