Merge "ftrace: Add filter for ftrace/print buf"

Android.bp

@@ -9949,6 +9949,7 @@ filegroup {
         "src/traced/probes/ftrace/ftrace_config_utils.cc",
         "src/traced/probes/ftrace/ftrace_controller.cc",
         "src/traced/probes/ftrace/ftrace_data_source.cc",
+        "src/traced/probes/ftrace/ftrace_print_filter.cc",
         "src/traced/probes/ftrace/ftrace_stats.cc",
         "src/traced/probes/ftrace/printk_formats_parser.cc",
         "src/traced/probes/ftrace/proto_translation_table.cc",
@@ -10096,6 +10097,7 @@ filegroup {
         "src/traced/probes/ftrace/ftrace_config_muxer_unittest.cc",
         "src/traced/probes/ftrace/ftrace_config_unittest.cc",
         "src/traced/probes/ftrace/ftrace_controller_unittest.cc",
+        "src/traced/probes/ftrace/ftrace_print_filter_unittest.cc",
         "src/traced/probes/ftrace/ftrace_procfs_unittest.cc",
         "src/traced/probes/ftrace/printk_formats_parser_unittest.cc",
         "src/traced/probes/ftrace/proto_translation_table_unittest.cc",

BUILD

@@ -1995,6 +1995,8 @@ perfetto_filegroup(
         "src/traced/probes/ftrace/ftrace_data_source.cc",
         "src/traced/probes/ftrace/ftrace_data_source.h",
         "src/traced/probes/ftrace/ftrace_metadata.h",
+        "src/traced/probes/ftrace/ftrace_print_filter.cc",
+        "src/traced/probes/ftrace/ftrace_print_filter.h",
         "src/traced/probes/ftrace/ftrace_stats.cc",
         "src/traced/probes/ftrace/ftrace_stats.h",
         "src/traced/probes/ftrace/printk_formats_parser.cc",

protos/perfetto/config/ftrace/ftrace_config.proto

@@ -18,7 +18,7 @@ syntax = "proto2";
 
 package perfetto.protos;
 
-// Next id: 22.
+// Next id: 23.
 message FtraceConfig {
   repeated string ftrace_events = 1;
   repeated string atrace_categories = 2;
@@ -37,6 +37,24 @@ message FtraceConfig {
   }
   optional CompactSchedConfig compact_sched = 12;
 
+  // Optional filter for "ftrace/print" events.
+  //
+  // The filter consists of multiple rules. A rule matches if its prefix matches
+  // exactly with the beginning of the "ftrace/print" "buf" field. As soon as a
+  // rule matches (the rules are processed in order), its `allow` field will be
+  // used as the outcome: if `allow` is true, the event will be included in the
+  // trace, otherwise it will be discarded. If an event does not match any rule,
+  // it will be allowed by default (a rule with an empty prefix and allow=false,
+  // disallows everything by default).
+  message PrintFilter {
+    message Rule {
+      optional string prefix = 1;
+      optional bool allow = 2;
+    }
+    repeated Rule rules = 1;
+  }
+  optional PrintFilter print_filter = 22;
+
   // Enables symbol name resolution against /proc/kallsyms.
   // It requires that either traced_probes is running as root or that
   // kptr_restrict has been manually lowered.

protos/perfetto/config/perfetto_config.proto

@@ -466,7 +466,7 @@ message ChromeConfig {
 
 // Begin of protos/perfetto/config/ftrace/ftrace_config.proto
 
-// Next id: 22.
+// Next id: 23.
 message FtraceConfig {
   repeated string ftrace_events = 1;
   repeated string atrace_categories = 2;
@@ -485,6 +485,24 @@ message FtraceConfig {
   }
   optional CompactSchedConfig compact_sched = 12;
 
+  // Optional filter for "ftrace/print" events.
+  //
+  // The filter consists of multiple rules. A rule matches if its prefix matches
+  // exactly with the beginning of the "ftrace/print" "buf" field. As soon as a
+  // rule matches (the rules are processed in order), its `allow` field will be
+  // used as the outcome: if `allow` is true, the event will be included in the
+  // trace, otherwise it will be discarded. If an event does not match any rule,
+  // it will be allowed by default (a rule with an empty prefix and allow=false,
+  // disallows everything by default).
+  message PrintFilter {
+    message Rule {
+      optional string prefix = 1;
+      optional bool allow = 2;
+    }
+    repeated Rule rules = 1;
+  }
+  optional PrintFilter print_filter = 22;
+
   // Enables symbol name resolution against /proc/kallsyms.
   // It requires that either traced_probes is running as root or that
   // kptr_restrict has been manually lowered.

