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6bebc06d54
Tests are no longer applicable as libbpf 1.0 can be assumed. Signed-off-by: Ian Rogers <irogers@google.com> Acked/Tested-by: Jiri Olsa <jolsa@kernel.org> Acked/Tested-by: Jiri Olsa <jolsa@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andres Freund <andres@anarazel.de> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Christy Lee <christylee@fb.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Quentin Monnet <quentin@isovalent.com> Cc: Roberto Sassu <roberto.sassu@huawei.com> Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20230116010115.490713-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
584 lines
15 KiB
C
584 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <errno.h>
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#include <stdlib.h>
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#include <bpf/bpf.h>
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#include <bpf/btf.h>
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#include <bpf/libbpf.h>
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#include <linux/btf.h>
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#include <linux/err.h>
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#include <linux/string.h>
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#include <internal/lib.h>
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#include <symbol/kallsyms.h>
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#include "bpf-event.h"
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#include "bpf-utils.h"
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#include "debug.h"
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#include "dso.h"
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#include "symbol.h"
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#include "machine.h"
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#include "env.h"
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#include "session.h"
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#include "map.h"
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#include "evlist.h"
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#include "record.h"
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#include "util/synthetic-events.h"
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static int snprintf_hex(char *buf, size_t size, unsigned char *data, size_t len)
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{
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int ret = 0;
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size_t i;
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for (i = 0; i < len; i++)
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ret += snprintf(buf + ret, size - ret, "%02x", data[i]);
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return ret;
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}
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static int machine__process_bpf_event_load(struct machine *machine,
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union perf_event *event,
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struct perf_sample *sample __maybe_unused)
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{
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struct bpf_prog_info_node *info_node;
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struct perf_env *env = machine->env;
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struct perf_bpil *info_linear;
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int id = event->bpf.id;
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unsigned int i;
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/* perf-record, no need to handle bpf-event */
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if (env == NULL)
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return 0;
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info_node = perf_env__find_bpf_prog_info(env, id);
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if (!info_node)
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return 0;
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info_linear = info_node->info_linear;
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for (i = 0; i < info_linear->info.nr_jited_ksyms; i++) {
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u64 *addrs = (u64 *)(uintptr_t)(info_linear->info.jited_ksyms);
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u64 addr = addrs[i];
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struct map *map = maps__find(machine__kernel_maps(machine), addr);
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if (map) {
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map->dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
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map->dso->bpf_prog.id = id;
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map->dso->bpf_prog.sub_id = i;
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map->dso->bpf_prog.env = env;
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}
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}
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return 0;
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}
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int machine__process_bpf(struct machine *machine, union perf_event *event,
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struct perf_sample *sample)
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{
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if (dump_trace)
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perf_event__fprintf_bpf(event, stdout);
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switch (event->bpf.type) {
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case PERF_BPF_EVENT_PROG_LOAD:
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return machine__process_bpf_event_load(machine, event, sample);
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case PERF_BPF_EVENT_PROG_UNLOAD:
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/*
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* Do not free bpf_prog_info and btf of the program here,
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* as annotation still need them. They will be freed at
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* the end of the session.
