diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/perf/util/bpf-event.c | 576 |
1 files changed, 576 insertions, 0 deletions
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c new file mode 100644 index 000000000..c50d2c7a2 --- /dev/null +++ b/tools/perf/util/bpf-event.c @@ -0,0 +1,576 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <errno.h> +#include <stdlib.h> +#include <bpf/bpf.h> +#include <bpf/btf.h> +#include <bpf/libbpf.h> +#include <linux/btf.h> +#include <linux/err.h> +#include <linux/string.h> +#include <internal/lib.h> +#include <symbol/kallsyms.h> +#include "bpf-event.h" +#include "debug.h" +#include "dso.h" +#include "symbol.h" +#include "machine.h" +#include "env.h" +#include "session.h" +#include "map.h" +#include "evlist.h" +#include "record.h" +#include "util/synthetic-events.h" + +#define ptr_to_u64(ptr) ((__u64)(unsigned long)(ptr)) + +static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len) +{ + int ret = 0; + size_t i; + + for (i = 0; i < len; i++) + ret += snprintf(buf + ret, size - ret, "%02x", data[i]); + return ret; +} + +static int machine__process_bpf_event_load(struct machine *machine, + union perf_event *event, + struct perf_sample *sample __maybe_unused) +{ + struct bpf_prog_info_linear *info_linear; + struct bpf_prog_info_node *info_node; + struct perf_env *env = machine->env; + int id = event->bpf.id; + unsigned int i; + + /* perf-record, no need to handle bpf-event */ + if (env == NULL) + return 0; + + info_node = perf_env__find_bpf_prog_info(env, id); + if (!info_node) + return 0; + info_linear = info_node->info_linear; + + for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) { + u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms); + u64 addr = addrs[i]; + struct map *map = maps__find(&machine->kmaps, addr); + + if (map) { + map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO; + map->dso->bpf_prog.id = id; + map->dso->bpf_prog.sub_id = i; + map->dso->bpf_prog.env = env; + } + } + return 0; +} + +int machine__process_bpf(struct machine *machine, union perf_event *event, + struct perf_sample *sample) +{ + if (dump_trace) + perf_event__fprintf_bpf(event, stdout); + + switch (event->bpf.type) { + case PERF_BPF_EVENT_PROG_LOAD: + return machine__process_bpf_event_load(machine, event, sample); + + case PERF_BPF_EVENT_PROG_UNLOAD: + /* + * Do not free bpf_prog_info and btf of the program here, + * as annotation still need them. They will be freed at + * the end of the session. + */ + break; + default: + pr_debug("unexpected bpf event type of %d\n", event->bpf.type); + break; + } + return 0; +} + +static int perf_env__fetch_btf(struct perf_env *env, + u32 btf_id, + struct btf *btf) +{ + struct btf_node *node; + u32 data_size; + const void *data; + + data = btf__get_raw_data(btf, &data_size); + + node = malloc(data_size + sizeof(struct btf_node)); + if (!node) + return -1; + + node->id = btf_id; + node->data_size = data_size; + memcpy(node->data, data, data_size); + + if (!perf_env__insert_btf(env, node)) { + /* Insertion failed because of a duplicate. */ + free(node); + return -1; + } + return 0; +} + +static int synthesize_bpf_prog_name(char *buf, int size, + struct bpf_prog_info *info, + struct btf *btf, + u32 sub_id) +{ + u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags); + void *func_infos = (void *)(uintptr_t)(info->func_info); + u32 sub_prog_cnt = info->nr_jited_ksyms; + const struct bpf_func_info *finfo; + const char *short_name = NULL; + const struct btf_type *t; + int name_len; + + name_len = snprintf(buf, size, "bpf_prog_"); + name_len += snprintf_hex(buf + name_len, size - name_len, + prog_tags[sub_id], BPF_TAG_SIZE); + if (btf) { + finfo = func_infos + sub_id * info->func_info_rec_size; + t = btf__type_by_id(btf, finfo->type_id); + short_name = btf__name_by_offset(btf, t->name_off); + } else