d2912cb15bdda (Thomas Gleixner 2019-06-04 10:11:33 +0200 1) // SPDX-License-Identifier: GPL-2.0-only
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 2) /*
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 3) * inode.c - part of tracefs, a pseudo file system for activating tracing
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 4) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 5) * Based on debugfs by: Greg Kroah-Hartman <greg@kroah.com>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 6) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 7) * Copyright (C) 2014 Red Hat Inc, author: Steven Rostedt <srostedt@redhat.com>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 8) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 9) * tracefs is the file system that is used by the tracing infrastructure.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 10) */
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 11)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 12) #include <linux/module.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 13) #include <linux/fs.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 14) #include <linux/mount.h>
cc31004a4aa78 (Steven Rostedt (Red Hat) 2015-01-21 11:28:23 -0500 15) #include <linux/kobject.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 16) #include <linux/namei.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 17) #include <linux/tracefs.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 18) #include <linux/fsnotify.h>
bf8e602186ec4 (Steven Rostedt (VMware) 2019-10-11 20:41:41 -0400 19) #include <linux/security.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 20) #include <linux/seq_file.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 21) #include <linux/parser.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 22) #include <linux/magic.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 23) #include <linux/slab.h>
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 24)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 25) #define TRACEFS_DEFAULT_MODE 0700
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 26)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 27) static struct vfsmount *tracefs_mount;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 28) static int tracefs_mount_count;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 29) static bool tracefs_registered;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 30)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 31) static ssize_t default_read_file(struct file *file, char __user *buf,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 32) size_t count, loff_t *ppos)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 33) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 34) return 0;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 35) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 36)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 37) static ssize_t default_write_file(struct file *file, const char __user *buf,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 38) size_t count, loff_t *ppos)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 39) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 40) return count;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 41) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 42)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 43) static const struct file_operations tracefs_file_operations = {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 44) .read = default_read_file,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 45) .write = default_write_file,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 46) .open = simple_open,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 47) .llseek = noop_llseek,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 48) };
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 49)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 50) static struct tracefs_dir_ops {
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 51) int (*mkdir)(const char *name);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 52) int (*rmdir)(const char *name);
5248ee8560306 (Zubin Mithra 2018-07-25 10:19:01 -0700 53) } tracefs_ops __ro_after_init;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 54)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 55) static char *get_dname(struct dentry *dentry)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 56) {
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 57) const char *dname;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 58) char *name;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 59) int len = dentry->d_name.len;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 60)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 61) dname = dentry->d_name.name;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 62) name = kmalloc(len + 1, GFP_KERNEL);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 63) if (!name)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 64) return NULL;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 65) memcpy(name, dname, len);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 66) name[len] = 0;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 67) return name;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 68) }
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 69)
549c7297717c3 (Christian Brauner 2021-01-21 14:19:43 +0100 70) static int tracefs_syscall_mkdir(struct user_namespace *mnt_userns,
549c7297717c3 (Christian Brauner 2021-01-21 14:19:43 +0100 71) struct inode *inode, struct dentry *dentry,
549c7297717c3 (Christian Brauner 2021-01-21 14:19:43 +0100 72) umode_t mode)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 73) {
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 74) char *name;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 75) int ret;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 76)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 77) name = get_dname(dentry);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 78) if (!name)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 79) return -ENOMEM;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 80)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 81) /*
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 82) * The mkdir call can call the generic functions that create
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 83) * the files within the tracefs system. It is up to the individual
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 84) * mkdir routine to handle races.
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 85) */
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 86) inode_unlock(inode);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 87) ret = tracefs_ops.mkdir(name);
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 88) inode_lock(inode);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 89)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 90) kfree(name);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 91)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 92) return ret;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 93) }
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 94)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 95) static int tracefs_syscall_rmdir(struct inode *inode, struct dentry *dentry)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 96) {
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 97) char *name;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 98) int ret;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 99)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 100) name = get_dname(dentry);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 101) if (!name)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 102) return -ENOMEM;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 103)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 104) /*
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 105) * The rmdir call can call the generic functions that create
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 106) * the files within the tracefs system. It is up to the individual
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 107) * rmdir routine to handle races.
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 108) * This time we need to unlock not only the parent (inode) but
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 109) * also the directory that is being deleted.
