linux-kernel - [PATCH 22/27] perf intel-pt: Fix decoding when there are address filters

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Message-Id: <1475159756-21326-23-git-send-email-acme@kernel.org>
Date:   Thu, 29 Sep 2016 11:35:51 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Ingo Molnar <mingo@...nel.org>
Cc:     linux-kernel@...r.kernel.org, Linux Weekly News <lwn@....net>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Jiri Olsa <jolsa@...hat.com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Mathieu Poirier <mathieu.poirier@...aro.org>,
        Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: [PATCH 22/27] perf intel-pt: Fix decoding when there are address filters

From: Adrian Hunter <adrian.hunter@...el.com>

Due to errata SKL014 "Intel PT TIP.PGD May Not Have Target IP Payload",
the Intel PT decoder needs to match address filters against TIP.PGD
packets.  Parse the address filters and implement the decoder's
'pgd_ip()' callback to match the IP against the filter regions.

Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
Cc: Jiri Olsa <jolsa@...hat.com>
Cc: Masami Hiramatsu <mhiramat@...nel.org>
Cc: Mathieu Poirier <mathieu.poirier@...aro.org>
Link: http://lkml.kernel.org/r/1474641528-18776-17-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@...hat.com>
---
 tools/perf/util/intel-pt.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)

diff --git a/tools/perf/util/intel-pt.c b/tools/perf/util/intel-pt.c
index c9fec19a7914..dc041d4368c8 100644
--- a/tools/perf/util/intel-pt.c
+++ b/tools/perf/util/intel-pt.c
@@ -105,6 +105,7 @@ struct intel_pt {
 	unsigned long num_events;
 
 	char *filter;
+	struct addr_filters filts;
 };
 
 enum switch_state {
@@ -550,6 +551,76 @@ out_no_cache:
 	return 0;
 }
 
+static bool intel_pt_match_pgd_ip(struct intel_pt *pt, uint64_t ip,
+				  uint64_t offset, const char *filename)
+{
+	struct addr_filter *filt;
+	bool have_filter   = false;
+	bool hit_tracestop = false;
+	bool hit_filter    = false;
+
+	list_for_each_entry(filt, &pt->filts.head, list) {
+		if (filt->start)
+			have_filter = true;
+
+		if ((filename && !filt->filename) ||
+		    (!filename && filt->filename) ||
+		    (filename && strcmp(filename, filt->filename)))
+			continue;
+
+		if (!(offset >= filt->addr && offset < filt->addr + filt->size))
+			continue;
+
+		intel_pt_log("TIP.PGD ip %#"PRIx64" offset %#"PRIx64" in %s hit filter: %s offset %#"PRIx64" size %#"PRIx64"\n",
+			     ip, offset, filename ? filename : "[kernel]",
+			     filt->start ? "filter" : "stop",
+			     filt->addr, filt->size);
+
+		if (filt->start)
+			hit_filter = true;
+		else
+			hit_tracestop = true;
+	}
+
+	if (!hit_tracestop && !hit_filter)
+		intel_pt_log("TIP.PGD ip %#"PRIx64" offset %#"PRIx64" in %s is not in a filter region\n",
+			     ip, offset, filename ? filename : "[kernel]");
+
+	return hit_tracestop || (have_filter && !hit_filter);
+}
+
+static int __intel_pt_pgd_ip(uint64_t ip, void *data)
+{
+	struct intel_pt_queue *ptq = data;
+	struct thread *thread;
+	struct addr_location al;
+	u8 cpumode;
+	u64 offset;
+
+	if (ip >= ptq->pt->kernel_start)
+		return intel_pt_match_pgd_ip(ptq->pt, ip, ip, NULL);
+
+	cpumode = PERF_RECORD_MISC_USER;
+
+	thread = ptq->thread;
+	if (!thread)
+		return -EINVAL;
+
+	thread__find_addr_map(thread, cpumode, MAP__FUNCTION, ip, &al);
+	if (!al.map || !al.map->dso)
+		return -EINVAL;
+
+	offset = al.map->map_ip(al.map, ip);
+
+	return intel_pt_match_pgd_ip(ptq->pt, ip, offset,
+				     al.map->dso->long_name);
+}
+
+static bool intel_pt_pgd_ip(uint64_t ip, void *data)
+{
+	return __intel_pt_pgd_ip(ip, data) > 0;
+}
+
 static bool intel_pt_get_config(struct intel_pt *pt,
 				struct perf_event_attr *attr, u64 *config)
 {
@@ -726,6 +797,9 @@ static struct intel_pt_queue *intel_pt_alloc_queue(struct intel_pt *pt,
 	params.tsc_ctc_ratio_n = pt->tsc_ctc_ratio_n;
 	params.tsc_ctc_ratio_d = pt->tsc_ctc_ratio_d;
 
+	if (pt->filts.cnt > 0)
+		params.pgd_ip = intel_pt_pgd_ip;
+
 	if (pt->synth_opts.instructions) {
 		if (pt->synth_opts.period) {
 			switch (pt->synth_opts.period_type) {
@@ -1776,6 +1850,7 @@ static void intel_pt_free(struct perf_session *session)
 	intel_pt_free_events(session);
 	session->auxtrace = NULL;
 	thread__put(pt->unknown_thread);
+	addr_filters__exit(&pt->filts);
 	zfree(&pt->filter);
 	free(pt);
 }
@@ -2073,6 +2148,8 @@ int intel_pt_process_auxtrace_info(union perf_event *event,
 	if (!pt)
 		return -ENOMEM;
 
+	addr_filters__init(&pt->filts);
+
 	perf_config(intel_pt_perf_config, pt);
 
 	err = auxtrace_queues__init(&pt->queues);
@@ -2147,6 +2224,10 @@ int intel_pt_process_auxtrace_info(union perf_event *event,
 				err = -EINVAL;
 				goto err_free_queues;
 			}
+			err = addr_filters__parse_bare_filter(&pt->filts,
+							      filter);
+			if (err)
+				goto err_free_queues;
 		}
 		intel_pt_print_info_str("Filter string", pt->filter);
 	}
@@ -2268,6 +2349,7 @@ err_free_queues:
 	auxtrace_queues__free(&pt->queues);
 	session->auxtrace = NULL;
 err_free:
+	addr_filters__exit(&pt->filts);
 	zfree(&pt->filter);
 	free(pt);
 	return err;
-- 
2.7.4