Revision 7fa598f9706d40bd16f2ab286bdf5808e1393d35 authored by Steven Rostedt (VMware) on 27 October 2021, 16:08:54 UTC, committed by Steven Rostedt (VMware) on 28 October 2021, 01:47:55 UTC
When the syscall trace points are not configured in, the kselftests for ftrace will try to attach an event probe (eprobe) to one of the system call trace points. This triggered a WARNING, because the failure only expects to see memory issues. But this is not the only failure. The user may attempt to attach to a non existent event, and the kernel must not warn about it. Link: https://lkml.kernel.org/r/20211027120854.0680aa0f@gandalf.local.home Fixes: 7491e2c442781 ("tracing: Add a probe that attaches to trace events") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
1 parent 4e84dc4
inode.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* inode.c - securityfs
*
* Copyright (C) 2005 Greg Kroah-Hartman <gregkh@suse.de>
*
* Based on fs/debugfs/inode.c which had the following copyright notice:
* Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 IBM Inc.
*/
/* #define DEBUG */
#include <linux/sysfs.h>
#include <linux/kobject.h>
#include <linux/fs.h>
#include <linux/fs_context.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/namei.h>
#include <linux/security.h>
#include <linux/lsm_hooks.h>
#include <linux/magic.h>
static struct vfsmount *mount;
static int mount_count;
static void securityfs_free_inode(struct inode *inode)
{
if (S_ISLNK(inode->i_mode))
kfree(inode->i_link);
free_inode_nonrcu(inode);
}
static const struct super_operations securityfs_super_operations = {
.statfs = simple_statfs,
.free_inode = securityfs_free_inode,
};
static int securityfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
static const struct tree_descr files[] = {{""}};
int error;
error = simple_fill_super(sb, SECURITYFS_MAGIC, files);
if (error)
return error;
sb->s_op = &securityfs_super_operations;
return 0;
}
static int securityfs_get_tree(struct fs_context *fc)
{
return get_tree_single(fc, securityfs_fill_super);
}
static const struct fs_context_operations securityfs_context_ops = {
.get_tree = securityfs_get_tree,
};
static int securityfs_init_fs_context(struct fs_context *fc)
{
fc->ops = &securityfs_context_ops;
return 0;
}
static struct file_system_type fs_type = {
.owner = THIS_MODULE,
.name = "securityfs",
.init_fs_context = securityfs_init_fs_context,
.kill_sb = kill_litter_super,
};
/**
* securityfs_create_dentry - create a dentry in the securityfs filesystem
*
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the securityfs filesystem.
* @data: a pointer to something that the caller will want to get to later
* on. The inode.i_private pointer will point to this value on
* the open() call.
* @fops: a pointer to a struct file_operations that should be used for
* this file.
* @iops: a point to a struct of inode_operations that should be used for
* this file/dir
*
* This is the basic "create a file/dir/symlink" function for
* securityfs. It allows for a wide range of flexibility in creating
* a file, or a directory (if you want to create a directory, the
* securityfs_create_dir() function is recommended to be used
* instead).
*
* This function returns a pointer to a dentry if it succeeds. This
* pointer must be passed to the securityfs_remove() function when the
* file is to be removed (no automatic cleanup happens if your module
* is unloaded, you are responsible here). If an error occurs, the
* function will return the error value (via ERR_PTR).
*
* If securityfs is not enabled in the kernel, the value %-ENODEV is
* returned.
*/
static struct dentry *securityfs_create_dentry(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops,
const struct inode_operations *iops)
{
struct dentry *dentry;
struct inode *dir, *inode;
int error;
if (!(mode & S_IFMT))
mode = (mode & S_IALLUGO) | S_IFREG;
pr_debug("securityfs: creating file '%s'\n",name);
error = simple_pin_fs(&fs_type, &mount, &mount_count);
if (error)
return ERR_PTR(error);
if (!parent)
parent = mount->mnt_root;
dir = d_inode(parent);
inode_lock(dir);
dentry = lookup_one_len(name, parent, strlen(name));
if (IS_ERR(dentry))
goto out;
if (d_really_is_positive(dentry)) {
error = -EEXIST;
goto out1;
}
inode = new_inode(dir->i_sb);
if (!inode) {
error = -ENOMEM;
goto out1;
}
inode->i_ino = get_next_ino();
inode->i_mode = mode;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
inode->i_private = data;
if (S_ISDIR(mode)) {
inode->i_op = &simple_dir_inode_operations;
inode->i_fop = &simple_dir_operations;
inc_nlink(inode);
inc_nlink(dir);
} else if (S_ISLNK(mode)) {
inode->i_op = iops ? iops : &simple_symlink_inode_operations;
inode->i_link = data;
} else {
inode->i_fop = fops;
}
d_instantiate(dentry, inode);
dget(dentry);
inode_unlock(dir);
return dentry;
out1:
dput(dentry);
dentry = ERR_PTR(error);
out:
inode_unlock(dir);
simple_release_fs(&mount, &mount_count);
return dentry;
}
/**
* securityfs_create_file - create a file in the securityfs filesystem
*
* @name: a pointer to a string containing the name of the file to create.