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 110) */
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 111) inode_unlock(inode);
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 112) inode_unlock(dentry->d_inode);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 113)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 114) ret = tracefs_ops.rmdir(name);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 115)
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 116) inode_lock_nested(inode, I_MUTEX_PARENT);
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 117) inode_lock(dentry->d_inode);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 118)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 119) kfree(name);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 120)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 121) return ret;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 122) }
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 123)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 124) static const struct inode_operations tracefs_dir_inode_operations = {
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 125) .lookup = simple_lookup,
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 126) .mkdir = tracefs_syscall_mkdir,
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 127) .rmdir = tracefs_syscall_rmdir,
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 128) };
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 129)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 130) static struct inode *tracefs_get_inode(struct super_block *sb)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 131) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 132) struct inode *inode = new_inode(sb);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 133) if (inode) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 134) inode->i_ino = get_next_ino();
078cd8279e659 (Deepa Dinamani 2016-09-14 07:48:04 -0700 135) inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 136) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 137) return inode;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 138) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 139)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 140) struct tracefs_mount_opts {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 141) kuid_t uid;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 142) kgid_t gid;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 143) umode_t mode;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 144) };
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 145)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 146) enum {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 147) Opt_uid,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 148) Opt_gid,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 149) Opt_mode,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 150) Opt_err
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 151) };
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 152)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 153) static const match_table_t tokens = {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 154) {Opt_uid, "uid=%u"},
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 155) {Opt_gid, "gid=%u"},
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 156) {Opt_mode, "mode=%o"},
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 157) {Opt_err, NULL}
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 158) };
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 159)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 160) struct tracefs_fs_info {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 161) struct tracefs_mount_opts mount_opts;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 162) };
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 163)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 164) static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 165) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 166) substring_t args[MAX_OPT_ARGS];
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 167) int option;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 168) int token;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 169) kuid_t uid;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 170) kgid_t gid;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 171) char *p;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 172)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 173) opts->mode = TRACEFS_DEFAULT_MODE;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 174)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 175) while ((p = strsep(&data, ",")) != NULL) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 176) if (!*p)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 177) continue;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 178)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 179) token = match_token(p, tokens, args);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 180) switch (token) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 181) case Opt_uid:
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 182) if (match_int(&args[0], &option))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 183) return -EINVAL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 184) uid = make_kuid(current_user_ns(), option);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 185) if (!uid_valid(uid))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 186) return -EINVAL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 187) opts->uid = uid;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 188) break;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 189) case Opt_gid:
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 190) if (match_int(&args[0], &option))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 191) return -EINVAL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 192) gid = make_kgid(current_user_ns(), option);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 193) if (!gid_valid(gid))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 194) return -EINVAL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 195) opts->gid = gid;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 196) break;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 197) case Opt_mode:
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 198) if (match_octal(&args[0], &option))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 199) return -EINVAL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 200) opts->mode = option & S_IALLUGO;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 201) break;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 202) /*
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 203) * We might like to report bad mount options here;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 204) * but traditionally tracefs has ignored all mount options
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 205) */
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 206) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 207) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 208)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 209) return 0;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 210) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 211)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 212) static int tracefs_apply_options(struct super_block *sb)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 213) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 214) struct tracefs_fs_info *fsi = sb->s_fs_info;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 215) struct inode *inode = sb->s_root->d_inode;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 216) struct tracefs_mount_opts *opts = &fsi->mount_opts;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 217)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 218) inode->i_mode &= ~S_IALLUGO;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 219) inode->i_mode |= opts->mode;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 220)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 221) inode->i_uid = opts->uid;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 222) inode->i_gid = opts->gid;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 223)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 224) return 0;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 225) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 226)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 227) static int tracefs_remount(struct super_block *sb, int *flags, char *data)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 228) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 229) int err;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 230) struct tracefs_fs_info *fsi = sb->s_fs_info;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 231)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 232) sync_filesystem(sb);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 233) err = tracefs_parse_options(data, &fsi->mount_opts);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 234) if (err)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 235) goto fail;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 236)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 237) tracefs_apply_options(sb);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 238)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 239) fail:
