linux-stable/samples/ftrace/ftrace-direct.c
Colin Ian King 760f8bc7c8 ftrace/selftests: Fix spelling mistake "wakeing" -> "waking"
There is a spelling mistake in a trace_printk message. As well as in
the selftests that search for this string.

Link: http://lkml.kernel.org/r/20191115085938.38947-1-colin.king@canonical.com
Link: http://lkml.kernel.org/r/20191115090356.39572-1-colin.king@canonical.com

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-11-15 11:30:38 -05:00

45 lines
963 B
C

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/sched.h> /* for wake_up_process() */
#include <linux/ftrace.h>
void my_direct_func(struct task_struct *p)
{
trace_printk("waking up %s-%d\n", p->comm, p->pid);
}
extern void my_tramp(void *);
asm (
" .pushsection .text, \"ax\", @progbits\n"
" my_tramp:"
" pushq %rbp\n"
" movq %rsp, %rbp\n"
" pushq %rdi\n"
" call my_direct_func\n"
" popq %rdi\n"
" leave\n"
" ret\n"
" .popsection\n"
);
static int __init ftrace_direct_init(void)
{
return register_ftrace_direct((unsigned long)wake_up_process,
(unsigned long)my_tramp);
}
static void __exit ftrace_direct_exit(void)
{
unregister_ftrace_direct((unsigned long)wake_up_process,
(unsigned long)my_tramp);
}
module_init(ftrace_direct_init);
module_exit(ftrace_direct_exit);
MODULE_AUTHOR("Steven Rostedt");
MODULE_DESCRIPTION("Example use case of using register_ftrace_direct()");
MODULE_LICENSE("GPL");