From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- tools/perf/tests/stat.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 tools/perf/tests/stat.c (limited to 'tools/perf/tests/stat.c') diff --git a/tools/perf/tests/stat.c b/tools/perf/tests/stat.c new file mode 100644 index 000000000..d60983657 --- /dev/null +++ b/tools/perf/tests/stat.c @@ -0,0 +1,121 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "event.h" +#include "tests.h" +#include "stat.h" +#include "counts.h" +#include "debug.h" +#include "util/synthetic-events.h" + +static bool has_term(struct perf_record_stat_config *config, + u64 tag, u64 val) +{ + unsigned i; + + for (i = 0; i < config->nr; i++) { + if ((config->data[i].tag == tag) && + (config->data[i].val == val)) + return true; + } + + return false; +} + +static int process_stat_config_event(const struct perf_tool *tool __maybe_unused, + union perf_event *event, + struct perf_sample *sample __maybe_unused, + struct machine *machine __maybe_unused) +{ + struct perf_record_stat_config *config = &event->stat_config; + struct perf_stat_config test_stat_config = {}; + +#define HAS(term, val) \ + has_term(config, PERF_STAT_CONFIG_TERM__##term, val) + + TEST_ASSERT_VAL("wrong nr", config->nr == PERF_STAT_CONFIG_TERM__MAX); + TEST_ASSERT_VAL("wrong aggr_mode", HAS(AGGR_MODE, AGGR_CORE)); + TEST_ASSERT_VAL("wrong scale", HAS(SCALE, 1)); + TEST_ASSERT_VAL("wrong interval", HAS(INTERVAL, 1)); + +#undef HAS + + perf_event__read_stat_config(&test_stat_config, config); + + TEST_ASSERT_VAL("wrong aggr_mode", test_stat_config.aggr_mode == AGGR_CORE); + TEST_ASSERT_VAL("wrong scale", test_stat_config.scale == 1); + TEST_ASSERT_VAL("wrong interval", test_stat_config.interval == 1); + return 0; +} + +static int test__synthesize_stat_config(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ + struct perf_stat_config test_stat_config = { + .aggr_mode = AGGR_CORE, + .scale = 1, + .interval = 1, + }; + + TEST_ASSERT_VAL("failed to synthesize stat_config", + !perf_event__synthesize_stat_config(NULL, &test_stat_config, + process_stat_config_event, + NULL)); + + return 0; +} + +static int process_stat_event(const struct perf_tool *tool __maybe_unused, + union perf_event *event, + struct perf_sample *sample __maybe_unused, + struct machine *machine __maybe_unused) +{ + struct perf_record_stat *st = &event->stat; + + TEST_ASSERT_VAL("wrong cpu", st->cpu == 1); + TEST_ASSERT_VAL("wrong thread", st->thread == 2); + TEST_ASSERT_VAL("wrong id", st->id == 3); + TEST_ASSERT_VAL("wrong val", st->val == 100); + TEST_ASSERT_VAL("wrong run", st->ena == 200); + TEST_ASSERT_VAL("wrong ena", st->run == 300); + return 0; +} + +static int test__synthesize_stat(struct test_suite *test __maybe_unused, int subtest __maybe_unused) +{ + struct perf_counts_values count; + + count.val = 100; + count.ena = 200; + count.run = 300; + + TEST_ASSERT_VAL("failed to synthesize stat_config", + !perf_event__synthesize_stat(NULL, (struct perf_cpu){.cpu = 1}, 2, 3, + &count, process_stat_event, NULL)); + + return 0; +} + +static int process_stat_round_event(const struct perf_tool *tool __maybe_unused, + union perf_event *event, + struct perf_sample *sample __maybe_unused, + struct machine *machine __maybe_unused) +{ + struct perf_record_stat_round *stat_round = &event->stat_round; + + TEST_ASSERT_VAL("wrong time", stat_round->time == 0xdeadbeef); + TEST_ASSERT_VAL("wrong type", stat_round->type == PERF_STAT_ROUND_TYPE__INTERVAL); + return 0; +} + +static int test__synthesize_stat_round(struct test_suite *test __maybe_unused, int subtest __maybe_unused) +{ + TEST_ASSERT_VAL("failed to synthesize stat_config", + !perf_event__synthesize_stat_round(NULL, 0xdeadbeef, PERF_STAT_ROUND_TYPE__INTERVAL, + process_stat_round_event, NULL)); + + return 0; +} + +DEFINE_SUITE("Synthesize stat config", synthesize_stat_config); +DEFINE_SUITE("Synthesize stat", synthesize_stat); +DEFINE_SUITE("Synthesize stat round", synthesize_stat_round); -- cgit v1.3.1