[v7,perf,bpf-next,6/8] perf util: handle PERF_RECORD_KSYMBOL

Message ID 20190111001933.4153792-7-songliubraving@fb.com
State Superseded
Delegated to: BPF Maintainers
Headers show
Series
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Commit Message

Song Liu Jan. 11, 2019, 12:19 a.m.
This patch handles PERF_RECORD_KSYMBOL in perf record/report.
Specifically, map and symbol are created for ksymbol register, and
removed for ksymbol unregister.

This patch also set perf_event_attr.ksymbol properly. The flag is
ON by default.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/perf/util/event.c   | 21 +++++++++++++++
 tools/perf/util/event.h   | 20 ++++++++++++++
 tools/perf/util/evsel.c   |  9 +++++++
 tools/perf/util/evsel.h   |  1 +
 tools/perf/util/machine.c | 57 +++++++++++++++++++++++++++++++++++++++
 tools/perf/util/machine.h |  3 +++
 tools/perf/util/session.c |  4 +++
 tools/perf/util/tool.h    |  4 ++-
 8 files changed, 118 insertions(+), 1 deletion(-)

Comments

Arnaldo Carvalho de Melo Jan. 14, 2019, 5:11 p.m. | #1
Em Thu, Jan 10, 2019 at 04:19:31PM -0800, Song Liu escreveu:
> This patch handles PERF_RECORD_KSYMBOL in perf record/report.
> Specifically, map and symbol are created for ksymbol register, and
> removed for ksymbol unregister.
> 
> This patch also set perf_event_attr.ksymbol properly. The flag is
> ON by default.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/event.c   | 21 +++++++++++++++
>  tools/perf/util/event.h   | 20 ++++++++++++++
>  tools/perf/util/evsel.c   |  9 +++++++
>  tools/perf/util/evsel.h   |  1 +
>  tools/perf/util/machine.c | 57 +++++++++++++++++++++++++++++++++++++++
>  tools/perf/util/machine.h |  3 +++
>  tools/perf/util/session.c |  4 +++
>  tools/perf/util/tool.h    |  4 ++-
>  8 files changed, 118 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> index 937a5a4f71cc..3c8a6a8dd260 100644
> --- a/tools/perf/util/event.c
> +++ b/tools/perf/util/event.c
> @@ -24,6 +24,7 @@
>  #include "symbol/kallsyms.h"
>  #include "asm/bug.h"
>  #include "stat.h"
> +#include "session.h"
>  
>  #define DEFAULT_PROC_MAP_PARSE_TIMEOUT 500
>  
> @@ -45,6 +46,7 @@ static const char *perf_event__names[] = {
>  	[PERF_RECORD_SWITCH]			= "SWITCH",
>  	[PERF_RECORD_SWITCH_CPU_WIDE]		= "SWITCH_CPU_WIDE",
>  	[PERF_RECORD_NAMESPACES]		= "NAMESPACES",
> +	[PERF_RECORD_KSYMBOL]			= "KSYMBOL",
>  	[PERF_RECORD_HEADER_ATTR]		= "ATTR",
>  	[PERF_RECORD_HEADER_EVENT_TYPE]		= "EVENT_TYPE",
>  	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
> @@ -1329,6 +1331,14 @@ int perf_event__process_switch(struct perf_tool *tool __maybe_unused,
>  	return machine__process_switch_event(machine, event);
>  }
>  
> +int perf_event__process_ksymbol(struct perf_tool *tool __maybe_unused,
> +				union perf_event *event,
> +				struct perf_sample *sample __maybe_unused,
> +				struct machine *machine)
> +{
> +	return machine__process_ksymbol(machine, event, sample);
> +}
> +
>  size_t perf_event__fprintf_mmap(union perf_event *event, FILE *fp)
>  {
>  	return fprintf(fp, " %d/%d: [%#" PRIx64 "(%#" PRIx64 ") @ %#" PRIx64 "]: %c %s\n",
> @@ -1461,6 +1471,14 @@ static size_t perf_event__fprintf_lost(union perf_event *event, FILE *fp)
>  	return fprintf(fp, " lost %" PRIu64 "\n", event->lost.lost);
>  }
>  
> +size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp)
> +{
> +	return fprintf(fp, " ksymbol event with addr %lx len %u type %u flags 0x%x name %s\n",
> +		       event->ksymbol_event.addr, event->ksymbol_event.len,
> +		       event->ksymbol_event.ksym_type,
> +		       event->ksymbol_event.flags, event->ksymbol_event.name);
> +}
> +
>  size_t perf_event__fprintf(union perf_event *event, FILE *fp)
>  {
>  	size_t ret = fprintf(fp, "PERF_RECORD_%s",
> @@ -1496,6 +1514,9 @@ size_t perf_event__fprintf(union perf_event *event, FILE *fp)
>  	case PERF_RECORD_LOST:
>  		ret += perf_event__fprintf_lost(event, fp);
>  		break;
> +	case PERF_RECORD_KSYMBOL:
> +		ret += perf_event__fprintf_ksymbol(event, fp);
> +		break;
>  	default:
>  		ret += fprintf(fp, "\n");
>  	}
> diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
> index eb95f3384958..018322f2a13e 100644
> --- a/tools/perf/util/event.h
> +++ b/tools/perf/util/event.h
> @@ -5,6 +5,7 @@
>  #include <limits.h>
>  #include <stdio.h>
>  #include <linux/kernel.h>
> +#include <linux/bpf.h>
>  
>  #include "../perf.h"
>  #include "build-id.h"
> @@ -84,6 +85,19 @@ struct throttle_event {
>  	u64 stream_id;
>  };
>  
> +#ifndef KSYM_NAME_LEN
> +#define KSYM_NAME_LEN 256
> +#endif
> +
> +struct ksymbol_event {
> +	struct perf_event_header header;
> +	u64 addr;
> +	u32 len;
> +	u16 ksym_type;
> +	u16 flags;
> +	char name[KSYM_NAME_LEN];
> +};
> +
>  #define PERF_SAMPLE_MASK				\
>  	(PERF_SAMPLE_IP | PERF_SAMPLE_TID |		\
>  	 PERF_SAMPLE_TIME | PERF_SAMPLE_ADDR |		\
> @@ -651,6 +665,7 @@ union perf_event {
>  	struct stat_round_event		stat_round;
>  	struct time_conv_event		time_conv;