if (sub_id == 0 && sub_prog_cnt == 1) { + /* no subprog */ + if (info->name[0]) + short_name = info->name; + } else + short_name = "F"; + if (short_name) + name_len += snprintf(buf + name_len, size - name_len, + "_%s", short_name); + return name_len; +} + +/* + * Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf + * program. One PERF_RECORD_BPF_EVENT is generated for the program. And + * one PERF_RECORD_KSYMBOL is generated for each sub program. + * + * Returns: + * 0 for success; + * -1 for failures; + * -2 for lack of kernel support. + */ +static int perf_event__synthesize_one_bpf_prog(struct perf_session *session, + perf_event__handler_t process, + struct machine *machine, + int fd, + union perf_event *event, + struct record_opts *opts) +{ + struct perf_record_ksymbol *ksymbol_event = &event->ksymbol; + struct perf_record_bpf_event *bpf_event = &event->bpf; + struct bpf_prog_info_linear *info_linear; + struct perf_tool *tool = session->tool; + struct bpf_prog_info_node *info_node; + struct bpf_prog_info *info; + struct btf *btf = NULL; + struct perf_env *env; + u32 sub_prog_cnt, i; + int err = 0; + u64 arrays; + + /* + * for perf-record and perf-report use header.env; + * otherwise, use global perf_env. + */ + env = session->data ? &session->header.env : &perf_env; + + arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS; + arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS; + arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO; + arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS; + arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS; + arrays |= 1UL << BPF_PROG_INFO_LINE_INFO; + arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO; + + info_linear = bpf_program__get_prog_info_linear(fd, arrays); + if (IS_ERR_OR_NULL(info_linear)) { + info_linear = NULL; + pr_debug("%s: failed to get BPF program info. aborting\n", __func__); + return -1; + } + + if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) { + pr_debug("%s: the kernel is too old, aborting\n", __func__); + return -2; + } + + info = &info_linear->info; + + /* number of ksyms, func_lengths, and tags should match */ + sub_prog_cnt = info->nr_jited_ksyms; + if (sub_prog_cnt != info->nr_prog_tags || + sub_prog_cnt != info->nr_jited_func_lens) + return -1; + + /* check BTF func info support */ + if (info->btf_id && info->nr_func_info && info->func_info_rec_size) { + /* btf func info number should be same as sub_prog_cnt */ + if (sub_prog_cnt != info->nr_func_info) { + pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__); + err = -1; + goto out; + } + if (btf__get_from_id(info->btf_id, &btf)) { + pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id); + err = -1; + btf = NULL; + goto out; + } + perf_env__fetch_btf(env, info->btf_id, btf); + } + + /* Synthesize PERF_RECORD_KSYMBOL */ + for (i = 0; i < sub_prog_cnt; i++) { + __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); + __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); + int name_len; + + *ksymbol_event = (struct perf_record_ksymbol) { + .header = { + .type = PERF_RECORD_KSYMBOL, + .size = offsetof(struct perf_record_ksymbol, name), + }, + .addr = prog_addrs[i], + .len = prog_lens[i], + .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, + .flags = 0, + }; + + name_len = synthesize_bpf_prog_name(ksymbol_event->name, + KSYM_NAME_LEN, info, btf, i); + ksymbol_event->header.size += PERF_ALIGN(name_len + 1, + sizeof(u64)); + + memset((void *)event + event->header.size, 0, machine->id_hdr_size); + event->header.size += machine->id_hdr_size; + err = perf_tool__process_synth_event(tool, event, + machine, process); + } + + if (!opts->no_bpf_event) { + /* Synthesize PERF_RECORD_BPF_EVENT */ + *bpf_event = (struct perf_record_bpf_event) { + .header = { + .type = PERF_RECORD_BPF_EVENT, + .size = sizeof(struct perf_record_bpf_event), + }, + .type = PERF_BPF_EVENT_PROG_LOAD, + .flags = 0, + .id = info->id, + }; + memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE); + memset((void *)event + event->header.size, 0, machine->id_hdr_size); + event->header.size += machine->id_hdr_size; + + /* save bpf_prog_info to env */ + info_node = malloc(sizeof(struct bpf_prog_info_node)); + if (!info_node) { + err = -1; + goto out; + } + + info_node->info_linear = info_linear; + perf_env__insert_bpf_prog_info(env, info_node); + info_linear = NULL; + + /* + * process after saving bpf_prog_info to env, so that + * required information is ready for look up + */ + err = perf_tool__process_synth_event(tool, event, + machine, process); + } + +out: + free(info_linear); + free(btf); + return err ? -1 : 0; +} + +struct kallsyms_parse { + union perf_event *event; + perf_event__handler_t process; + struct machine *machine; + struct perf_tool *tool; +}; + +static int +process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data) +{ + struct machine *machine = data->machine; + union perf_event *event = data->event; + struct perf_record_ksymbol *ksymbol; + int len; + + ksymbol = &event->ksymbol; + + *ksymbol = (struct perf_record_ksymbol) { + .header = { + .type = PERF_RECORD_KSYMBOL, + .size = offsetof(struct perf_record_ksymbol, name), + }, + .addr = addr, + .len = page_size, + .ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF, + .flags = 0, + }; + + len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name); + ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64)); + memset((void *) event + event->header.size, 0, machine->id_hdr_size); + event->header.size += machine->id_hdr_size; + + return perf_tool__process_synth_event(data->tool, event, machine, + data->process); +} + +static int +kallsyms_process_symbol(void *data, const char *_name, + char type __maybe_unused, u64 start) +{ + char disp[KSYM_NAME_LEN]; + char *module, *name; + unsigned long id; + int err = 0; + + module = strchr(_name, '\t'); + if (!module) + return 0; + + /* We are going after [bpf] module ... */ + if (strcmp(module + 1, "[bpf]")) + return 0; + + name = memdup(_name, (module - _name) + 1); + if (!name) + return -ENOMEM; + + name[module - _name] = 0; + + /* .. and only for trampolines and dispatchers */ + if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) || + (sscanf(name, "bpf_dispatcher_%s", disp) == 1)) + err = process_bpf_image(name, start, data); + + free(name); + return err; +} + +int perf_event__synthesize_bpf_events(struct perf_session *session, + perf_event__handler_t process, + struct machine *machine, + struct record_opts *opts) +{ + const char *kallsyms_filename = "/proc/kallsyms"; + struct kallsyms_parse arg; + union perf_event *event; + __u32 id = 0; + int err; + int fd; + + event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size); + if (!event) + return -1; + + /* Synthesize all the bpf programs in system. */ + while (true) { + err = bpf_prog_get_next_id(id, &id); + if (err) { + if (errno == ENOENT) { + err = 0; + break; + } + pr_debug("%s: can't get next program: %s%s\n", + __func__, strerror(errno), + errno == EINVAL ? " -- kernel too old?" : ""); + /* don't report error on old kernel or EPERM */ + err = (errno == EINVAL || errno == EPERM) ? 