xref: /openbmc/linux/fs/proc/task_nommu.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 int task_statm(struct mm_struct *mm, int *shared, int *text,
96 	       int *data, int *resident)
97 {
98 	struct vm_area_struct *vma;
99 	struct vm_region *region;
100 	struct rb_node *p;
101 	int size = kobjsize(mm);
102 
103 	down_read(&mm->mmap_sem);
104 	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p)) {
105 		vma = rb_entry(p, struct vm_area_struct, vm_rb);
106 		size += kobjsize(vma);
107 		region = vma->vm_region;
108 		if (region) {
109 			size += kobjsize(region);
110 			size += region->vm_end - region->vm_start;
111 		}
112 	}
113 
114 	*text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK))
115 		>> PAGE_SHIFT;
116 	*data = (PAGE_ALIGN(mm->start_stack) - (mm->start_data & PAGE_MASK))
117 		>> PAGE_SHIFT;
118 	up_read(&mm->mmap_sem);
119 	size >>= PAGE_SHIFT;
120 	size += *text + *data;
121 	*resident = size;
122 	return size;
123 }
124 
125 static void pad_len_spaces(struct seq_file *m, int len)
126 {
127 	len = 25 + sizeof(void*) * 6 - len;
128 	if (len < 1)
129 		len = 1;
130 	seq_printf(m, "%*c", len, ' ');
131 }
132 
133 /*
134  * display a single VMA to a sequenced file
135  */
136 static int nommu_vma_show(struct seq_file *m, struct vm_area_struct *vma)
137 {
138 	struct mm_struct *mm = vma->vm_mm;
139 	unsigned long ino = 0;
140 	struct file *file;
141 	dev_t dev = 0;
142 	int flags, len;
143 	unsigned long long pgoff = 0;
144 
145 	flags = vma->vm_flags;
146 	file = vma->vm_file;
147 
148 	if (file) {
149 		struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
150 		dev = inode->i_sb->s_dev;
151 		ino = inode->i_ino;
152 		pgoff = (loff_t)vma->vm_pgoff << PAGE_SHIFT;
153 	}
154 
155 	seq_printf(m,
156 		   "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu %n",
157 		   vma->vm_start,
158 		   vma->vm_end,
159 		   flags & VM_READ ? 'r' : '-',
160 		   flags & VM_WRITE ? 'w' : '-',
161 		   flags & VM_EXEC ? 'x' : '-',
162 		   flags & VM_MAYSHARE ? flags & VM_SHARED ? 'S' : 's' : 'p',
163 		   pgoff,
164 		   MAJOR(dev), MINOR(dev), ino, &len);
165 
166 	if (file) {
167 		pad_len_spaces(m, len);
168 		seq_path(m, &file->f_path, "");
169 	} else if (mm) {
170 		if (vma->vm_start <= mm->start_stack &&
171 			vma->vm_end >= mm->start_stack) {
172 			pad_len_spaces(m, len);
173 			seq_puts(m, "[stack]");
174 		}
175 	}
176 
177 	seq_putc(m, '\n');
178 	return 0;
179 }
180 
181 /*
182  * display mapping lines for a particular process's /proc/pid/maps
183  */
184 static int show_map(struct seq_file *m, void *_p)
185 {
186 	struct rb_node *p = _p;
187 
188 	return nommu_vma_show(m, rb_entry(p, struct vm_area_struct, vm_rb));
189 }
190 
191 static void *m_start(struct seq_file *m, loff_t *pos)
192 {
193 	struct proc_maps_private *priv = m->private;
194 	struct mm_struct *mm;
195 	struct rb_node *p;
196 	loff_t n = *pos;
197 
198 	/* pin the task and mm whilst we play with them */
199 	priv->task = get_pid_task(priv->pid, PIDTYPE_PID);
200 	if (!priv->task)
201 		return NULL;
202 
203 	mm = mm_for_maps(priv->task);
204 	if (!mm) {
205 		put_task_struct(priv->task);
206 		priv->task = NULL;
207 		return NULL;
208 	}
209 	down_read(&mm->mmap_sem);
210 
211 	/* start from the Nth VMA */
212 	for (p = rb_first(&mm->mm_rb); p; p = rb_next(p))
213 		if (n-- == 0)
214 			return p;
215 	return NULL;
216 }
217 
218 static void m_stop(struct seq_file *m, void *_vml)
219 {
220 	struct proc_maps_private *priv = m->private;
221 
222 	if (priv->task) {
223 		struct mm_struct *mm = priv->task->mm;
224 		up_read(&mm->mmap_sem);
225 		mmput(mm);
226 		put_task_struct(priv->task);
227 	}
228 }
229 
230 static void *m_next(struct seq_file *m, void *_p, loff_t *pos)
231 {
232 	struct rb_node *p = _p;
233 
234 	(*pos)++;
235 	return p ? rb_next(p) : NULL;
236 }
237 
238 static const struct seq_operations proc_pid_maps_ops = {
239 	.start	= m_start,
240 	.next	= m_next,
241 	.stop	= m_stop,
242 	.show	= show_map
243 };
244 
245 static int maps_open(struct inode *inode, struct file *file)
246 {
247 	struct proc_maps_private *priv;
248 	int ret = -ENOMEM;
249 
250 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
251 	if (priv) {
252 		priv->pid = proc_pid(inode);
253 		ret = seq_open(file, &proc_pid_maps_ops);
254 		if (!ret) {
255 			struct seq_file *m = file->private_data;
256 			m->private = priv;
257 		} else {
258 			kfree(priv);
259 		}
260 	}
261 	return ret;
262 }
263 
264 const struct file_operations proc_maps_operations = {
265 	.open		= maps_open,
266 	.read		= seq_read,
267 	.llseek		= seq_lseek,
268 	.release	= seq_release_private,
269 };
270 
271