#include <linux/unistd.h>
#include <linux/kmod.h>
#include <linux/slab.h>
-#include <linux/mnt_namespace.h>
#include <linux/completion.h>
#include <linux/file.h>
+#include <linux/fdtable.h>
#include <linux/workqueue.h>
#include <linux/security.h>
#include <linux/mount.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/resource.h>
+#include <linux/notifier.h>
+#include <linux/suspend.h>
#include <asm/uaccess.h>
+#include <trace/events/module.h>
+
extern int max_threads;
static struct workqueue_struct *khelper_wq;
-#ifdef CONFIG_KMOD
+#ifdef CONFIG_MODULES
/*
modprobe_path is set via /proc/sys.
char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe";
/**
- * request_module - try to load a kernel module
- * @fmt: printf style format string for the name of the module
- * @varargs: arguements as specified in the format string
+ * __request_module - try to load a kernel module
+ * @wait: wait (or not) for the operation to complete
+ * @fmt: printf style format string for the name of the module
+ * @...: arguments as specified in the format string
*
* Load a module using the user mode module loader. The function returns
* zero on success or a negative errno code on failure. Note that a
* If module auto-loading support is disabled then this function
* becomes a no-operation.
*/
-int request_module(const char *fmt, ...)
+int __request_module(bool wait, const char *fmt, ...)
{
va_list args;
char module_name[MODULE_NAME_LEN];
if (ret >= MODULE_NAME_LEN)
return -ENAMETOOLONG;
+ ret = security_kernel_module_request(module_name);
+ if (ret)
+ return ret;
+
/* If modprobe needs a service that is in a module, we get a recursive
* loop. Limit the number of running kmod threads to max_threads/2 or
* MAX_KMOD_CONCURRENT, whichever is the smaller. A cleaner method
return -ENOMEM;
}
- ret = call_usermodehelper(modprobe_path, argv, envp, 1);
+ trace_module_request(module_name, wait, _RET_IP_);
+
+ ret = call_usermodehelper(modprobe_path, argv, envp,
+ wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
atomic_dec(&kmod_concurrent);
return ret;
}
-EXPORT_SYMBOL(request_module);
-#endif /* CONFIG_KMOD */
+EXPORT_SYMBOL(__request_module);
+#endif /* CONFIG_MODULES */
struct subprocess_info {
struct work_struct work;
struct completion *complete;
+ struct cred *cred;
char *path;
char **argv;
char **envp;
- struct key *ring;
enum umh_wait wait;
int retval;
struct file *stdin;
static int ____call_usermodehelper(void *data)
{
struct subprocess_info *sub_info = data;
- struct key *new_session, *old_session;
int retval;
- /* Unblock all signals and set the session keyring. */
- new_session = key_get(sub_info->ring);
+ BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+
+ /* Unblock all signals */
spin_lock_irq(¤t->sighand->siglock);
- old_session = __install_session_keyring(current, new_session);
flush_signal_handlers(current, 1);
sigemptyset(¤t->blocked);
recalc_sigpending();
spin_unlock_irq(¤t->sighand->siglock);
- key_put(old_session);
+ /* Install the credentials */
+ commit_creds(sub_info->cred);
+ sub_info->cred = NULL;
/* Install input pipe when needed */
if (sub_info->stdin) {
}
/* We can run anywhere, unlike our parent keventd(). */
- set_cpus_allowed(current, CPU_MASK_ALL);
+ set_cpus_allowed_ptr(current, cpu_all_mask);
/*
* Our parent is keventd, which runs with elevated scheduling priority.
*/
set_user_nice(current, 0);
- retval = -EPERM;
- if (current->fs->root)
- retval = kernel_execve(sub_info->path,
- sub_info->argv, sub_info->envp);
+ retval = kernel_execve(sub_info->path, sub_info->argv, sub_info->envp);
/* Exec failed? */
sub_info->retval = retval;
{
if (info->cleanup)
(*info->cleanup)(info->argv, info->envp);
+ if (info->cred)
+ put_cred(info->cred);
kfree(info);
}
EXPORT_SYMBOL(call_usermodehelper_freeinfo);
pid_t pid;
enum umh_wait wait = sub_info->wait;
+ BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+
/* CLONE_VFORK: wait until the usermode helper has execve'd
* successfully We need the data structures to stay around
* until that is done. */
}
}
+#ifdef CONFIG_PM_SLEEP
+/*
+ * If set, call_usermodehelper_exec() will exit immediately returning -EBUSY
+ * (used for preventing user land processes from being created after the user
+ * land has been frozen during a system-wide hibernation or suspend operation).
+ */
+static int usermodehelper_disabled;
+
+/* Number of helpers running */
+static atomic_t running_helpers = ATOMIC_INIT(0);
+
+/*
+ * Wait queue head used by usermodehelper_pm_callback() to wait for all running
+ * helpers to finish.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
+
+/*
+ * Time to wait for running_helpers to become zero before the setting of
+ * usermodehelper_disabled in usermodehelper_pm_callback() fails
+ */
+#define RUNNING_HELPERS_TIMEOUT (5 * HZ)
+
+/**
+ * usermodehelper_disable - prevent new helpers from being started
+ */
+int usermodehelper_disable(void)
+{
+ long retval;
+
+ usermodehelper_disabled = 1;
+ smp_mb();
+ /*
+ * From now on call_usermodehelper_exec() won't start any new
+ * helpers, so it is sufficient if running_helpers turns out to
+ * be zero at one point (it may be increased later, but that
+ * doesn't matter).
