From f915fcb38553eb9150a918348d932fd292de71dc Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:37 +0200 Subject: bpf: Count stats for kprobe_multi programs Adding support to gather missed stats for kprobe_multi programs due to bpf_prog_active protection. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Tested-by: Song Liu Reviewed-by: Song Liu Link: https://lore.kernel.org/bpf/20230920213145.1941596-2-jolsa@kernel.org --- kernel/trace/bpf_trace.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 868008f56fec..54827d04c9a6 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2710,6 +2710,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, int err; if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) { + bpf_prog_inc_misses_counter(link->link.prog); err = 0; goto out; } -- cgit From e2b2cd592adbd303bcc02451d32fedd511000fb0 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:38 +0200 Subject: bpf: Add missed value to kprobe_multi link info Add missed value to kprobe_multi link info to hold the stats of missed kprobe_multi probe. The missed counter gets incremented when fprobe fails the recursion check or there's no rethook available for return probe. In either case the attached bpf program is not executed. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Tested-by: Song Liu Reviewed-by: Song Liu Acked-by: Hou Tao Link: https://lore.kernel.org/bpf/20230920213145.1941596-3-jolsa@kernel.org --- include/uapi/linux/bpf.h | 1 + kernel/trace/bpf_trace.c | 1 + tools/include/uapi/linux/bpf.h | 1 + 3 files changed, 3 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 5f13db15a3c7..1da5b1bcce71 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6532,6 +6532,7 @@ struct bpf_link_info { __aligned_u64 addrs; __u32 count; /* in/out: kprobe_multi function count */ __u32 flags; + __u64 missed; } kprobe_multi; struct { __u32 type; /* enum bpf_perf_event_type */ diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 54827d04c9a6..6aec6e7d612a 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2614,6 +2614,7 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link); info->kprobe_multi.count = kmulti_link->cnt; info->kprobe_multi.flags = kmulti_link->flags; + info->kprobe_multi.missed = kmulti_link->fp.nmissed; if (!uaddrs) return 0; diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 5f13db15a3c7..1da5b1bcce71 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -6532,6 +6532,7 @@ struct bpf_link_info { __aligned_u64 addrs; __u32 count; /* in/out: kprobe_multi function count */ __u32 flags; + __u64 missed; } kprobe_multi; struct { __u32 type; /* enum bpf_perf_event_type */ -- cgit From 3acf8ace68230e9558cf916847f1cc9f208abdf1 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:39 +0200 Subject: bpf: Add missed value to kprobe perf link info Add missed value to kprobe attached through perf link info to hold the stats of missed kprobe handler execution. The kprobe's missed counter gets incremented when kprobe handler is not executed due to another kprobe running on the same cpu. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230920213145.1941596-4-jolsa@kernel.org --- include/linux/trace_events.h | 6 ++++-- include/uapi/linux/bpf.h | 1 + kernel/bpf/syscall.c | 14 ++++++++------ kernel/trace/bpf_trace.c | 5 +++-- kernel/trace/trace_kprobe.c | 14 +++++++++++--- tools/include/uapi/linux/bpf.h | 1 + 6 files changed, 28 insertions(+), 13 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 21ae37e49319..5eb88a66eb68 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -761,7 +761,8 @@ struct bpf_raw_event_map *bpf_get_raw_tracepoint(const char *name); void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp); int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, u32 *fd_type, const char **buf, - u64 *probe_offset, u64 *probe_addr); + u64 *probe_offset, u64 *probe_addr, + unsigned long *missed); int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog); #else @@ -801,7 +802,7 @@ static inline void bpf_put_raw_tracepoint(struct bpf_raw_event_map *btp) static inline int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, u32 *fd_type, const char **buf, u64 *probe_offset, - u64 *probe_addr) + u64 *probe_addr, unsigned long *missed) { return -EOPNOTSUPP; } @@ -877,6 +878,7 @@ extern void perf_kprobe_destroy(struct perf_event *event); extern int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, const char **symbol, u64 *probe_offset, u64 *probe_addr, + unsigned long *missed, bool perf_type_tracepoint); #endif #ifdef CONFIG_UPROBE_EVENTS diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1da5b1bcce71..70bfa997e896 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -6548,6 +6548,7 @@ struct bpf_link_info { __u32 name_len; __u32 offset; /* offset from func_name */ __u64 addr; + __u64 missed; } kprobe; /* BPF_PERF_EVENT_KPROBE, BPF_PERF_EVENT_KRETPROBE */ struct { __aligned_u64 tp_name; /* in/out */ diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 85c1d908f70f..6b5280f14a53 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3374,7 +3374,7 @@ static void bpf_perf_link_dealloc(struct bpf_link *link) static int bpf_perf_link_fill_common(const struct perf_event *event, char __user *uname, u32 ulen, u64 *probe_offset, u64 *probe_addr, - u32 *fd_type) + u32 *fd_type, unsigned long *missed) { const char *buf; u32 prog_id; @@ -3385,7 +3385,7 @@ static int bpf_perf_link_fill_common(const struct perf_event *event, return -EINVAL; err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, - probe_offset, probe_addr); + probe_offset, probe_addr, missed); if (err) return err; if (!uname) @@ -3408,6 +3408,7 @@ static int bpf_perf_link_fill_common(const struct perf_event *event, static int bpf_perf_link_fill_kprobe(const struct perf_event *event, struct bpf_link_info *info) { + unsigned long missed; char __user *uname; u64 addr, offset; u32 ulen, type; @@ -3416,7 +3417,7 @@ static int bpf_perf_link_fill_kprobe(const struct perf_event *event, uname = u64_to_user_ptr(info->perf_event.kprobe.func_name); ulen = info->perf_event.kprobe.name_len; err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr, - &type); + &type, &missed); if (err) return err; if (type == BPF_FD_TYPE_KRETPROBE) @@ -3425,6 +3426,7 @@ static int bpf_perf_link_fill_kprobe(const struct perf_event *event, info->perf_event.type = BPF_PERF_EVENT_KPROBE; info->perf_event.kprobe.offset = offset; + info->perf_event.kprobe.missed = missed; if (!kallsyms_show_value(current_cred())) addr = 0; info->perf_event.kprobe.addr = addr; @@ -3444,7 +3446,7 @@ static int bpf_perf_link_fill_uprobe(const struct perf_event *event, uname = u64_to_user_ptr(info->perf_event.uprobe.file_name); ulen = info->perf_event.uprobe.name_len; err = bpf_perf_link_fill_common(event, uname, ulen, &offset, &addr, - &type); + &type, NULL); if (err) return err; @@ -3480,7 +3482,7 @@ static int bpf_perf_link_fill_tracepoint(const struct perf_event *event, uname = u64_to_user_ptr(info->perf_event.tracepoint.tp_name); ulen = info->perf_event.tracepoint.name_len; info->perf_event.type = BPF_PERF_EVENT_TRACEPOINT; - return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL); + return bpf_perf_link_fill_common(event, uname, ulen, NULL, NULL, NULL, NULL); } static int bpf_perf_link_fill_perf_event(const struct perf_event *event, @@ -4813,7 +4815,7 @@ static int bpf_task_fd_query(const union bpf_attr *attr, err = bpf_get_perf_event_info(event, &prog_id, &fd_type, &buf, &probe_offset, - &probe_addr); + &probe_addr, NULL); if (!err) err = bpf_task_fd_query_copy(attr, uattr, prog_id, fd_type, buf, diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 6aec6e7d612a..f6a7d2524949 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2384,7 +2384,8 @@ int bpf_probe_unregister(struct bpf_raw_event_map *btp, struct bpf_prog *prog) int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, u32 *fd_type, const char **buf, - u64 *probe_offset, u64 *probe_addr) + u64 *probe_offset, u64 *probe_addr, + unsigned long *missed) { bool is_tracepoint, is_syscall_tp; struct bpf_prog *prog; @@ -2419,7 +2420,7 @@ int bpf_get_perf_event_info(const struct perf_event *event, u32 *prog_id, #ifdef CONFIG_KPROBE_EVENTS if (flags & TRACE_EVENT_FL_KPROBE) err = bpf_get_kprobe_info(event, fd_type, buf, - probe_offset, probe_addr, + probe_offset, probe_addr, missed, event->attr.type == PERF_TYPE_TRACEPOINT); #endif #ifdef CONFIG_UPROBE_EVENTS diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 3d7a180a8427..961a78ffd6d2 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1189,6 +1189,12 @@ static const struct file_operations kprobe_events_ops = { .write = probes_write, }; +static unsigned long trace_kprobe_missed(struct trace_kprobe *tk) +{ + return trace_kprobe_is_return(tk) ? + tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed; +} + /* Probes profiling interfaces */ static int probes_profile_seq_show(struct seq_file *m, void *v) { @@ -1200,8 +1206,7 @@ static int probes_profile_seq_show(struct seq_file *m, void *v) return 0; tk = to_trace_kprobe(ev); - nmissed = trace_kprobe_is_return(tk) ? - tk->rp.kp.nmissed + tk->rp.nmissed : tk->rp.kp.nmissed; + nmissed = trace_kprobe_missed(tk); seq_printf(m, " %-44s %15lu %15lu\n", trace_probe_name(&tk->tp), trace_kprobe_nhit(tk), @@ -1547,7 +1552,8 @@ NOKPROBE_SYMBOL(kretprobe_perf_func); int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, const char **symbol, u64 *probe_offset, - u64 *probe_addr, bool perf_type_tracepoint) + u64 *probe_addr, unsigned long *missed, + bool perf_type_tracepoint) { const char *pevent = trace_event_name(event->tp_event); const char *group = event->tp_event->class->system; @@ -1566,6 +1572,8 @@ int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type, *probe_addr = kallsyms_show_value(current_cred()) ? (unsigned long)tk->rp.kp.addr : 0; *symbol = tk->symbol; + if (missed) + *missed = trace_kprobe_missed(tk); return 0; } #endif /* CONFIG_PERF_EVENTS */ diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 1da5b1bcce71..70bfa997e896 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -6548,6 +6548,7 @@ struct bpf_link_info { __u32 name_len; __u32 offset; /* offset from func_name */ __u64 addr; + __u64 missed; } kprobe; /* BPF_PERF_EVENT_KPROBE, BPF_PERF_EVENT_KRETPROBE */ struct { __aligned_u64 tp_name; /* in/out */ -- cgit From dd8657894c11b03c6eb0fd53fe9d7fec2072d18b Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:40 +0200 Subject: bpf: Count missed stats in trace_call_bpf Increase misses stats in case bpf array execution is skipped because of recursion check in trace_call_bpf. Adding bpf_prog_inc_misses_counters that increase misses counts for all bpf programs in bpf_prog_array. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Tested-by: Song Liu Reviewed-by: Song Liu Link: https://lore.kernel.org/bpf/20230920213145.1941596-5-jolsa@kernel.org --- include/linux/bpf.h | 16 ++++++++++++++++ kernel/trace/bpf_trace.c | 3 +++ 2 files changed, 19 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 30063a760b5a..a82efd34b741 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2922,6 +2922,22 @@ static inline int sock_map_bpf_prog_query(const union bpf_attr *attr, #endif /* CONFIG_BPF_SYSCALL */ #endif /* CONFIG_NET && CONFIG_BPF_SYSCALL */ +static __always_inline void +bpf_prog_inc_misses_counters(const struct bpf_prog_array *array) +{ + const struct bpf_prog_array_item *item; + struct bpf_prog *prog; + + if (unlikely(!array)) + return; + + item = &array->items[0]; + while ((prog = READ_ONCE(item->prog))) { + bpf_prog_inc_misses_counter(prog); + item++; + } +} + #if defined(CONFIG_INET) && defined(CONFIG_BPF_SYSCALL) void bpf_sk_reuseport_detach(struct sock *sk); int bpf_fd_reuseport_array_lookup_elem(struct bpf_map *map, void *key, diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f6a7d2524949..df697c74d519 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -117,6 +117,9 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx) * and don't send kprobe event into ring-buffer, * so return zero here */ + rcu_read_lock(); + bpf_prog_inc_misses_counters(rcu_dereference(call->prog_array)); + rcu_read_unlock(); ret = 0; goto out; } -- cgit From b24fc35521b09b5feaf5d06a75e8a43042592d0b Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:41 +0200 Subject: bpftool: Display missed count for kprobe_multi link Adding 'missed' field to display missed counts for kprobes attached by kprobe multi link, like: # bpftool link 5: kprobe_multi prog 76 kprobe.multi func_cnt 1 missed 1 addr func [module] ffffffffa039c030 fp3_test [fprobe_test] # bpftool link -jp [{ "id": 5, "type": "kprobe_multi", "prog_id": 76, "retprobe": false, "func_cnt": 1, "missed": 1, "funcs": [{ "addr": 18446744072102723632, "func": "fp3_test", "module": "fprobe_test" } ] } ] Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20230920213145.1941596-6-jolsa@kernel.org --- tools/bpf/bpftool/link.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index 2e5c231e08ac..d15d74cd1bed 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -265,6 +265,7 @@ show_kprobe_multi_json(struct bpf_link_info *info, json_writer_t *wtr) jsonw_bool_field(json_wtr, "retprobe", info->kprobe_multi.flags & BPF_F_KPROBE_MULTI_RETURN); jsonw_uint_field(json_wtr, "func_cnt", info->kprobe_multi.count); + jsonw_uint_field(json_wtr, "missed", info->kprobe_multi.missed); jsonw_name(json_wtr, "funcs"); jsonw_start_array(json_wtr); addrs = u64_to_ptr(info->kprobe_multi.addrs); @@ -641,6 +642,8 @@ static void show_kprobe_multi_plain(struct bpf_link_info *info) else printf("\n\tkprobe.multi "); printf("func_cnt %u ", info->kprobe_multi.count); + if (info->kprobe_multi.missed) + printf("missed %llu ", info->kprobe_multi.missed); addrs = (__u64 *)u64_to_ptr(info->kprobe_multi.addrs); qsort(addrs, info->kprobe_multi.count, sizeof(__u64), cmp_u64); -- cgit From b563b9bae8c3a6583e34820856dc6eafc2239aaf Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:42 +0200 Subject: bpftool: Display missed count for kprobe perf link Adding 'missed' field to display missed counts for kprobes attached by perf event link, like: # bpftool link 5: perf_event prog 82 kprobe ffffffff815203e0 ksys_write 6: perf_event prog 83 kprobe ffffffff811d1e50 scheduler_tick missed 682217 # bpftool link -jp [{ "id": 5, "type": "perf_event", "prog_id": 82, "retprobe": false, "addr": 18446744071584220128, "func": "ksys_write", "offset": 0, "missed": 0 },{ "id": 6, "type": "perf_event", "prog_id": 83, "retprobe": false, "addr": 18446744071580753488, "func": "scheduler_tick", "offset": 0, "missed": 693469 } ] Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20230920213145.1941596-7-jolsa@kernel.org --- tools/bpf/bpftool/link.