Contributors: 26
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Davide Libenzi |
444 |
42.09% |
4 |
8.70% |
| Daniel Colascione |
217 |
20.57% |
1 |
2.17% |
| Christian Brauner |
73 |
6.92% |
7 |
15.22% |
| David Howells |
53 |
5.02% |
4 |
8.70% |
| Dawid Osuchowski |
32 |
3.03% |
1 |
2.17% |
| Jan Kara |
29 |
2.75% |
1 |
2.17% |
| Ulrich Drepper |
28 |
2.65% |
2 |
4.35% |
| Al Viro |
27 |
2.56% |
6 |
13.04% |
| Christian Bornträger |
26 |
2.46% |
1 |
2.17% |
| OGAWA Hirofumi |
21 |
1.99% |
1 |
2.17% |
| Nicholas Piggin |
21 |
1.99% |
1 |
2.17% |
| Shivank Garg |
18 |
1.71% |
1 |
2.17% |
| Dave Hansen |
11 |
1.04% |
1 |
2.17% |
| Paul Moore |
10 |
0.95% |
1 |
2.17% |
| Paolo Bonzini |
8 |
0.76% |
1 |
2.17% |
| Anatol Pomozov |
7 |
0.66% |
1 |
2.17% |
| Sean Christopherson |
5 |
0.47% |
1 |
2.17% |
| Avi Kivity |
5 |
0.47% |
1 |
2.17% |
| Alexey Dobriyan |
5 |
0.47% |
2 |
4.35% |
| Eric W. Biedermann |
4 |
0.38% |
1 |
2.17% |
| Roland Dreier |
3 |
0.28% |
1 |
2.17% |
| Linus Torvalds (pre-git) |
3 |
0.28% |
2 |
4.35% |
| Jeff Layton |
2 |
0.19% |
1 |
2.17% |
| Namhyung Kim |
1 |
0.09% |
1 |
2.17% |
| Linus Torvalds |
1 |
0.09% |
1 |
2.17% |
| Thomas Gleixner |
1 |
0.09% |
1 |
2.17% |
| Total |
1055 |
|
46 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* fs/anon_inodes.c
*
* Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org>
*
* Thanks to Arnd Bergmann for code review and suggestions.
* More changes for Thomas Gleixner suggestions.
*
*/
#include <linux/cred.h>
#include <linux/file.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/magic.h>
#include <linux/anon_inodes.h>
#include <linux/pseudo_fs.h>
#include <linux/uaccess.h>
#include "internal.h"
static struct vfsmount *anon_inode_mnt __ro_after_init;
static struct inode *anon_inode_inode __ro_after_init;
/*
* User space expects anonymous inodes to have no file type in st_mode.
*
* In particular, 'lsof' has this legacy logic:
*
* type = s->st_mode & S_IFMT;
* switch (type) {
* ...
* case 0:
* if (!strcmp(p, "anon_inode"))
* Lf->ntype = Ntype = N_ANON_INODE;
*
* to detect our old anon_inode logic.
*
* Rather than mess with our internal sane inode data, just fix it
* up here in getattr() by masking off the format bits.
*/
int anon_inode_getattr(struct mnt_idmap *idmap, const struct path *path,
struct kstat *stat, u32 request_mask,
unsigned int query_flags)
{
struct inode *inode = d_inode(path->dentry);
generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
stat->mode &= ~S_IFMT;
return 0;
}
int anon_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
struct iattr *attr)
{
return -EOPNOTSUPP;
}
static const struct inode_operations anon_inode_operations = {
.getattr = anon_inode_getattr,
.setattr = anon_inode_setattr,
};
/*
* anon_inodefs_dname() is called from d_path().
*/
static char *anon_inodefs_dname(struct dentry *dentry, char *buffer, int buflen)
{
return dynamic_dname(buffer, buflen, "anon_inode:%s",
dentry->d_name.name);
}
static const struct dentry_operations anon_inodefs_dentry_operations = {
.d_dname = anon_inodefs_dname,
};
static int anon_inodefs_init_fs_context(struct fs_context *fc)
{
struct pseudo_fs_context *ctx = init_pseudo(fc, ANON_INODE_FS_MAGIC);
if (!ctx)
return -ENOMEM;
fc->s_iflags |= SB_I_NOEXEC;
fc->s_iflags |= SB_I_NODEV;
ctx->dops = &anon_inodefs_dentry_operations;
return 0;
}
static struct file_system_type anon_inode_fs_type = {
.name = "anon_inodefs",
.init_fs_context = anon_inodefs_init_fs_context,
.kill_sb = kill_anon_super,
};
/**
* anon_inode_make_secure_inode - allocate an anonymous inode with security context
* @sb: [in] Superblock to allocate from
* @name: [in] Name of the class of the newfile (e.g., "secretmem")
* @context_inode:
* [in] Optional parent inode for security inheritance
*
* The function ensures proper security initialization through the LSM hook
* security_inode_init_security_anon().
