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Diffstat (limited to 'kernel/kmod.c')
-rw-r--r--kernel/kmod.c97
1 files changed, 52 insertions, 45 deletions
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 2456d1a0bef..b46dbb90866 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -113,15 +113,15 @@ int request_module(const char *fmt, ...)
return ret;
}
EXPORT_SYMBOL(request_module);
-#endif /* CONFIG_KMOD */
+#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;
@@ -134,19 +134,20 @@ struct subprocess_info {
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(&current->sighand->siglock);
- old_session = __install_session_keyring(current, new_session);
flush_signal_handlers(current, 1);
sigemptyset(&current->blocked);
recalc_sigpending();
spin_unlock_irq(&current->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) {
@@ -185,6 +186,8 @@ void call_usermodehelper_freeinfo(struct subprocess_info *info)
{
if (info->cleanup)
(*info->cleanup)(info->argv, info->envp);
+ if (info->cred)
+ put_cred(info->cred);
kfree(info);
}
EXPORT_SYMBOL(call_usermodehelper_freeinfo);
@@ -240,6 +243,8 @@ static void __call_usermodehelper(struct work_struct *work)
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. */
@@ -265,7 +270,7 @@ static void __call_usermodehelper(struct work_struct *work)
}
}
-#ifdef CONFIG_PM
+#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
@@ -288,39 +293,37 @@ static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
*/
#define RUNNING_HELPERS_TIMEOUT (5 * HZ)
-static int usermodehelper_pm_callback(struct notifier_block *nfb,
- unsigned long action,
- void *ignored)
+/**
+ * usermodehelper_disable - prevent new helpers from being started
+ */
+int usermodehelper_disable(void)
{
long retval;
- switch (action) {
- case PM_HIBERNATION_PREPARE:
- case PM_SUSPEND_PREPARE:
- 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,
+ 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 NOTIFY_OK;
- } else {
- usermodehelper_disabled = 0;
- return NOTIFY_BAD;
- }
- case PM_POST_HIBERNATION:
- case PM_POST_SUSPEND:
- usermodehelper_disabled = 0;
- return NOTIFY_OK;
- }
+ if (retval)
+ return 0;
- return NOTIFY_DONE;
+ 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)
@@ -334,18 +337,12 @@ static void helper_unlock(void)
if (atomic_dec_and_test(&running_helpers))
wake_up(&running_helpers_waitq);
}
-
-static void register_pm_notifier_callback(void)
-{
- pm_notifier(usermodehelper_pm_callback, 0);
-}
-#else /* CONFIG_PM */
+#else /* CONFIG_PM_SLEEP */
#define usermodehelper_disabled 0
static inline void helper_lock(void) {}
static inline void helper_unlock(void) {}
-static inline void register_pm_notifier_callback(void) {}
-#endif /* CONFIG_PM */
+#endif /* CONFIG_PM_SLEEP */
/**
* call_usermodehelper_setup - prepare to call a usermode helper
@@ -370,6 +367,9 @@ struct subprocess_info *call_usermodehelper_setup(char *path, char **argv,
sub_info->path = path;
sub_info->argv = argv;
sub_info->envp = envp;
+ sub_info->cred = prepare_usermodehelper_creds();
+ if (!sub_info->cred)
+ return NULL;
out:
return sub_info;
@@ -384,7 +384,13 @@ EXPORT_SYMBOL(call_usermodehelper_setup);
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);
@@ -452,6 +458,8 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info,
DECLARE_COMPLETION_ONSTACK(done);
int retval = 0;
+ BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+
helper_lock();
if (sub_info->path[0] == '\0')
goto out;
@@ -515,5 +523,4 @@ void __init usermodehelper_init(void)
{
khelper_wq = create_singlethread_workqueue("khelper");
BUG_ON(!khelper_wq);
- register_pm_notifier_callback();
}