Release 4.10 tools/perf/util/intel-bts.c

/*
 * intel-bts.c: Intel Processor Trace support
 * Copyright (c) 2013-2015, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 */

#include <endian.h>
#include <byteswap.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>

#include "cpumap.h"
#include "color.h"
#include "evsel.h"
#include "evlist.h"
#include "machine.h"
#include "session.h"
#include "util.h"
#include "thread.h"
#include "thread-stack.h"
#include "debug.h"
#include "tsc.h"
#include "auxtrace.h"
#include "intel-pt-decoder/intel-pt-insn-decoder.h"
#include "intel-bts.h"


#define MAX_TIMESTAMP (~0ULL)


#define INTEL_BTS_ERR_NOINSN  5

#define INTEL_BTS_ERR_LOST    9

#if __BYTE_ORDER == __BIG_ENDIAN

#define le64_to_cpu bswap_64
#else

#define le64_to_cpu
#endif


struct intel_bts {
	
struct auxtrace			auxtrace;
	
struct auxtrace_queues		queues;
	
struct auxtrace_heap		heap;
	
u32				auxtrace_type;
	
struct perf_session		*session;
	
struct machine			*machine;
	
bool				sampling_mode;
	
bool				snapshot_mode;
	
bool				data_queued;
	
u32				pmu_type;
	
struct perf_tsc_conversion	tc;
	
bool				cap_user_time_zero;
	
struct itrace_synth_opts	synth_opts;
	
bool				sample_branches;
	
u32				branches_filter;
	
u64				branches_sample_type;
	
u64				branches_id;
	
size_t				branches_event_size;
	
bool				synth_needs_swap;
	
unsigned long			num_events;
};


struct intel_bts_queue {
	
struct intel_bts	*bts;
	
unsigned int		queue_nr;
	
struct auxtrace_buffer	*buffer;
	
bool			on_heap;
	
bool			done;
	
pid_t			pid;
	
pid_t			tid;
	
int			cpu;
	
u64			time;
	
struct intel_pt_insn	intel_pt_insn;
	
u32			sample_flags;
};


struct branch {
	
u64 from;
	
u64 to;
	
u64 misc;
};



static void intel_bts_dump(struct intel_bts *bts __maybe_unused,
			   unsigned char *buf, size_t len)
{
	struct branch *branch;
	size_t i, pos = 0, br_sz = sizeof(struct branch), sz;
	const char *color = PERF_COLOR_BLUE;

	color_fprintf(stdout, color,
		      ". ... Intel BTS data: size %zu bytes\n",
		      len);

	while (len) {
		if (len >= br_sz)
			sz = br_sz;
		else
			sz = len;
		printf(".");
		color_fprintf(stdout, color, "  %08x: ", pos);
		for (i = 0; i < sz; i++)
			color_fprintf(stdout, color, " %02x", buf[i]);
		for (; i < br_sz; i++)
			color_fprintf(stdout, color, "   ");
		if (len >= br_sz) {
			branch = (struct branch *)buf;
			color_fprintf(stdout, color, " %"PRIx64" -> %"PRIx64" %s\n",
				      le64_to_cpu(branch->from),
				      le64_to_cpu(branch->to),
				      le64_to_cpu(branch->misc) & 0x10 ?
							"pred" : "miss");
		} else {
			color_fprintf(stdout, color, " Bad record!\n");
		}
		pos += sz;
		buf += sz;
		len -= sz;
	}
}

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static void intel_bts_dump_event(struct intel_bts *bts, unsigned char *buf,
				 size_t len)
{
	printf(".\n");
	intel_bts_dump(bts, buf, len);
}

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static int intel_bts_lost(struct intel_bts *bts, struct perf_sample *sample)
{
	union perf_event event;
	int err;

	auxtrace_synth_error(&event.auxtrace_error, PERF_AUXTRACE_ERROR_ITRACE,
			     INTEL_BTS_ERR_LOST, sample->cpu, sample->pid,
			     sample->tid, 0, "Lost trace data");

	err = perf_session__deliver_synth_event(bts->session, &event, NULL);
	if (err)
		pr_err("Intel BTS: failed to deliver error event, error %d\n",
		       err);

	return err;
}

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static struct intel_bts_queue *intel_bts_alloc_queue(struct intel_bts *bts,
						     unsigned int queue_nr)
{
	struct intel_bts_queue *btsq;

	btsq = zalloc(sizeof(struct intel_bts_queue));
	if (!btsq)
		return NULL;

	btsq->bts = bts;
	btsq->queue_nr = queue_nr;
	btsq->pid = -1;
	btsq->tid = -1;
	btsq->cpu = -1;