*
* Return: Pointer to new inode on success, ERR_PTR on failure.
*/
struct inode *anon_inode_make_secure_inode(struct super_block *sb, const char *name,
const struct inode *context_inode)
{
struct inode *inode;
int error;
inode = alloc_anon_inode(sb);
if (IS_ERR(inode))
return inode;
inode->i_flags &= ~S_PRIVATE;
inode->i_op = &anon_inode_operations;
error = security_inode_init_security_anon(inode, &QSTR(name),
context_inode);
if (error) {
iput(inode);
return ERR_PTR(error);
}
return inode;
}
EXPORT_SYMBOL_GPL_FOR_MODULES(anon_inode_make_secure_inode, "kvm");
static struct file *__anon_inode_getfile(const char *name,
const struct file_operations *fops,
void *priv, int flags,
const struct inode *context_inode,
bool make_inode)
{
struct inode *inode;
struct file *file;
if (fops->owner && !try_module_get(fops->owner))
return ERR_PTR(-ENOENT);
if (make_inode) {
inode = anon_inode_make_secure_inode(anon_inode_mnt->mnt_sb,
name, context_inode);
if (IS_ERR(inode)) {
file = ERR_CAST(inode);
goto err;
}
} else {
inode = anon_inode_inode;
if (IS_ERR(inode)) {
file = ERR_PTR(-ENODEV);
goto err;
}
/*
* We know the anon_inode inode count is always
* greater than zero, so ihold() is safe.
*/
ihold(inode);
}
file = alloc_file_pseudo(inode, anon_inode_mnt, name,
flags & (O_ACCMODE | O_NONBLOCK), fops);
if (IS_ERR(file))
goto err_iput;
file->f_mapping = inode->i_mapping;
file->private_data = priv;
return file;
err_iput:
iput(inode);
err:
module_put(fops->owner);
return file;
}
/**
* anon_inode_getfile - creates a new file instance by hooking it up to an
* anonymous inode, and a dentry that describe the "class"
* of the file
*
* @name: [in] name of the "class" of the new file
* @fops: [in] file operations for the new file
* @priv: [in] private data for the new file (will be file's private_data)
* @flags: [in] flags
*
* Creates a new file by hooking it on a single inode. This is useful for files
* that do not need to have a full-fledged inode in order to operate correctly.
* All the files created with anon_inode_getfile() will share a single inode,
* hence saving memory and avoiding code duplication for the file/inode/dentry
* setup. Returns the newly created file* or an error pointer.
*/
struct file *anon_inode_getfile(const char *name,
const struct file_operations *fops,
void *priv, int flags)
{
return __anon_inode_getfile(name, fops, priv, flags, NULL, false);
}
EXPORT_SYMBOL_GPL(anon_inode_getfile);
/**
* anon_inode_getfile_fmode - creates a new file instance by hooking it up to an
* anonymous inode, and a dentry that describe the "class"
* of the file
*
* @name: [in] name of the "class" of the new file
* @fops: [in] file operations for the new file
* @priv: [in] private data for the new file (will be file's private_data)
* @flags: [in] flags
* @f_mode: [in] fmode
*
* Creates a new file by hooking it on a single inode. This is useful for files
* that do not need to have a full-fledged inode in order to operate correctly.
* All the files created with anon_inode_getfile() will share a single inode,
* hence saving memory and avoiding code duplication for the file/inode/dentry
* setup. Allows setting the fmode. Returns the newly created file* or an error
* pointer.
*/
struct file *anon_inode_getfile_fmode(const char *name,
const struct file_operations *fops,
void *priv, int flags, fmode_t f_mode)
{
struct file *file;
file = __anon_inode_getfile(name, fops, priv, flags, NULL, false);
if (!IS_ERR(file))
file->f_mode |= f_mode;
return file;
}
EXPORT_SYMBOL_GPL(anon_inode_getfile_fmode);
/**
* anon_inode_create_getfile - Like anon_inode_getfile(), but creates a new
* !S_PRIVATE anon inode rather than reuse the
* singleton anon inode and calls the
* inode_init_security_anon() LSM hook.
