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/maps.c | 245 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 245 insertions(+) create mode 100644 tools/perf/tests/maps.c (limited to 'tools/perf/tests/maps.c') diff --git a/tools/perf/tests/maps.c b/tools/perf/tests/maps.c new file mode 100644 index 000000000..2c05d62f4 --- /dev/null +++ b/tools/perf/tests/maps.c @@ -0,0 +1,245 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include "tests.h" +#include "map.h" +#include "maps.h" +#include "dso.h" +#include "debug.h" + +struct map_def { + const char *name; + u64 start; + u64 end; +}; + +struct check_maps_cb_args { + struct map_def *merged; + unsigned int i; +}; + +static int check_maps_cb(struct map *map, void *data) +{ + struct check_maps_cb_args *args = data; + struct map_def *merged = &args->merged[args->i]; + + if (map__start(map) != merged->start || + map__end(map) != merged->end || + strcmp(dso__name(map__dso(map)), merged->name) || + refcount_read(map__refcnt(map)) != 1) { + return 1; + } + args->i++; + return 0; +} + +static int failed_cb(struct map *map, void *data __maybe_unused) +{ + pr_debug("\tstart: %" PRIu64 " end: %" PRIu64 " name: '%s' refcnt: %d\n", + map__start(map), + map__end(map), + dso__name(map__dso(map)), + refcount_read(map__refcnt(map))); + + return 0; +} + +static int check_maps(struct map_def *merged, unsigned int size, struct maps *maps) +{ + bool failed = false; + + if (maps__nr_maps(maps) != size) { + pr_debug("Expected %d maps, got %d", size, maps__nr_maps(maps)); + failed = true; + } else { + struct check_maps_cb_args args = { + .merged = merged, + .i = 0, + }; + failed = maps__for_each_map(maps, check_maps_cb, &args); + } + if (failed) { + pr_debug("Expected:\n"); + for (unsigned int i = 0; i < size; i++) { + pr_debug("\tstart: %" PRIu64 " end: %" PRIu64 " name: '%s' refcnt: 1\n", + merged[i].start, merged[i].end, merged[i].name); + } + pr_debug("Got:\n"); + maps__for_each_map(maps, failed_cb, NULL); + } + return failed ? TEST_FAIL : TEST_OK; +} + +static int test__maps__merge_in(struct test_suite *t __maybe_unused, int subtest __maybe_unused) +{ + unsigned int i; + struct map_def bpf_progs[] = { + { "bpf_prog_1", 200, 300 }, + { "bpf_prog_2", 500, 600 }, + { "bpf_prog_3", 800, 900 }, + }; + struct map_def merged12[] = { + { "kcore1", 100, 200 }, + { "bpf_prog_1", 200, 300 }, + { "kcore1", 300, 500 }, + { "bpf_prog_2", 500, 600 }, + { "kcore1", 600, 800 }, + { "bpf_prog_3", 800, 900 }, + { "kcore1", 900, 1000 }, + }; + struct map_def merged3[] = { + { "kcore1", 100, 200 }, + { "bpf_prog_1", 200, 300 }, + { "kcore1", 300, 500 }, + { "bpf_prog_2", 500, 600 }, + { "kcore1", 600, 800 }, + { "bpf_prog_3", 800, 900 }, + { "kcore1", 900, 1000 }, + { "kcore3", 1000, 1100 }, + }; + struct map *map_kcore1, *map_kcore2, *map_kcore3; + int ret; + struct maps *maps = maps__new(NULL); + + TEST_ASSERT_VAL("failed to create maps", maps); + + for (i = 0; i < ARRAY_SIZE(bpf_progs); i++) { + struct map *map; + + map = dso__new_map(bpf_progs[i].name); + TEST_ASSERT_VAL("failed to create map", map); + + map__set_start(map, bpf_progs[i].start); + map__set_end(map, bpf_progs[i].end); + TEST_ASSERT_VAL("failed to insert map", maps__insert(maps, map) == 0); + map__put(map); + } + + map_kcore1 = dso__new_map("kcore1"); + TEST_ASSERT_VAL("failed to create map", map_kcore1); + + map_kcore2 = dso__new_map("kcore2"); + TEST_ASSERT_VAL("failed to create map", map_kcore2); + + map_kcore3 = dso__new_map("kcore3"); + TEST_ASSERT_VAL("failed to create map", map_kcore3); + + /* kcore1 map overlaps over all bpf maps */ + map__set_start(map_kcore1, 100); + map__set_end(map_kcore1, 