From b06457c83af669bb9ef71f5b84a3132657dce8a1 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Fri, 8 Nov 2019 13:12:33 -0500 Subject: 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) --- samples/Kconfig | 8 ++++++++ samples/Makefile | 1 + samples/ftrace/Makefile | 3 +++ samples/ftrace/ftrace-direct.c | 45 ++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 57 insertions(+) create mode 100644 samples/ftrace/Makefile create mode 100644 samples/ftrace/ftrace-direct.c (limited to 'samples') diff --git a/samples/Kconfig b/samples/Kconfig index c8dacb4dda80..65b5967dac0c 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -19,6 +19,14 @@ config SAMPLE_TRACE_PRINTK This builds a module that calls trace_printk() and can be used to test various trace_printk() calls from a module. +config SAMPLE_FTRACE_DIRECT + tristate "Build register_ftrace_direct() example" + depends on DYNAMIC_FTRACE_WITH_DIRECT_CALLS && m + depends on X86_64 # has x86_64 inlined asm + help + This builds an ftrace direct function example + that hooks to wake_up_process and prints the parameters. + config SAMPLE_KOBJECT tristate "Build kobject examples" help diff --git a/samples/Makefile b/samples/Makefile index 7d6e4ca28d69..cd496d633370 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_SAMPLE_RPMSG_CLIENT) += rpmsg/ subdir-$(CONFIG_SAMPLE_SECCOMP) += seccomp obj-$(CONFIG_SAMPLE_TRACE_EVENTS) += trace_events/ obj-$(CONFIG_SAMPLE_TRACE_PRINTK) += trace_printk/ +obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace/ obj-$(CONFIG_VIDEO_PCI_SKELETON) += v4l/ obj-y += vfio-mdev/ subdir-$(CONFIG_SAMPLE_VFS) += vfs diff --git a/samples/ftrace/Makefile b/samples/ftrace/Makefile new file mode 100644 index 000000000000..3718ab39eba3 --- /dev/null +++ b/samples/ftrace/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0-only + +obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct.o diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c new file mode 100644 index 000000000000..1483f067b000 --- /dev/null +++ b/samples/ftrace/ftrace-direct.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include + +#include /* for wake_up_process() */ +#include + +void my_direct_func(struct task_struct *p) +{ + trace_printk("wakeing 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"); -- cgit v1.2.3-59-g8ed1b From 156473a0ff4f9c209114b4c3ad968099eb541e33 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Fri, 8 Nov 2019 15:27:45 -0500 Subject: 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) --- samples/ftrace/Makefile | 1 + samples/ftrace/ftrace-direct-too.c | 51 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 52 insertions(+) create mode 100644 samples/ftrace/ftrace-direct-too.c (limited to 'samples') diff --git a/samples/ftrace/Makefile b/samples/ftrace/Makefile index 3718ab39eba3..d8217c4e072e 100644 --- a/samples/ftrace/Makefile +++ b/samples/ftrace/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0-only obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct.o +obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace-direct-too.o diff --git a/samples/ftrace/ftrace-direct-too.c b/samples/ftrace/ftrace-direct-too.c new file mode 100644 index 000000000000..27efa5f6ff52 --- /dev/null +++ b/samples/ftrace/ftrace-direct-too.c @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include + +#include /* for handle_mm_fault() */ +#include + +void my_direct_func(struct vm_area_struct *vma, + unsigned long address, unsigned int flags) +{ + trace_printk("handle mm fault vma=%p address=%lx flags=%x\n", + vma, address, flags); +} + +extern void my_tramp(void *); + +asm ( +" .pushsection .text, \"ax\", @progbits\n" +" my_tramp:" +" pushq %rbp\n" +" movq %rsp, %rbp\n" +" pushq %rdi\n" +" pushq %rsi\n" +" pushq %rdx\n" +" call my_direct_func\n" +" popq %rdx\n" +" popq %rsi\n" +" popq %rdi\n" +" leave\n" +" ret\n" +" .popsection\n" +); + + +static int __init ftrace_direct_init(void) +{ + return register_ftrace_direct((unsigned long)handle_mm_fault, + (unsigned long)my_tramp); +} + +static void __exit ftrace_direct_exit(void) +{ + unregister_ftrace_direct((unsigned long)handle_mm_fault, + (unsigned long)my_tramp); +} + +module_init(ftrace_direct_init); +module_exit(ftrace_direct_exit); + +MODULE_AUTHOR("Steven Rostedt"); +MODULE_DESCRIPTION("Another example use case of using register_ftrace_direct()"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3-59-g8ed1b From ae0cc3b7e7f5e37b946876e114068f92b33dfa5a Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Thu, 14 Nov 2019 14:41:47 -0500 Subject: 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) --- samples/ftrace/Makefile | 1 + samples/ftrace/ftrace-direct-modify.c | 88 +++++++++++++++++++++++++++++++++++ 2 files changed, 89 insertions(+) create mode 100644 samples/ftrace/ftrace-direct-modify.c (limited to 'samples') diff --git a/samples/ftrace/Makefile b/samples/ftrace/Makefile index d8217c4e072e..fb0c3ae18295 100644 --- a/samples/ftrace/Makefile +++ b/samples/ftrace/Makefile @@ -2,3 +2,4 @@ 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 diff --git a/samples/ftrace/ftrace-direct-modify.c b/samples/ftrace/ftrace-direct-modify.c new file mode 100644 index 000000000000..e04229d21475 --- /dev/null +++ b/samples/ftrace/ftrace-direct-modify.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include + +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" +" my_tramp1:" +" pushq %rbp\n" +" movq %rsp, %rbp\n" +" call my_direct_func1\n" +" leave\n" +" ret\n" +" my_tramp2:" +" pushq %rbp\n" +" movq %rsp, %rbp\n" +" call my_direct_func2\n" +" leave\n" +" ret\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"); -- cgit v1.2.3-59-g8ed1b From 760f8bc7c89c87bff9c01a8746e85dcc6e771ea8 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Fri, 15 Nov 2019 08:59:38 +0000 Subject: 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 Signed-off-by: Steven Rostedt (VMware) --- samples/ftrace/ftrace-direct.c | 2 +- tools/testing/selftests/ftrace/test.d/direct/ftrace-direct.tc | 2 +- tools/testing/selftests/ftrace/test.d/direct/kprobe-direct.tc | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-) (limited to 'samples') diff --git a/samples/ftrace/ftrace-direct.c b/samples/ftrace/ftrace-direct.c index 1483f067b000..a2e3063bd306 100644 --- a/samples/ftrace/ftrace-direct.c +++ b/samples/ftrace/ftrace-direct.c @@ -6,7 +6,7 @@ void my_direct_func(struct task_struct *p) { - trace_printk("wakeing up %s-%d\n", p->comm, p->pid); + trace_printk("waking up %s-%d\n", p->comm, p->pid); } extern void my_tramp(void *); diff --git a/tools/testing/selftests/ftrace/test.d/direct/ftrace-direct.tc b/tools/testing/selftests/ftrace/test.d/direct/ftrace-direct.tc index cbc7a30c2e0f..d75a8695bc21 100644 --- a/tools/testing/selftests/ftrace/test.d/direct/ftrace-direct.tc +++ b/tools/testing/selftests/ftrace/test.d/direct/ftrace-direct.tc @@ -11,7 +11,7 @@ fi echo "Let the module run a little" sleep 1 -grep -q "my_direct_func: wakeing up" trace +grep -q "my_direct_func: waking up" trace rmmod ftrace-direct diff --git a/tools/testing/selftests/ftrace/test.d/direct/kprobe-direct.tc b/tools/testing/selftests/ftrace/test.d/direct/kprobe-direct.tc index 017a7409b103..801ecb63e84c 100644 --- a/tools/testing/selftests/ftrace/test.d/direct/kprobe-direct.tc +++ b/tools/testing/selftests/ftrace/test.d/direct/kprobe-direct.tc @@ -16,7 +16,7 @@ fi echo "Let the module run a little" sleep 1 -grep -q "my_direct_func: wakeing up" trace +grep -q "my_direct_func: waking up" trace rmmod ftrace-direct @@ -26,7 +26,7 @@ start_direct() { echo > trace modprobe ftrace-direct sleep 1 - grep -q "my_direct_func: wakeing up" trace + grep -q "my_direct_func: waking up" trace } stop_direct() { -- cgit v1.2.3-59-g8ed1b From 89ed42495ef4a020435f2b999093bb5731eeb8b9 Mon Sep 17 00:00:00 2001 From: Divya Indi Date: Wed, 20 Nov 2019 11:08:39 -0800 Subject: 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 Signed-off-by: Divya Indi [ Moved to samples/ftrace ] Signed-off-by: Steven Rostedt (VMware) --- samples/Kconfig | 7 ++ samples/Makefile | 1 + samples/ftrace/Makefile | 3 + samples/ftrace/sample-trace-array.c | 131 ++++++++++++++++++++++++++++++++++++ samples/ftrace/sample-trace-array.h | 84 +++++++++++++++++++++++ 5 files changed, 226 insertions(+) create mode 100644 samples/ftrace/sample-trace-array.c create mode 100644 samples/ftrace/sample-trace-array.h (limited to 'samples') diff --git a/samples/Kconfig b/samples/Kconfig index 65b5967dac0c..ad64b223f3d0 100644 --- a/samples/Kconfig +++ b/samples/Kconfig @@ -27,6 +27,13 @@ config SAMPLE_FTRACE_DIRECT This builds an ftrace direct function example that hooks to wake_up_process and prints the parameters. +config SAMPLE_TRACE_ARRAY + tristate "Build sample module for kernel access to Ftrace instancess" + depends on EVENT_TRACING && m + help + This builds a module that demonstrates the use of various APIs to + access Ftrace instances from within the kernel. + config SAMPLE_KOBJECT tristate "Build kobject examples" help diff --git a/samples/Makefile b/samples/Makefile index cd496d633370..297f8934773f 100644 --- a/samples/Makefile +++ b/samples/Makefile @@ -18,6 +18,7 @@ subdir-$(CONFIG_SAMPLE_SECCOMP) += seccomp obj-$(CONFIG_SAMPLE_TRACE_EVENTS) += trace_events/ obj-$(CONFIG_SAMPLE_TRACE_PRINTK) += trace_printk/ obj-$(CONFIG_SAMPLE_FTRACE_DIRECT) += ftrace/ +obj-$(CONFIG_SAMPLE_TRACE_ARRAY) += ftrace/ obj-$(CONFIG_VIDEO_PCI_SKELETON) += v4l/ obj-y += vfio-mdev/ subdir-$(CONFIG_SAMPLE_VFS) += vfs diff --git a/samples/ftrace/Makefile b/samples/ftrace/Makefile index fb0c3ae18295..4ce896e10b2e 100644 --- a/samples/ftrace/Makefile +++ b/samples/ftrace/Makefile @@ -3,3 +3,6 @@ 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 diff --git a/samples/ftrace/sample-trace-array.c b/samples/ftrace/sample-trace-array.c new file mode 100644 index 000000000000..d523450d73eb --- /dev/null +++ b/samples/ftrace/sample-trace-array.c @@ -0,0 +1,131 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include +#include +#include + +/* + * Any file that uses trace points, must include the header. + * But only one file, must include the header by defining + * CREATE_TRACE_POINTS first. This will make the C code that + * creates the handles for the trace points. + */ +#define CREATE_TRACE_POINTS +#include "sample-trace-array.h" + +struct trace_array *tr; +static void mytimer_handler(struct timer_list *unused); +static struct task_struct *simple_tsk; + +/* + * mytimer: Timer setup to disable tracing for event "sample_event". This + * timer is only for the purposes of the sample module to demonstrate access of + * Ftrace instances from within kernel. + */ +static DEFINE_TIMER(mytimer, mytimer_handler); + +static void mytimer_handler(struct timer_list *unused) +{ + /* + * Disable tracing for event "sample_event". + */ + trace_array_set_clr_event(tr, "sample-subsystem", "sample_event", + false); +} + +static void simple_thread_func(int count) +{ + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(HZ); + + /* + * Printing count value using trace_array_printk() - trace_printk() + * equivalent for the instance buffers. + */ + trace_array_printk(tr, _THIS_IP_, "trace_array_printk: count=%d\n", + count); + /* + * Tracepoint for event "sample_event". This will print the + * current value of count and current jiffies. + */ + trace_sample_event(count, jiffies); +} + +static int simple_thread(void *arg) +{ + int count = 0; + unsigned long delay = msecs_to_jiffies(5000); + + /* + * Enable tracing for "sample_event". + */ + trace_array_set_clr_event(tr, "sample-subsystem", "sample_event", true); + + /* + * Adding timer - mytimer. This timer will disable tracing after + * delay seconds. + * + */ + add_timer(&mytimer); + mod_timer(&mytimer, jiffies+delay); + + while (!kthread_should_stop()) + simple_thread_func(count++); + + del_timer(&mytimer); + + /* + * trace_array_put() decrements the reference counter associated with + * the trace array - "tr". We are done using the trace array, hence + * decrement the reference counter so that it can be destroyed using + * trace_array_destroy(). + */ + trace_array_put(tr); + + return 0; +} + +static int __init sample_trace_array_init(void) +{ + /* + * Return a pointer to the trace array with name "sample-instance" if it + * exists, else create a new trace array. + * + * NOTE: This function increments the reference counter + * associated with the trace array - "tr". + */ + tr = trace_array_get_by_name("sample-instance"); + + if (!tr) + return -1; + /* + * If context specific per-cpu buffers havent already been allocated. + */ + trace_printk_init_buffers(); + + simple_tsk = kthread_run(simple_thread, NULL, "sample-instance"); + if (IS_ERR(simple_tsk)) + return -1; + return 0; +} + +static void __exit sample_trace_array_exit(void) +{ + kthread_stop(simple_tsk); + + /* + * We are unloading our module and no longer require the trace array. + * Remove/destroy "tr" using trace_array_destroy() + */ + trace_array_destroy(tr); +} + +module_init(sample_trace_array_init); +module_exit(sample_trace_array_exit); + +MODULE_AUTHOR("Divya Indi"); +MODULE_DESCRIPTION("Sample module for kernel access to Ftrace instances"); +MODULE_LICENSE("GPL"); diff --git a/samples/ftrace/sample-trace-array.h b/samples/ftrace/sample-trace-array.h new file mode 100644 index 000000000000..6f8962428158 --- /dev/null +++ b/samples/ftrace/sample-trace-array.h @@ -0,0 +1,84 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * If TRACE_SYSTEM is defined, that will be the directory created + * in the ftrace directory under /sys/kernel/tracing/events/ + * + * The define_trace.h below will also look for a file name of + * TRACE_SYSTEM.h where TRACE_SYSTEM is what is defined here. + * In this case, it would look for sample-trace.h + * + * If the header name will be different than the system name + * (as in this case), then you can override the header name that + * define_trace.h will look up by defining TRACE_INCLUDE_FILE + * + * This file is called sample-trace-array.h but we want the system + * to be called "sample-subsystem". Therefore we must define the name of this + * file: + * + * #define TRACE_INCLUDE_FILE sample-trace-array + * + * As we do in the bottom of this file. + * + * Notice that TRACE_SYSTEM should be defined outside of #if + * protection, just like TRACE_INCLUDE_FILE. + */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM sample-subsystem + +/* + * TRACE_SYSTEM is expected to be a C valid variable (alpha-numeric + * and underscore), although it may start with numbers. If for some + * reason it is not, you need to add the following lines: + */ +#undef TRACE_SYSTEM_VAR +#define TRACE_SYSTEM_VAR sample_subsystem + +/* + * But the above is only needed if TRACE_SYSTEM is not alpha-numeric + * and underscored. By default, TRACE_SYSTEM_VAR will be equal to + * TRACE_SYSTEM. As TRACE_SYSTEM_VAR must be alpha-numeric, if + * TRACE_SYSTEM is not, then TRACE_SYSTEM_VAR must be defined with + * only alpha-numeric and underscores. + * + * The TRACE_SYSTEM_VAR is only used internally and not visible to + * user space. + */ + +/* + * Notice that this file is not protected like a normal header. + * We also must allow for rereading of this file. The + * + * || defined(TRACE_HEADER_MULTI_READ) + * + * serves this purpose. + */ +#if !defined(_SAMPLE_TRACE_ARRAY_H) || defined(TRACE_HEADER_MULTI_READ) +#define _SAMPLE_TRACE_ARRAY_H + +#include +TRACE_EVENT(sample_event, + + TP_PROTO(int count, unsigned long time), + + TP_ARGS(count, time), + + TP_STRUCT__entry( + __field(int, count) + __field(unsigned long, time) + ), + + TP_fast_assign( + __entry->count = count; + __entry->time = time; + ), + + TP_printk("count value=%d at jiffies=%lu", __entry->count, + __entry->time) + ); +#endif + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . +#define TRACE_INCLUDE_FILE sample-trace-array +#include -- cgit v1.2.3-59-g8ed1b