/*
* sys_execve() executes a new program.
*/
-static int __do_execve_file(int fd, struct filename *filename,
- struct user_arg_ptr argv,
- struct user_arg_ptr envp,
- int flags, struct file *file)
+static int do_execveat_common(int fd, struct filename *filename,
+ struct user_arg_ptr argv,
+ struct user_arg_ptr envp,
+ int flags)
{
char *pathbuf = NULL;
struct linux_binprm *bprm;
+ struct file *file;
struct files_struct *displaced;
int retval;
check_unsafe_exec(bprm);
current->in_execve = 1;
- if (!file)
- file = do_open_execat(fd, filename, flags);
+ file = do_open_execat(fd, filename, flags);
retval = PTR_ERR(file);
if (IS_ERR(file))
goto out_unmark;
sched_exec();
bprm->file = file;
- if (!filename) {
- bprm->filename = "none";
- } else if (fd == AT_FDCWD || filename->name[0] == '/') {
+ if (fd == AT_FDCWD || filename->name[0] == '/') {
bprm->filename = filename->name;
} else {
if (filename->name[0] == '\0')
task_numa_free(current, false);
free_bprm(bprm);
kfree(pathbuf);
- if (filename)
- putname(filename);
+ putname(filename);
if (displaced)
put_files_struct(displaced);
return retval;
if (displaced)
reset_files_struct(displaced);
out_ret:
- if (filename)
- putname(filename);
+ putname(filename);
return retval;
}
-static int do_execveat_common(int fd, struct filename *filename,
- struct user_arg_ptr argv,
- struct user_arg_ptr envp,
- int flags)
-{
- return __do_execve_file(fd, filename, argv, envp, flags, NULL);
-}
-
-int do_execve_file(struct file *file, void *__argv, void *__envp)
-{
- struct user_arg_ptr argv = { .ptr.native = __argv };
- struct user_arg_ptr envp = { .ptr.native = __envp };
-
- return __do_execve_file(AT_FDCWD, NULL, argv, envp, 0, file);
-}
-
int do_execve(struct filename *filename,
const char __user *const __user *__argv,
const char __user *const __user *__envp)
const char __user * const __user *,
const char __user * const __user *,
int);
-int do_execve_file(struct file *file, void *__argv, void *__envp);
#endif /* _LINUX_BINFMTS_H */
#define _LINUX_BPFILTER_H
#include <uapi/linux/bpfilter.h>
-#include <linux/umh.h>
+#include <linux/usermode_driver.h>
struct sock;
int bpfilter_ip_set_sockopt(struct sock *sk, int optname, char __user *optval,
unsigned int optlen);
int bpfilter_ip_get_sockopt(struct sock *sk, int optname, char __user *optval,
int __user *optlen);
+void bpfilter_umh_cleanup(struct umd_info *info);
+
struct bpfilter_umh_ops {
- struct umh_info info;
+ struct umd_info info;
/* since ip_getsockopt() can run in parallel, serialize access to umh */
struct mutex lock;
int (*sockopt)(struct sock *sk, int optname,
char __user *optval,
unsigned int optlen, bool is_set);
int (*start)(void);
- bool stop;
};
extern struct bpfilter_umh_ops bpfilter_ops;
#endif
#define PF_KTHREAD 0x00200000 /* I am a kernel thread */
#define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
#define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
-#define PF_UMH 0x02000000 /* I'm an Usermodehelper process */
#define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
#define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
#define PF_MEMALLOC_NOCMA 0x10000000 /* All allocation request will have _GFP_MOVABLE cleared */
#endif
-void __exit_umh(struct task_struct *tsk);
