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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /samples/user_events
downloadlinux-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/user_events')
-rw-r--r--samples/user_events/Makefile5
-rw-r--r--samples/user_events/example.c73
2 files changed, 78 insertions, 0 deletions
diff --git a/samples/user_events/Makefile b/samples/user_events/Makefile
new file mode 100644
index 000000000..7252b589d
--- /dev/null
+++ b/samples/user_events/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+CFLAGS += -Wl,-no-as-needed -Wall -I../../usr/include
+
+example: example.o
+example.o: example.c
diff --git a/samples/user_events/example.c b/samples/user_events/example.c
new file mode 100644
index 000000000..28165a096
--- /dev/null
+++ b/samples/user_events/example.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, Microsoft Corporation.
+ *
+ * Authors:
+ * Beau Belgrave <beaub@linux.microsoft.com>
+ */
+
+#include <errno.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/uio.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <linux/user_events.h>
+
+const char *data_file = "/sys/kernel/tracing/user_events_data";
+int enabled = 0;
+
+static int event_reg(int fd, const char *command, int *write, int *enabled)
+{
+ struct user_reg reg = {0};
+
+ reg.size = sizeof(reg);
+ reg.enable_bit = 31;
+ reg.enable_size = sizeof(*enabled);
+ reg.enable_addr = (__u64)enabled;
+ reg.name_args = (__u64)command;
+
+ if (ioctl(fd, DIAG_IOCSREG, &reg) == -1)
+ return -1;
+
+ *write = reg.write_index;
+
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ int data_fd, write;
+ struct iovec io[2];
+ __u32 count = 0;
+
+ data_fd = open(data_file, O_RDWR);
+
+ if (event_reg(data_fd, "test u32 count", &write, &enabled) == -1)
+ return errno;
+
+ /* Setup iovec */
+ io[0].iov_base = &write;
+ io[0].iov_len = sizeof(write);
+ io[1].iov_base = &count;
+ io[1].iov_len = sizeof(count);
+ask:
+ printf("Press enter to check status...\n");
+ getchar();
+
+ /* Check if anyone is listening */
+ if (enabled) {
+ /* Yep, trace out our data */
+ writev(data_fd, (const struct iovec *)io, 2);
+
+ /* Increase the count */
+ count++;
+
+ printf("Something was attached, wrote data\n");
+ }
+
+ goto ask;
+
+ return 0;
+}