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*/
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break;
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default:
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pr_debug("unexpected bpf event type of %d\n", event->bpf.type);
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break;
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}
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return 0;
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}
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static int perf_env__fetch_btf(struct perf_env *env,
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u32 btf_id,
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struct btf *btf)
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{
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struct btf_node *node;
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u32 data_size;
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const void *data;
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data = btf__raw_data(btf, &data_size);
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node = malloc(data_size + sizeof(struct btf_node));
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if (!node)
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return -1;
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node->id = btf_id;
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node->data_size = data_size;
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memcpy(node->data, data, data_size);
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if (!perf_env__insert_btf(env, node)) {
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/* Insertion failed because of a duplicate. */
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free(node);
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return -1;
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}
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return 0;
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}
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static int synthesize_bpf_prog_name(char *buf, int size,
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struct bpf_prog_info *info,
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struct btf *btf,
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u32 sub_id)
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{
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u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags);
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void *func_infos = (void *)(uintptr_t)(info->func_info);
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u32 sub_prog_cnt = info->nr_jited_ksyms;
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const struct bpf_func_info *finfo;
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const char *short_name = NULL;
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const struct btf_type *t;
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int name_len;
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name_len = snprintf(buf, size, "bpf_prog_");
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name_len += snprintf_hex(buf + name_len, size - name_len,
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prog_tags[sub_id], BPF_TAG_SIZE);
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if (btf) {
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finfo = func_infos + sub_id * info->func_info_rec_size;
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t = btf__type_by_id(btf, finfo->type_id);
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short_name = btf__name_by_offset(btf, t->name_off);
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} else if (sub_id == 0 && sub_prog_cnt == 1) {
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/* no subprog */
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if (info->name[0])
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short_name = info->name;
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} else
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short_name = "F";
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if (short_name)
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name_len += snprintf(buf + name_len, size - name_len,
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"_%s", short_name);
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return name_len;
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}
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/*
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* Synthesize PERF_RECORD_KSYMBOL and PERF_RECORD_BPF_EVENT for one bpf
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* program. One PERF_RECORD_BPF_EVENT is generated for the program. And
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* one PERF_RECORD_KSYMBOL is generated for each sub program.
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*
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* Returns:
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* 0 for success;
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* -1 for failures;
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* -2 for lack of kernel support.
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*/
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static int perf_event__synthesize_one_bpf_prog(struct perf_session *session,
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perf_event__handler_t process,
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struct machine *machine,
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int fd,
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union perf_event *event,
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struct record_opts *opts)
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{
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struct perf_record_ksymbol *ksymbol_event = &event->ksymbol;
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struct perf_record_bpf_event *bpf_event = &event->bpf;
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struct perf_tool *tool = session->tool;
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struct bpf_prog_info_node *info_node;
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struct perf_bpil *info_linear;
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struct bpf_prog_info *info;
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struct btf *btf = NULL;
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struct perf_env *env;
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u32 sub_prog_cnt, i;
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int err = 0;
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u64 arrays;
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/*
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* for perf-record and perf-report use header.env;
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* otherwise, use global perf_env.
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*/
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env = session->data ? &session->header.env : &perf_env;
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arrays = 1UL << PERF_BPIL_JITED_KSYMS;
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arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
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arrays |= 1UL << PERF_BPIL_FUNC_INFO;
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arrays |= 1UL << PERF_BPIL_PROG_TAGS;
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arrays |= 1UL << PERF_BPIL_JITED_INSNS;
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arrays |= 1UL << PERF_BPIL_LINE_INFO;
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arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;
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info_linear = get_bpf_prog_info_linear(fd, arrays);
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if (IS_ERR_OR_NULL(info_linear)) {
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info_linear = NULL;
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pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
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return -1;
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}
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if (info_linear->info_len < offsetof(struct bpf_prog_info, prog_tags)) {
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free(info_linear);
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pr_debug("%s: the kernel is too old, aborting\n", __func__);
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return -2;
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}
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info = &info_linear->info;
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if (!info->jited_ksyms) {
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free(info_linear);
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return -1;
