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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 /tools/perf/tests/backward-ring-buffer.c
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 'tools/perf/tests/backward-ring-buffer.c')
-rw-r--r--tools/perf/tests/backward-ring-buffer.c170
1 files changed, 170 insertions, 0 deletions
diff --git a/tools/perf/tests/backward-ring-buffer.c b/tools/perf/tests/backward-ring-buffer.c
new file mode 100644
index 000000000..c5e7999f2
--- /dev/null
+++ b/tools/perf/tests/backward-ring-buffer.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test backward bit in event attribute, read ring buffer from end to
+ * beginning
+ */
+
+#include <evlist.h>
+#include <sys/prctl.h>
+#include "record.h"
+#include "tests.h"
+#include "debug.h"
+#include "parse-events.h"
+#include "util/mmap.h"
+#include <errno.h>
+#include <linux/string.h>
+#include <perf/mmap.h>
+
+#define NR_ITERS 111
+
+static void testcase(void)
+{
+ int i;
+
+ for (i = 0; i < NR_ITERS; i++) {
+ char proc_name[15];
+
+ snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
+ prctl(PR_SET_NAME, proc_name);
+ }
+}
+
+static int count_samples(struct evlist *evlist, int *sample_count,
+ int *comm_count)
+{
+ int i;
+
+ for (i = 0; i < evlist->core.nr_mmaps; i++) {
+ struct mmap *map = &evlist->overwrite_mmap[i];
+ union perf_event *event;
+
+ perf_mmap__read_init(&map->core);
+ while ((event = perf_mmap__read_event(&map->core)) != NULL) {
+ const u32 type = event->header.type;
+
+ switch (type) {
+ case PERF_RECORD_SAMPLE:
+ (*sample_count)++;
+ break;
+ case PERF_RECORD_COMM:
+ (*comm_count)++;
+ break;
+ default:
+ pr_err("Unexpected record of type %d\n", type);
+ return TEST_FAIL;
+ }
+ }
+ perf_mmap__read_done(&map->core);
+ }
+ return TEST_OK;
+}
+
+static int do_test(struct evlist *evlist, int mmap_pages,
+ int *sample_count, int *comm_count)
+{
+ int err;
+ char sbuf[STRERR_BUFSIZE];
+
+ err = evlist__mmap(evlist, mmap_pages);
+ if (err < 0) {
+ pr_debug("evlist__mmap: %s\n",
+ str_error_r(errno, sbuf, sizeof(sbuf)));
+ return TEST_FAIL;
+ }
+
+ evlist__enable(evlist);
+ testcase();
+ evlist__disable(evlist);
+
+ err = count_samples(evlist, sample_count, comm_count);
+ evlist__munmap(evlist);
+ return err;
+}
+
+
+static int test__backward_ring_buffer(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
+{
+ int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
+ char pid[16], sbuf[STRERR_BUFSIZE];
+ struct evlist *evlist;
+ struct evsel *evsel __maybe_unused;
+ struct parse_events_error parse_error;
+ struct record_opts opts = {
+ .target = {
+ .uses_mmap = true,
+ },
+ .freq = 0,
+ .mmap_pages = 256,
+ .default_interval = 1,
+ };
+
+ snprintf(pid, sizeof(pid), "%d", getpid());
+ pid[sizeof(pid) - 1] = '\0';
+ opts.target.tid = opts.target.pid = pid;
+
+ evlist = evlist__new();
+ if (!evlist) {
+ pr_debug("Not enough memory to create evlist\n");
+ return TEST_FAIL;
+ }
+
+ err = evlist__create_maps(evlist, &opts.target);
+ if (err < 0) {
+ pr_debug("Not enough memory to create thread/cpu maps\n");
+ goto out_delete_evlist;
+ }
+
+ parse_events_error__init(&parse_error);
+ /*
+ * Set backward bit, ring buffer should be writing from end. Record
+ * it in aux evlist
+ */
+ err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
+ parse_events_error__exit(&parse_error);
+ if (err) {
+ pr_debug("Failed to parse tracepoint event, try use root\n");
+ ret = TEST_SKIP;
+ goto out_delete_evlist;
+ }
+
+ evlist__config(evlist, &opts, NULL);
+
+ err = evlist__open(evlist);
+ if (err < 0) {
+ pr_debug("perf_evlist__open: %s\n",
+ str_error_r(errno, sbuf, sizeof(sbuf)));
+ goto out_delete_evlist;
+ }
+
+ ret = TEST_FAIL;
+ err = do_test(evlist, opts.mmap_pages, &sample_count,
+ &comm_count);
+ if (err != TEST_OK)
+ goto out_delete_evlist;
+
+ if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
+ pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
+ sample_count, comm_count);
+ goto out_delete_evlist;
+ }
+
+ evlist__close(evlist);
+
+ err = evlist__open(evlist);
+ if (err < 0) {
+ pr_debug("perf_evlist__open: %s\n",
+ str_error_r(errno, sbuf, sizeof(sbuf)));
+ goto out_delete_evlist;
+ }
+
+ err = do_test(evlist, 1, &sample_count, &comm_count);
+ if (err != TEST_OK)
+ goto out_delete_evlist;
+
+ ret = TEST_OK;
+out_delete_evlist:
+ evlist__delete(evlist);
+ return ret;
+}
+
+DEFINE_SUITE("Read backward ring buffer", backward_ring_buffer);