-
-static inline void exit_umh(struct task_struct *tsk)
-{
- if (unlikely(tsk->flags & PF_UMH))
- __exit_umh(tsk);
-}
-
#ifdef CONFIG_DEBUG_RSEQ
void rseq_syscall(struct pt_regs *regs);
#define delay_group_leader(p) \
(thread_group_leader(p) && !thread_group_empty(p))
+extern bool thread_group_exited(struct pid *pid);
+
extern struct sighand_struct *__lock_task_sighand(struct task_struct *task,
unsigned long *flags);
const char *path;
char **argv;
char **envp;
- struct file *file;
int wait;
int retval;
- pid_t pid;
int (*init)(struct subprocess_info *info, struct cred *new);
void (*cleanup)(struct subprocess_info *info);
void *data;
int (*init)(struct subprocess_info *info, struct cred *new),
void (*cleanup)(struct subprocess_info *), void *data);
-struct subprocess_info *call_usermodehelper_setup_file(struct file *file,
- int (*init)(struct subprocess_info *info, struct cred *new),
- void (*cleanup)(struct subprocess_info *), void *data);
-struct umh_info {
- const char *cmdline;
- struct file *pipe_to_umh;
- struct file *pipe_from_umh;
- struct list_head list;
- void (*cleanup)(struct umh_info *info);
- pid_t pid;
-};
-int fork_usermode_blob(void *data, size_t len, struct umh_info *info);
-
extern int
call_usermodehelper_exec(struct subprocess_info *info, int wait);
--- /dev/null
+#ifndef __LINUX_USERMODE_DRIVER_H__
+#define __LINUX_USERMODE_DRIVER_H__
+
+#include <linux/umh.h>
+#include <linux/path.h>
+
+struct umd_info {
+ const char *driver_name;
+ struct file *pipe_to_umh;
+ struct file *pipe_from_umh;
+ struct path wd;
+ struct pid *tgid;
+};
+int umd_load_blob(struct umd_info *info, const void *data, size_t len);
+int umd_unload_blob(struct umd_info *info);
+int fork_usermode_driver(struct umd_info *info);
+
+#endif /* __LINUX_USERMODE_DRIVER_H__ */
notifier.o ksysfs.o cred.o reboot.o \
async.o range.o smpboot.o ucount.o
+obj-$(CONFIG_BPFILTER) += usermode_driver.o
obj-$(CONFIG_MODULES) += kmod.o
obj-$(CONFIG_MULTIUSER) += groups.o
exit_task_namespaces(tsk);
exit_task_work(tsk);
exit_thread(tsk);
- exit_umh(tsk);
/*
* Flush inherited counters to the parent - before the parent
}
#endif
+/**
+ * thread_group_exited - check that a thread group has exited
+ * @pid: tgid of thread group to be checked.
+ *
+ * Test if the thread group represented by tgid has exited (all
+ * threads are zombies, dead or completely gone).
+ *
+ * Return: true if the thread group has exited. false otherwise.
+ */
+bool thread_group_exited(struct pid *pid)
+{
+ struct task_struct *task;
+ bool exited;
+
+ rcu_read_lock();
+ task = pid_task(pid, PIDTYPE_PID);
+ exited = !task ||
+ (READ_ONCE(task->exit_state) && thread_group_empty(task));
+ rcu_read_unlock();
+
+ return exited;
+}
+EXPORT_SYMBOL(thread_group_exited);
+
__weak void abort(void)
{
BUG();
*/
static __poll_t pidfd_poll(struct file *file, struct poll_table_struct *pts)
{
- struct task_struct *task;
struct pid *pid = file->private_data;
__poll_t poll_flags = 0;
poll_wait(file, &pid->wait_pidfd, pts);
- rcu_read_lock();
- task = pid_task(pid, PIDTYPE_PID);
/*
* Inform pollers only when the whole thread group exits.
* If the thread group leader exits before all other threads in the
* group, then poll(2) should block, similar to the wait(2) family.