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 240) return err;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 241) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 242)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 243) static int tracefs_show_options(struct seq_file *m, struct dentry *root)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 244) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 245) struct tracefs_fs_info *fsi = root->d_sb->s_fs_info;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 246) struct tracefs_mount_opts *opts = &fsi->mount_opts;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 247)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 248) if (!uid_eq(opts->uid, GLOBAL_ROOT_UID))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 249) seq_printf(m, ",uid=%u",
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 250) from_kuid_munged(&init_user_ns, opts->uid));
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 251) if (!gid_eq(opts->gid, GLOBAL_ROOT_GID))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 252) seq_printf(m, ",gid=%u",
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 253) from_kgid_munged(&init_user_ns, opts->gid));
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 254) if (opts->mode != TRACEFS_DEFAULT_MODE)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 255) seq_printf(m, ",mode=%o", opts->mode);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 256)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 257) return 0;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 258) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 259)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 260) static const struct super_operations tracefs_super_operations = {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 261) .statfs = simple_statfs,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 262) .remount_fs = tracefs_remount,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 263) .show_options = tracefs_show_options,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 264) };
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 265)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 266) static int trace_fill_super(struct super_block *sb, void *data, int silent)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 267) {
cda37124f4e95 (Eric Biggers 2017-03-25 21:15:37 -0700 268) static const struct tree_descr trace_files[] = {{""}};
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 269) struct tracefs_fs_info *fsi;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 270) int err;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 271)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 272) fsi = kzalloc(sizeof(struct tracefs_fs_info), GFP_KERNEL);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 273) sb->s_fs_info = fsi;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 274) if (!fsi) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 275) err = -ENOMEM;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 276) goto fail;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 277) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 278)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 279) err = tracefs_parse_options(data, &fsi->mount_opts);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 280) if (err)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 281) goto fail;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 282)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 283) err = simple_fill_super(sb, TRACEFS_MAGIC, trace_files);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 284) if (err)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 285) goto fail;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 286)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 287) sb->s_op = &tracefs_super_operations;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 288)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 289) tracefs_apply_options(sb);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 290)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 291) return 0;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 292)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 293) fail:
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 294) kfree(fsi);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 295) sb->s_fs_info = NULL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 296) return err;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 297) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 298)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 299) static struct dentry *trace_mount(struct file_system_type *fs_type,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 300) int flags, const char *dev_name,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 301) void *data)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 302) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 303) return mount_single(fs_type, flags, data, trace_fill_super);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 304) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 305)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 306) static struct file_system_type trace_fs_type = {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 307) .owner = THIS_MODULE,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 308) .name = "tracefs",
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 309) .mount = trace_mount,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 310) .kill_sb = kill_litter_super,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 311) };
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 312) MODULE_ALIAS_FS("tracefs");
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 313)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 314) static struct dentry *start_creating(const char *name, struct dentry *parent)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 315) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 316) struct dentry *dentry;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 317) int error;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 318)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 319) pr_debug("tracefs: creating file '%s'\n",name);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 320)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 321) error = simple_pin_fs(&trace_fs_type, &tracefs_mount,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 322) &tracefs_mount_count);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 323) if (error)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 324) return ERR_PTR(error);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 325)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 326) /* If the parent is not specified, we create it in the root.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 327) * We need the root dentry to do this, which is in the super
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 328) * block. A pointer to that is in the struct vfsmount that we
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 329) * have around.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 330) */
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 331) if (!parent)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 332) parent = tracefs_mount->mnt_root;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 333)
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 334) inode_lock(parent->d_inode);
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 335) if (unlikely(IS_DEADDIR(parent->d_inode)))
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 336) dentry = ERR_PTR(-ENOENT);
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 337) else
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 338) dentry = lookup_one_len(name, parent, strlen(name));
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 339) if (!IS_ERR(dentry) && dentry->d_inode) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 340) dput(dentry);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 341) dentry = ERR_PTR(-EEXIST);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 342) }
d227c3ae4e94e (Daniel Borkmann 2015-11-04 23:33:17 +0100 343)
d227c3ae4e94e (Daniel Borkmann 2015-11-04 23:33:17 +0100 344) if (IS_ERR(dentry)) {
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 345) inode_unlock(parent->d_inode);
d227c3ae4e94e (Daniel Borkmann 2015-11-04 23:33:17 +0100 346) simple_release_fs(&tracefs_mount, &tracefs_mount_count);
d227c3ae4e94e (Daniel Borkmann 2015-11-04 23:33:17 +0100 347) }
d227c3ae4e94e (Daniel Borkmann 2015-11-04 23:33:17 +0100 348)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 349) return dentry;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 350) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 351)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 352) static struct dentry *failed_creating(struct dentry *dentry)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 353) {
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 354) inode_unlock(dentry->d_parent->d_inode);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 355) dput(dentry);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 356) simple_release_fs(&tracefs_mount, &tracefs_mount_count);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 357) return NULL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 358) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 359)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 360) static struct dentry *end_creating(struct dentry *dentry)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 361) {
5955102c9984f (Al Viro 2016-01-22 15:40:57 -0500 362) inode_unlock(dentry->d_parent->d_inode);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 363) return dentry;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 364) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 365)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 366) /**