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}
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/* number of ksyms, func_lengths, and tags should match */
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sub_prog_cnt = info->nr_jited_ksyms;
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if (sub_prog_cnt != info->nr_prog_tags ||
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sub_prog_cnt != info->nr_jited_func_lens) {
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free(info_linear);
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return -1;
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}
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/* check BTF func info support */
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if (info->btf_id && info->nr_func_info && info->func_info_rec_size) {
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/* btf func info number should be same as sub_prog_cnt */
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if (sub_prog_cnt != info->nr_func_info) {
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pr_debug("%s: mismatch in BPF sub program count and BTF function info count, aborting\n", __func__);
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free(info_linear);
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return -1;
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}
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btf = btf__load_from_kernel_by_id(info->btf_id);
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if (libbpf_get_error(btf)) {
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pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
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err = -1;
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goto out;
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}
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perf_env__fetch_btf(env, info->btf_id, btf);
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}
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/* Synthesize PERF_RECORD_KSYMBOL */
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for (i = 0; i < sub_prog_cnt; i++) {
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__u32 *prog_lens = (__u32 *)(uintptr_t)(info->jited_func_lens);
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__u64 *prog_addrs = (__u64 *)(uintptr_t)(info->jited_ksyms);
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int name_len;
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*ksymbol_event = (struct perf_record_ksymbol) {
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.header = {
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.type = PERF_RECORD_KSYMBOL,
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.size = offsetof(struct perf_record_ksymbol, name),
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},
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.addr = prog_addrs[i],
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.len = prog_lens[i],
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.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
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.flags = 0,
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};
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name_len = synthesize_bpf_prog_name(ksymbol_event->name,
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KSYM_NAME_LEN, info, btf, i);
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ksymbol_event->header.size += PERF_ALIGN(name_len + 1,
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sizeof(u64));
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memset((void *)event + event->header.size, 0, machine->id_hdr_size);
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event->header.size += machine->id_hdr_size;
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err = perf_tool__process_synth_event(tool, event,
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machine, process);
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}
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if (!opts->no_bpf_event) {
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/* Synthesize PERF_RECORD_BPF_EVENT */
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*bpf_event = (struct perf_record_bpf_event) {
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.header = {
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.type = PERF_RECORD_BPF_EVENT,
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.size = sizeof(struct perf_record_bpf_event),
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},
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.type = PERF_BPF_EVENT_PROG_LOAD,
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.flags = 0,
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.id = info->id,
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};
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memcpy(bpf_event->tag, info->tag, BPF_TAG_SIZE);
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memset((void *)event + event->header.size, 0, machine->id_hdr_size);
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event->header.size += machine->id_hdr_size;
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/* save bpf_prog_info to env */
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info_node = malloc(sizeof(struct bpf_prog_info_node));
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if (!info_node) {
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err = -1;
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goto out;
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}
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info_node->info_linear = info_linear;
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perf_env__insert_bpf_prog_info(env, info_node);
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info_linear = NULL;
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/*
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* process after saving bpf_prog_info to env, so that
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* required information is ready for look up
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*/
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err = perf_tool__process_synth_event(tool, event,
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machine, process);
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}
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out:
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free(info_linear);
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btf__free(btf);
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return err ? -1 : 0;
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}
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struct kallsyms_parse {
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union perf_event *event;
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perf_event__handler_t process;
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struct machine *machine;
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struct perf_tool *tool;
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};
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static int
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process_bpf_image(char *name, u64 addr, struct kallsyms_parse *data)
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{
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struct machine *machine = data->machine;
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union perf_event *event = data->event;
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struct perf_record_ksymbol *ksymbol;
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int len;
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ksymbol = &event->ksymbol;
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*ksymbol = (struct perf_record_ksymbol) {
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.header = {
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.type = PERF_RECORD_KSYMBOL,
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.size = offsetof(struct perf_record_ksymbol, name),
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},
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.addr = addr,
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.len = page_size,
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.ksym_type = PERF_RECORD_KSYMBOL_TYPE_BPF,
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.flags = 0,
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};
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len = scnprintf(ksymbol->name, KSYM_NAME_LEN, "%s", name);
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ksymbol->header.size += PERF_ALIGN(len + 1, sizeof(u64));
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memset((void *) event + event->header.size, 0, machine->id_hdr_size);
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event->header.size += machine->id_hdr_size;
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return perf_tool__process_synth_event(data->tool, event, machine,
