diff options
| -rw-r--r-- | tools/perf/util/bpf-event.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c index a3207d900339..0cd41a862952 100644 --- a/tools/perf/util/bpf-event.c +++ b/tools/perf/util/bpf-event.c @@ -6,6 +6,9 @@ #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" @@ -290,11 +293,82 @@ out: 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; @@ -303,6 +377,8 @@ int perf_event__synthesize_bpf_events(struct perf_session *session, 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) { @@ -335,6 +411,23 @@ int perf_event__synthesize_bpf_events(struct perf_session *session, 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; } |