// 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__set_binary_type(dso, DSO_BINARY_TYPE__BPF_PROG_INFO);
dso__bpf_prog(dso)->id = id;
dso__bpf_prog(dso)->sub_id = i;
dso__bpf_prog(dso)->env = env;
map__put(map);
}
}
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;
const 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;
const 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;
if (opts->no_bpf_event)
return 0;
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);
}
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