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1/**
2 * @file oprofilefs.c
3 *
4 * @remark Copyright 2002 OProfile authors
5 * @remark Read the file COPYING
6 *
7 * @author John Levon
8 *
9 * A simple filesystem for configuration and
10 * access of oprofile.
11 */
12
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/oprofile.h>
16#include <linux/fs.h>
17#include <linux/fs_context.h>
18#include <linux/pagemap.h>
19#include <linux/uaccess.h>
20
21#include "oprof.h"
22
23#define OPROFILEFS_MAGIC 0x6f70726f
24
25DEFINE_RAW_SPINLOCK(oprofilefs_lock);
26
27static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode)
28{
29 struct inode *inode = new_inode(sb);
30
31 if (inode) {
32 inode->i_ino = get_next_ino();
33 inode->i_mode = mode;
34 inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
35 }
36 return inode;
37}
38
39
40static const struct super_operations s_ops = {
41 .statfs = simple_statfs,
42 .drop_inode = generic_delete_inode,
43};
44
45
46ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset)
47{
48 return simple_read_from_buffer(buf, count, offset, str, strlen(str));
49}
50
51
52#define TMPBUFSIZE 50
53
54ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset)
55{
56 char tmpbuf[TMPBUFSIZE];
57 size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val);
58 if (maxlen > TMPBUFSIZE)
59 maxlen = TMPBUFSIZE;
60 return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen);
61}
62
63
64/*
65 * Note: If oprofilefs_ulong_from_user() returns 0, then *val remains
66 * unchanged and might be uninitialized. This follows write syscall
67 * implementation when count is zero: "If count is zero ... [and if]
68 * no errors are detected, 0 will be returned without causing any
69 * other effect." (man 2 write)
70 */
71int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
72{
73 char tmpbuf[TMPBUFSIZE];
74 unsigned long flags;
75
76 if (!count)
77 return 0;
78
79 if (count > TMPBUFSIZE - 1)
80 return -EINVAL;
81
82 memset(tmpbuf, 0x0, TMPBUFSIZE);
83
84 if (copy_from_user(tmpbuf, buf, count))
85 return -EFAULT;
86
87 raw_spin_lock_irqsave(&oprofilefs_lock, flags);
88 *val = simple_strtoul(tmpbuf, NULL, 0);
89 raw_spin_unlock_irqrestore(&oprofilefs_lock, flags);
90 return count;
91}
92
93
94static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
95{
96 unsigned long *val = file->private_data;
97 return oprofilefs_ulong_to_user(*val, buf, count, offset);
98}
99
100
101static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset)
102{
103 unsigned long value;
104 int retval;
105
106 if (*offset)
107 return -EINVAL;
108
109 retval = oprofilefs_ulong_from_user(&value, buf, count);
110 if (retval <= 0)
111 return retval;
112
113 retval = oprofile_set_ulong(file->private_data, value);
114 if (retval)
115 return retval;
116
117 return count;
118}
119
120
121static const struct file_operations ulong_fops = {
122 .read = ulong_read_file,
123 .write = ulong_write_file,
124 .open = simple_open,
125 .llseek = default_llseek,
126};
127
128
129static const struct file_operations ulong_ro_fops = {
130 .read = ulong_read_file,
131 .open = simple_open,
132 .llseek = default_llseek,
133};
134
135
136static int __oprofilefs_create_file(struct dentry *root, char const *name,
137 const struct file_operations *fops, int perm, void *priv)
138{
139 struct dentry *dentry;
140 struct inode *inode;
141
142 if (!root)
143 return -ENOMEM;
144
145 inode_lock(d_inode(root));
146 dentry = d_alloc_name(root, name);
147 if (!dentry) {
148 inode_unlock(d_inode(root));
149 return -ENOMEM;
150 }
151 inode = oprofilefs_get_inode(root->d_sb, S_IFREG | perm);
152 if (!inode) {
153 dput(dentry);
154 inode_unlock(d_inode(root));
155 return -ENOMEM;
156 }
157 inode->i_fop = fops;
158 inode->i_private = priv;