*/
- if (!task || (task->exit_state && thread_group_empty(task)))
+ if (thread_group_exited(pid))
poll_flags = EPOLLIN | EPOLLRDNORM;
- rcu_read_unlock();
return poll_flags;
}
#include <linux/ptrace.h>
#include <linux/async.h>
#include <linux/uaccess.h>
-#include <linux/shmem_fs.h>
-#include <linux/pipe_fs_i.h>
#include <trace/events/module.h>
static kernel_cap_t usermodehelper_inheritable = CAP_FULL_SET;
static DEFINE_SPINLOCK(umh_sysctl_lock);
static DECLARE_RWSEM(umhelper_sem);
-static LIST_HEAD(umh_list);
-static DEFINE_MUTEX(umh_list_lock);
static void call_usermodehelper_freeinfo(struct subprocess_info *info)
{
commit_creds(new);
- sub_info->pid = task_pid_nr(current);
- if (sub_info->file) {
- retval = do_execve_file(sub_info->file,
- sub_info->argv, sub_info->envp);
- if (!retval)
- current->flags |= PF_UMH;
- } else
- retval = do_execve(getname_kernel(sub_info->path),
- (const char __user *const __user *)sub_info->argv,
- (const char __user *const __user *)sub_info->envp);
+ retval = do_execve(getname_kernel(sub_info->path),
+ (const char __user *const __user *)sub_info->argv,
+ (const char __user *const __user *)sub_info->envp);
out:
sub_info->retval = retval;
/*
}
EXPORT_SYMBOL(call_usermodehelper_setup);
-struct subprocess_info *call_usermodehelper_setup_file(struct file *file,
- int (*init)(struct subprocess_info *info, struct cred *new),
- void (*cleanup)(struct subprocess_info *info), void *data)
-{
- struct subprocess_info *sub_info;
- struct umh_info *info = data;
- const char *cmdline = (info->cmdline) ? info->cmdline : "usermodehelper";
-
- sub_info = kzalloc(sizeof(struct subprocess_info), GFP_KERNEL);
- if (!sub_info)
- return NULL;
-
- sub_info->argv = argv_split(GFP_KERNEL, cmdline, NULL);
- if (!sub_info->argv) {
- kfree(sub_info);
- return NULL;
- }
-
- INIT_WORK(&sub_info->work, call_usermodehelper_exec_work);
- sub_info->path = "none";
- sub_info->file = file;
- sub_info->init = init;
- sub_info->cleanup = cleanup;
- sub_info->data = data;
- return sub_info;
-}
-
-static int umh_pipe_setup(struct subprocess_info *info, struct cred *new)
-{
- struct umh_info *umh_info = info->data;
- struct file *from_umh[2];
- struct file *to_umh[2];
- int err;
-
- /* create pipe to send data to umh */
- err = create_pipe_files(to_umh, 0);
- if (err)
- return err;
- err = replace_fd(0, to_umh[0], 0);
- fput(to_umh[0]);
- if (err < 0) {
- fput(to_umh[1]);
- return err;
- }
-
- /* create pipe to receive data from umh */
- err = create_pipe_files(from_umh, 0);
- if (err) {
- fput(to_umh[1]);
- replace_fd(0, NULL, 0);
- return err;
- }
- err = replace_fd(1, from_umh[1], 0);
- fput(from_umh[1]);
- if (err < 0) {
- fput(to_umh[1]);
- replace_fd(0, NULL, 0);
- fput(from_umh[0]);
- return err;
- }
-
- umh_info->pipe_to_umh = to_umh[1];
- umh_info->pipe_from_umh = from_umh[0];
- return 0;
-}
-
-static void umh_clean_and_save_pid(struct subprocess_info *info)
-{
- struct umh_info *umh_info = info->data;
-
- /* cleanup if umh_pipe_setup() was successful but exec failed */
- if (info->pid && info->retval) {
- fput(umh_info->pipe_to_umh);
- fput(umh_info->pipe_from_umh);
- }
-
- argv_free(info->argv);
- umh_info->pid = info->pid;
-}
-
-/**
- * fork_usermode_blob - fork a blob of bytes as a usermode process
- * @data: a blob of bytes that can be do_execv-ed as a file
- * @len: length of the blob
- * @info: information about usermode process (shouldn't be NULL)
- *
- * If info->cmdline is set it will be used as command line for the
- * user process, else "usermodehelper" is used.
