From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- tools/perf/tests/expand-cgroup.c | 216 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 216 insertions(+) create mode 100644 tools/perf/tests/expand-cgroup.c (limited to 'tools/perf/tests/expand-cgroup.c') diff --git a/tools/perf/tests/expand-cgroup.c b/tools/perf/tests/expand-cgroup.c new file mode 100644 index 000000000..04d626117 --- /dev/null +++ b/tools/perf/tests/expand-cgroup.c @@ -0,0 +1,216 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "tests.h" +#include "debug.h" +#include "evlist.h" +#include "cgroup.h" +#include "rblist.h" +#include "metricgroup.h" +#include "parse-events.h" +#include "pmu-events/pmu-events.h" +#include "pfm.h" +#include "target.h" +#include +#include +#include +#include + +static int test_expand_events(struct evlist *evlist) +{ + int i, ret = TEST_FAIL; + int nr_events; + bool was_group_event; + int nr_members; /* for the first evsel only */ + const char cgrp_str[] = "A,B,C"; + const char *cgrp_name[] = { "A", "B", "C" }; + int nr_cgrps = ARRAY_SIZE(cgrp_name); + char **ev_name; + struct evsel *evsel; + + TEST_ASSERT_VAL("evlist is empty", !evlist__empty(evlist)); + + nr_events = evlist__nr_entries(evlist); + ev_name = calloc(nr_events, sizeof(*ev_name)); + if (ev_name == NULL) { + pr_debug("memory allocation failure\n"); + return TEST_FAIL; + } + i = 0; + evlist__for_each_entry(evlist, evsel) { + ev_name[i] = strdup(evsel->name); + if (ev_name[i] == NULL) { + pr_debug("memory allocation failure\n"); + goto out; + } + i++; + } + /* remember grouping info */ + was_group_event = evsel__is_group_event(evlist__first(evlist)); + nr_members = evlist__first(evlist)->core.nr_members; + + ret = evlist__expand_cgroup(evlist, cgrp_str, false); + if (ret < 0) { + pr_debug("failed to expand events for cgroups\n"); + goto out; + } + + ret = TEST_FAIL; + if (evlist__nr_entries(evlist) != nr_events * nr_cgrps) { + pr_debug("event count doesn't match\n"); + goto out; + } + + i = 0; + evlist__for_each_entry(evlist, evsel) { + if (!evsel__name_is(evsel, ev_name[i % nr_events])) { + pr_debug("event name doesn't match:\n"); + pr_debug(" evsel[%d]: %s\n expected: %s\n", + i, evsel->name, ev_name[i % nr_events]); + goto out; + } + if (strcmp(evsel->cgrp->name, cgrp_name[i / nr_events])) { + pr_debug("cgroup name doesn't match:\n"); + pr_debug(" evsel[%d]: %s\n expected: %s\n", + i, evsel->cgrp->name, cgrp_name[i / nr_events]); + goto out; + } + + if ((i % nr_events) == 0) { + if (evsel__is_group_event(evsel) != was_group_event) { + pr_debug("event group doesn't match: got %s, expect %s\n", + evsel__is_group_event(evsel) ? "true" : "false", + was_group_event ? "true" : "false"); + goto out; + } + if (evsel->core.nr_members != nr_members) { + pr_debug("event group member doesn't match: %d vs %d\n", + evsel->core.nr_members, nr_members); + goto out; + } + } + i++; + } + ret = TEST_OK; + +out: for (i = 0; i < nr_events; i++) + free(ev_name[i]); + free(ev_name); + return ret; +} + +static int expand_default_events(void) +{ + int ret; + struct target target = {}; + struct evlist *evlist = evlist__new_default(&target, /*sample_callchains=*/false); + + TEST_ASSERT_VAL("failed to get evlist", evlist); + + ret = test_expand_events(evlist); + evlist__put(evlist); + return ret; +} + +static int expand_group_events(void) +{ + int ret; + struct evlist *evlist; + struct parse_events_error err; + const char event_str[] = "{cycles,instructions}"; + + symbol_conf.event_group = true; + + evlist = evlist__new(); + TEST_ASSERT_VAL("failed to get evlist", evlist); + + parse_events_error__init(&err); + ret = parse_events(evlist, event_str, &err); + if (ret < 0) { + pr_debug("failed to parse event '%s', err %d\n", event_str, ret); + parse_events_error__print(&err, event_str); + goto out; + } + + ret = test_expand_events(evlist); +out: + parse_events_error__exit(&err); + evlist__put(evlist); + return ret; +} + +static int expand_libpfm_events(void) +{ + int ret; + struct evlist *evlist; + const char event_str[] = "CYCLES"; + struct option opt = { + .value = &evlist, + }; + + symbol_conf.event_group = true; + + evlist = evlist__new(); + TEST_ASSERT_VAL("failed to get evlist", evlist); + + ret = parse_libpfm_events_option(&opt, event_str, 0); + if (ret < 0) { + pr_debug("failed to parse libpfm event '%s', err %d\n", + event_str, ret); + goto out; + } + if (evlist__empty(evlist)) { + pr_debug("libpfm was not enabled\n"); + goto out; + } + + ret = test_expand_events(evlist); +out: + evlist__put(evlist); + return ret; +} + +static int expand_metric_events(void) +{ + int ret; + struct evlist *evlist; + const char metric_str[] = "CPI"; + const struct pmu_metrics_table *pme_test; + + evlist = evlist__new(); + TEST_ASSERT_VAL("failed to get evlist", evlist); + + pme_test = find_core_metrics_table("testarch", "testcpu"); + ret = metricgroup__parse_groups_test(evlist, pme_test, metric_str, + /*cputype_filter=*/false); + if (ret < 0) { + pr_debug("failed to parse '%s' metric\n", metric_str); + goto out; + } + + ret = test_expand_events(evlist); + +out: + evlist__put(evlist); + return ret; +} + +static int test__expand_cgroup_events(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ + int ret; + + ret = expand_default_events(); + TEST_ASSERT_EQUAL("failed to expand default events", ret, 0); + + ret = expand_group_events(); + TEST_ASSERT_EQUAL("failed to expand event group", ret, 0); + + ret = expand_libpfm_events(); + TEST_ASSERT_EQUAL("failed to expand event group", ret, 0); + + ret = expand_metric_events(); + TEST_ASSERT_EQUAL("failed to expand metric events", ret, 0); + + return ret; +} + +DEFINE_SUITE("Event expansion for cgroups", expand_cgroup_events); -- cgit v1.3.1