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 367) * tracefs_create_file - create a file in the tracefs filesystem
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 368) * @name: a pointer to a string containing the name of the file to create.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 369) * @mode: the permission that the file should have.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 370) * @parent: a pointer to the parent dentry for this file. This should be a
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 371) * directory dentry if set. If this parameter is NULL, then the
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 372) * file will be created in the root of the tracefs filesystem.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 373) * @data: a pointer to something that the caller will want to get to later
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 374) * on. The inode.i_private pointer will point to this value on
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 375) * the open() call.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 376) * @fops: a pointer to a struct file_operations that should be used for
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 377) * this file.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 378) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 379) * This is the basic "create a file" function for tracefs. It allows for a
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 380) * wide range of flexibility in creating a file, or a directory (if you want
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 381) * to create a directory, the tracefs_create_dir() function is
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 382) * recommended to be used instead.)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 383) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 384) * This function will return a pointer to a dentry if it succeeds. This
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 385) * pointer must be passed to the tracefs_remove() function when the file is
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 386) * to be removed (no automatic cleanup happens if your module is unloaded,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 387) * you are responsible here.) If an error occurs, %NULL will be returned.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 388) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 389) * If tracefs is not enabled in the kernel, the value -%ENODEV will be
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 390) * returned.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 391) */
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 392) struct dentry *tracefs_create_file(const char *name, umode_t mode,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 393) struct dentry *parent, void *data,
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 394) const struct file_operations *fops)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 395) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 396) struct dentry *dentry;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 397) struct inode *inode;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 398)
bf8e602186ec4 (Steven Rostedt (VMware) 2019-10-11 20:41:41 -0400 399) if (security_locked_down(LOCKDOWN_TRACEFS))
bf8e602186ec4 (Steven Rostedt (VMware) 2019-10-11 20:41:41 -0400 400) return NULL;
bf8e602186ec4 (Steven Rostedt (VMware) 2019-10-11 20:41:41 -0400 401)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 402) if (!(mode & S_IFMT))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 403) mode |= S_IFREG;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 404) BUG_ON(!S_ISREG(mode));
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 405) dentry = start_creating(name, parent);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 406)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 407) if (IS_ERR(dentry))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 408) return NULL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 409)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 410) inode = tracefs_get_inode(dentry->d_sb);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 411) if (unlikely(!inode))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 412) return failed_creating(dentry);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 413)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 414) inode->i_mode = mode;
3ed270b129a45 (Steven Rostedt (VMware) 2019-10-11 13:54:58 -0400 415) inode->i_fop = fops ? fops : &tracefs_file_operations;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 416) inode->i_private = data;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 417) d_instantiate(dentry, inode);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 418) fsnotify_create(dentry->d_parent->d_inode, dentry);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 419) return end_creating(dentry);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 420) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 421)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 422) static struct dentry *__create_dir(const char *name, struct dentry *parent,
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 423) const struct inode_operations *ops)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 424) {
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 425) struct dentry *dentry = start_creating(name, parent);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 426) struct inode *inode;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 427)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 428) if (IS_ERR(dentry))
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 429) return NULL;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 430)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 431) inode = tracefs_get_inode(dentry->d_sb);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 432) if (unlikely(!inode))
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 433) return failed_creating(dentry);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 434)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 435) inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 436) inode->i_op = ops;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 437) inode->i_fop = &simple_dir_operations;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 438)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 439) /* directory inodes start off with i_nlink == 2 (for "." entry) */
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 440) inc_nlink(inode);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 441) d_instantiate(dentry, inode);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 442) inc_nlink(dentry->d_parent->d_inode);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 443) fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 444) return end_creating(dentry);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 445) }
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 446)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 447) /**
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 448) * tracefs_create_dir - create a directory in the tracefs filesystem
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 449) * @name: a pointer to a string containing the name of the directory to
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 450) * create.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 451) * @parent: a pointer to the parent dentry for this file. This should be a
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 452) * directory dentry if set. If this parameter is NULL, then the
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 453) * directory will be created in the root of the tracefs filesystem.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 454) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 455) * This function creates a directory in tracefs with the given name.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 456) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 457) * This function will return a pointer to a dentry if it succeeds. This
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 458) * pointer must be passed to the tracefs_remove() function when the file is
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 459) * to be removed. If an error occurs, %NULL will be returned.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 460) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 461) * If tracing is not enabled in the kernel, the value -%ENODEV will be
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 462) * returned.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 463) */
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 464) struct dentry *tracefs_create_dir(const char *name, struct dentry *parent)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 465) {
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 466) return __create_dir(name, parent, &simple_dir_inode_operations);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 467) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 468)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 469) /**
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 470) * tracefs_create_instance_dir - create the tracing instances directory
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 471) * @name: The name of the instances directory to create
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 472) * @parent: The parent directory that the instances directory will exist
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 473) * @mkdir: The function to call when a mkdir is performed.