* @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the securityfs filesystem.
* @data: a pointer to something that the caller will want to get to later
* on. The inode.i_private pointer will point to this value on
* the open() call.
* @fops: a pointer to a struct file_operations that should be used for
* this file.
*
* This function creates a file in securityfs with the given @name.
*
* This function returns a pointer to a dentry if it succeeds. This
* pointer must be passed to the securityfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here). If an error occurs, the function will return
* the error value (via ERR_PTR).
*
* If securityfs is not enabled in the kernel, the value %-ENODEV is
* returned.
*/
struct dentry *securityfs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
return securityfs_create_dentry(name, mode, parent, data, fops, NULL);
}
EXPORT_SYMBOL_GPL(securityfs_create_file);
/**
* securityfs_create_dir - create a directory in the securityfs filesystem
*
* @name: a pointer to a string containing the name of the directory to
* create.
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this parameter is %NULL, then the
* directory will be created in the root of the securityfs filesystem.
*
* This function creates a directory in securityfs with the given @name.
*
* This function returns a pointer to a dentry if it succeeds. This
* pointer must be passed to the securityfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here). If an error occurs, the function will return
* the error value (via ERR_PTR).
*
* If securityfs is not enabled in the kernel, the value %-ENODEV is
* returned.
*/
struct dentry *securityfs_create_dir(const char *name, struct dentry *parent)
{
return securityfs_create_file(name, S_IFDIR | 0755, parent, NULL, NULL);
}
EXPORT_SYMBOL_GPL(securityfs_create_dir);
/**
* securityfs_create_symlink - create a symlink in the securityfs filesystem
*
* @name: a pointer to a string containing the name of the symlink to
* create.
* @parent: a pointer to the parent dentry for the symlink. This should be a
* directory dentry if set. If this parameter is %NULL, then the
* directory will be created in the root of the securityfs filesystem.
* @target: a pointer to a string containing the name of the symlink's target.
* If this parameter is %NULL, then the @iops parameter needs to be
* setup to handle .readlink and .get_link inode_operations.
* @iops: a pointer to the struct inode_operations to use for the symlink. If
* this parameter is %NULL, then the default simple_symlink_inode
* operations will be used.
*
* This function creates a symlink in securityfs with the given @name.
*
* This function returns a pointer to a dentry if it succeeds. This
* pointer must be passed to the securityfs_remove() function when the file is
* to be removed (no automatic cleanup happens if your module is unloaded,
* you are responsible here). If an error occurs, the function will return
* the error value (via ERR_PTR).
*
* If securityfs is not enabled in the kernel, the value %-ENODEV is
* returned.
*/
struct dentry *securityfs_create_symlink(const char *name,
struct dentry *parent,
const char *target,
const struct inode_operations *iops)
{
struct dentry *dent;
char *link = NULL;
if (target) {
link = kstrdup(target, GFP_KERNEL);
if (!link)
return ERR_PTR(-ENOMEM);
}
dent = securityfs_create_dentry(name, S_IFLNK | 0444, parent,
link, NULL, iops);
if (IS_ERR(dent))
kfree(link);
return dent;
}
EXPORT_SYMBOL_GPL(securityfs_create_symlink);
/**
* securityfs_remove - removes a file or directory from the securityfs filesystem
*
* @dentry: a pointer to a the dentry of the file or directory to be removed.
*
* This function removes a file or directory in securityfs that was previously
* created with a call to another securityfs function (like
* securityfs_create_file() or variants thereof.)
*
* This function is required to be called in order for the file to be
* removed. No automatic cleanup of files will happen when a module is
* removed; you are responsible here.
*/
void securityfs_remove(struct dentry *dentry)
{
struct inode *dir;
if (!dentry || IS_ERR(dentry))
return;
dir = d_inode(dentry->d_parent);
inode_lock(dir);
if (simple_positive(dentry)) {
if (d_is_dir(dentry))
simple_rmdir(dir, dentry);
else
simple_unlink(dir, dentry);
dput(dentry);
}
inode_unlock(dir);
simple_release_fs(&mount, &mount_count);
}
EXPORT_SYMBOL_GPL(securityfs_remove);
#ifdef CONFIG_SECURITY
static struct dentry *lsm_dentry;
static ssize_t lsm_read(struct file *filp, char __user *buf, size_t count,
loff_t *ppos)
{
return simple_read_from_buffer(buf, count, ppos, lsm_names,
strlen(lsm_names));
}
static const struct file_operations lsm_ops = {
.read = lsm_read,
.llseek = generic_file_llseek,
};
#endif
static int __init securityfs_init(void)
{
int retval;
retval = sysfs_create_mount_point(kernel_kobj, "security");
if (retval)
return retval;
retval = register_filesystem(&fs_type);
if (retval) {
sysfs_remove_mount_point(kernel_kobj, "security");
return retval;
}
#ifdef CONFIG_SECURITY
lsm_dentry = securityfs_create_file("lsm", 0444, NULL, NULL,
&lsm_ops);
#endif
return 0;
}
core_initcall(securityfs_init);
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