linux/samples/ftrace/Makefile

# SPDX-License-Identifier: GPL-2.0-only

obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct.o
obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-too.o
obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-modify.o

CFLAGS_sample-trace-array.o := -I$(src)
obj-$(CONFIG_SAMPLE_TRACE_ARRAY) += sample-trace-array.o
ftrace: Add sample module that uses register_ftrace_direct() Add a sample module that shows a simple use case for regsiter_ftrace_direct(), and how to use it. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 2019-11-08 13:12:33 -05:00			`# SPDX-License-Identifier: GPL-2.0-only`

			`obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct.o`
ftrace: Add another example of register_ftrace_direct() use case Add another module sample that registers a direct trampoline to a function via register_ftrace_direct(). Having another module that does this allows to test the use case of multiple direct callers registered, as more than one direct caller goes into another path, and is needed to perform proper testing of the register_ftrace_direct() call. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 2019-11-08 15:27:45 -05:00			`obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-too.o`
ftrace/samples: Add a sample module that implements modify_ftrace_direct() Add a sample module that tests modify_ftrace_direct(), and this can be used by the selftests as well. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 2019-11-14 14:41:47 -05:00			`obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-modify.o`
tracing: Sample module to demonstrate kernel access to Ftrace instances. This is a sample module to demonstrate the use of the newly introduced and exported APIs to access Ftrace instances from within the kernel. Newly introduced APIs used here - 1. Create/Lookup a trace array with the given name. struct trace_array trace_array_get_by_name(const char name) 2. Destroy/Remove a trace array. int trace_array_destroy(struct trace_array tr) 4. Enable/Disable trace events: int trace_array_set_clr_event(struct trace_array tr, const char system, const char event, bool enable); Exported APIs - 1. trace_printk equivalent for instances. int trace_array_printk(struct trace_array tr, unsigned long ip, const char fmt, ...); 2. Helper function. void trace_printk_init_buffers(void); 3. To decrement the reference counter. void trace_array_put(struct trace_array *tr) Sample output(contents of /sys/kernel/tracing/instances/sample-instance) NOTE: Tracing disabled after ~5 sec) _-----=> irqs-off / _----=> need-resched \| / _---=> hardirq/softirq \|\| / _--=> preempt-depth \|\|\| / delay TASK-PID CPU# \|\|\|\| TIMESTAMP FUNCTION \| \| \| \|\|\|\| \| \| sample-instance-1452 [002] .... 49.430948: simple_thread: trace_array_printk: count=0 sample-instance-1452 [002] .... 49.430951: sample_event: count value=0 at jiffies=4294716608 sample-instance-1452 [002] .... 50.454847: simple_thread: trace_array_printk: count=1 sample-instance-1452 [002] .... 50.454849: sample_event: count value=1 at jiffies=4294717632 sample-instance-1452 [002] .... 51.478748: simple_thread: trace_array_printk: count=2 sample-instance-1452 [002] .... 51.478750: sample_event: count value=2 at jiffies=4294718656 sample-instance-1452 [002] .... 52.502652: simple_thread: trace_array_printk: count=3 sample-instance-1452 [002] .... 52.502655: sample_event: count value=3 at jiffies=4294719680 sample-instance-1452 [002] .... 53.526533: simple_thread: trace_array_printk: count=4 sample-instance-1452 [002] .... 53.526535: sample_event: count value=4 at jiffies=4294720704 sample-instance-1452 [002] .... 54.550438: simple_thread: trace_array_printk: count=5 sample-instance-1452 [002] .... 55.574336: simple_thread: trace_array_printk: count=6 Link: http://lkml.kernel.org/r/1574276919-11119-3-git-send-email-divya.indi@oracle.com Reviewed-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com> Signed-off-by: Divya Indi <divya.indi@oracle.com> [ Moved to samples/ftrace ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 2019-11-20 11:08:39 -08:00
			`CFLAGS_sample-trace-array.o := -I$(src)`
			`obj-$(CONFIG_SAMPLE_TRACE_ARRAY) += sample-trace-array.o`