Blame view
drivers/oprofile/oprofilefs.c
6.43 KB
81f7e3824
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 |
/** * @file oprofilefs.c * * @remark Copyright 2002 OProfile authors * @remark Read the file COPYING * * @author John Levon * * A simple filesystem for configuration and * access of oprofile. */ #include <linux/init.h> #include <linux/module.h> #include <linux/oprofile.h> #include <linux/fs.h> #include <linux/pagemap.h> #include <linux/uaccess.h> #include "oprof.h" #define OPROFILEFS_MAGIC 0x6f70726f DEFINE_RAW_SPINLOCK(oprofilefs_lock); static struct inode *oprofilefs_get_inode(struct super_block *sb, int mode) { struct inode *inode = new_inode(sb); if (inode) { inode->i_ino = get_next_ino(); inode->i_mode = mode; inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); } return inode; } static const struct super_operations s_ops = { .statfs = simple_statfs, .drop_inode = generic_delete_inode, }; ssize_t oprofilefs_str_to_user(char const *str, char __user *buf, size_t count, loff_t *offset) { return simple_read_from_buffer(buf, count, offset, str, strlen(str)); } #define TMPBUFSIZE 50 ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t count, loff_t *offset) { char tmpbuf[TMPBUFSIZE]; size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu ", val); if (maxlen > TMPBUFSIZE) maxlen = TMPBUFSIZE; return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen); } /* * Note: If oprofilefs_ulong_from_user() returns 0, then *val remains * unchanged and might be uninitialized. This follows write syscall * implementation when count is zero: "If count is zero ... [and if] * no errors are detected, 0 will be returned without causing any * other effect." (man 2 write) */ int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count) { char tmpbuf[TMPBUFSIZE]; unsigned long flags; if (!count) return 0; if (count > TMPBUFSIZE - 1) return -EINVAL; memset(tmpbuf, 0x0, TMPBUFSIZE); if (copy_from_user(tmpbuf, buf, count)) return -EFAULT; raw_spin_lock_irqsave(&oprofilefs_lock, flags); *val = simple_strtoul(tmpbuf, NULL, 0); raw_spin_unlock_irqrestore(&oprofilefs_lock, flags); return count; } static ssize_t ulong_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) { unsigned long *val = file->private_data; return oprofilefs_ulong_to_user(*val, buf, count, offset); } static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_t count, loff_t *offset) { unsigned long value; int retval; if (*offset) return -EINVAL; retval = oprofilefs_ulong_from_user(&value, buf, count); if (retval <= 0) return retval; retval = oprofile_set_ulong(file->private_data, value); if (retval) return retval; return count; } static const struct file_operations ulong_fops = { .read = ulong_read_file, .write = ulong_write_file, .open = simple_open, .llseek = default_llseek, }; static const struct file_operations ulong_ro_fops = { .read = ulong_read_file, .open = simple_open, .llseek = default_llseek, }; static int __oprofilefs_create_file(struct dentry *root, char const *name, const struct file_operations *fops, int perm, void *priv) { struct dentry *dentry; struct inode *inode; inode_lock(d_inode(root)); dentry = d_alloc_name(root, name); if (!dentry) { inode_unlock(d_inode(root)); return -ENOMEM; } inode = oprofilefs_get_inode(root->d_sb, S_IFREG | perm); if (!inode) { dput(dentry); inode_unlock(d_inode(root)); return -ENOMEM; } inode->i_fop = fops; inode->i_private = priv; d_add(dentry, inode); inode_unlock(d_inode(root)); return 0; } int oprofilefs_create_ulong(struct dentry *root, char const *name, unsigned long *val) { return __oprofilefs_create_file(root, name, &ulong_fops, 0644, val); } int oprofilefs_create_ro_ulong(struct dentry *root, char const *name, unsigned long *val) { return __oprofilefs_create_file(root, name, &ulong_ro_fops, 0444, val); } static ssize_t atomic_read_file(struct file *file, char __user *buf, size_t count, loff_t *offset) { atomic_t *val = file->private_data; return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset); } static const struct file_operations atomic_ro_fops = { .read = atomic_read_file, .open = simple_open, .llseek = default_llseek, }; int oprofilefs_create_ro_atomic(struct dentry *root, char const *name, atomic_t *val) { return __oprofilefs_create_file(root, name, &atomic_ro_fops, 0444, val); } int oprofilefs_create_file(struct dentry *root, char const *name, const struct file_operations *fops) { return __oprofilefs_create_file(root, name, fops, 0644, NULL); } int oprofilefs_create_file_perm(struct dentry *root, char const *name, const struct file_operations *fops, int perm) { return __oprofilefs_create_file(root, name, fops, perm, NULL); } struct dentry *oprofilefs_mkdir(struct dentry *parent, char const *name) { struct dentry *dentry; struct inode *inode; inode_lock(d_inode(parent)); dentry = d_alloc_name(parent, name); if (!dentry) { inode_unlock(d_inode(parent)); return NULL; } inode = oprofilefs_get_inode(parent->d_sb, S_IFDIR | 0755); if (!inode) { dput(dentry); inode_unlock(d_inode(parent)); return NULL; } inode->i_op = &simple_dir_inode_operations; inode->i_fop = &simple_dir_operations; d_add(dentry, inode); inode_unlock(d_inode(parent)); return dentry; } static int oprofilefs_fill_super(struct super_block *sb, void *data, int silent) { struct inode *root_inode; sb->s_blocksize = PAGE_SIZE; sb->s_blocksize_bits = PAGE_SHIFT; sb->s_magic = OPROFILEFS_MAGIC; sb->s_op = &s_ops; sb->s_time_gran = 1; root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755); if (!root_inode) return -ENOMEM; root_inode->i_op = &simple_dir_inode_operations; root_inode->i_fop = &simple_dir_operations; sb->s_root = d_make_root(root_inode); if (!sb->s_root) return -ENOMEM; oprofile_create_files(sb->s_root); // FIXME: verify kill_litter_super removes our dentries return 0; } static struct dentry *oprofilefs_mount(struct file_system_type *fs_type, int flags, const char *dev_name, void *data) { return mount_single(fs_type, flags, data, oprofilefs_fill_super); } static struct file_system_type oprofilefs_type = { .owner = THIS_MODULE, .name = "oprofilefs", .mount = oprofilefs_mount, .kill_sb = kill_litter_super, }; MODULE_ALIAS_FS("oprofilefs"); int __init oprofilefs_register(void) { return register_filesystem(&oprofilefs_type); } void __exit oprofilefs_unregister(void) { unregister_filesystem(&oprofilefs_type); } |