Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c
new file mode 100644
index 0000000..89e6bf2
--- /dev/null
+++ b/samples/ftrace/ftrace-direct-modify.c
@@ -0,0 +1,97 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/module.h>
+#include <linux/kthread.h>
+#include <linux/ftrace.h>
+
+extern void my_direct_func1(void);
+extern void my_direct_func2(void);
+
+void my_direct_func1(void)
+{
+ trace_printk("my direct func1\n");
+}
+
+void my_direct_func2(void)
+{
+ trace_printk("my direct func2\n");
+}
+
+extern void my_tramp1(void *);
+extern void my_tramp2(void *);
+
+static unsigned long my_ip = (unsigned long)schedule;
+
+asm (
+" .pushsection .text, \"ax\", @progbits\n"
+" .type my_tramp1, @function\n"
+" .globl my_tramp1\n"
+" my_tramp1:"
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+" call my_direct_func1\n"
+" leave\n"
+" .size my_tramp1, .-my_tramp1\n"
+" ret\n"
+" .type my_tramp2, @function\n"
+" .globl my_tramp2\n"
+" my_tramp2:"
+" pushq %rbp\n"
+" movq %rsp, %rbp\n"
+" call my_direct_func2\n"
+" leave\n"
+" ret\n"
+" .size my_tramp2, .-my_tramp2\n"
+" .popsection\n"
+);
+
+static unsigned long my_tramp = (unsigned long)my_tramp1;
+static unsigned long tramps[2] = {
+ (unsigned long)my_tramp1,
+ (unsigned long)my_tramp2,
+};
+
+static int simple_thread(void *arg)
+{
+ static int t;
+ int ret = 0;
+
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(2 * HZ);
+
+ if (ret)
+ continue;
+ t ^= 1;
+ ret = modify_ftrace_direct(my_ip, my_tramp, tramps[t]);
+ if (!ret)
+ my_tramp = tramps[t];
+ WARN_ON_ONCE(ret);
+ }
+
+ return 0;
+}
+
+static struct task_struct *simple_tsk;
+
+static int __init ftrace_direct_init(void)
+{
+ int ret;
+
+ ret = register_ftrace_direct(my_ip, my_tramp);
+ if (!ret)
+ simple_tsk = kthread_run(simple_thread, NULL, "event-sample-fn");
+ return ret;
+}
+
+static void __exit ftrace_direct_exit(void)
+{
+ kthread_stop(simple_tsk);
+ unregister_ftrace_direct(my_ip, my_tramp);
+}
+
+module_init(ftrace_direct_init);
+module_exit(ftrace_direct_exit);
+
+MODULE_AUTHOR("Steven Rostedt");
+MODULE_DESCRIPTION("Example use case of using modify_ftrace_direct()");
+MODULE_LICENSE("GPL");