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/tools/bpf/bpftool/link.c b/tools/bpf/bpftool/link.c index d15d74cd1bed..4b1407b05056 100644 --- a/tools/bpf/bpftool/link.c +++ b/tools/bpf/bpftool/link.c @@ -302,6 +302,7 @@ show_perf_event_kprobe_json(struct bpf_link_info *info, json_writer_t *wtr) jsonw_string_field(wtr, "func", u64_to_ptr(info->perf_event.kprobe.func_name)); jsonw_uint_field(wtr, "offset", info->perf_event.kprobe.offset); + jsonw_uint_field(wtr, "missed", info->perf_event.kprobe.missed); } static void @@ -686,6 +687,8 @@ static void show_perf_event_kprobe_plain(struct bpf_link_info *info) printf("%s", buf); if (info->perf_event.kprobe.offset) printf("+%#x", info->perf_event.kprobe.offset); + if (info->perf_event.kprobe.missed) + printf(" missed %llu", info->perf_event.kprobe.missed); printf(" "); } -- cgit From 01e4ae474e39b855f911caec355bb79e722562b3 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:43 +0200 Subject: selftests/bpf: Add test for missed counts of perf event link kprobe Adding test that puts kprobe on bpf_fentry_test1 that calls bpf_kfunc_common_test kfunc, which has also kprobe on. The latter won't get triggered due to kprobe recursion check and kprobe missed counter is incremented. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Acked-by: Hou Tao Link: https://lore.kernel.org/bpf/20230920213145.1941596-8-jolsa@kernel.org --- .../selftests/bpf/bpf_testmod/bpf_testmod.c | 5 +++ .../selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h | 2 + tools/testing/selftests/bpf/prog_tests/missed.c | 47 ++++++++++++++++++++++ tools/testing/selftests/bpf/progs/missed_kprobe.c | 30 ++++++++++++++ 4 files changed, 84 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/missed.c create mode 100644 tools/testing/selftests/bpf/progs/missed_kprobe.c diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c index cefc5dd72573..a5e246f7b202 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod.c @@ -138,6 +138,10 @@ __bpf_kfunc void bpf_iter_testmod_seq_destroy(struct bpf_iter_testmod_seq *it) it->cnt = 0; } +__bpf_kfunc void bpf_kfunc_common_test(void) +{ +} + struct bpf_testmod_btf_type_tag_1 { int a; }; @@ -343,6 +347,7 @@ BTF_SET8_START(bpf_testmod_common_kfunc_ids) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_new, KF_ITER_NEW) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_next, KF_ITER_NEXT | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_iter_testmod_seq_destroy, KF_ITER_DESTROY) +BTF_ID_FLAGS(func, bpf_kfunc_common_test) BTF_SET8_END(bpf_testmod_common_kfunc_ids) static const struct btf_kfunc_id_set bpf_testmod_common_kfunc_set = { diff --git a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h index f5c5b1375c24..7c664dd61059 100644 --- a/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h +++ b/tools/testing/selftests/bpf/bpf_testmod/bpf_testmod_kfunc.h @@ -104,4 +104,6 @@ void bpf_kfunc_call_test_fail1(struct prog_test_fail1 *p); void bpf_kfunc_call_test_fail2(struct prog_test_fail2 *p); void bpf_kfunc_call_test_fail3(struct prog_test_fail3 *p); void bpf_kfunc_call_test_mem_len_fail1(void *mem, int len); + +void bpf_kfunc_common_test(void) __ksym; #endif /* _BPF_TESTMOD_KFUNC_H */ diff --git a/tools/testing/selftests/bpf/prog_tests/missed.c b/tools/testing/selftests/bpf/prog_tests/missed.c new file mode 100644 index 000000000000..ca52be3d80f3 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/missed.