>  	struct feature_event		feat;
> +	struct ksymbol_event		ksymbol_event;
>  };
>  
>  void perf_event__print_totals(void);
> @@ -748,6 +763,10 @@ int perf_event__process_exit(struct perf_tool *tool,
>  			     union perf_event *event,
>  			     struct perf_sample *sample,
>  			     struct machine *machine);
> +int perf_event__process_ksymbol(struct perf_tool *tool,
> +				union perf_event *event,
> +				struct perf_sample *sample,
> +				struct machine *machine);
>  int perf_tool__process_synth_event(struct perf_tool *tool,
>  				   union perf_event *event,
>  				   struct machine *machine,
> @@ -811,6 +830,7 @@ size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp);
>  size_t perf_event__fprintf_thread_map(union perf_event *event, FILE *fp);
>  size_t perf_event__fprintf_cpu_map(union perf_event *event, FILE *fp);
>  size_t perf_event__fprintf_namespaces(union perf_event *event, FILE *fp);
> +size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp);
>  size_t perf_event__fprintf(union perf_event *event, FILE *fp);
>  
>  int kallsyms__get_function_start(const char *kallsyms_filename,
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index dbc0466db368..de34ce875648 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -1035,6 +1035,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
>  	attr->mmap  = track;
>  	attr->mmap2 = track && !perf_missing_features.mmap2;
>  	attr->comm  = track;
> +	attr->ksymbol = track && !perf_missing_features.ksymbol;
>  
>  	if (opts->record_namespaces)
>  		attr->namespaces  = track;
> @@ -1652,6 +1653,7 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
>  	PRINT_ATTRf(context_switch, p_unsigned);
>  	PRINT_ATTRf(write_backward, p_unsigned);
>  	PRINT_ATTRf(namespaces, p_unsigned);
> +	PRINT_ATTRf(ksymbol, p_unsigned);
>  
>  	PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
>  	PRINT_ATTRf(bp_type, p_unsigned);
> @@ -1811,6 +1813,8 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
>  				     PERF_SAMPLE_BRANCH_NO_CYCLES);
>  	if (perf_missing_features.group_read && evsel->attr.inherit)
>  		evsel->attr.read_format &= ~(PERF_FORMAT_GROUP|PERF_FORMAT_ID);
> +	if (perf_missing_features.ksymbol)
> +		evsel->attr.ksymbol = 0;
>  retry_sample_id:
>  	if (perf_missing_features.sample_id_all)
>  		evsel->attr.sample_id_all = 0;
> @@ -1955,6 +1959,11 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
>  		perf_missing_features.exclude_guest = true;
>  		pr_debug2("switching off exclude_guest, exclude_host\n");
>  		goto fallback_missing_features;
> +	} else if (!perf_missing_features.ksymbol &&
> +		   evsel->attr.ksymbol) {
> +		perf_missing_features.ksymbol = true;
> +		pr_debug2("switching off ksymbol\n");
> +		goto fallback_missing_features;
>  	} else if (!perf_missing_features.sample_id_all) {
>  		perf_missing_features.sample_id_all = true;
>  		pr_debug2("switching off sample_id_all\n");
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 82a289ce8b0c..4a8c3e7f4808 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -168,6 +168,7 @@ struct perf_missing_features {
>  	bool lbr_flags;
>  	bool write_backward;
>  	bool group_read;
> +	bool ksymbol;
>  };
>  
>  extern struct perf_missing_features perf_missing_features;
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 6fcb3bce0442..1734ca027661 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -681,6 +681,61 @@ int machine__process_switch_event(struct machine *machine __maybe_unused,
>  	return 0;
>  }
>  
> +static int machine__process_ksymbol_register(
> +	struct machine *machine,
> +	union perf_event *event,
> +	struct perf_sample *sample __maybe_unused)
> +{
> +	struct symbol *sym;
> +	struct map *map;
> +
> +	map = map_groups__find(&machine->kmaps, event->ksymbol_event.addr);
> +	if (!map) {
> +		map = dso__new_map("bpf_prog");
> +		if (!map)
> +			return -ENOMEM;
> +
> +		map->start = event->ksymbol_event.addr;
> +		map->pgoff = map->start;
> +		map->end = map->start + event->ksymbol_event.len;
> +		map_groups__insert(&machine->kmaps, map);
> +	}
> +
> +	sym = symbol__new(event->ksymbol_event.addr, event->ksymbol_event.len,
> +			  0, 0, event->ksymbol_event.name);
> +	if (!sym)
> +		return -ENOMEM;
> +	dso__insert_symbol(map->dso, sym);
> +	return 0;
> +}
> +
> +static int machine__process_ksymbol_unregister(
> +	struct machine *machine,
> +	union perf_event *event,
> +	struct perf_sample *sample __maybe_unused)
> +{
> +	struct map *map;
> +
> +	map = map_groups__find(&machine->kmaps, event->ksymbol_event.addr);
> +	if (map)
> +		map_groups__remove(&machine->kmaps, map);
> +
> +	return 0;
> +}
> +
> +int machine__process_ksymbol(struct machine *machine __maybe_unused,
> +			     union perf_event *event,
> +			     struct perf_sample *sample)
> +{
> +	if (dump_trace)
> +		perf_event__fprintf_ksymbol(event, stderr);

This should be stdout, otherwise we get garbled output from 'perf report
-D', that is what sets dump_trace to true.

Ditto for the machine__process_bpf_event case, i.e. this patch, each
hunk applied to the respective patch introducing the handling of those
events:

diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
index ee60c8b1e636..b06cd1789f1f 100644
--- a/tools/perf/util/bpf-event.c
+++ b/tools/perf/util/bpf-event.c
@@ -24,7 +24,7 @@ int machine__process_bpf_event(struct machine *machine __maybe_unused,
 			       struct perf_sample *sample __maybe_unused)
 {
 	if (dump_trace)
-		perf_event__fprintf_bpf_event(event, stderr);
+		perf_event__fprintf_bpf_event(event, stdout);
 	return 0;
 }
 
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 292992d7b504..34bd8018e45a 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -729,7 +729,7 @@ int machine__process_ksymbol(struct machine *machine __maybe_unused,
 			     struct perf_sample *sample)
 {
 	if (dump_trace)
-		perf_event__fprintf_ksymbol(event, stderr);
+		perf_event__fprintf_ksymbol(event, stdout);
 
 	if (event->ksymbol_event.flags & PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER)
 		return machine__process_ksymbol_unregister(machine, event,

> +
> +	if (event->ksymbol_event.flags & PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER)
> +		return machine__process_ksymbol_unregister(machine, event,
> +							   sample);
> +	return machine__process_ksymbol_register(machine, event, sample);
> +}
> +
>  static void dso__adjust_kmod_long_name(struct dso *dso, const char *filename)
>  {
>  	const char *dup_filename;
> @@ -1812,6 +1867,8 @@ int machine__process_event(struct machine *machine, union perf_event *event,
>  	case PERF_RECORD_SWITCH:
>  	case PERF_RECORD_SWITCH_CPU_WIDE:
>  		ret = machine__process_switch_event(machine, event); break;
> +	case PERF_RECORD_KSYMBOL:
> +		ret = machine__process_ksymbol(machine, event, sample); break;
>  	default:
>  		ret = -1;
>  		break;
> diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
> index a5d1da60f751..4ecd380ce1b4 100644
> --- a/tools/perf/util/machine.h
> +++ b/tools/perf/util/machine.h
> @@ -130,6 +130,9 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event
>  				struct perf_sample *sample);
>  int machine__process_mmap2_event(struct machine *machine, union perf_event *event,
>  				 struct perf_sample *sample);
> +int machine__process_ksymbol(struct machine *machine,
> +			     union perf_event *event,
> +			     struct perf_sample *sample);
>  int machine__process_event(struct machine *machine, union perf_event *event,
>  				struct perf_sample *sample);
>  
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index 78a067777144..a9c98c3914ed 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -376,6 +376,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
>  		tool->itrace_start = perf_event__process_itrace_start;
>  	if (tool->context_switch == NULL)
>  		tool->context_switch = perf_event__process_switch;
> +	if (tool->ksymbol == NULL)
> +		tool->ksymbol = perf_event__process_ksymbol;
>  	if (tool->read == NULL)
>  		tool->read = process_event_sample_stub;
>  	if (tool->throttle == NULL)
> @@ -1305,6 +1307,8 @@ static int machines__deliver_event(struct machines *machines,
>  	case PERF_RECORD_SWITCH:
>  	case PERF_RECORD_SWITCH_CPU_WIDE:
>  		return tool->context_switch(tool, event, sample, machine);
> +	case PERF_RECORD_KSYMBOL:
> +		return tool->ksymbol(tool, event, sample, machine);
>  	default:
>  		++evlist->stats.nr_unknown_events;
>  		return -1;
> diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
> index 56e4ca54020a..9c81ca2f3cf7 100644
> --- a/tools/perf/util/tool.h
> +++ b/tools/perf/util/tool.h
> @@ -53,7 +53,9 @@ struct perf_tool {
>  			itrace_start,
>  			context_switch,
>  			throttle,
> -			unthrottle;
> +			unthrottle,
> +			ksymbol;
> +
>  	event_attr_op	attr;
>  	event_attr_op	event_update;
>  	event_op2	tracing_data;
> -- 
> 2.17.1
Arnaldo Carvalho de Melo Jan. 15, 2019, 5:56 p.m. | #2
Em Thu, Jan 10, 2019 at 04:19:31PM -0800, Song Liu escreveu:
> This patch handles PERF_RECORD_KSYMBOL in perf record/report.
> Specifically, map and symbol are created for ksymbol register, and
> removed for ksymbol unregister.
> 
> This patch also set perf_event_attr.ksymbol properly. The flag is
> ON by default.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>
> ---
>  tools/perf/util/event.c   | 21 +++++++++++++++
>  tools/perf/util/event.h   | 20 ++++++++++++++
>  tools/perf/util/evsel.c   |  9 +++++++
>  tools/perf/util/evsel.h   |  1 +
>  tools/perf/util/machine.c | 57 +++++++++++++++++++++++++++++++++++++++
>  tools/perf/util/machine.h |  3 +++
>  tools/perf/util/session.c |  4 +++
>  tools/perf/util/tool.h    |  4 ++-
>  8 files changed, 118 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
> index 937a5a4f71cc..3c8a6a8dd260 100644
> --- a/tools/perf/util/event.c
> +++ b/tools/perf/util/event.c
> @@ -24,6 +24,7 @@
>  #include "symbol/kallsyms.h"
>  #include "asm/bug.h"
>  #include "stat.h"
> +#include "session.h"
>  
>  #define DEFAULT_PROC_MAP_PARSE_TIMEOUT 500
>  
> @@ -45,6 +46,7 @@ static const char *perf_event__names[] = {
>  	[PERF_RECORD_SWITCH]			= "SWITCH",
>  	[PERF_RECORD_SWITCH_CPU_WIDE]		= "SWITCH_CPU_WIDE",
>  	[PERF_RECORD_NAMESPACES]		= "NAMESPACES",
> +	[PERF_RECORD_KSYMBOL]			= "KSYMBOL",
>  	[PERF_RECORD_HEADER_ATTR]		= "ATTR",
