Merge branch 'stable-3.2' into pandora-3.2

[pandora-kernel.git] / kernel / kmod.c

diff --git a/kernel/kmod.c b/kernel/kmod.c
index e5e30b6..a16dac1 100644 (file)
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -58,6 +58,43 @@ static DEFINE_SPINLOCK(umh_sysctl_lock);
 */
 char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe";
 
+static void free_modprobe_argv(struct subprocess_info *info)
+{
+       kfree(info->argv[3]); /* check call_modprobe() */
+       kfree(info->argv);
+}
+
+static int call_modprobe(char *module_name, int wait)
+{
+       static char *envp[] = {
+               "HOME=/",
+               "TERM=linux",
+               "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
+               NULL
+       };
+
+       char **argv = kmalloc(sizeof(char *[5]), GFP_KERNEL);
+       if (!argv)
+               goto out;
+
+       module_name = kstrdup(module_name, GFP_KERNEL);
+       if (!module_name)
+               goto free_argv;
+
+       argv[0] = modprobe_path;
+       argv[1] = "-q";
+       argv[2] = "--";
+       argv[3] = module_name;  /* check free_modprobe_argv() */
+       argv[4] = NULL;
+
+       return call_usermodehelper_fns(modprobe_path, argv, envp,
+               wait | UMH_KILLABLE, NULL, free_modprobe_argv, NULL);
+free_argv:
+       kfree(argv);
+out:
+       return -ENOMEM;
+}
+
 /**
  * __request_module - try to load a kernel module
  * @wait: wait (or not) for the operation to complete
@@ -79,11 +116,6 @@ int __request_module(bool wait, const char *fmt, ...)
        char module_name[MODULE_NAME_LEN];
        unsigned int max_modprobes;
        int ret;
-       char *argv[] = { modprobe_path, "-q", "--", module_name, NULL };
-       static char *envp[] = { "HOME=/",
-                               "TERM=linux",
-                               "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
-                               NULL };
        static atomic_t kmod_concurrent = ATOMIC_INIT(0);
 #define MAX_KMOD_CONCURRENT 50 /* Completely arbitrary value - KAO */
        static int kmod_loop_msg;
@@ -126,9 +158,7 @@ int __request_module(bool wait, const char *fmt, ...)
 
        trace_module_request(module_name, wait, _RET_IP_);
 
-       ret = call_usermodehelper_fns(modprobe_path, argv, envp,
-                       wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC,
-                       NULL, NULL, NULL);
+       ret = call_modprobe(module_name, wait ? UMH_WAIT_PROC : UMH_WAIT_EXEC);
 
        atomic_dec(&kmod_concurrent);
        return ret;
@@ -186,7 +216,7 @@ static int ____call_usermodehelper(void *data)
        /* Exec failed? */
 fail:
        sub_info->retval = retval;
-       do_exit(0);
+       return 0;
 }
 
 void call_usermodehelper_freeinfo(struct subprocess_info *info)
@@ -199,7 +229,15 @@ EXPORT_SYMBOL(call_usermodehelper_freeinfo);
 
 static void umh_complete(struct subprocess_info *sub_info)
 {
-       complete(sub_info->complete);
+       struct completion *comp = xchg(&sub_info->complete, NULL);
+       /*
+        * See call_usermodehelper_exec(). If xchg() returns NULL
+        * we own sub_info, the UMH_KILLABLE caller has gone away.
+        */
+       if (comp)
+               complete(comp);
+       else
+               call_usermodehelper_freeinfo(sub_info);
 }
 
 /* Keventd can't block, but this (a child) can. */
@@ -250,6 +288,9 @@ static void __call_usermodehelper(struct work_struct *work)
        enum umh_wait wait = sub_info->wait;
        pid_t pid;
 
+       if (wait != UMH_NO_WAIT)
+               wait &= ~UMH_KILLABLE;
+
        /* CLONE_VFORK: wait until the usermode helper has execve'd
         * successfully We need the data structures to stay around
         * until that is done.  */
@@ -426,6 +467,11 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info,
        int retval = 0;
 
        helper_lock();
+       if (!sub_info->path) {
+               retval = -EINVAL;
+               goto out;
+       }
+
        if (sub_info->path[0] == '\0')
                goto out;
 
@@ -440,9 +486,21 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info,
        queue_work(khelper_wq, &sub_info->work);
        if (wait == UMH_NO_WAIT)        /* task has freed sub_info */
                goto unlock;
+
+       if (wait & UMH_KILLABLE) {
+               retval = wait_for_completion_killable(&done);
+               if (!retval)
+                       goto wait_done;
+
+               /* umh_complete() will see NULL and free sub_info */
+               if (xchg(&sub_info->complete, NULL))
+                       goto unlock;
+               /* fallthrough, umh_complete() was already called */
+       }
+
        wait_for_completion(&done);
+wait_done:
        retval = sub_info->retval;
-
 out:
        call_usermodehelper_freeinfo(sub_info);
 unlock: