path: root/tools/perf/util/dlfilter.c

// SPDX-License-Identifier: GPL-2.0
/*
 * dlfilter.c: Interface to perf script --dlfilter shared object
 * Copyright (c) 2021, Intel Corporation.
 */
#include <dlfcn.h>
#include <stdlib.h>
#include <string.h>
#include <linux/zalloc.h>
#include <linux/build_bug.h>

#include "debug.h"
#include "event.h"
#include "evsel.h"
#include "dso.h"
#include "map.h"
#include "thread.h"
#include "symbol.h"
#include "dlfilter.h"
#include "perf_dlfilter.h"

static void al_to_d_al(struct addr_location *al, struct perf_dlfilter_al *d_al)
{
	struct symbol *sym = al->sym;

	d_al->size = sizeof(*d_al);
	if (al->map) {
		struct dso *dso = al->map->dso;

		if (symbol_conf.show_kernel_path && dso->long_name)
			d_al->dso = dso->long_name;
		else
			d_al->dso = dso->name;
		d_al->is_64_bit = dso->is_64_bit;
		d_al->buildid_size = dso->bid.size;
		d_al->buildid = dso->bid.data;
	} else {
		d_al->dso = NULL;
		d_al->is_64_bit = 0;
		d_al->buildid_size = 0;
		d_al->buildid = NULL;
	}
	if (sym) {
		d_al->sym = sym->name;
		d_al->sym_start = sym->start;
		d_al->sym_end = sym->end;
		if (al->addr < sym->end)
			d_al->symoff = al->addr - sym->start;
		else
			d_al->symoff = al->addr - al->map->start - sym->start;
		d_al->sym_binding = sym->binding;
	} else {
		d_al->sym = NULL;
		d_al->sym_start = 0;
		d_al->sym_end = 0;
		d_al->symoff = 0;
		d_al->sym_binding = 0;
	}
	d_al->addr = al->addr;
	d_al->comm = NULL;
	d_al->filtered = 0;
}

static struct addr_location *get_al(struct dlfilter *d)
{
	struct addr_location *al = d->al;

	if (!al->thread && machine__resolve(d->machine, al, d->sample) < 0)
		return NULL;
	return al;
}

static struct thread *get_thread(struct dlfilter *d)
{
	struct addr_location *al = get_al(d);

	return al ? al->thread : NULL;
}

static const struct perf_dlfilter_al *dlfilter__resolve_ip(void *ctx)
{
	struct dlfilter *d = (struct dlfilter *)ctx;
	struct perf_dlfilter_al *d_al = d->d_ip_al;
	struct addr_location *al;

	if (!d->ctx_valid)
		return NULL;

	/* 'size' is also used to indicate already initialized */
	if (d_al->size)
		return d_al;

	al = get_al(d);
	if (!al)
		return NULL;

	al_to_d_al(al, d_al);

	d_al->is_kernel_ip = machine__kernel_ip(d->machine, d->sample->ip);
	d_al->comm = al->thread ? thread__comm_str(al->thread) : ":-1";
	d_al->filtered = al->filtered;

	return d_al;
}

static const struct perf_dlfilter_al *dlfilter__resolve_addr(void *ctx)
{
	struct dlfilter *d = (struct dlfilter *)ctx;
	struct perf_dlfilter_al *d_addr_al = d->d_addr_al;
	struct addr_location *addr_al = d->addr_al;

	if (!d->ctx_valid || !d->d_sample->addr_correlates_sym)
		return NULL;

	/* 'size' is also used to indicate already initialized */
	if (d_addr_al->size)
		return d_addr_al;

	if (!addr_al->thread) {
		struct thread *thread = get_thread(d);

		if (!thread)
			return NULL;
		thread__resolve(thread, addr_al, d->sample);
	}

	al_to_d_al(addr_al, d_addr_al);

	d_addr_al->is_kernel_ip = machine__kernel_ip(d->machine, d->sample->addr);

	return d_addr_al;
}

static const struct perf_dlfilter_fns perf_dlfilter_fns = {
	.resolve_ip      = dlfilter__resolve_ip,
	.resolve_addr    = dlfilter__resolve_addr,
};

#define CHECK_FLAG(x) BUILD_BUG_ON((u64)PERF_DLFILTER_FLAG_ ## x != (u64)PERF_IP_FLAG_ ## x)

static int dlfilter__init(struct dlfilter *d, const char *file)
{
	CHECK_FLAG(BRANCH);
	CHECK_FLAG(CALL);
	CHECK_FLAG(RETURN);
	CHECK_FLAG(CONDITIONAL);
	CHECK_FLAG(SYSCALLRET);
	CHECK_FLAG(ASYNC);
	CHECK_FLAG(INTERRUPT);
	CHECK_FLAG(TX_ABORT);
	CHECK_FLAG(TRACE_BEGIN);
	CHECK_FLAG(TRACE_END);
	CHECK_FLAG(IN_TX);
	CHECK_FLAG(VMENTRY);
	CHECK_FLAG(VMEXIT);