- *
- * Returns either negative error or zero which indicates success
- * in executing a blob of bytes as a usermode process. In such
- * case 'struct umh_info *info' is populated with two pipes
- * and a pid of the process. The caller is responsible for health
- * check of the user process, killing it via pid, and closing the
- * pipes when user process is no longer needed.
- */
-int fork_usermode_blob(void *data, size_t len, struct umh_info *info)
-{
- struct subprocess_info *sub_info;
- struct file *file;
- ssize_t written;
- loff_t pos = 0;
- int err;
-
- file = shmem_kernel_file_setup("", len, 0);
- if (IS_ERR(file))
- return PTR_ERR(file);
-
- written = kernel_write(file, data, len, &pos);
- if (written != len) {
- err = written;
- if (err >= 0)
- err = -ENOMEM;
- goto out;
- }
-
- err = -ENOMEM;
- sub_info = call_usermodehelper_setup_file(file, umh_pipe_setup,
- umh_clean_and_save_pid, info);
- if (!sub_info)
- goto out;
-
- err = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
- if (!err) {
- mutex_lock(&umh_list_lock);
- list_add(&info->list, &umh_list);
- mutex_unlock(&umh_list_lock);
- }
-out:
- fput(file);
- return err;
-}
-EXPORT_SYMBOL_GPL(fork_usermode_blob);
-
/**
* call_usermodehelper_exec - start a usermode application
* @sub_info: information about the subprocessa
return 0;
}
-void __exit_umh(struct task_struct *tsk)
-{
- struct umh_info *info;
- pid_t pid = tsk->pid;
-
- mutex_lock(&umh_list_lock);
- list_for_each_entry(info, &umh_list, list) {
- if (info->pid == pid) {
- list_del(&info->list);
- mutex_unlock(&umh_list_lock);
- goto out;
- }
- }
- mutex_unlock(&umh_list_lock);
- return;
-out:
- if (info->cleanup)
- info->cleanup(info);
-}
-
struct ctl_table usermodehelper_table[] = {
{
.procname = "bset",
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * umd - User mode driver support
+ */
+#include <linux/shmem_fs.h>
+#include <linux/pipe_fs_i.h>
+#include <linux/mount.h>
+#include <linux/fs_struct.h>
+#include <linux/task_work.h>
+#include <linux/usermode_driver.h>
+
+static struct vfsmount *blob_to_mnt(const void *data, size_t len, const char *name)
+{
+ struct file_system_type *type;
+ struct vfsmount *mnt;
+ struct file *file;
+ ssize_t written;
+ loff_t pos = 0;
+
+ type = get_fs_type("tmpfs");
+ if (!type)
+ return ERR_PTR(-ENODEV);
+
+ mnt = kern_mount(type);
+ put_filesystem(type);
+ if (IS_ERR(mnt))
+ return mnt;
+
+ file = file_open_root(mnt->mnt_root, mnt, name, O_CREAT | O_WRONLY, 0700);
+ if (IS_ERR(file)) {
+ mntput(mnt);
+ return ERR_CAST(file);
+ }
+
+ written = kernel_write(file, data, len, &pos);
+ if (written != len) {
+ int err = written;
+ if (err >= 0)
+ err = -ENOMEM;
+ filp_close(file, NULL);
+ mntput(mnt);
+ return ERR_PTR(err);
+ }
+
+ fput(file);
+
+ /* Flush delayed fput so exec can open the file read-only */
