Driver core: add CONFIG_UEVENT_HELPER_PATH

The kernel creates a process for every event that is send, even when
there is no binary it could execute.  We are needlessly creating around
200-300 failing processes during early bootup, until we have the chance
to disable it from userspace.

This change allows us to disable /sbin/hotplug entirely, if you want to,
by setting UEVENT_HELPER_PATH="" in the kernel config.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 5d6312e..d7da109 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -1,5 +1,13 @@
 menu "Generic Driver Options"
 
+config UEVENT_HELPER_PATH
+	string "path to uevent helper"
+	depends on HOTPLUG
+	default "/sbin/hotplug"
+	help
+	  Path to uevent helper program forked by the kernel for
+	  every uevent.
+
 config STANDALONE
 	bool "Select only drivers that don't need compile-time external firmware" if EXPERIMENTAL
 	default y