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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /tools/perf/util/bpf-event.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/util/bpf-event.c')
-rw-r--r--tools/perf/util/bpf-event.c585
1 files changed, 585 insertions, 0 deletions
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
new file mode 100644
index 0000000000..b00b5a2634
--- /dev/null
+++ b/tools/perf/util/bpf-event.c
@@ -0,0 +1,585 @@
+// 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 "bpf-utils.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"
+
+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_node *info_node;
+ struct perf_env *env = machine->env;
+ struct perf_bpil *info_linear;
+ 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__kernel_maps(machine), addr);
+
+ if (map) {
+ struct dso *dso = map__dso(map);
+
+ dso->binary_type = DSO_BINARY_TYPE__BPF_PROG_INFO;
+ dso->bpf_prog.id = id;
+ dso->bpf_prog.sub_id = i;
+ 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__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 perf_tool *tool = session->tool;
+ struct bpf_prog_info_node *info_node;
+ struct perf_bpil *info_linear;
+ 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 << PERF_BPIL_JITED_KSYMS;
+ arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
+ arrays |= 1UL << PERF_BPIL_FUNC_INFO;
+ arrays |= 1UL << PERF_BPIL_PROG_TAGS;
+ arrays |= 1UL << PERF_BPIL_JITED_INSNS;
+ arrays |= 1UL << PERF_BPIL_LINE_INFO;
+ arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;
+
+ info_linear = get_bpf_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)) {
+ free(info_linear);
+ pr_debug("%s: the kernel is too old, aborting\n", __func__);
+ return -2;
+ }
+
+ info = &info_linear->info;
+ if (!info->jited_ksyms) {
+ free(info_linear);
+ return -1;
+ }
+
+ /* 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) {
+ free(info_linear);
+ 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__);
+ free(info_linear);
+ return -1;
+ }
+ btf = btf__load_from_kernel_by_id(info->btf_id);
+ if (libbpf_get_error(btf)) {
+ pr_debug("%s: failed to get BTF of id %u, aborting\n", __func__, info->btf_id);
+ err = -1;
+ 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);
+ btf__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_node *info_node;
+ struct perf_bpil *info_linear;
+ 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 << PERF_BPIL_JITED_KSYMS;
+ arrays |= 1UL << PERF_BPIL_JITED_FUNC_LENS;
+ arrays |= 1UL << PERF_BPIL_FUNC_INFO;
+ arrays |= 1UL << PERF_BPIL_PROG_TAGS;
+ arrays |= 1UL << PERF_BPIL_JITED_INSNS;
+ arrays |= 1UL << PERF_BPIL_LINE_INFO;
+ arrays |= 1UL << PERF_BPIL_JITED_LINE_INFO;
+
+ info_linear = get_bpf_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;
+
+ 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);
+}