patch-2_6_7-vs1_9_1_12

[linux-2.6.git] / kernel / kmod.c

diff --git a/kernel/kmod.c b/kernel/kmod.c
index 8754003..ea62192 100644 (file)
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -47,7 +47,7 @@ static struct workqueue_struct *khelper_wq;
 /*
        modprobe_path is set via /proc/sys.
 */
-char modprobe_path[256] = "/sbin/modprobe";
+char modprobe_path[KMOD_PATH_LEN] = "/sbin/modprobe";
 
 /**
  * request_module - try to load a kernel module
@@ -132,7 +132,7 @@ EXPORT_SYMBOL(request_module);
        events.  the command is expected to load drivers when
        necessary, and may perform additional system setup.
 */
-char hotplug_path[256] = "/sbin/hotplug";
+char hotplug_path[KMOD_PATH_LEN] = "/sbin/hotplug";
 
 EXPORT_SYMBOL(hotplug_path);
 
@@ -192,10 +192,20 @@ static int wait_for_helper(void *data)
        allow_signal(SIGCHLD);
 
        pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD);
-       if (pid < 0)
+       if (pid < 0) {
                sub_info->retval = pid;
-       else
-               sys_wait4(pid, &sub_info->retval, 0, NULL);
+       } else {
+               /*
+                * Normally it is bogus to call wait4() from in-kernel because
+                * wait4() wants to write the exit code to a userspace address.
+                * But wait_for_helper() always runs as keventd, and put_user()
+                * to a kernel address works OK for kernel threads, due to their
+                * having an mm_segment_t which spans the entire address space.
+                *
+                * Thus the __user pointer cast is valid here.
+                */
+               sys_wait4(pid, (int __user *) &sub_info->retval, 0, NULL);
+       }
 
        complete(sub_info->complete);
        return 0;
@@ -269,4 +279,4 @@ static __init int usermodehelper_init(void)
        BUG_ON(!khelper_wq);
        return 0;
 }
-__initcall(usermodehelper_init);
+core_initcall(usermodehelper_init);