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "missed_kprobe.skel.h" + +/* + * Putting kprobe on bpf_fentry_test1 that calls bpf_kfunc_common_test + * kfunc, which has also kprobe on. The latter won't get triggered due + * to kprobe recursion check and kprobe missed counter is incremented. + */ +static void test_missed_perf_kprobe(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, topts); + struct bpf_link_info info = {}; + struct missed_kprobe *skel; + __u32 len = sizeof(info); + int err, prog_fd; + + skel = missed_kprobe__open_and_load(); + if (!ASSERT_OK_PTR(skel, "missed_kprobe__open_and_load")) + goto cleanup; + + err = missed_kprobe__attach(skel); + if (!ASSERT_OK(err, "missed_kprobe__attach")) + goto cleanup; + + prog_fd = bpf_program__fd(skel->progs.trigger); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, 0, "test_run"); + + err = bpf_link_get_info_by_fd(bpf_link__fd(skel->links.test2), &info, &len); + if (!ASSERT_OK(err, "bpf_link_get_info_by_fd")) + goto cleanup; + + ASSERT_EQ(info.type, BPF_LINK_TYPE_PERF_EVENT, "info.type"); + ASSERT_EQ(info.perf_event.type, BPF_PERF_EVENT_KPROBE, "info.perf_event.type"); + ASSERT_EQ(info.perf_event.kprobe.missed, 1, "info.perf_event.kprobe.missed"); + +cleanup: + missed_kprobe__destroy(skel); +} + +void test_missed(void) +{ + if (test__start_subtest("perf_kprobe")) + test_missed_perf_kprobe(); +} diff --git a/tools/testing/selftests/bpf/progs/missed_kprobe.c b/tools/testing/selftests/bpf/progs/missed_kprobe.c new file mode 100644 index 000000000000..7f9ef701f5de --- /dev/null +++ b/tools/testing/selftests/bpf/progs/missed_kprobe.c @@ -0,0 +1,30 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "vmlinux.h" +#include +#include +#include "../bpf_testmod/bpf_testmod_kfunc.h" + +char _license[] SEC("license") = "GPL"; + +/* + * No tests in here, just to trigger 'bpf_fentry_test*' + * through tracing test_run + */ +SEC("fentry/bpf_modify_return_test") +int BPF_PROG(trigger) +{ + return 0; +} + +SEC("kprobe/bpf_fentry_test1") +int test1(struct pt_regs *ctx) +{ + bpf_kfunc_common_test(); + return 0; +} + +SEC("kprobe/bpf_kfunc_common_test") +int test2(struct pt_regs *ctx) +{ + return 0; +} -- cgit From 59e83c0187c5eed648c28aea637a5cf3e246921b Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:44 +0200 Subject: selftests/bpf: Add test for recursion counts of perf event link kprobe Adding selftest that puts kprobe.multi on bpf_fentry_test1 that calls bpf_kfunc_common_test kfunc which has 3 perf event kprobes and 1 kprobe.multi attached. Because fprobe (kprobe.multi attach layear) does not have strict recursion check the kprobe's bpf_prog_active check is hit for test2-5. Disabling this test for arm64, because there's no fprobe support yet. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Tested-by: Song Liu Reviewed-by: Song Liu Acked-by: Hou Tao Link: https://lore.kernel.org/bpf/20230920213145.1941596-9-jolsa@kernel.org --- tools/testing/selftests/bpf/DENYLIST.aarch64 | 1 + tools/testing/selftests/bpf/prog_tests/missed.c | 51 ++++++++++++++++++++++ .../selftests/bpf/progs/missed_kprobe_recursion.c | 48 ++++++++++++++++++++ 3 files changed, 100 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/missed_kprobe_recursion.c diff --git a/tools/testing/selftests/bpf/DENYLIST.aarch64 b/tools/testing/selftests/bpf/DENYLIST.aarch64 index 1e827c24761c..5c2cc7e8c5d0 100644 --- a/tools/testing/selftests/bpf/DENYLIST.aarch64 +++ b/tools/testing/selftests/bpf/DENYLIST.aarch64 @@ -10,3 +10,4 @@ fexit_test/fexit_many_args # fexit_many_args:FAIL:fexit_ma fill_link_info/kprobe_multi_link_info # bpf_program__attach_kprobe_multi_opts unexpected error: -95 fill_link_info/kretprobe_multi_link_info # bpf_program__attach_kprobe_multi_opts unexpected error: -95 fill_link_info/kprobe_multi_invalid_ubuff # bpf_program__attach_kprobe_multi_opts unexpected error: -95 +missed/kprobe_recursion # missed_kprobe_recursion__attach unexpected error: -95 (errno 95) diff --git a/tools/testing/selftests/bpf/prog_tests/missed.c b/tools/testing/selftests/bpf/prog_tests/missed.c index ca52be3d80f3..54aaf2f8ad8c 100644 --- a/tools/testing/selftests/bpf/prog_tests/missed.c +++ b/tools/testing/selftests/bpf/prog_tests/missed.