>  	[PERF_RECORD_HEADER_EVENT_TYPE]		= "EVENT_TYPE",
>  	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
> @@ -1329,6 +1331,14 @@ int perf_event__process_switch(struct perf_tool *tool __maybe_unused,
>  	return machine__process_switch_event(machine, event);
>  }
>  
> +int perf_event__process_ksymbol(struct perf_tool *tool __maybe_unused,
> +				union perf_event *event,
> +				struct perf_sample *sample __maybe_unused,
> +				struct machine *machine)
> +{
> +	return machine__process_ksymbol(machine, event, sample);
> +}
> +
>  size_t perf_event__fprintf_mmap(union perf_event *event, FILE *fp)
>  {
>  	return fprintf(fp, " %d/%d: [%#" PRIx64 "(%#" PRIx64 ") @ %#" PRIx64 "]: %c %s\n",
> @@ -1461,6 +1471,14 @@ static size_t perf_event__fprintf_lost(union perf_event *event, FILE *fp)
>  	return fprintf(fp, " lost %" PRIu64 "\n", event->lost.lost);
>  }
>  
> +size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp)
> +{
> +	return fprintf(fp, " ksymbol event with addr %lx len %u type %u flags 0x%x name %s\n",
> +		       event->ksymbol_event.addr, event->ksymbol_event.len,
> +		       event->ksymbol_event.ksym_type,
> +		       event->ksymbol_event.flags, event->ksymbol_event.name);
> +}
> +
>  size_t perf_event__fprintf(union perf_event *event, FILE *fp)
>  {
>  	size_t ret = fprintf(fp, "PERF_RECORD_%s",
> @@ -1496,6 +1514,9 @@ size_t perf_event__fprintf(union perf_event *event, FILE *fp)
>  	case PERF_RECORD_LOST:
>  		ret += perf_event__fprintf_lost(event, fp);
>  		break;
> +	case PERF_RECORD_KSYMBOL:
> +		ret += perf_event__fprintf_ksymbol(event, fp);
> +		break;
>  	default:
>  		ret += fprintf(fp, "\n");
>  	}
> diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
> index eb95f3384958..018322f2a13e 100644
> --- a/tools/perf/util/event.h
> +++ b/tools/perf/util/event.h
> @@ -5,6 +5,7 @@
>  #include <limits.h>
>  #include <stdio.h>
>  #include <linux/kernel.h>
> +#include <linux/bpf.h>
>  
>  #include "../perf.h"
>  #include "build-id.h"
> @@ -84,6 +85,19 @@ struct throttle_event {
>  	u64 stream_id;
>  };
>  
> +#ifndef KSYM_NAME_LEN
> +#define KSYM_NAME_LEN 256
> +#endif
> +
> +struct ksymbol_event {
> +	struct perf_event_header header;
> +	u64 addr;
> +	u32 len;
> +	u16 ksym_type;
> +	u16 flags;
> +	char name[KSYM_NAME_LEN];
> +};
> +
>  #define PERF_SAMPLE_MASK				\
>  	(PERF_SAMPLE_IP | PERF_SAMPLE_TID |		\
>  	 PERF_SAMPLE_TIME | PERF_SAMPLE_ADDR |		\
> @@ -651,6 +665,7 @@ union perf_event {
>  	struct stat_round_event		stat_round;
>  	struct time_conv_event		time_conv;
>  	struct feature_event		feat;
> +	struct ksymbol_event		ksymbol_event;
>  };
>  
>  void perf_event__print_totals(void);
> @@ -748,6 +763,10 @@ int perf_event__process_exit(struct perf_tool *tool,
>  			     union perf_event *event,
>  			     struct perf_sample *sample,
>  			     struct machine *machine);
> +int perf_event__process_ksymbol(struct perf_tool *tool,
> +				union perf_event *event,
> +				struct perf_sample *sample,
> +				struct machine *machine);
>  int perf_tool__process_synth_event(struct perf_tool *tool,
>  				   union perf_event *event,
>  				   struct machine *machine,
> @@ -811,6 +830,7 @@ size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp);
>  size_t perf_event__fprintf_thread_map(union perf_event *event, FILE *fp);
>  size_t perf_event__fprintf_cpu_map(union perf_event *event, FILE *fp);
>  size_t perf_event__fprintf_namespaces(union perf_event *event, FILE *fp);
> +size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp);
>  size_t perf_event__fprintf(union perf_event *event, FILE *fp);
>  
>  int kallsyms__get_function_start(const char *kallsyms_filename,
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index dbc0466db368..de34ce875648 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -1035,6 +1035,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
>  	attr->mmap  = track;
>  	attr->mmap2 = track && !perf_missing_features.mmap2;
>  	attr->comm  = track;
> +	attr->ksymbol = track && !perf_missing_features.ksymbol;
>  
>  	if (opts->record_namespaces)
>  		attr->namespaces  = track;
> @@ -1652,6 +1653,7 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
>  	PRINT_ATTRf(context_switch, p_unsigned);
>  	PRINT_ATTRf(write_backward, p_unsigned);
>  	PRINT_ATTRf(namespaces, p_unsigned);
> +	PRINT_ATTRf(ksymbol, p_unsigned);
>  
>  	PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
>  	PRINT_ATTRf(bp_type, p_unsigned);
> @@ -1811,6 +1813,8 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
>  				     PERF_SAMPLE_BRANCH_NO_CYCLES);
>  	if (perf_missing_features.group_read && evsel->attr.inherit)
>  		evsel->attr.read_format &= ~(PERF_FORMAT_GROUP|PERF_FORMAT_ID);
> +	if (perf_missing_features.ksymbol)
> +		evsel->attr.ksymbol = 0;
>  retry_sample_id:
>  	if (perf_missing_features.sample_id_all)
>  		evsel->attr.sample_id_all = 0;
> @@ -1955,6 +1959,11 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
>  		perf_missing_features.exclude_guest = true;
>  		pr_debug2("switching off exclude_guest, exclude_host\n");
>  		goto fallback_missing_features;
> +	} else if (!perf_missing_features.ksymbol &&
> +		   evsel->attr.ksymbol) {
> +		perf_missing_features.ksymbol = true;
> +		pr_debug2("switching off ksymbol\n");
> +		goto fallback_missing_features;


