microblaze: uaccess: fix put_user and get_user macros
[linux-2.6.git] / kernel / kmod.c
index beedbdc..bf0e231 100644 (file)
@@ -24,9 +24,9 @@
 #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/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.
@@ -49,9 +51,10 @@ static struct workqueue_struct *khelper_wq;
 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
@@ -62,7 +65,7 @@ char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe";
  * 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];
@@ -83,6 +86,10 @@ int request_module(const char *fmt, ...)
        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
@@ -107,20 +114,23 @@ int request_module(const char *fmt, ...)
                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;
@@ -133,19 +143,20 @@ 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) {
@@ -165,7 +176,7 @@ static int ____call_usermodehelper(void *data)
        }
 
        /* 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.
@@ -173,10 +184,7 @@ static int ____call_usermodehelper(void *data)
         */
        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;
@@ -187,6 +195,8 @@ 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);
@@ -242,6 +252,8 @@ 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.  */
@@ -267,7 +279,7 @@ 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
@@ -290,39 +302,37 @@ 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)
@@ -336,34 +346,29 @@ 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
- * @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;
 
@@ -371,6 +376,11 @@ struct subprocess_info *call_usermodehelper_setup(char *path,
        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;
@@ -385,7 +395,13 @@ 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);
 
@@ -419,12 +435,12 @@ int call_usermodehelper_stdinpipe(struct subprocess_info *sub_info,
 {
        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);
@@ -451,13 +467,14 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info,
                             enum umh_wait wait)
 {
        DECLARE_COMPLETION_ONSTACK(done);
-       int retval;
+       int retval = 0;
+
+       BUG_ON(atomic_read(&sub_info->cred->usage) != 1);
+       validate_creds(sub_info->cred);
 
        helper_lock();
-       if (sub_info->path[0] == '\0') {
-               retval = 0;
+       if (sub_info->path[0] == '\0')
                goto out;
-       }
 
        if (!khelper_wq || usermodehelper_disabled) {
                retval = -EBUSY;
@@ -468,13 +485,14 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info,
        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;
 }
@@ -497,18 +515,20 @@ int call_usermodehelper_pipe(char *path, char **argv, char **envp,
        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);
@@ -517,5 +537,4 @@ void __init usermodehelper_init(void)
 {
        khelper_wq = create_singlethread_workqueue("khelper");
        BUG_ON(!khelper_wq);
-       register_pm_notifier_callback();
 }