159 d_add(dentry, inode);
160 inode_unlock(d_inode(root));
161 return 0;
162}
163
164
165int oprofilefs_create_ulong(struct dentry *root,
166 char const *name, unsigned long *val)
167{
168 return __oprofilefs_create_file(root, name,
169 &ulong_fops, 0644, val);
170}
171
172
173int oprofilefs_create_ro_ulong(struct dentry *root,
174 char const *name, unsigned long *val)
175{
176 return __oprofilefs_create_file(root, name,
177 &ulong_ro_fops, 0444, val);
178}
179
180
181static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
182{
183 atomic_t *val = file->private_data;
184 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
185}
186
187
188static const struct file_operations atomic_ro_fops = {
189 .read = atomic_read_file,
190 .open = simple_open,
191 .llseek = default_llseek,
192};
193
194
195int oprofilefs_create_ro_atomic(struct dentry *root,
196 char const *name, atomic_t *val)
197{
198 return __oprofilefs_create_file(root, name,
199 &atomic_ro_fops, 0444, val);
200}
201
202
203int oprofilefs_create_file(struct dentry *root,
204 char const *name, const struct file_operations *fops)
205{
206 return __oprofilefs_create_file(root, name, fops, 0644, NULL);
207}
208
209
210int oprofilefs_create_file_perm(struct dentry *root,
211 char const *name, const struct file_operations *fops, int perm)
212{
213 return __oprofilefs_create_file(root, name, fops, perm, NULL);
214}
215
216
217struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name)
218{
219 struct dentry *dentry;
220 struct inode *inode;
221
222 inode_lock(d_inode(parent));
223 dentry = d_alloc_name(parent, name);
224 if (!dentry) {
225 inode_unlock(d_inode(parent));
226 return NULL;
227 }
228 inode = oprofilefs_get_inode(parent->d_sb, S_IFDIR | 0755);
229 if (!inode) {
230 dput(dentry);
231 inode_unlock(d_inode(parent));
232 return NULL;
233 }
234 inode->i_op = &simple_dir_inode_operations;
235 inode->i_fop = &simple_dir_operations;
236 d_add(dentry, inode);
237 inode_unlock(d_inode(parent));
238 return dentry;
239}
240
241
242static int oprofilefs_fill_super(struct super_block *sb, struct fs_context *fc)
243{
244 struct inode *root_inode;
245
246 sb->s_blocksize = PAGE_SIZE;
247 sb->s_blocksize_bits = PAGE_SHIFT;
248 sb->s_magic = OPROFILEFS_MAGIC;
249 sb->s_op = &s_ops;
250 sb->s_time_gran = 1;
251
252 root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
253 if (!root_inode)
254 return -ENOMEM;
255 root_inode->i_op = &simple_dir_inode_operations;
256 root_inode->i_fop = &simple_dir_operations;
257 sb->s_root = d_make_root(root_inode);
258 if (!sb->s_root)
259 return -ENOMEM;
260
261 oprofile_create_files(sb->s_root);
262
263 // FIXME: verify kill_litter_super removes our dentries
264 return 0;
265}
266
267static int oprofilefs_get_tree(struct fs_context *fc)
268{
269 return get_tree_single(fc, oprofilefs_fill_super);
270}
271
272static const struct fs_context_operations oprofilefs_context_ops = {
273 .get_tree = oprofilefs_get_tree,
274};
275
276static int oprofilefs_init_fs_context(struct fs_context *fc)
277{
278 fc->ops = &oprofilefs_context_ops;
279 return 0;
280}
281
282static struct file_system_type oprofilefs_type = {
283 .owner = THIS_MODULE,
284 .name = "oprofilefs",
285 .init_fs_context = oprofilefs_init_fs_context,
286 .kill_sb = kill_litter_super,
287};
288MODULE_ALIAS_FS("oprofilefs");
289
290
291int __init oprofilefs_register(void)
292{
293 return register_filesystem(&oprofilefs_type);
294}
295
296
297void __exit oprofilefs_unregister(void)
298{
299 unregister_filesystem(&oprofilefs_type);
300}
1/**
2 * @file oprofilefs.c
3 *
4 * @remark Copyright 2002 OProfile authors
5 * @remark Read the file COPYING
6 *
7 * @author John Levon
8 *
9 * A simple filesystem for configuration and
10 * access of oprofile.