Please move this to the top, see the comment there:

	if (err != -EINVAL || cpu > 0 || thread > 0)
		goto out_close;

	/*
	 * Must probe features in the order they were added to the
	 * perf_event_attr interface.
	 */
	if (!perf_missing_features.write_backward && evsel->attr.write_backward) {
		perf_missing_features.write_backward = true;
		pr_debug2("switching off write_backward\n");
		goto out_close;
	} else if (!perf_missing_features.clockid_wrong && evsel->attr.use_clockid) {
		perf_missing_features.clockid_wrong = true;
		pr_debug2("switching off clockid\n");
		goto fallback_missing_features;


So that when one asks for, say, attr.write_backward _and_ attr.ksymbol,
we first disable attr.ksymbol, to try the fallback, as it was added
after attr.write_backward.

Think about an older kernel where attr.write_backward is present but not
attr.ksymbol.

Ditto for the attr.bpf_event.

>  	} else if (!perf_missing_features.sample_id_all) {
>  		perf_missing_features.sample_id_all = true;
>  		pr_debug2("switching off sample_id_all\n");
> diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
> index 82a289ce8b0c..4a8c3e7f4808 100644
> --- a/tools/perf/util/evsel.h
> +++ b/tools/perf/util/evsel.h
> @@ -168,6 +168,7 @@ struct perf_missing_features {
>  	bool lbr_flags;
>  	bool write_backward;
>  	bool group_read;
> +	bool ksymbol;
>  };
>  
>  extern struct perf_missing_features perf_missing_features;
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 6fcb3bce0442..1734ca027661 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -681,6 +681,61 @@ int machine__process_switch_event(struct machine *machine __maybe_unused,
>  	return 0;
>  }
>  
> +static int machine__process_ksymbol_register(
> +	struct machine *machine,
> +	union perf_event *event,
> +	struct perf_sample *sample __maybe_unused)
> +{
> +	struct symbol *sym;
> +	struct map *map;
> +
> +	map = map_groups__find(&machine->kmaps, event->ksymbol_event.addr);
> +	if (!map) {
> +		map = dso__new_map("bpf_prog");
> +		if (!map)
> +			return -ENOMEM;
> +
> +		map->start = event->ksymbol_event.addr;
> +		map->pgoff = map->start;
> +		map->end = map->start + event->ksymbol_event.len;
> +		map_groups__insert(&machine->kmaps, map);
> +	}
> +
> +	sym = symbol__new(event->ksymbol_event.addr, event->ksymbol_event.len,
> +			  0, 0, event->ksymbol_event.name);
> +	if (!sym)
> +		return -ENOMEM;
> +	dso__insert_symbol(map->dso, sym);
> +	return 0;
> +}
> +
> +static int machine__process_ksymbol_unregister(
> +	struct machine *machine,
> +	union perf_event *event,
> +	struct perf_sample *sample __maybe_unused)
> +{
> +	struct map *map;
> +
> +	map = map_groups__find(&machine->kmaps, event->ksymbol_event.addr);
> +	if (map)
> +		map_groups__remove(&machine->kmaps, map);
> +
> +	return 0;
> +}
> +
> +int machine__process_ksymbol(struct machine *machine __maybe_unused,
> +			     union perf_event *event,
> +			     struct perf_sample *sample)
> +{
> +	if (dump_trace)
> +		perf_event__fprintf_ksymbol(event, stderr);
> +
> +	if (event->ksymbol_event.flags & PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER)
> +		return machine__process_ksymbol_unregister(machine, event,
> +							   sample);
> +	return machine__process_ksymbol_register(machine, event, sample);
> +}
> +
>  static void dso__adjust_kmod_long_name(struct dso *dso, const char *filename)
>  {
>  	const char *dup_filename;
> @@ -1812,6 +1867,8 @@ int machine__process_event(struct machine *machine, union perf_event *event,
>  	case PERF_RECORD_SWITCH:
>  	case PERF_RECORD_SWITCH_CPU_WIDE:
>  		ret = machine__process_switch_event(machine, event); break;
> +	case PERF_RECORD_KSYMBOL:
> +		ret = machine__process_ksymbol(machine, event, sample); break;
>  	default:
>  		ret = -1;
>  		break;
> diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
> index a5d1da60f751..4ecd380ce1b4 100644
> --- a/tools/perf/util/machine.h
> +++ b/tools/perf/util/machine.h
> @@ -130,6 +130,9 @@ int machine__process_mmap_event(struct machine *machine, union perf_event *event
>  				struct perf_sample *sample);
>  int machine__process_mmap2_event(struct machine *machine, union perf_event *event,
>  				 struct perf_sample *sample);
> +int machine__process_ksymbol(struct machine *machine,
> +			     union perf_event *event,
> +			     struct perf_sample *sample);
>  int machine__process_event(struct machine *machine, union perf_event *event,
>  				struct perf_sample *sample);
>  
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index 78a067777144..a9c98c3914ed 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -376,6 +376,8 @@ void perf_tool__fill_defaults(struct perf_tool *tool)
>  		tool->itrace_start = perf_event__process_itrace_start;
>  	if (tool->context_switch == NULL)
>  		tool->context_switch = perf_event__process_switch;
> +	if (tool->ksymbol == NULL)
> +		tool->ksymbol = perf_event__process_ksymbol;
>  	if (tool->read == NULL)
>  		tool->read = process_event_sample_stub;
>  	if (tool->throttle == NULL)
> @@ -1305,6 +1307,8 @@ static int machines__deliver_event(struct machines *machines,
>  	case PERF_RECORD_SWITCH:
>  	case PERF_RECORD_SWITCH_CPU_WIDE:
>  		return tool->context_switch(tool, event, sample, machine);
> +	case PERF_RECORD_KSYMBOL:
> +		return tool->ksymbol(tool, event, sample, machine);
>  	default:
>  		++evlist->stats.nr_unknown_events;
>  		return -1;
> diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
> index 56e4ca54020a..9c81ca2f3cf7 100644
> --- a/tools/perf/util/tool.h
> +++ b/tools/perf/util/tool.h
> @@ -53,7 +53,9 @@ struct perf_tool {
>  			itrace_start,
>  			context_switch,
>  			throttle,
> -			unthrottle;
> +			unthrottle,
> +			ksymbol;
> +
>  	event_attr_op	attr;
>  	event_attr_op	event_update;
>  	event_op2	tracing_data;
> -- 
> 2.17.1
Song Liu Jan. 15, 2019, 7:58 p.m. | #3
> On Jan 15, 2019, at 9:56 AM, Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> 
> Em Thu, Jan 10, 2019 at 04:19:31PM -0800, Song Liu escreveu:
>> This patch handles PERF_RECORD_KSYMBOL in perf record/report.
>> Specifically, map and symbol are created for ksymbol register, and
>> removed for ksymbol unregister.
>> 
>> This patch also set perf_event_attr.ksymbol properly. The flag is
>> ON by default.
>> 
>> Signed-off-by: Song Liu <songliubraving@fb.com>
>> ---
>> tools/perf/util/event.c   | 21 +++++++++++++++
>> tools/perf/util/event.h   | 20 ++++++++++++++
>> tools/perf/util/evsel.c   |  9 +++++++
>> tools/perf/util/evsel.h   |  1 +
>> tools/perf/util/machine.c | 57 +++++++++++++++++++++++++++++++++++++++
>> tools/perf/util/machine.h |  3 +++
>> tools/perf/util/session.c |  4 +++
>> tools/perf/util/tool.h    |  4 ++-
>> 8 files changed, 118 insertions(+), 1 deletion(-)
>> 
>> diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
>> index 937a5a4f71cc..3c8a6a8dd260 100644
>> --- a/tools/perf/util/event.c
>> +++ b/tools/perf/util/event.c
>> @@ -24,6 +24,7 @@
>> #include "symbol/kallsyms.h"
>> #include "asm/bug.h"
>> #include "stat.h"
>> +#include "session.h"
>> 
>> #define DEFAULT_PROC_MAP_PARSE_TIMEOUT 500
>> 
>> @@ -45,6 +46,7 @@ static const char *perf_event__names[] = {
>> 	[PERF_RECORD_SWITCH]			= "SWITCH",
>> 	[PERF_RECORD_SWITCH_CPU_WIDE]		= "SWITCH_CPU_WIDE",
>> 	[PERF_RECORD_NAMESPACES]		= "NAMESPACES",
>> +	[PERF_RECORD_KSYMBOL]			= "KSYMBOL",
>> 	[PERF_RECORD_HEADER_ATTR]		= "ATTR",
>> 	[PERF_RECORD_HEADER_EVENT_TYPE]		= "EVENT_TYPE",
>> 	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
>> @@ -1329,6 +1331,14 @@ int perf_event__process_switch(struct perf_tool *tool __maybe_unused,
>> 	return machine__process_switch_event(machine, event);
>> }
>> 
>> +int perf_event__process_ksymbol(struct perf_tool *tool __maybe_unused,
>> +				union perf_event *event,
>> +				struct perf_sample *sample __maybe_unused,
>> +				struct machine *machine)
>> +{
>> +	return machine__process_ksymbol(machine, event, sample);
>> +}
>> +
>> size_t perf_event__fprintf_mmap(union perf_event *event, FILE *fp)
>> {
>> 	return fprintf(fp, " %d/%d: [%#" PRIx64 "(%#" PRIx64 ") @ %#" PRIx64 "]: %c %s\n",
>> @@ -1461,6 +1471,14 @@ static size_t perf_event__fprintf_lost(union perf_event *event, FILE *fp)
>> 	return fprintf(fp, " lost %" PRIu64 "\n", event->lost.lost);
>> }
>> 
>> +size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp)
>> +{
>> +	return fprintf(fp, " ksymbol event with addr %lx len %u type %u flags 0x%x name %s\n",
>> +		       event->ksymbol_event.addr, event->ksymbol_event.len,
>> +		       event->ksymbol_event.ksym_type,
>> +		       event->ksymbol_event.flags, event->ksymbol_event.name);
>> +}
>> +
>> size_t perf_event__fprintf(union perf_event *event, FILE *fp)
>> {
>> 	size_t ret = fprintf(fp, "PERF_RECORD_%s",
>> @@ -1496,6 +1514,9 @@ size_t perf_event__fprintf(union perf_event *event, FILE *fp)
>> 	case PERF_RECORD_LOST:
>> 		ret += perf_event__fprintf_lost(event, fp);
>> 		break;
>> +	case PERF_RECORD_KSYMBOL:
>> +		ret += perf_event__fprintf_ksymbol(event, fp);
>> +		break;
>> 	default:
>> 		ret += fprintf(fp, "\n");
>> 	}
>> diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
>> index eb95f3384958..018322f2a13e 100644
>> --- a/tools/perf/util/event.h
>> +++ b/tools/perf/util/event.h
>> @@ -5,6 +5,7 @@
>> #include <limits.h>
>> #include <stdio.h>
>> #include <linux/kernel.h>
>> +#include <linux/bpf.h>
>> 
>> #include "../perf.h"
>> #include "build-id.h"
>> @@ -84,6 +85,19 @@ struct throttle_event {
>> 	u64 stream_id;
>> };
>> 
>> +#ifndef KSYM_NAME_LEN
>> +#define KSYM_NAME_LEN 256
>> +#endif
>> +
>> +struct ksymbol_event {
>> +	struct perf_event_header header;
>> +	u64 addr;
>> +	u32 len;
>> +	u16 ksym_type;
>> +	u16 flags;
>> +	char name[KSYM_NAME_LEN];
>> +};
>> +
>> #define PERF_SAMPLE_MASK				\
>> 	(PERF_SAMPLE_IP | PERF_SAMPLE_TID |		\
>> 	 PERF_SAMPLE_TIME | PERF_SAMPLE_ADDR |		\
>> @@ -651,6 +665,7 @@ union perf_event {
>> 	struct stat_round_event		stat_round;
>> 	struct time_conv_event		time_conv;
>> 	struct feature_event		feat;
>> +	struct ksymbol_event		ksymbol_event;
>> };
>> 
>> void perf_event__print_totals(void);
>> @@ -748,6 +763,10 @@ int perf_event__process_exit(struct perf_tool *tool,
>> 			     union perf_event *event,
>> 			     struct perf_sample *sample,
>> 			     struct machine *machine);
>> +int perf_event__process_ksymbol(struct perf_tool *tool,
>> +				union perf_event *event,
>> +				struct perf_sample *sample,
>> +				struct machine *machine);
>> int perf_tool__process_synth_event(struct perf_tool *tool,
>> 				   union perf_event *event,
>> 				   struct machine *machine,
>> @@ -811,6 +830,7 @@ size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp);
>> size_t perf_event__fprintf_thread_map(union perf_event *event, FILE *fp);
>> size_t perf_event__fprintf_cpu_map(union perf_event *event, FILE *fp);
>> size_t perf_event__fprintf_namespaces(union perf_event *event, FILE *fp);
>> +size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp);
>> size_t perf_event__fprintf(union perf_event *event, FILE *fp);
>> 
>> int kallsyms__get_function_start(const char *kallsyms_filename,
>> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
>> index dbc0466db368..de34ce875648 100644
>> --- a/tools/perf/util/evsel.c
>> +++ b/tools/perf/util/evsel.c
>> @@ -1035,6 +1035,7 @@ void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
>> 	attr->mmap  = track;
>> 	attr->mmap2 = track && !perf_missing_features.mmap2;
>> 	attr->comm  = track;
>> +	attr->ksymbol = track && !perf_missing_features.ksymbol;
>> 
>> 	if (opts->record_namespaces)
>> 		attr->namespaces  = track;
>> @@ -1652,6 +1653,7 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
>> 	PRINT_ATTRf(context_switch, p_unsigned);
>> 	PRINT_ATTRf(write_backward, p_unsigned);
>> 	PRINT_ATTRf(namespaces, p_unsigned);
>> +	PRINT_ATTRf(ksymbol, p_unsigned);
>> 
>> 	PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
>> 	PRINT_ATTRf(bp_type, p_unsigned);
>> @@ -1811,6 +1813,8 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
>> 				     PERF_SAMPLE_BRANCH_NO_CYCLES);
>> 	if (perf_missing_features.group_read && evsel->attr.inherit)
>> 		evsel->attr.read_format &= ~(PERF_FORMAT_GROUP|PERF_FORMAT_ID);
>> +	if (perf_missing_features.ksymbol)
>> +		evsel->attr.ksymbol = 0;
>> retry_sample_id:
>> 	if (perf_missing_features.sample_id_all)
>> 		evsel->attr.sample_id_all = 0;
>> @@ -1955,6 +1959,11 @@ int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
>> 		perf_missing_features.exclude_guest = true;
>> 		pr_debug2("switching off exclude_guest, exclude_host\n");
>> 		goto fallback_missing_features;
>> +	} else if (!perf_missing_features.ksymbol &&
>> +		   evsel->attr.ksymbol) {
>> +		perf_missing_features.ksymbol = true;
>> +		pr_debug2("switching off ksymbol\n");
>> +		goto fallback_missing_features;
> 
> 
> Please move this to the top, see the comment there:
> 
> 	if (err != -EINVAL || cpu > 0 || thread > 0)
> 		goto out_close;
> 
> 	/*
> 	 * Must probe features in the order they were added to the
> 	 * perf_event_attr interface.
> 	 */
> 	if (!perf_missing_features.write_backward && evsel->attr.write_backward) {
> 		perf_missing_features.write_backward = true;
> 		pr_debug2("switching off write_backward\n");
> 		goto out_close;
> 	} else if (!perf_missing_features.clockid_wrong && evsel->attr.use_clockid) {
> 		perf_missing_features.clockid_wrong = true;
> 		pr_debug2("switching off clockid\n");
> 		goto fallback_missing_features;
> 
> 
> So that when one asks for, say, attr.write_backward _and_ attr.ksymbol,
> we first disable attr.ksymbol, to try the fallback, as it was added
> after attr.write_backward.
> 
> Think about an older kernel where attr.write_backward is present but not
> attr.ksymbol.
> 
> Ditto for the attr.bpf_event.
> 