+ flush_delayed_fput();
+ task_work_run();
+ return mnt;
+}
+
+/**
+ * umd_load_blob - Remember a blob of bytes for fork_usermode_driver
+ * @info: information about usermode driver
+ * @data: a blob of bytes that can be executed as a file
+ * @len: The lentgh of the blob
+ *
+ */
+int umd_load_blob(struct umd_info *info, const void *data, size_t len)
+{
+ struct vfsmount *mnt;
+
+ if (WARN_ON_ONCE(info->wd.dentry || info->wd.mnt))
+ return -EBUSY;
+
+ mnt = blob_to_mnt(data, len, info->driver_name);
+ if (IS_ERR(mnt))
+ return PTR_ERR(mnt);
+
+ info->wd.mnt = mnt;
+ info->wd.dentry = mnt->mnt_root;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(umd_load_blob);
+
+/**
+ * umd_unload_blob - Disassociate @info from a previously loaded blob
+ * @info: information about usermode driver
+ *
+ */
+int umd_unload_blob(struct umd_info *info)
+{
+ if (WARN_ON_ONCE(!info->wd.mnt ||
+ !info->wd.dentry ||
+ info->wd.mnt->mnt_root != info->wd.dentry))
+ return -EINVAL;
+
+ kern_unmount(info->wd.mnt);
+ info->wd.mnt = NULL;
+ info->wd.dentry = NULL;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(umd_unload_blob);
+
+static int umd_setup(struct subprocess_info *info, struct cred *new)
+{
+ struct umd_info *umd_info = info->data;
+ struct file *from_umh[2];
+ struct file *to_umh[2];
+ int err;
+
+ /* create pipe to send data to umh */
+ err = create_pipe_files(to_umh, 0);
+ if (err)
+ return err;
+ err = replace_fd(0, to_umh[0], 0);
+ fput(to_umh[0]);
+ if (err < 0) {
+ fput(to_umh[1]);
+ return err;
+ }
+
+ /* create pipe to receive data from umh */
+ err = create_pipe_files(from_umh, 0);
+ if (err) {
+ fput(to_umh[1]);
+ replace_fd(0, NULL, 0);
+ return err;
+ }
+ err = replace_fd(1, from_umh[1], 0);
+ fput(from_umh[1]);
+ if (err < 0) {
+ fput(to_umh[1]);
+ replace_fd(0, NULL, 0);
+ fput(from_umh[0]);
+ return err;
+ }
+
+ set_fs_pwd(current->fs, &umd_info->wd);
+ umd_info->pipe_to_umh = to_umh[1];
+ umd_info->pipe_from_umh = from_umh[0];
+ umd_info->tgid = get_pid(task_tgid(current));
+ return 0;
+}
+
+static void umd_cleanup(struct subprocess_info *info)
+{
+ struct umd_info *umd_info = info->data;
+
+ /* cleanup if umh_setup() was successful but exec failed */
+ if (info->retval) {
+ fput(umd_info->pipe_to_umh);
+ fput(umd_info->pipe_from_umh);
+ put_pid(umd_info->tgid);
+ umd_info->tgid = NULL;
+ }
+}
+
+/**
+ * fork_usermode_driver - fork a usermode driver
+ * @info: information about usermode driver (shouldn't be NULL)
+ *
+ * Returns either negative error or zero which indicates success in
+ * executing a usermode driver. In such case 'struct umd_info *info'
+ * is populated with two pipes and a tgid of the process. The caller is
+ * responsible for health check of the user process, killing it via
+ * tgid, and closing the pipes when user process is no longer needed.