11 */
12
13#include <linux/init.h>
14#include <linux/module.h>
15#include <linux/oprofile.h>
16#include <linux/fs.h>
17#include <linux/pagemap.h>
18#include <asm/uaccess.h>
19
20#include "oprof.h"
21
22#define OPROFILEFS_MAGIC 0x6f70726f
23
24DEFINE_RAW_SPINLOCK(oprofilefs_lock);
25
26static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode)
27{
28 struct inode *inode = new_inode(sb);
29
30 if (inode) {
31 inode->i_ino = get_next_ino();
32 inode->i_mode = mode;
33 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
34 }
35 return inode;
36}
37
38
39static const struct super_operations s_ops = {
40 .statfs = simple_statfs,
41 .drop_inode = generic_delete_inode,
42};
43
44
45ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset)
46{
47 return simple_read_from_buffer(buf, count, offset, str, strlen(str));
48}
49
50
51#define TMPBUFSIZE 50
52
53ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset)
54{
55 char tmpbuf[TMPBUFSIZE];
56 size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val);
57 if (maxlen > TMPBUFSIZE)
58 maxlen = TMPBUFSIZE;
59 return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen);
60}
61
62
63/*
64 * Note: If oprofilefs_ulong_from_user() returns 0, then *val remains
65 * unchanged and might be uninitialized. This follows write syscall
66 * implementation when count is zero: "If count is zero ... [and if]
67 * no errors are detected, 0 will be returned without causing any
68 * other effect." (man 2 write)
69 */
70int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count)
71{
72 char tmpbuf[TMPBUFSIZE];
73 unsigned long flags;
74
75 if (!count)
76 return 0;
77
78 if (count > TMPBUFSIZE - 1)
79 return -EINVAL;
80
81 memset(tmpbuf, 0x0, TMPBUFSIZE);
82
83 if (copy_from_user(tmpbuf, buf, count))
84 return -EFAULT;
85
86 raw_spin_lock_irqsave(&oprofilefs_lock, flags);
87 *val = simple_strtoul(tmpbuf, NULL, 0);
88 raw_spin_unlock_irqrestore(&oprofilefs_lock, flags);
89 return count;
90}
91
92
93static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
94{
95 unsigned long *val = file->private_data;
96 return oprofilefs_ulong_to_user(*val, buf, count, offset);
97}
98
99
100static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset)
101{
102 unsigned long value;
103 int retval;
104
105 if (*offset)
106 return -EINVAL;
107
108 retval = oprofilefs_ulong_from_user(&value, buf, count);
109 if (retval <= 0)
110 return retval;
111
112 retval = oprofile_set_ulong(file->private_data, value);
113 if (retval)
114 return retval;
115
116 return count;
117}
118
119
120static const struct file_operations ulong_fops = {
121 .read = ulong_read_file,
122 .write = ulong_write_file,
123 .open = simple_open,
124 .llseek = default_llseek,
125};
126
127
128static const struct file_operations ulong_ro_fops = {
129 .read = ulong_read_file,
130 .open = simple_open,
131 .llseek = default_llseek,
132};
133
134
135static int __oprofilefs_create_file(struct dentry *root, char const *name,
136 const struct file_operations *fops, int perm, void *priv)
137{
138 struct dentry *dentry;
139 struct inode *inode;
140
141 inode_lock(d_inode(root));
142 dentry = d_alloc_name(root, name);
143 if (!dentry) {
144 inode_unlock(d_inode(root));
145 return -ENOMEM;
146 }
147 inode = oprofilefs_get_inode(root->d_sb, S_IFREG | perm);
148 if (!inode) {
149 dput(dentry);
150 inode_unlock(d_inode(root));
151 return -ENOMEM;
152 }