protos/perfetto/trace/perfetto_trace.proto

@@ -466,7 +466,7 @@ message ChromeConfig {
 
 // Begin of protos/perfetto/config/ftrace/ftrace_config.proto
 
-// Next id: 22.
+// Next id: 23.
 message FtraceConfig {
   repeated string ftrace_events = 1;
   repeated string atrace_categories = 2;
@@ -485,6 +485,24 @@ message FtraceConfig {
   }
   optional CompactSchedConfig compact_sched = 12;
 
+  // Optional filter for "ftrace/print" events.
+  //
+  // The filter consists of multiple rules. A rule matches if its prefix matches
+  // exactly with the beginning of the "ftrace/print" "buf" field. As soon as a
+  // rule matches (the rules are processed in order), its `allow` field will be
+  // used as the outcome: if `allow` is true, the event will be included in the
+  // trace, otherwise it will be discarded. If an event does not match any rule,
+  // it will be allowed by default (a rule with an empty prefix and allow=false,
+  // disallows everything by default).
+  message PrintFilter {
+    message Rule {
+      optional string prefix = 1;
+      optional bool allow = 2;
+    }
+    repeated Rule rules = 1;
+  }
+  optional PrintFilter print_filter = 22;
+
   // Enables symbol name resolution against /proc/kallsyms.
   // It requires that either traced_probes is running as root or that
   // kptr_restrict has been manually lowered.

src/traced/probes/ftrace/BUILD.gn

@@ -66,14 +66,15 @@ perfetto_unittest_source_set("unittests") {
   sources = [
     "cpu_reader_unittest.cc",
     "cpu_stats_parser_unittest.cc",
-    "vendor_tracepoints_unittest.cc",
     "event_info_unittest.cc",
     "ftrace_config_muxer_unittest.cc",
     "ftrace_config_unittest.cc",
     "ftrace_controller_unittest.cc",
+    "ftrace_print_filter_unittest.cc",
     "ftrace_procfs_unittest.cc",
     "printk_formats_parser_unittest.cc",
     "proto_translation_table_unittest.cc",
+    "vendor_tracepoints_unittest.cc",
   ]
 }
 
@@ -137,8 +138,6 @@ source_set("ftrace") {
     "cpu_reader.h",
     "cpu_stats_parser.cc",
     "cpu_stats_parser.h",
-    "vendor_tracepoints.cc",
-    "vendor_tracepoints.h",
     "event_info.cc",
     "event_info.h",
     "event_info_constants.cc",
@@ -152,12 +151,16 @@ source_set("ftrace") {
     "ftrace_data_source.cc",
     "ftrace_data_source.h",
     "ftrace_metadata.h",
+    "ftrace_print_filter.cc",
+    "ftrace_print_filter.h",
     "ftrace_stats.cc",
     "ftrace_stats.h",
     "printk_formats_parser.cc",
     "printk_formats_parser.h",
     "proto_translation_table.cc",
     "proto_translation_table.h",
+    "vendor_tracepoints.cc",
+    "vendor_tracepoints.h",
   ]
 }
 

src/traced/probes/ftrace/cpu_reader.cc

@@ -37,6 +37,7 @@
 #include "src/traced/probes/ftrace/ftrace_config_muxer.h"
 #include "src/traced/probes/ftrace/ftrace_controller.h"
 #include "src/traced/probes/ftrace/ftrace_data_source.h"
+#include "src/traced/probes/ftrace/ftrace_print_filter.h"
 #include "src/traced/probes/ftrace/proto_translation_table.h"
 
 #include "protos/perfetto/trace/ftrace/ftrace_event.pbzero.h"
@@ -622,6 +623,9 @@ size_t CpuReader::ParsePagePayload(const uint8_t* start_of_payload,
           const CompactSchedWakingFormat& sched_waking_format =
               table->compact_sched_format().sched_waking;
 
+          bool ftrace_print_filter_enabled =
+              ds_config->print_filter.has_value();
+
           // compact sched_switch
           if (compact_sched_enabled &&
               ftrace_event_id == sched_switch_format.event_id) {
@@ -640,6 +644,15 @@ size_t CpuReader::ParsePagePayload(const uint8_t* start_of_payload,
             ParseSchedWakingCompact(start, timestamp, &sched_waking_format,
                                     compact_sched_buffer, metadata);
 