+ */
+int fork_usermode_driver(struct umd_info *info)
+{
+ struct subprocess_info *sub_info;
+ const char *argv[] = { info->driver_name, NULL };
+ int err;
+
+ if (WARN_ON_ONCE(info->tgid))
+ return -EBUSY;
+
+ err = -ENOMEM;
+ sub_info = call_usermodehelper_setup(info->driver_name,
+ (char **)argv, NULL, GFP_KERNEL,
+ umd_setup, umd_cleanup, info);
+ if (!sub_info)
+ goto out;
+
+ err = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
+out:
+ return err;
+}
+EXPORT_SYMBOL_GPL(fork_usermode_driver);
+
+
static void shutdown_umh(void)
{
- struct task_struct *tsk;
+ struct umd_info *info = &bpfilter_ops.info;
+ struct pid *tgid = info->tgid;
- if (bpfilter_ops.stop)
- return;
-
- tsk = get_pid_task(find_vpid(bpfilter_ops.info.pid), PIDTYPE_PID);
- if (tsk) {
- send_sig(SIGKILL, tsk, 1);
- put_task_struct(tsk);
+ if (tgid) {
+ kill_pid(tgid, SIGKILL, 1);
+ wait_event(tgid->wait_pidfd, thread_group_exited(tgid));
+ bpfilter_umh_cleanup(info);
}
}
req.cmd = optname;
req.addr = (long __force __user)optval;
req.len = optlen;
- if (!bpfilter_ops.info.pid)
+ if (!bpfilter_ops.info.tgid)
goto out;
n = kernel_write(bpfilter_ops.info.pipe_to_umh, &req, sizeof(req),
&pos);
int err;
/* fork usermode process */
- err = fork_usermode_blob(&bpfilter_umh_start,
- &bpfilter_umh_end - &bpfilter_umh_start,
- &bpfilter_ops.info);
+ err = fork_usermode_driver(&bpfilter_ops.info);
if (err)
return err;
- bpfilter_ops.stop = false;
- pr_info("Loaded bpfilter_umh pid %d\n", bpfilter_ops.info.pid);
+ pr_info("Loaded bpfilter_umh pid %d\n", pid_nr(bpfilter_ops.info.tgid));
/* health check that usermode process started correctly */
if (__bpfilter_process_sockopt(NULL, 0, NULL, 0, 0) != 0) {
{
int err;
+ err = umd_load_blob(&bpfilter_ops.info,
+ &bpfilter_umh_start,
+ &bpfilter_umh_end - &bpfilter_umh_start);
+ if (err)
+ return err;
+
mutex_lock(&bpfilter_ops.lock);
- if (!bpfilter_ops.stop) {
- err = -EFAULT;
- goto out;
- }
err = start_umh();
if (!err && IS_ENABLED(CONFIG_INET)) {
bpfilter_ops.sockopt = &__bpfilter_process_sockopt;
bpfilter_ops.start = &start_umh;
}
-out:
mutex_unlock(&bpfilter_ops.lock);
+ if (err)
+ umd_unload_blob(&bpfilter_ops.info);
return err;
}
bpfilter_ops.sockopt = NULL;
}
mutex_unlock(&bpfilter_ops.lock);
+
+ umd_unload_blob(&bpfilter_ops.info);
}
module_init(load_umh);
module_exit(fini_umh);
/* SPDX-License-Identifier: GPL-2.0 */
- .section .rodata, "a"
+ .section .init.rodata, "a"
.global bpfilter_umh_start
bpfilter_umh_start:
.incbin "net/bpfilter/bpfilter_umh"
struct bpfilter_umh_ops bpfilter_ops;
EXPORT_SYMBOL_GPL(bpfilter_ops);
-static void bpfilter_umh_cleanup(struct umh_info *info)
+void bpfilter_umh_cleanup(struct umd_info *info)
{
- mutex_lock(&bpfilter_ops.lock);
- bpfilter_ops.stop = true;
fput(info->pipe_to_umh);
fput(info->pipe_from_umh);
- info->pid = 0;
- mutex_unlock(&bpfilter_ops.lock);
+ put_pid(info->tgid);
+ info->tgid = NULL;
}
+EXPORT_SYMBOL_GPL(bpfilter_umh_cleanup);
static int bpfilter_mbox_request(struct sock *sk, int optname,
char __user *optval,
goto out;
}
}
- if (bpfilter_ops.stop) {
+ if (bpfilter_ops.info.tgid &&
+ thread_group_exited(bpfilter_ops.info.tgid))
+ bpfilter_umh_cleanup(&bpfilter_ops.info);
+
+ if (!bpfilter_ops.info.tgid) {
err = bpfilter_ops.start();
if (err)
goto out;
static int __init bpfilter_sockopt_init(void)
{
mutex_init(&bpfilter_ops.lock);
- bpfilter_ops.stop = true;
- bpfilter_ops.info.cmdline = "bpfilter_umh";
- bpfilter_ops.info.cleanup = &bpfilter_umh_cleanup;
+ bpfilter_ops.info.tgid = NULL;
+ bpfilter_ops.info.driver_name = "bpfilter_umh";
return 0;
}
projects / linux-2.6-microblaze.git / commitdiff