153 inode->i_fop = fops;
154 inode->i_private = priv;
155 d_add(dentry, inode);
156 inode_unlock(d_inode(root));
157 return 0;
158}
159
160
161int oprofilefs_create_ulong(struct dentry *root,
162 char const *name, unsigned long *val)
163{
164 return __oprofilefs_create_file(root, name,
165 &ulong_fops, 0644, val);
166}
167
168
169int oprofilefs_create_ro_ulong(struct dentry *root,
170 char const *name, unsigned long *val)
171{
172 return __oprofilefs_create_file(root, name,
173 &ulong_ro_fops, 0444, val);
174}
175
176
177static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset)
178{
179 atomic_t *val = file->private_data;
180 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
181}
182
183
184static const struct file_operations atomic_ro_fops = {
185 .read = atomic_read_file,
186 .open = simple_open,
187 .llseek = default_llseek,
188};
189
190
191int oprofilefs_create_ro_atomic(struct dentry *root,
192 char const *name, atomic_t *val)
193{
194 return __oprofilefs_create_file(root, name,
195 &atomic_ro_fops, 0444, val);
196}
197
198
199int oprofilefs_create_file(struct dentry *root,
200 char const *name, const struct file_operations *fops)
201{
202 return __oprofilefs_create_file(root, name, fops, 0644, NULL);
203}
204
205
206int oprofilefs_create_file_perm(struct dentry *root,
207 char const *name, const struct file_operations *fops, int perm)
208{
209 return __oprofilefs_create_file(root, name, fops, perm, NULL);
210}
211
212
213struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name)
214{
215 struct dentry *dentry;
216 struct inode *inode;
217
218 inode_lock(d_inode(parent));
219 dentry = d_alloc_name(parent, name);
220 if (!dentry) {
221 inode_unlock(d_inode(parent));
222 return NULL;
223 }
224 inode = oprofilefs_get_inode(parent->d_sb, S_IFDIR | 0755);
225 if (!inode) {
226 dput(dentry);
227 inode_unlock(d_inode(parent));
228 return NULL;
229 }
230 inode->i_op = &simple_dir_inode_operations;
231 inode->i_fop = &simple_dir_operations;
232 d_add(dentry, inode);
233 inode_unlock(d_inode(parent));
234 return dentry;
235}
236
237
238static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent)
239{
240 struct inode *root_inode;
241
242 sb->s_blocksize = PAGE_SIZE;
243 sb->s_blocksize_bits = PAGE_SHIFT;
244 sb->s_magic = OPROFILEFS_MAGIC;
245 sb->s_op = &s_ops;
246 sb->s_time_gran = 1;
247
248 root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
249 if (!root_inode)
250 return -ENOMEM;
251 root_inode->i_op = &simple_dir_inode_operations;
252 root_inode->i_fop = &simple_dir_operations;
253 sb->s_root = d_make_root(root_inode);
254 if (!sb->s_root)
255 return -ENOMEM;
256
257 oprofile_create_files(sb->s_root);
258
259 // FIXME: verify kill_litter_super removes our dentries
260 return 0;
261}
262
263
264static struct dentry *oprofilefs_mount(struct file_system_type *fs_type,
265 int flags, const char *dev_name, void *data)
266{
267 return mount_single(fs_type, flags, data, oprofilefs_fill_super);
268}
269
270
271static struct file_system_type oprofilefs_type = {
272 .owner = THIS_MODULE,
273 .name = "oprofilefs",
274 .mount = oprofilefs_mount,
275 .kill_sb = kill_litter_super,
276};
277MODULE_ALIAS_FS("oprofilefs");
278
279
280int __init oprofilefs_register(void)
281{
282 return register_filesystem(&oprofilefs_type);
283}
284
285
286void __exit oprofilefs_unregister(void)
287{
288 unregister_filesystem(&oprofilefs_type);
289}