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data->process);
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}
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static int
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kallsyms_process_symbol(void *data, const char *_name,
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char type __maybe_unused, u64 start)
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{
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char disp[KSYM_NAME_LEN];
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char *module, *name;
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unsigned long id;
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int err = 0;
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module = strchr(_name, '\t');
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if (!module)
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return 0;
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/* We are going after [bpf] module ... */
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if (strcmp(module + 1, "[bpf]"))
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return 0;
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name = memdup(_name, (module - _name) + 1);
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if (!name)
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return -ENOMEM;
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name[module - _name] = 0;
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/* .. and only for trampolines and dispatchers */
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if ((sscanf(name, "bpf_trampoline_%lu", &id) == 1) ||
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(sscanf(name, "bpf_dispatcher_%s", disp) == 1))
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err = process_bpf_image(name, start, data);
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free(name);
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return err;
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}
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int perf_event__synthesize_bpf_events(struct perf_session *session,
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perf_event__handler_t process,
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struct machine *machine,
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struct record_opts *opts)
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{
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const char *kallsyms_filename = "/proc/kallsyms";
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struct kallsyms_parse arg;
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union perf_event *event;
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__u32 id = 0;
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int err;
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int fd;
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event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
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if (!event)
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return -1;
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/* Synthesize all the bpf programs in system. */
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while (true) {
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err = bpf_prog_get_next_id(id, &id);
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if (err) {
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if (errno == ENOENT) {
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err = 0;
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break;
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}
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pr_debug("%s: can't get next program: %s%s\n",
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__func__, strerror(errno),
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errno == EINVAL ? " -- kernel too old?" : "");
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/* don't report error on old kernel or EPERM */
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err = (errno == EINVAL || errno == EPERM) ? 0 : -1;
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break;
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}
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fd = bpf_prog_get_fd_by_id(id);
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if (fd < 0) {
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pr_debug("%s: failed to get fd for prog_id %u\n",
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__func__, id);
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continue;
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}
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err = perf_event__synthesize_one_bpf_prog(session, process,
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machine, fd,
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event, opts);
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close(fd);
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if (err) {
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/* do not return error for old kernel */
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if (err == -2)
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err = 0;
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break;
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}
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}
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/* Synthesize all the bpf images - trampolines/dispatchers. */
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if (symbol_conf.kallsyms_name != NULL)
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kallsyms_filename = symbol_conf.kallsyms_name;
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arg = (struct kallsyms_parse) {
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.event = event,
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.process = process,
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.machine = machine,
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.tool = session->tool,
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};
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if (kallsyms__parse(kallsyms_filename, &arg, kallsyms_process_symbol)) {
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pr_err("%s: failed to synthesize bpf images: %s\n",
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__func__, strerror(errno));
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}
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free(event);
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return err;
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}
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|
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static void perf_env__add_bpf_info(struct perf_env *env, u32 id)
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{
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struct bpf_prog_info_node *info_node;
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struct perf_bpil *info_linear;
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struct btf *btf = NULL;
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u64 arrays;
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u32 btf_id;
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int fd;
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fd = bpf_prog_get_fd_by_id(id);
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if (fd < 0)
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return;
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arrays = 1UL << PERF_BPIL_JITED_KSYMS;
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arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
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arrays |= 1UL << PERF_BPIL_FUNC_INFO;
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arrays |= 1UL << PERF_BPIL_PROG_TAGS;
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arrays |= 1UL << PERF_BPIL_JITED_INSNS;
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arrays |= 1UL << PERF_BPIL_LINE_INFO;
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arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;
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info_linear = get_bpf_prog_info_linear(fd, arrays);
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if (IS_ERR_OR_NULL(info_linear)) {
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pr_debug("%s: failed to get BPF program info. aborting\n", __func__);
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goto out;
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}
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|
|
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;
|
|
|
|
btf = btf__load_from_kernel_by_id(btf_id);
|
|
if (libbpf_get_error(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:
|
|
btf__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 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);
|
|
}
|