+          } else if (ftrace_print_filter_enabled &&
+                     ftrace_event_id == ds_config->print_filter->event_id()) {
+            if (ds_config->print_filter->IsEventInteresting(start, next)) {
+              protos::pbzero::FtraceEvent* event = bundle->add_event();
+              event->set_timestamp(timestamp);
+              if (!ParseEvent(ftrace_event_id, start, next, table, event,
+                              metadata))
+                return 0;
+            }
           } else {
             // Common case: parse all other types of enabled events.
             protos::pbzero::FtraceEvent* event = bundle->add_event();

src/traced/probes/ftrace/cpu_reader_benchmark.cc

@@ -21,6 +21,7 @@
 #include "protos/perfetto/trace/ftrace/ftrace_event_bundle.pbzero.h"
 #include "src/traced/probes/ftrace/cpu_reader.h"
 #include "src/traced/probes/ftrace/ftrace_config_muxer.h"
+#include "src/traced/probes/ftrace/ftrace_print_filter.h"
 #include "src/traced/probes/ftrace/proto_translation_table.h"
 #include "src/traced/probes/ftrace/test/cpu_reader_support.h"
 
@@ -559,6 +560,7 @@ ExamplePage g_full_page_print{
 
 void DoParse(const ExamplePage& test_case,
              const std::vector<GroupAndName>& enabled_events,
+             base::Optional<FtraceConfig::PrintFilter> print_filter,
              benchmark::State& state) {
   ScatteredStreamWriterNullDelegate delegate(base::kPageSize);
   ScatteredStreamWriter stream(&delegate);
@@ -570,9 +572,15 @@ void DoParse(const ExamplePage& test_case,
   FtraceDataSourceConfig ds_config{EventFilter{},
                                    EventFilter{},
                                    DisabledCompactSchedConfigForTesting(),
+                                   base::nullopt,
                                    {},
                                    {},
                                    false /*symbolize_ksyms*/};
+  if (print_filter.has_value()) {
+    ds_config.print_filter =
+        FtracePrintFilterConfig::Create(print_filter.value(), table);
+    PERFETTO_CHECK(ds_config.print_filter.has_value());
+  }
   for (const GroupAndName& enabled_event : enabled_events) {
     ds_config.event_filter.AddEnabledEvent(
         table->EventToFtraceId(enabled_event));
@@ -601,14 +609,27 @@ void DoParse(const ExamplePage& test_case,
 
 void BM_ParsePageFullOfSchedSwitch(benchmark::State& state) {
   DoParse(g_full_page_sched_switch, {GroupAndName("sched", "sched_switch")},
-          state);
+          base::nullopt, state);
 }
 BENCHMARK(BM_ParsePageFullOfSchedSwitch);
 
 void BM_ParsePageFullOfPrint(benchmark::State& state) {
-  DoParse(g_full_page_print, {GroupAndName("ftrace", "print")}, state);
+  DoParse(g_full_page_print, {GroupAndName("ftrace", "print")}, base::nullopt,
+          state);
 }
 BENCHMARK(BM_ParsePageFullOfPrint);
 
+void BM_ParsePageFullOfPrintWithFilterRules(benchmark::State& state) {
+  FtraceConfig::PrintFilter filter_conf;
+  for (int i = 0; i < state.range(0); i++) {
+    auto* rule = filter_conf.add_rules();
+    rule->set_prefix("X");  // This rule will not match
+    rule->set_allow(false);
+  }
+  DoParse(g_full_page_print, {GroupAndName("ftrace", "print")}, filter_conf,
+          state);
+}
+BENCHMARK(BM_ParsePageFullOfPrintWithFilterRules)->DenseRange(0, 16, 1);
+
 }  // namespace
 }  // namespace perfetto

src/traced/probes/ftrace/cpu_reader_fuzzer.cc

@@ -57,6 +57,7 @@ void FuzzCpuReaderProcessPagesForDataSource(const uint8_t* data, size_t size) {
   FtraceDataSourceConfig ds_config{EventFilter{},
                                    EventFilter{},
                                    DisabledCompactSchedConfigForTesting(),
+                                   base::nullopt,
                                    {},
                                    {},
                                    /*symbolize_ksyms=*/false};

src/traced/probes/ftrace/cpu_reader_unittest.cc

@@ -60,13 +60,13 @@ using testing::Return;
 using testing::StartsWith;
 
 namespace perfetto {
-
 namespace {
 
 FtraceDataSourceConfig EmptyConfig() {
   return FtraceDataSourceConfig{EventFilter{},
                                 EventFilter{},
                                 DisabledCompactSchedConfigForTesting(),
+                                base::nullopt,
                                 {},
                                 {},
                                 false /*symbolize_ksyms*/};
@@ -186,8 +186,6 @@ class BinaryWriter {
   uint8_t* ptr_;
 };
 
-}  // namespace
-
 TEST(PageFromXxdTest, OneLine) {
   std::string text = R"(
     00000000: 0000 0000 0000 0000 0000 0000 0000 0000  ................
@@ -756,6 +754,87 @@ TEST(CpuReaderTest, ParseThreePrint) {
   }
 }
 
