test: Add data relocation test

This patch adds a test case that the klp-module has a
`.klp.rela.<module name>..rodata.<...>` section. This pattern can be an
error if architecture-specific relocation in the kernel does not fully
support Livepatch.

The prerequisite for this test is that CONFIG_USB_SERIAL_IR=m and
CONFIG_USB_SERIAL_WWAN=m are set. In the patched-modules,
ir-usb.ko's static local variables refers to usb_wwan.ko's symbols,
so `.klp.rela.ir-usb..rodata.<...>` section are generated into
test-data-reloc.ko.

Modifications to drivers/usb/serial/bus.c are not directly related to
the purpose of this test, but are necessary for testing with the
data-reloc-LOADED.test.

Signed-off-by: Keiya Nobuta <nobuta.keiya@fujitsu.com>

Author: keiya-nobuta

test/integration/linux-5.10.11/data-reloc-LOADED.test

@@ -0,0 +1,4 @@
+sudo modprobe usb_wwan
+sudo modprobe ir-usb
+
+cat /sys/bus/usb-serial/drivers/generic/new_id | grep "kpatch"

test/integration/linux-5.10.11/data-reloc.patch

@@ -0,0 +1,35 @@
+diff --git a/drivers/usb/serial/bus.c b/drivers/usb/serial/bus.c
+index eb0195cf37dd..79c2df488b5a 100644
+--- a/drivers/usb/serial/bus.c
++++ b/drivers/usb/serial/bus.c
+@@ -137,9 +137,7 @@ static ssize_t new_id_store(struct device_driver *driver,
+ 
+ static ssize_t new_id_show(struct device_driver *driver, char *buf)
+ {
+-	struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
+-
+-	return usb_show_dynids(&usb_drv->dynids, buf);
++	return snprintf(buf, PAGE_SIZE, "kpatch\n");
+ }
+ static DRIVER_ATTR_RW(new_id);
+ 
+diff --git a/drivers/usb/serial/ir-usb.c b/drivers/usb/serial/ir-usb.c
+index 172261a908d8..4fdd666cc75a 100644
+--- a/drivers/usb/serial/ir-usb.c
++++ b/drivers/usb/serial/ir-usb.c
+@@ -194,10 +194,15 @@ static u8 ir_xbof_change(u8 xbof)
+ 	return(result);
+ }
+ 
++#include "usb-wwan.h"
+ static int ir_startup(struct usb_serial *serial)
+ {
+ 	struct usb_irda_cs_descriptor *irda_desc;
+ 	int rates;
++	volatile int i = 0;
++	static volatile void *funcs[] = {usb_wwan_open, usb_wwan_close};
++
++	printk("kpatch: usb_wwan_open=%p\n", funcs[i]);
+ 
+ 	irda_desc = irda_usb_find_class_desc(serial, 0);
+ 	if (!irda_desc) {