*
* @name: [in] name of the "class" of the new file
* @fops: [in] file operations for the new file
* @priv: [in] private data for the new file (will be file's private_data)
* @flags: [in] flags
* @context_inode:
* [in] the logical relationship with the new inode (optional)
*
* Create a new anonymous inode and file pair. This can be done for two
* reasons:
*
* - for the inode to have its own security context, so that LSMs can enforce
* policy on the inode's creation;
*
* - if the caller needs a unique inode, for example in order to customize
* the size returned by fstat()
*
* The LSM may use @context_inode in inode_init_security_anon(), but a
* reference to it is not held.
*
* Returns the newly created file* or an error pointer.
*/
struct file *anon_inode_create_getfile(const char *name,
const struct file_operations *fops,
void *priv, int flags,
const struct inode *context_inode)
{
return __anon_inode_getfile(name, fops, priv, flags,
context_inode, true);
}
EXPORT_SYMBOL_GPL(anon_inode_create_getfile);
static int __anon_inode_getfd(const char *name,
const struct file_operations *fops,
void *priv, int flags,
const struct inode *context_inode,
bool make_inode)
{
int error, fd;
struct file *file;
error = get_unused_fd_flags(flags);
if (error < 0)
return error;
fd = error;
file = __anon_inode_getfile(name, fops, priv, flags, context_inode,
make_inode);
if (IS_ERR(file)) {
error = PTR_ERR(file);
goto err_put_unused_fd;
}
fd_install(fd, file);
return fd;
err_put_unused_fd:
put_unused_fd(fd);
return error;
}
/**
* anon_inode_getfd - creates a new file instance by hooking it up to
* an anonymous inode and a dentry that describe
* the "class" of the file
*
* @name: [in] name of the "class" of the new file
* @fops: [in] file operations for the new file
* @priv: [in] private data for the new file (will be file's private_data)
* @flags: [in] flags
*
* Creates a new file by hooking it on a single inode. This is
* useful for files that do not need to have a full-fledged inode in
* order to operate correctly. All the files created with
* anon_inode_getfd() will use the same singleton inode, reducing
* memory use and avoiding code duplication for the file/inode/dentry
* setup. Returns a newly created file descriptor or an error code.
*/
int anon_inode_getfd(const char *name, const struct file_operations *fops,
void *priv, int flags)
{
return __anon_inode_getfd(name, fops, priv, flags, NULL, false);
}
EXPORT_SYMBOL_GPL(anon_inode_getfd);
/**
* anon_inode_create_getfd - Like anon_inode_getfd(), but creates a new
* !S_PRIVATE anon inode rather than reuse the singleton anon inode, and calls
* the inode_init_security_anon() LSM hook.
*
* @name: [in] name of the "class" of the new file
* @fops: [in] file operations for the new file
* @priv: [in] private data for the new file (will be file's private_data)
* @flags: [in] flags
* @context_inode:
* [in] the logical relationship with the new inode (optional)
*
* Create a new anonymous inode and file pair. This can be done for two
* reasons:
*
* - for the inode to have its own security context, so that LSMs can enforce
* policy on the inode's creation;
*
* - if the caller needs a unique inode, for example in order to customize
* the size returned by fstat()
*
* The LSM may use @context_inode in inode_init_security_anon(), but a
* reference to it is not held.
*
* Returns a newly created file descriptor or an error code.
*/
int anon_inode_create_getfd(const char *name, const struct file_operations *fops,
void *priv, int flags,
const struct inode *context_inode)
{
return __anon_inode_getfd(name, fops, priv, flags, context_inode, true);
}
static int __init anon_inode_init(void)
{
anon_inode_mnt = kern_mount(&anon_inode_fs_type);
if (IS_ERR(anon_inode_mnt))
panic("anon_inode_init() kernel mount failed (%ld)\n", PTR_ERR(anon_inode_mnt));
anon_inode_inode = alloc_anon_inode(anon_inode_mnt->mnt_sb);
if (IS_ERR(anon_inode_inode))
panic("anon_inode_init() inode allocation failed (%ld)\n", PTR_ERR(anon_inode_inode));
anon_inode_inode->i_op = &anon_inode_operations;
return 0;
}
fs_initcall(anon_inode_init);