1000); + + /* kcore2 map hides behind bpf_prog_2 */ + map__set_start(map_kcore2, 550); + map__set_end(map_kcore2, 570); + + /* kcore3 map hides behind bpf_prog_3, kcore1 and adds new map */ + map__set_start(map_kcore3, 880); + map__set_end(map_kcore3, 1100); + + ret = maps__merge_in(maps, map_kcore1); + TEST_ASSERT_VAL("failed to merge map", !ret); + + ret = check_maps(merged12, ARRAY_SIZE(merged12), maps); + TEST_ASSERT_VAL("merge check failed", !ret); + + ret = maps__merge_in(maps, map_kcore2); + TEST_ASSERT_VAL("failed to merge map", !ret); + + ret = check_maps(merged12, ARRAY_SIZE(merged12), maps); + TEST_ASSERT_VAL("merge check failed", !ret); + + ret = maps__merge_in(maps, map_kcore3); + TEST_ASSERT_VAL("failed to merge map", !ret); + + ret = check_maps(merged3, ARRAY_SIZE(merged3), maps); + TEST_ASSERT_VAL("merge check failed", !ret); + + maps__zput(maps); + map__zput(map_kcore1); + map__zput(map_kcore2); + map__zput(map_kcore3); + return TEST_OK; +} + +static int test__maps__fixup_overlap_and_insert(struct test_suite *t __maybe_unused, + int subtest __maybe_unused) +{ + struct map_def initial_maps[] = { + { "target_map", 1000, 2000 }, + { "next_map", 3000, 4000 }, + }; + struct map_def insert_split = { "split_map", 1400, 1600 }; + struct map_def expected_after_split[] = { + { "target_map", 1000, 1400 }, + { "split_map", 1400, 1600 }, + { "target_map", 1600, 2000 }, + { "next_map", 3000, 4000 }, + }; + + struct map_def insert_eclipse = { "eclipse_map", 2500, 4500 }; + struct map_def expected_final[] = { + { "target_map", 1000, 1400 }, + { "split_map", 1400, 1600 }, + { "target_map", 1600, 2000 }, + { "eclipse_map", 2500, 4500 }, + /* "next_map" (3000-4000) is removed */ + }; + + struct map *map_split, *map_eclipse; + int ret; + unsigned int i; + struct maps *maps = maps__new(NULL); + + TEST_ASSERT_VAL("failed to create maps", maps); + + for (i = 0; i < ARRAY_SIZE(initial_maps); i++) { + struct map *map = dso__new_map(initial_maps[i].name); + + TEST_ASSERT_VAL("failed to create map", map); + map__set_start(map, initial_maps[i].start); + map__set_end(map, initial_maps[i].end); + TEST_ASSERT_VAL("failed to insert map", maps__insert(maps, map) == 0); + map__put(map); + } + + // Check splitting. + map_split = dso__new_map(insert_split.name); + TEST_ASSERT_VAL("failed to create split map", map_split); + map__set_start(map_split, insert_split.start); + map__set_end(map_split, insert_split.end); + + ret = maps__fixup_overlap_and_insert(maps, map_split); + TEST_ASSERT_VAL("failed to fixup and insert split map", !ret); + + map__zput(map_split); + ret = check_maps(expected_after_split, ARRAY_SIZE(expected_after_split), maps); + TEST_ASSERT_VAL("split check failed", !ret); + + // Check cover 1 map with another. + map_eclipse = dso__new_map(insert_eclipse.name); + TEST_ASSERT_VAL("failed to create eclipse map", map_eclipse); + map__set_start(map_eclipse, insert_eclipse.start); + map__set_end(map_eclipse, insert_eclipse.end); + + ret = maps__fixup_overlap_and_insert(maps, map_eclipse); + TEST_ASSERT_VAL("failed to fixup and insert eclipse map", !ret); + + map__zput(map_eclipse); + ret = check_maps(expected_final, ARRAY_SIZE(expected_final), maps); + TEST_ASSERT_VAL("eclipse check failed", !ret); + + maps__zput(maps); + return TEST_OK; +} + +static struct test_case tests__maps[] = { + TEST_CASE("Test merge_in interface", maps__merge_in), + TEST_CASE("Test fix up overlap interface", maps__fixup_overlap_and_insert), + { .name = NULL, } +}; + +struct test_suite suite__maps = { + .desc = "Maps - per process mmaps abstraction", + .test_cases = tests__maps, +}; -- cgit v1.3.1