	memset(d, 0, sizeof(*d));
	d->file = strdup(file);
	if (!d->file)
		return -1;
	return 0;
}

static void dlfilter__exit(struct dlfilter *d)
{
	zfree(&d->file);
}

static int dlfilter__open(struct dlfilter *d)
{
	d->handle = dlopen(d->file, RTLD_NOW);
	if (!d->handle) {
		pr_err("dlopen failed for: '%s'\n", d->file);
		return -1;
	}
	d->start = dlsym(d->handle, "start");
	d->filter_event = dlsym(d->handle, "filter_event");
	d->stop = dlsym(d->handle, "stop");
	d->fns = dlsym(d->handle, "perf_dlfilter_fns");
	if (d->fns)
		memcpy(d->fns, &perf_dlfilter_fns, sizeof(struct perf_dlfilter_fns));
	return 0;
}

static int dlfilter__close(struct dlfilter *d)
{
	return dlclose(d->handle);
}

struct dlfilter *dlfilter__new(const char *file)
{
	struct dlfilter *d = malloc(sizeof(*d));

	if (!d)
		return NULL;

	if (dlfilter__init(d, file))
		goto err_free;

	if (dlfilter__open(d))
		goto err_exit;

	return d;

err_exit:
	dlfilter__exit(d);
err_free:
	free(d);
	return NULL;
}

static void dlfilter__free(struct dlfilter *d)
{
	if (d) {
		dlfilter__exit(d);
		free(d);
	}
}

int dlfilter__start(struct dlfilter *d, struct perf_session *session)
{
	if (d) {
		d->session = session;
		if (d->start)
			return d->start(&d->data, d);
	}
	return 0;
}

static int dlfilter__stop(struct dlfilter *d)
{
	if (d && d->stop)
		return d->stop(d->data, d);
	return 0;
}

void dlfilter__cleanup(struct dlfilter *d)
{
	if (d) {
		dlfilter__stop(d);
		dlfilter__close(d);
		dlfilter__free(d);
	}
}

#define ASSIGN(x) d_sample.x = sample->x

int dlfilter__do_filter_event(struct dlfilter *d,
			      union perf_event *event,
			      struct perf_sample *sample,
			      struct evsel *evsel,
			      struct machine *machine,
			      struct addr_location *al,
			      struct addr_location *addr_al)
{
	struct perf_dlfilter_sample d_sample;
	struct perf_dlfilter_al d_ip_al;
	struct perf_dlfilter_al d_addr_al;
	int ret;

	d->event       = event;
	d->sample      = sample;
	d->evsel       = evsel;
	d->machine     = machine;
	d->al          = al;
	d->addr_al     = addr_al;
	d->d_sample    = &d_sample;
	d->d_ip_al     = &d_ip_al;
	d->d_addr_al   = &d_addr_al;

	d_sample.size  = sizeof(d_sample);
	d_ip_al.size   = 0; /* To indicate d_ip_al is not initialized */
	d_addr_al.size = 0; /* To indicate d_addr_al is not initialized */

	ASSIGN(ip);
	ASSIGN(pid);
	ASSIGN(tid);
	ASSIGN(time);
	ASSIGN(addr);
	ASSIGN(id);
	ASSIGN(stream_id);
	ASSIGN(period);
	ASSIGN(weight);
	ASSIGN(ins_lat);
	ASSIGN(p_stage_cyc);
	ASSIGN(transaction);
	ASSIGN(insn_cnt);
	ASSIGN(cyc_cnt);
	ASSIGN(cpu);
	ASSIGN(flags);
	ASSIGN(data_src);
	ASSIGN(phys_addr);
	ASSIGN(data_page_size);
	ASSIGN(code_page_size);
	ASSIGN(cgroup);
	ASSIGN(cpumode);
	ASSIGN(misc);
	ASSIGN(raw_size);
	ASSIGN(raw_data);

	if (sample->branch_stack) {
		d_sample.brstack_nr = sample->branch_stack->nr;
		d_sample.brstack = (struct perf_branch_entry *)perf_sample__branch_entries(sample);
	} else {
		d_sample.brstack_nr = 0;
		d_sample.brstack = NULL;
	}

	if (sample->callchain) {
		d_sample.raw_callchain_nr = sample->callchain->nr;
		d_sample.raw_callchain = (__u64 *)sample->callchain->ips;
	} else {
		d_sample.raw_callchain_nr = 0;
		d_sample.raw_callchain = NULL;
	}

	d_sample.addr_correlates_sym =
		(evsel->core.attr.sample_type & PERF_SAMPLE_ADDR) &&
		sample_addr_correlates_sym(&evsel->core.attr);

	d_sample.event = evsel__name(evsel);

	d->ctx_valid = true;

	ret = d->filter_event(d->data, &d_sample, d);

	d->ctx_valid = false;

	return ret;
}