perf script: Add API for filtering via dynamically loaded shared object

In some cases, users want to filter very large amounts of data (e.g.
from AUX area tracing like Intel PT) looking for something specific.
While scripting such as Python can be used, Python is 10 to 20 times
slower than C. So define a C API so that custom filters can be written
and loaded.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210627131818.810-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 330 insertions, 0 deletions

diff --git a/tools/perf/util/dlfilter.c b/tools/perf/util/dlfilter.c
new file mode 100644
index 000000000000..03c4bf150656
--- /dev/null
+++ b/tools/perf/util/dlfilter.c
@@ -0,0 +1,330 @@
+// 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;
+}