	return btsq;
}

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static int intel_bts_setup_queue(struct intel_bts *bts,
				 struct auxtrace_queue *queue,
				 unsigned int queue_nr)
{
	struct intel_bts_queue *btsq = queue->priv;

	if (list_empty(&queue->head))
		return 0;

	if (!btsq) {
		btsq = intel_bts_alloc_queue(bts, queue_nr);
		if (!btsq)
			return -ENOMEM;
		queue->priv = btsq;

		if (queue->cpu != -1)
			btsq->cpu = queue->cpu;
		btsq->tid = queue->tid;
	}

	if (bts->sampling_mode)
		return 0;

	if (!btsq->on_heap && !btsq->buffer) {
		int ret;

		btsq->buffer = auxtrace_buffer__next(queue, NULL);
		if (!btsq->buffer)
			return 0;

		ret = auxtrace_heap__add(&bts->heap, queue_nr,
					 btsq->buffer->reference);
		if (ret)
			return ret;
		btsq->on_heap = true;
	}

	return 0;
}

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static int intel_bts_setup_queues(struct intel_bts *bts)
{
	unsigned int i;
	int ret;

	for (i = 0; i < bts->queues.nr_queues; i++) {
		ret = intel_bts_setup_queue(bts, &bts->queues.queue_array[i],
					    i);
		if (ret)
			return ret;
	}
	return 0;
}

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static inline int intel_bts_update_queues(struct intel_bts *bts)
{
	if (bts->queues.new_data) {
		bts->queues.new_data = false;
		return intel_bts_setup_queues(bts);
	}
	return 0;
}

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static unsigned char *intel_bts_find_overlap(unsigned char *buf_a, size_t len_a,
					     unsigned char *buf_b, size_t len_b)
{
	size_t offs, len;

	if (len_a > len_b)
		offs = len_a - len_b;
	else
		offs = 0;

	for (; offs < len_a; offs += sizeof(struct branch)) {
		len = len_a - offs;
		if (!memcmp(buf_a + offs, buf_b, len))
			return buf_b + len;
	}

	return buf_b;
}

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static int intel_bts_do_fix_overlap(struct auxtrace_queue *queue,
				    struct auxtrace_buffer *b)
{
	struct auxtrace_buffer *a;
	void *start;

	if (b->list.prev == &queue->head)
		return 0;
	a = list_entry(b->list.prev, struct auxtrace_buffer, list);
	start = intel_bts_find_overlap(a->data, a->size, b->data, b->size);
	if (!start)
		return -EINVAL;
	b->use_size = b->data + b->size - start;
	b->use_data = start;
	return 0;
}

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static int intel_bts_synth_branch_sample(struct intel_bts_queue *btsq,
					 struct branch *branch)
{
	int ret;
	struct intel_bts *bts = btsq->bts;
	union perf_event event;
	struct perf_sample sample = { .ip = 0, };

	if (bts->synth_opts.initial_skip &&
	    bts->num_events++ <= bts->synth_opts.initial_skip)
		return 0;

	event.sample.header.type = PERF_RECORD_SAMPLE;
	event.sample.header.misc = PERF_RECORD_MISC_USER;
	event.sample.header.size = sizeof(struct perf_event_header);

	sample.cpumode = PERF_RECORD_MISC_USER;
	sample.ip = le64_to_cpu(branch->from);
	sample.pid = btsq->pid;
	sample.tid = btsq->tid;
	sample.addr = le64_to_cpu(branch->to);
	sample.id = btsq->bts->branches_id;
	sample.stream_id = btsq->bts->branches_id;
	sample.period = 1;
	sample.cpu = btsq->cpu;
	sample.flags = btsq->sample_flags;
	sample.insn_len = btsq->intel_pt_insn.length;
	memcpy(sample.insn, btsq->intel_pt_insn.buf, INTEL_PT_INSN_BUF_SZ);

	if (bts->synth_opts.inject) {
		event.sample.header.size = bts->branches_event_size;
		ret = perf_event__synthesize_sample(&event,
						    bts->branches_sample_type,
						    0, &sample,
						    bts->synth_needs_swap);
		if (ret)
			return ret;
	}

	ret = perf_session__deliver_synth_event(bts->session, &event, &sample);
	if (ret)
		pr_err("Intel BTS: failed to deliver branch event, error %d\n",
		       ret);

	return ret;
}

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static int intel_bts_get_next_insn(struct intel_bts_queue *btsq, u64 ip)
{
	struct machine *machine = btsq->bts->machine;
	struct thread *thread;
	struct addr_location al;
	unsigned char buf[INTEL_PT_INSN_BUF_SZ];
	ssize_t len;
	int x86_64;
	uint8_t cpumode;
	int err = -1;

	if (machine__kernel_ip(machine, ip))
		cpumode = PERF_RECORD_MISC_KERNEL;
	else
		cpumode = PERF_RECORD_MISC_USER;

	thread = machine__find_thread(machine, -1, btsq->tid);
	if (!thread)
		return -1;

	thread__find_addr_map(thread, cpumode, MAP__FUNCTION, ip, &al);
	if (!al.map || !al.map->dso)
		goto out_put;

	len = dso__data_read_addr(al.map->dso, al.map, machine, ip, buf,
				  INTEL_PT_INSN_BUF_SZ);
	if (len <= 0)
		goto out_put;

	/* Load maps to ensure dso->is_64_bit has been updated */
	map__load(al.map);

	x86_64 = al.map->dso->is_64_bit;

	if (intel_pt_get_insn(buf, len, x86_64, &btsq->intel_pt_insn))
		goto out_put;

	err = 0;
out_put:
	thread__put(thread);
	return err;
}

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static int intel_bts_synth_error(struct intel_bts *bts, int cpu, pid_t pid,
				 pid_t tid, u64 ip)
{
	union perf_event event;
	int err;

	auxtrace_synth_error(&event.auxtrace_error, PERF_AUXTRACE_ERROR_ITRACE,
			     INTEL_BTS_ERR_NOINSN, cpu, pid, tid, ip,
			     "Failed to get instruction");

	err = perf_session__deliver_synth_event(bts->session, &event, NULL);
	if (err)
		pr_err("Intel BTS: failed to deliver error event, error %d\n",
		       err);

	return err;
}

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static int intel_bts_get_branch_type(struct intel_bts_queue *btsq,
				     struct branch *branch)
{
	int err;

	if (!branch->from) {
		if (branch->to)
			btsq->sample_flags = PERF_IP_FLAG_BRANCH |
					     PERF_IP_FLAG_TRACE_BEGIN;
		else
			btsq->sample_flags = 0;
		btsq->intel_pt_insn.length = 0;
	} else if (!branch->to) {
		btsq->sample_flags = PERF_IP_FLAG_BRANCH |
				     PERF_IP_FLAG_TRACE_END;
		btsq->intel_pt_insn.length = 0;
	} else {
		err = intel_bts_get_next_insn(btsq, branch->from);
		if (err) {
			btsq->sample_flags = 0;
			btsq->intel_pt_insn.length = 0;
			if (!btsq->bts->synth_opts.errors)
				return 0;
			err = intel_bts_synth_error(btsq->bts, btsq->cpu,
						    btsq->pid, btsq->tid,
						    branch->from);
			return err;
		}
		btsq->sample_flags = intel_pt_insn_type(btsq->intel_pt_insn.op);
		/* Check for an async branch into the kernel */
		if (!machine__kernel_ip(btsq->bts->machine, branch->from) &&
		    machine__kernel_ip(btsq->bts->machine, branch->to) &&
		    btsq->sample_flags != (PERF_IP_FLAG_BRANCH |
					   PERF_IP_FLAG_CALL |
					   PERF_IP_FLAG_SYSCALLRET))
			btsq->sample_flags = PERF_IP_FLAG_BRANCH |
					     PERF_IP_FLAG_CALL |
					     PERF_IP_FLAG_ASYNC |
					     PERF_IP_FLAG_INTERRUPT;
	}

	return 0;
}

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static int intel_bts_process_buffer(struct intel_bts_queue *btsq,
				    struct auxtrace_buffer *buffer,
				    struct thread *thread)
{
	struct branch *branch;
	size_t sz, bsz = sizeof(struct branch);
	u32 filter = btsq->bts->branches_filter;
	int err = 0;

	if (buffer->use_data) {
		sz = buffer->use_size;
		branch = buffer->use_data;
	} else {
		sz = buffer->size;
		branch = buffer->data;
	}

	if (!btsq->bts->sample_branches)
		return 0;

	for (; sz > bsz; branch += 1, sz -= bsz) {
		if (!branch->from && !branch->to)
			continue;
		intel_bts_get_branch_type(btsq, branch);
		if (btsq->bts->synth_opts.thread_stack)
			thread_stack__event(thread, btsq->sample_flags,
					    le64_to_cpu(branch->from),
					    le64_to_cpu(branch->to),
					    btsq->intel_pt_insn.length,
					    buffer->buffer_nr + 1);
		if (filter && !(filter & btsq->sample_flags))
			continue;
		err = intel_bts_synth_branch_sample(btsq, branch);
		if (err)
			break;
	}
	return err;
}

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static int intel_bts_process_queue(struct intel_bts_queue *btsq, u64 *timestamp)
{
	struct auxtrace_buffer *buffer = btsq->buffer, *old_buffer = buffer;
	struct auxtrace_queue *queue;
	struct thread *thread;
	int err;

	if (btsq->done)
		return 1;

	if (btsq->pid == -1) {
		thread = machine__find_thread(btsq->bts->machine, -1,
					      btsq->tid);
		if (thread)
			btsq->pid = thread->pid_;
	} else {
		thread = machine__findnew_thread(btsq->bts->machine, btsq->pid,
						 btsq->tid);
	}

	queue = &btsq->bts->queues.queue_array[btsq->queue_nr];

	if (!buffer)
		buffer = auxtrace_buffer__next(queue, NULL);

	if (!buffer) {
		if (!btsq->bts->sampling_mode)
			btsq->done = 1;
		err = 1;
		goto out_put;
	}

	/* Currently there is no support for split buffers */
	if (buffer->consecutive) {
		err = -EINVAL;
		goto out_put;
	}

	if (!buffer->data) {
		int fd = perf_data_file__fd(btsq->bts->session->file);

		buffer->data = auxtrace_buffer__get_data(buffer, fd);
		if (!buffer->data) {
			err = -ENOMEM;
			goto out_put;
		}
	}

	if (btsq->bts->snapshot_mode && !buffer->consecutive &&
	    intel_bts_do_fix_overlap(queue, buffer)) {
		err = -ENOMEM;
		goto out_put;
	}

	if (!btsq->bts->synth_opts.callchain &&
	    !btsq->bts->synth_opts.thread_stack && thread &&
	    (!old_buffer || btsq->bts->sampling_mode ||
	     (btsq->bts->snapshot_mode && !buffer->consecutive)))
		thread_stack__set_trace_nr(thread, buffer->buffer_nr + 1);

	err = intel_bts_process_buffer(btsq, buffer, thread);

	auxtrace_buffer__drop_data(buffer);

	btsq->buffer = auxtrace_buffer__next(queue, buffer);
	if (btsq->buffer) {
		if (timestamp)
			*timestamp = btsq->buffer->reference;
	} else {
		if (!btsq->bts->sampling_mode)
			btsq->done = 1;
	}
out_put:
	thread__put(thread);
	return err;
}

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static int intel_bts_flush_queue(struct intel_bts_queue *btsq)
{
	u64 ts = 0;
	int ret;

	while (1) {
		ret = intel_bts_process_queue(btsq, &ts);
		if (ret < 0)
			return ret;
		if (ret)
			break;
	}
	return 0;
}

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static int intel_bts_process_tid_exit(struct intel_bts *bts, pid_t tid)
{
	struct auxtrace_queues *queues = &bts->queues;
	unsigned int i;

	for (i = 0; i < queues->nr_queues; i++) {
		struct auxtrace_queue *queue = &bts->queues.queue_array[i];
		struct intel_bts_queue *btsq = queue->priv;

		if (btsq && btsq->tid == tid)
			return intel_bts_flush_queue(btsq);
	}
	return 0;
}

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static int intel_bts_process_queues(struct intel_bts *bts, u64 timestamp)
{
	while (1) {
		unsigned int queue_nr;
		struct auxtrace_queue *queue;
		struct intel_bts_queue *btsq;
		u64 ts = 0;
		int ret;

		if (!bts->heap.heap_cnt)
			return 0;

		if (bts->heap.heap_array[0].ordinal > timestamp)
			return 0;

		queue_nr = bts->heap.heap_array[0].queue_nr;
		queue = &bts->queues.queue_array[queue_nr];
		btsq = queue->priv;

		auxtrace_heap__pop(&bts->heap);

		ret = intel_bts_process_queue(btsq, &ts);
		if (ret < 0) {
			auxtrace_heap__add(&bts->heap, queue_nr, ts);
			return ret;
		}

		if (!ret) {
			ret = auxtrace_heap__add(&bts->heap, queue_nr, ts);
			if (ret < 0)
				return ret;
		} else {
			btsq->on_heap = false;
		}
	}

	return 0;
}

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static int intel_bts_process_event(struct perf_session *session,
				   union perf_event *event,
				   struct perf_sample *sample,
				   struct perf_tool *tool)
{
	struct intel_bts *bts = container_of(session->auxtrace, struct intel_bts,
					     auxtrace);
	u64 timestamp;
	int err;

	if (dump_trace)
		return 0;

	if (!tool->ordered_events) {
		pr_err("Intel BTS requires ordered events\n");
		return -EINVAL;
	}

	if (sample->time && sample->time != (u64)-1)
		timestamp = perf_time_to_tsc(sample->time, &bts->tc);
	else
		timestamp = 0;

	err = intel_bts_update_queues(bts);
	if (err)
		return err;

	err = intel_bts_process_queues(bts, timestamp);
	if (err)
		return err;
	if (event->header.type == PERF_RECORD_EXIT) {
		err = intel_bts_process_tid_exit(bts, event->fork.tid);