Thanks Arnaldo!

I will include the fix in next version.

Song

Patch

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 937a5a4f71cc..3c8a6a8dd260 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -24,6 +24,7 @@ 
 #include "symbol/kallsyms.h"
 #include "asm/bug.h"
 #include "stat.h"
+#include "session.h"
 
 #define DEFAULT_PROC_MAP_PARSE_TIMEOUT 500
 
@@ -45,6 +46,7 @@  static const char *perf_event__names[] = {
 	[PERF_RECORD_SWITCH]			= "SWITCH",
 	[PERF_RECORD_SWITCH_CPU_WIDE]		= "SWITCH_CPU_WIDE",
 	[PERF_RECORD_NAMESPACES]		= "NAMESPACES",
+	[PERF_RECORD_KSYMBOL]			= "KSYMBOL",
 	[PERF_RECORD_HEADER_ATTR]		= "ATTR",
 	[PERF_RECORD_HEADER_EVENT_TYPE]		= "EVENT_TYPE",
 	[PERF_RECORD_HEADER_TRACING_DATA]	= "TRACING_DATA",
@@ -1329,6 +1331,14 @@  int perf_event__process_switch(struct perf_tool *tool __maybe_unused,
 	return machine__process_switch_event(machine, event);
 }
 
+int perf_event__process_ksymbol(struct perf_tool *tool __maybe_unused,
+				union perf_event *event,
+				struct perf_sample *sample __maybe_unused,
+				struct machine *machine)
+{
+	return machine__process_ksymbol(machine, event, sample);
+}
+
 size_t perf_event__fprintf_mmap(union perf_event *event, FILE *fp)
 {
 	return fprintf(fp, " %d/%d: [%#" PRIx64 "(%#" PRIx64 ") @ %#" PRIx64 "]: %c %s\n",
@@ -1461,6 +1471,14 @@  static size_t perf_event__fprintf_lost(union perf_event *event, FILE *fp)
 	return fprintf(fp, " lost %" PRIu64 "\n", event->lost.lost);
 }
 
+size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp)
+{
+	return fprintf(fp, " ksymbol event with addr %lx len %u type %u flags 0x%x name %s\n",
+		       event->ksymbol_event.addr, event->ksymbol_event.len,
+		       event->ksymbol_event.ksym_type,
+		       event->ksymbol_event.flags, event->ksymbol_event.name);
+}
+
 size_t perf_event__fprintf(union perf_event *event, FILE *fp)
 {
 	size_t ret = fprintf(fp, "PERF_RECORD_%s",
@@ -1496,6 +1514,9 @@  size_t perf_event__fprintf(union perf_event *event, FILE *fp)
 	case PERF_RECORD_LOST:
 		ret += perf_event__fprintf_lost(event, fp);
 		break;
+	case PERF_RECORD_KSYMBOL:
+		ret += perf_event__fprintf_ksymbol(event, fp);
+		break;
 	default:
 		ret += fprintf(fp, "\n");
 	}
diff --git a/tools/perf/util/event.h b/tools/perf/util/event.h
index eb95f3384958..018322f2a13e 100644
--- a/tools/perf/util/event.h
+++ b/tools/perf/util/event.h
@@ -5,6 +5,7 @@ 
 #include <limits.h>
 #include <stdio.h>
 #include <linux/kernel.h>
+#include <linux/bpf.h>
 