+TEST(CpuReaderTest, ParsePrintWithAndWithoutFilter) {
+  const ExamplePage* test_case = &g_three_prints;
+
+  ProtoTranslationTable* table = GetTable(test_case->name);
+  auto page = PageFromXxd(test_case->data);
+
+  FtraceMetadata metadata{};
+  std::unique_ptr<CompactSchedBuffer> compact_buffer(new CompactSchedBuffer());
+  const uint8_t* parse_pos = page.get();
+  base::Optional<CpuReader::PageHeader> page_header =
+      CpuReader::ParsePageHeader(&parse_pos, table->page_header_size_len());
+
+  const uint8_t* page_end = page.get() + base::kPageSize;
+  ASSERT_TRUE(page_header.has_value());
+  ASSERT_FALSE(page_header->lost_events);
+  ASSERT_LE(parse_pos + page_header->size, page_end);
+
+  {
+    FtraceDataSourceConfig ds_config_no_filter = EmptyConfig();
+    ds_config_no_filter.event_filter.AddEnabledEvent(
+        table->EventToFtraceId(GroupAndName("ftrace", "print")));
+
+    BundleProvider bundle_provider(base::kPageSize);
+    size_t evt_bytes = CpuReader::ParsePagePayload(
+        parse_pos, &page_header.value(), table, &ds_config_no_filter,
+        compact_buffer.get(), bundle_provider.writer(), &metadata);
+    ASSERT_GE(evt_bytes, 0u);
+
+    auto bundle = bundle_provider.ParseProto();
+    using ::testing::Pointee;
+    using ::testing::Property;
+    EXPECT_THAT(
+        bundle,
+        Pointee(Property(
+            &protos::gen::FtraceEventBundle::event,
+            ElementsAre(Property(&protos::gen::FtraceEvent::print,
+                                 Property(&protos::gen::PrintFtraceEvent::buf,
+                                          "Hello, world!\n")),
+                        Property(&protos::gen::FtraceEvent::print,
+                                 Property(&protos::gen::PrintFtraceEvent::buf,
+                                          "Good afternoon, world!\n")),
+                        Property(&protos::gen::FtraceEvent::print,
+                                 Property(&protos::gen::PrintFtraceEvent::buf,
+                                          "Goodbye, world!\n"))))));
+  }
+
+  {
+    FtraceDataSourceConfig ds_config_with_filter = EmptyConfig();
+    ds_config_with_filter.event_filter.AddEnabledEvent(
+        table->EventToFtraceId(GroupAndName("ftrace", "print")));
+
+    FtraceConfig::PrintFilter conf;
+    auto* rule = conf.add_rules();
+    rule->set_prefix("Good ");
+    rule->set_allow(false);
+    ds_config_with_filter.print_filter =
+        FtracePrintFilterConfig::Create(conf, table);
+    ASSERT_TRUE(ds_config_with_filter.print_filter.has_value());
+
+    BundleProvider bundle_provider(base::kPageSize);
+    size_t evt_bytes = CpuReader::ParsePagePayload(
+        parse_pos, &page_header.value(), table, &ds_config_with_filter,
+        compact_buffer.get(), bundle_provider.writer(), &metadata);
+    ASSERT_GE(evt_bytes, 0u);
+
+    auto bundle = bundle_provider.ParseProto();
+    using ::testing::Pointee;
+    using ::testing::Property;
+    EXPECT_THAT(
+        bundle,
+        Pointee(Property(
+            &protos::gen::FtraceEventBundle::event,
+            ElementsAre(Property(&protos::gen::FtraceEvent::print,
+                                 Property(&protos::gen::PrintFtraceEvent::buf,
+                                          "Hello, world!\n")),
+                        Property(&protos::gen::FtraceEvent::print,
+                                 Property(&protos::gen::PrintFtraceEvent::buf,
+                                          "Goodbye, world!\n"))))));
+  }
+}
+
 // clang-format off
 // # tracer: nop
 // #
@@ -865,6 +944,7 @@ TEST(CpuReaderTest, ParseSixSchedSwitchCompactFormat) {
   FtraceDataSourceConfig ds_config{EventFilter{},
                                    EventFilter{},
                                    EnabledCompactSchedConfigForTesting(),
+                                   base::nullopt,
                                    {},
                                    {},
                                    false /* symbolize_ksyms*/};
@@ -2982,4 +3062,5 @@ TEST(CpuReaderTest, ZeroPaddedPageWorkaround) {
   ASSERT_TRUE(bundle);
 }
 
+}  // namespace
 }  // namespace perfetto