+ */
+ retval = wait_event_timeout(running_helpers_waitq,
+ atomic_read(&running_helpers) == 0,
+ RUNNING_HELPERS_TIMEOUT);
+ if (retval)
+ return 0;
+
+ usermodehelper_disabled = 0;
+ return -EAGAIN;
+}
+
+/**
+ * usermodehelper_enable - allow new helpers to be started again
+ */
+void usermodehelper_enable(void)
+{
+ usermodehelper_disabled = 0;
+}
+
+static void helper_lock(void)
+{
+ atomic_inc(&running_helpers);
+ smp_mb__after_atomic_inc();
+}
+
+static void helper_unlock(void)
+{
+ if (atomic_dec_and_test(&running_helpers))
+ wake_up(&running_helpers_waitq);
+}
+#else /* CONFIG_PM_SLEEP */
+#define usermodehelper_disabled 0
+
+static inline void helper_lock(void) {}
+static inline void helper_unlock(void) {}
+#endif /* CONFIG_PM_SLEEP */
+
/**
* call_usermodehelper_setup - prepare to call a usermode helper
- * @path - path to usermode executable
- * @argv - arg vector for process
- * @envp - environment for process
+ * @path: path to usermode executable
+ * @argv: arg vector for process
+ * @envp: environment for process
+ * @gfp_mask: gfp mask for memory allocation
*
- * Returns either NULL on allocation failure, or a subprocess_info
+ * Returns either %NULL on allocation failure, or a subprocess_info
* structure. This should be passed to call_usermodehelper_exec to
* exec the process and free the structure.
*/
-struct subprocess_info *call_usermodehelper_setup(char *path,
- char **argv, char **envp)
+struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
+ char **envp, gfp_t gfp_mask)
{
struct subprocess_info *sub_info;
- sub_info = kzalloc(sizeof(struct subprocess_info), GFP_ATOMIC);
+ sub_info = kzalloc(sizeof(struct subprocess_info), gfp_mask);
if (!sub_info)
goto out;
sub_info->path = path;
sub_info->argv = argv;
sub_info->envp = envp;
+ sub_info->cred = prepare_usermodehelper_creds();
+ if (!sub_info->cred) {
+ kfree(sub_info);
+ return NULL;
+ }
out:
return sub_info;
void call_usermodehelper_setkeys(struct subprocess_info *info,
struct key *session_keyring)
{
- info->ring = session_keyring;
+#ifdef CONFIG_KEYS
+ struct thread_group_cred *tgcred = info->cred->tgcred;
+ key_put(tgcred->session_keyring);
+ tgcred->session_keyring = key_get(session_keyring);
+#else
+ BUG();
+#endif
}
EXPORT_SYMBOL(call_usermodehelper_setkeys);
{
struct file *f;
- f = create_write_pipe();
+ f = create_write_pipe(0);
if (IS_ERR(f))
return PTR_ERR(f);
*filp = f;
- f = create_read_pipe(f);
+ f = create_read_pipe(f, 0);
if (IS_ERR(f)) {
free_write_pipe(*filp);
return PTR_ERR(f);
enum umh_wait wait)
{
DECLARE_COMPLETION_ONSTACK(done);
- int retval;
+ int retval = 0;
- if (sub_info->path[0] == '\0') {
- retval = 0;
+ BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+ validate_creds(sub_info->cred);
+
+ helper_lock();
+ if (sub_info->path[0] == '\0')
goto out;
- }
- if (!khelper_wq) {
+ if (!khelper_wq || usermodehelper_disabled) {
retval = -EBUSY;
goto out;
}
sub_info->wait = wait;
queue_work(khelper_wq, &sub_info->work);
- if (wait == UMH_NO_WAIT) /* task has freed sub_info */
- return 0;
+ if (wait == UMH_NO_WAIT) /* task has freed sub_info */
+ goto unlock;
wait_for_completion(&done);
retval = sub_info->retval;
- out:
+out:
call_usermodehelper_freeinfo(sub_info);
+unlock:
+ helper_unlock();
return retval;
}
EXPORT_SYMBOL(call_usermodehelper_exec);
struct subprocess_info *sub_info;
int ret;
- sub_info = call_usermodehelper_setup(path, argv, envp);
+ sub_info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL);
if (sub_info == NULL)
return -ENOMEM;
ret = call_usermodehelper_stdinpipe(sub_info, filp);
- if (ret < 0)
- goto out;
+ if (ret < 0) {
+ call_usermodehelper_freeinfo(sub_info);
+ return ret;
+ }
- return call_usermodehelper_exec(sub_info, 1);
+ ret = call_usermodehelper_exec(sub_info, UMH_WAIT_EXEC);
+ if (ret < 0) /* Failed to execute helper, close pipe */
+ filp_close(*filp, NULL);
- out:
- call_usermodehelper_freeinfo(sub_info);
return ret;
}
EXPORT_SYMBOL(call_usermodehelper_pipe);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff