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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /samples/ftrace/sample-trace-array.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
Diffstat (limited to 'samples/ftrace/sample-trace-array.c')
| -rw-r--r-- | samples/ftrace/sample-trace-array.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/samples/ftrace/sample-trace-array.c b/samples/ftrace/sample-trace-array.c new file mode 100644 index 000000000..414761610 --- /dev/null +++ b/samples/ftrace/sample-trace-array.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include <linux/module.h> +#include <linux/kthread.h> +#include <linux/trace.h> +#include <linux/trace_events.h> +#include <linux/timer.h> +#include <linux/err.h> +#include <linux/jiffies.h> +#include <linux/workqueue.h> + +/* + * 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; + +static void trace_work_fn(struct work_struct *work) +{ + /* + * Disable tracing for event "sample_event". + */ + trace_array_set_clr_event(tr, "sample-subsystem", "sample_event", + false); +} +static DECLARE_WORK(trace_work, trace_work_fn); + +/* + * 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) +{ + schedule_work(&trace_work); +} + +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++); + + timer_delete(&mytimer); + cancel_work_sync(&trace_work); + + /* + * 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", "sched,timer,kprobes"); + + if (!tr) + return -1; + /* + * If context specific per-cpu buffers havent already been allocated. + */ + trace_array_init_printk(tr); + + simple_tsk = kthread_run(simple_thread, NULL, "sample-instance"); + if (IS_ERR(simple_tsk)) { + trace_array_put(tr); + trace_array_destroy(tr); + 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"); |