0 : -1; + break; + } + fd = bpf_prog_get_fd_by_id(id); + if (fd < 0) { + pr_debug("%s: failed to get fd for prog_id %u\n", + __func__, id); + continue; + } + + err = perf_event__synthesize_one_bpf_prog(session, process, + machine, fd, + event, opts); + close(fd); + if (err) { + /* do not return error for old kernel */ + if (err == -2) + err = 0; + break; + } + } + + /* Synthesize all the bpf images - trampolines/dispatchers. */ + if (symbol_conf.kallsyms_name != NULL) + kallsyms_filename = symbol_conf.kallsyms_name; + + arg = (struct kallsyms_parse) { + .event = event, + .process = process, + .machine = machine, + .tool = session->tool, + }; + + if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) { + pr_err("%s: failed to synthesize bpf images: %s\n", + __func__, strerror(errno)); + } + + free(event); + return err; +} + +static void perf_env__add_bpf_info(struct perf_env *env, u32 id) +{ + struct bpf_prog_info_linear *info_linear; + struct bpf_prog_info_node *info_node; + struct btf *btf = NULL; + u64 arrays; + u32 btf_id; + int fd; + + fd = bpf_prog_get_fd_by_id(id); + if (fd < 0) + return; + + arrays = 1UL << BPF_PROG_INFO_JITED_KSYMS; + arrays |= 1UL << BPF_PROG_INFO_JITED_FUNC_LENS; + arrays |= 1UL << BPF_PROG_INFO_FUNC_INFO; + arrays |= 1UL << BPF_PROG_INFO_PROG_TAGS; + arrays |= 1UL << BPF_PROG_INFO_JITED_INSNS; + arrays |= 1UL << BPF_PROG_INFO_LINE_INFO; + arrays |= 1UL << BPF_PROG_INFO_JITED_LINE_INFO; + + info_linear = bpf_program__get_prog_info_linear(fd, arrays); + if (IS_ERR_OR_NULL(info_linear)) { + pr_debug("%s: failed to get BPF program info. aborting\n", __func__); + goto out; + } + + btf_id = info_linear->info.btf_id; + + info_node = malloc(sizeof(struct bpf_prog_info_node)); + if (info_node) { + info_node->info_linear = info_linear; + perf_env__insert_bpf_prog_info(env, info_node); + } else + free(info_linear); + + if (btf_id == 0) + goto out; + + if (btf__get_from_id(btf_id, &btf)) { + pr_debug("%s: failed to get BTF of id %u, aborting\n", + __func__, btf_id); + goto out; + } + perf_env__fetch_btf(env, btf_id, btf); + +out: + free(btf); + close(fd); +} + +static int bpf_event__sb_cb(union perf_event *event, void *data) +{ + struct perf_env *env = data; + + if (event->header.type != PERF_RECORD_BPF_EVENT) + return -1; + + switch (event->bpf.type) { + case PERF_BPF_EVENT_PROG_LOAD: + perf_env__add_bpf_info(env, event->bpf.id); + + case PERF_BPF_EVENT_PROG_UNLOAD: + /* + * Do not free bpf_prog_info and btf of the program here, + * as annotation still need them. They will be freed at + * the end of the session. + */ + break; + default: + pr_debug("unexpected bpf event type of %d\n", event->bpf.type); + break; + } + + return 0; +} + +int evlist__add_bpf_sb_event(struct evlist *evlist, struct perf_env *env) +{ + struct perf_event_attr attr = { + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_DUMMY, + .sample_id_all = 1, + .watermark = 1, + .bpf_event = 1, + .size = sizeof(attr), /* to capture ABI version */ + }; + + /* + * Older gcc versions don't support designated initializers, like above, + * for unnamed union members, such as the following: + */ + attr.wakeup_watermark = 1; + + return perf_evlist__add_sb_event(evlist, &attr, bpf_event__sb_cb, env); +} + +void __bpf_event__print_bpf_prog_info(struct bpf_prog_info *info, + struct perf_env *env, + FILE *fp) +{ + __u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens); + __u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms); + char name[KSYM_NAME_LEN]; + struct btf *btf = NULL; + u32 sub_prog_cnt, i; + + sub_prog_cnt = info->nr_jited_ksyms; + if (sub_prog_cnt != info->nr_prog_tags || + sub_prog_cnt != info->nr_jited_func_lens) + return; + + if (info->btf_id) { + struct btf_node *node; + + node = __perf_env__find_btf(env, info->btf_id); + if (node) + btf = btf__new((__u8 *)(node->data), + node->data_size); + } + + if (sub_prog_cnt == 1) { + synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, 0); + fprintf(fp, "# bpf_prog_info %u: %s addr 0x%llx size %u\n", + info->id, name, prog_addrs[0], prog_lens[0]); + goto out; + } + + fprintf(fp, "# bpf_prog_info %u:\n", info->id); + for (i = 0; i < sub_prog_cnt; i++) { + synthesize_bpf_prog_name(name, KSYM_NAME_LEN, info, btf, i); + + fprintf(fp, "# \tsub_prog %u: %s addr 0x%llx size %u\n", + i, name, prog_addrs[i], prog_lens[i]); + } +out: + btf__free(btf); +} |