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| author | Dmitry Torokhov <[email protected]> | 2020-01-10 14:56:04 -0800 |
|---|---|---|
| committer | Dmitry Torokhov <[email protected]> | 2020-01-10 14:56:04 -0800 |
| commit | 1bdd3e05a0a3b4a97ea88bc46fef8fb265c8b94c (patch) | |
| tree | 2244894a9ea0c941a8f32e5f3d196b4ea0eae24b /samples/ftrace/ftrace-direct.c | |
| parent | 643dd7416649bea2e8c61d8fdeeefb409a0ca5eb (diff) | |
| parent | c79f46a282390e0f5b306007bf7b11a46d529538 (diff) | |
Merge tag 'v5.5-rc5' into next
Sync up with mainline to get SPI "delay" API changes.
Diffstat (limited to 'samples/ftrace/ftrace-direct.c')
| -rw-r--r-- | samples/ftrace/ftrace-direct.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c new file mode 100644 index 000000000000..a2e3063bd306 --- /dev/null +++ b/samples/ftrace/ftrace-direct.c @@ -0,0 +1,45 @@ +// 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"); |