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 #include #include "missed_kprobe.skel.h" +#include "missed_kprobe_recursion.skel.h" /* * Putting kprobe on bpf_fentry_test1 that calls bpf_kfunc_common_test @@ -40,8 +41,58 @@ cleanup: missed_kprobe__destroy(skel); } +static __u64 get_missed_count(int fd) +{ + struct bpf_prog_info info = {}; + __u32 len = sizeof(info); + int err; + + err = bpf_prog_get_info_by_fd(fd, &info, &len); + if (!ASSERT_OK(err, "bpf_prog_get_info_by_fd")) + return (__u64) -1; + return info.recursion_misses; +} + +/* + * Putting kprobe.multi on bpf_fentry_test1 that calls bpf_kfunc_common_test + * kfunc which has 3 perf event kprobes and 1 kprobe.multi attached. + * + * Because fprobe (kprobe.multi attach layear) does not have strict recursion + * check the kprobe's bpf_prog_active check is hit for test2-5. + */ +static void test_missed_kprobe_recursion(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, topts); + struct missed_kprobe_recursion *skel; + int err, prog_fd; + + skel = missed_kprobe_recursion__open_and_load(); + if (!ASSERT_OK_PTR(skel, "missed_kprobe_recursion__open_and_load")) + goto cleanup; + + err = missed_kprobe_recursion__attach(skel); + if (!ASSERT_OK(err, "missed_kprobe_recursion__attach")) + goto cleanup; + + prog_fd = bpf_program__fd(skel->progs.trigger); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, 0, "test_run"); + + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test1)), 0, "test1_recursion_misses"); + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test2)), 1, "test2_recursion_misses"); + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test3)), 1, "test3_recursion_misses"); + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test4)), 1, "test4_recursion_misses"); + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test5)), 1, "test5_recursion_misses"); + +cleanup: + missed_kprobe_recursion__destroy(skel); +} + void test_missed(void) { if (test__start_subtest("perf_kprobe")) test_missed_perf_kprobe(); + if (test__start_subtest("kprobe_recursion")) + test_missed_kprobe_recursion(); } diff --git a/tools/testing/selftests/bpf/progs/missed_kprobe_recursion.c b/tools/testing/selftests/bpf/progs/missed_kprobe_recursion.c new file mode 100644 index 000000000000..8ea71cbd6c45 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/missed_kprobe_recursion.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "vmlinux.h" +#include +#include +#include "../bpf_testmod/bpf_testmod_kfunc.h" + +char _license[] SEC("license") = "GPL"; + +/* + * No tests in here, just to trigger 'bpf_fentry_test*' + * through tracing test_run + */ +SEC("fentry/bpf_modify_return_test") +int BPF_PROG(trigger) +{ + return 0; +} + +SEC("kprobe.multi/bpf_fentry_test1") +int test1(struct pt_regs *ctx) +{ + bpf_kfunc_common_test(); + return 0; +} + +SEC("kprobe/bpf_kfunc_common_test") +int test2(struct pt_regs *ctx) +{ + return 0; +} + +SEC("kprobe/bpf_kfunc_common_test") +int test3(struct pt_regs *ctx) +{ + return 0; +} + +SEC("kprobe/bpf_kfunc_common_test") +int test4(struct pt_regs *ctx) +{ + return 0; +} + +SEC("kprobe.multi/bpf_kfunc_common_test") +int test5(struct pt_regs *ctx) +{ + return 0; +} -- cgit From 85981e0f9e9fc882578f0ad7488d6c59193dd187 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 20 Sep 2023 23:31:45 +0200 Subject: selftests/bpf: Add test for recursion counts of perf event link tracepoint Adding selftest that puts kprobe on bpf_fentry_test1 that calls bpf_printk and invokes bpf_trace_printk tracepoint. The bpf_trace_printk tracepoint has test[234] programs attached to it. Because kprobe execution goes through bpf_prog_active check, programs attached to the tracepoint will fail the recursion check and increment the recursion_misses stats. Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Tested-by: Song Liu Reviewed-by: Song Liu Link: https://lore.kernel.org/bpf/20230920213145.1941596-10-jolsa@kernel.org --- tools/testing/selftests/bpf/prog_tests/missed.c | 40 +++++++++++++++++++++ .../selftests/bpf/progs/missed_tp_recursion.c | 41 ++++++++++++++++++++++ 2 files changed, 81 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/missed_tp_recursion.c diff --git a/tools/testing/selftests/bpf/prog_tests/missed.c b/tools/testing/selftests/bpf/prog_tests/missed.c index 54aaf2f8ad8c..24ade11f5c05 100644 --- a/tools/testing/selftests/bpf/prog_tests/missed.c +++ b/tools/testing/selftests/bpf/prog_tests/missed.c @@ -2,6 +2,7 @@ #include #include "missed_kprobe.skel.h" #include "missed_kprobe_recursion.skel.h" +#include "missed_tp_recursion.skel.h" /* * Putting kprobe on bpf_fentry_test1 that calls bpf_kfunc_common_test @@ -89,10 +90,49 @@ cleanup: missed_kprobe_recursion__destroy(skel); } +/* + * Putting kprobe on bpf_fentry_test1 that calls bpf_printk and invokes + * bpf_trace_printk tracepoint. The bpf_trace_printk tracepoint has test[234] + * programs attached to it. + * + * Because kprobe execution goes through bpf_prog_active check, programs + * attached to the tracepoint will fail the recursion check and increment + * the recursion_misses stats. + */ +static void test_missed_tp_recursion(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, topts); + struct missed_tp_recursion *skel; + int err, prog_fd; + + skel = missed_tp_recursion__open_and_load(); + if (!ASSERT_OK_PTR(skel, "missed_tp_recursion__open_and_load")) + goto cleanup; + + err = missed_tp_recursion__attach(skel); + if (!ASSERT_OK(err, "missed_tp_recursion__attach")) + goto cleanup; + + prog_fd = bpf_program__fd(skel->progs.trigger); + err = bpf_prog_test_run_opts(prog_fd, &topts); + ASSERT_OK(err, "test_run"); + ASSERT_EQ(topts.retval, 0, "test_run"); + + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test1)), 0, "test1_recursion_misses"); + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test2)), 1, "test2_recursion_misses"); + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test3)), 1, "test3_recursion_misses"); + ASSERT_EQ(get_missed_count(bpf_program__fd(skel->progs.test4)), 1, "test4_recursion_misses"); + +cleanup: + missed_tp_recursion__destroy(skel); +} + void test_missed(void) { if (test__start_subtest("perf_kprobe")) test_missed_perf_kprobe(); if (test__start_subtest("kprobe_recursion")) test_missed_kprobe_recursion(); + if (test__start_subtest("tp_recursion")) + test_missed_tp_recursion(); } diff --git a/tools/testing/selftests/bpf/progs/missed_tp_recursion.c b/tools/testing/selftests/bpf/progs/missed_tp_recursion.c new file mode 100644 index 000000000000..762385f827c5 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/missed_tp_recursion.c @@ -0,0 +1,41 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +/* + * No tests in here, just to trigger 'bpf_fentry_test*' + * through tracing test_run + */ +SEC("fentry/bpf_modify_return_test") +int BPF_PROG(trigger) +{ + return 0; +} + +SEC("kprobe/bpf_fentry_test1") +int test1(struct pt_regs *ctx) +{ + bpf_printk("test"); + return 0; +} + +SEC("tp/bpf_trace/bpf_trace_printk") +int test2(struct pt_regs *ctx) +{ + return 0; +} + +SEC("tp/bpf_trace/bpf_trace_printk") +int test3(struct pt_regs *ctx) +{ + return 0; +} + +SEC("tp/bpf_trace/bpf_trace_printk") +int test4(struct pt_regs *ctx) +{ + return 0; +} -- cgit