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 474) * @rmdir: The function to call when a rmdir is performed.
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 475) *
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 476) * Only one instances directory is allowed.
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 477) *
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 478) * The instances directory is special as it allows for mkdir and rmdir to
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 479) * to be done by userspace. When a mkdir or rmdir is performed, the inode
f2cc020d7876d (Ingo Molnar 2021-03-23 18:49:35 +0100 480) * locks are released and the methods passed in (@mkdir and @rmdir) are
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 481) * called without locks and with the name of the directory being created
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 482) * within the instances directory.
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 483) *
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 484) * Returns the dentry of the instances directory.
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 485) */
5248ee8560306 (Zubin Mithra 2018-07-25 10:19:01 -0700 486) __init struct dentry *tracefs_create_instance_dir(const char *name,
5248ee8560306 (Zubin Mithra 2018-07-25 10:19:01 -0700 487) struct dentry *parent,
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 488) int (*mkdir)(const char *name),
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 489) int (*rmdir)(const char *name))
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 490) {
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 491) struct dentry *dentry;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 492)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 493) /* Only allow one instance of the instances directory. */
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 494) if (WARN_ON(tracefs_ops.mkdir || tracefs_ops.rmdir))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 495) return NULL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 496)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 497) dentry = __create_dir(name, parent, &tracefs_dir_inode_operations);
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 498) if (!dentry)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 499) return NULL;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 500)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 501) tracefs_ops.mkdir = mkdir;
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 502) tracefs_ops.rmdir = rmdir;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 503)
eae473581cf93 (Steven Rostedt (Red Hat) 2015-01-21 10:01:39 -0500 504) return dentry;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 505) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 506)
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 507) static void remove_one(struct dentry *victim)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 508) {
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 509) simple_release_fs(&tracefs_mount, &tracefs_mount_count);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 510) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 511)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 512) /**
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 513) * tracefs_remove - recursively removes a directory
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 514) * @dentry: a pointer to a the dentry of the directory to be removed.
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 515) *
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 516) * This function recursively removes a directory tree in tracefs that
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 517) * was previously created with a call to another tracefs function
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 518) * (like tracefs_create_file() or variants thereof.)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 519) */
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 520) void tracefs_remove(struct dentry *dentry)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 521) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 522) if (IS_ERR_OR_NULL(dentry))
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 523) return;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 524)
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 525) simple_pin_fs(&trace_fs_type, &tracefs_mount, &tracefs_mount_count);
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 526) simple_recursive_removal(dentry, remove_one);
a3d1e7eb5abe3 (Al Viro 2019-11-18 09:43:10 -0500 527) simple_release_fs(&tracefs_mount, &tracefs_mount_count);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 528) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 529)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 530) /**
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 531) * tracefs_initialized - Tells whether tracefs has been registered
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 532) */
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 533) bool tracefs_initialized(void)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 534) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 535) return tracefs_registered;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 536) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 537)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 538) static int __init tracefs_init(void)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 539) {
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 540) int retval;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 541)
f9bb48825a6b5 (Eric W. Biederman 2015-05-13 17:35:41 -0500 542) retval = sysfs_create_mount_point(kernel_kobj, "tracing");
f9bb48825a6b5 (Eric W. Biederman 2015-05-13 17:35:41 -0500 543) if (retval)
cc31004a4aa78 (Steven Rostedt (Red Hat) 2015-01-21 11:28:23 -0500 544) return -EINVAL;
cc31004a4aa78 (Steven Rostedt (Red Hat) 2015-01-21 11:28:23 -0500 545)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 546) retval = register_filesystem(&trace_fs_type);
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 547) if (!retval)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 548) tracefs_registered = true;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 549)
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 550) return retval;
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 551) }
4282d60689d4f (Steven Rostedt (Red Hat) 2015-01-20 11:36:55 -0500 552) core_initcall(tracefs_init);
VisionFive2 Linux kernel
StarFive Tech Linux Kernel for VisionFive (JH7110) boards (mirror)
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