 #include "../perf.h"
 #include "build-id.h"
@@ -84,6 +85,19 @@  struct throttle_event {
 	u64 stream_id;
 };
 
+#ifndef KSYM_NAME_LEN
+#define KSYM_NAME_LEN 256
+#endif
+
+struct ksymbol_event {
+	struct perf_event_header header;
+	u64 addr;
+	u32 len;
+	u16 ksym_type;
+	u16 flags;
+	char name[KSYM_NAME_LEN];
+};
+
 #define PERF_SAMPLE_MASK				\
 	(PERF_SAMPLE_IP | PERF_SAMPLE_TID |		\
 	 PERF_SAMPLE_TIME | PERF_SAMPLE_ADDR |		\
@@ -651,6 +665,7 @@  union perf_event {
 	struct stat_round_event		stat_round;
 	struct time_conv_event		time_conv;
 	struct feature_event		feat;
+	struct ksymbol_event		ksymbol_event;
 };
 
 void perf_event__print_totals(void);
@@ -748,6 +763,10 @@  int perf_event__process_exit(struct perf_tool *tool,
 			     union perf_event *event,
 			     struct perf_sample *sample,
 			     struct machine *machine);
+int perf_event__process_ksymbol(struct perf_tool *tool,
+				union perf_event *event,
+				struct perf_sample *sample,
+				struct machine *machine);
 int perf_tool__process_synth_event(struct perf_tool *tool,
 				   union perf_event *event,
 				   struct machine *machine,
@@ -811,6 +830,7 @@  size_t perf_event__fprintf_switch(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_thread_map(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_cpu_map(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf_namespaces(union perf_event *event, FILE *fp);
+size_t perf_event__fprintf_ksymbol(union perf_event *event, FILE *fp);
 size_t perf_event__fprintf(union perf_event *event, FILE *fp);
 
 int kallsyms__get_function_start(const char *kallsyms_filename,
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index dbc0466db368..de34ce875648 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -1035,6 +1035,7 @@  void perf_evsel__config(struct perf_evsel *evsel, struct record_opts *opts,
 	attr->mmap  = track;
 	attr->mmap2 = track && !perf_missing_features.mmap2;
 	attr->comm  = track;
+	attr->ksymbol = track && !perf_missing_features.ksymbol;
 
 	if (opts->record_namespaces)
 		attr->namespaces  = track;
@@ -1652,6 +1653,7 @@  int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
 	PRINT_ATTRf(context_switch, p_unsigned);
 	PRINT_ATTRf(write_backward, p_unsigned);
 	PRINT_ATTRf(namespaces, p_unsigned);
+	PRINT_ATTRf(ksymbol, p_unsigned);
 
 	PRINT_ATTRn("{ wakeup_events, wakeup_watermark }", wakeup_events, p_unsigned);
 	PRINT_ATTRf(bp_type, p_unsigned);
@@ -1811,6 +1813,8 @@  int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
 				     PERF_SAMPLE_BRANCH_NO_CYCLES);
 	if (perf_missing_features.group_read && evsel->attr.inherit)
 		evsel->attr.read_format &= ~(PERF_FORMAT_GROUP|PERF_FORMAT_ID);
+	if (perf_missing_features.ksymbol)
+		evsel->attr.ksymbol = 0;
 retry_sample_id:
 	if (perf_missing_features.sample_id_all)
 		evsel->attr.sample_id_all = 0;
@@ -1955,6 +1959,11 @@  int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
 		perf_missing_features.exclude_guest = true;
 		pr_debug2("switching off exclude_guest, exclude_host\n");
 		goto fallback_missing_features;
+	} else if (!perf_missing_features.ksymbol &&
+		   evsel->attr.ksymbol) {
+		perf_missing_features.ksymbol = true;
+		pr_debug2("switching off ksymbol\n");
+		goto fallback_missing_features;
 	} else if (!perf_missing_features.sample_id_all) {
 		perf_missing_features.sample_id_all = true;
 		pr_debug2("switching off sample_id_all\n");
diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h
index 82a289ce8b0c..4a8c3e7f4808 100644
--- a/tools/perf/util/evsel.h
+++ b/tools/perf/util/evsel.h
@@ -168,6 +168,7 @@  struct perf_missing_features {
 	bool lbr_flags;
 	bool write_backward;
 	bool group_read;
+	bool ksymbol;
 };
 
 extern struct perf_missing_features perf_missing_features;
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 6fcb3bce0442..1734ca027661 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -681,6 +681,61 @@  int machine__process_switch_event(struct machine *machine __maybe_unused,
 	return 0;
 }
 
+static int machine__process_ksymbol_register(
+	struct machine *machine,
+	union perf_event *event,
+	struct perf_sample *sample __maybe_unused)
+{
+	struct symbol *sym;
+	struct map *map;
+
+	map = map_groups__find(&machine->kmaps, event->ksymbol_event.addr);
+	if (!map) {
+		map = dso__new_map("bpf_prog");
+		if (!map)
+			return -ENOMEM;
+
+		map->start = event->ksymbol_event.addr;
+		map->pgoff = map->start;
+		map->end = map->start + event->ksymbol_event.len;
+		map_groups__insert(&machine->kmaps, map);
+	}
+
+	sym = symbol__new(event->ksymbol_event.addr, event->ksymbol_event.len,
+			  0, 0, event->ksymbol_event.name);
+	if (!sym)
+		return -ENOMEM;
+	dso__insert_symbol(map->dso, sym);
+	return 0;
+}
+
+static int machine__process_ksymbol_unregister(
+	struct machine *machine,
+	union perf_event *event,
+	struct perf_sample *sample __maybe_unused)
+{
+	struct map *map;
+
+	map = map_groups__find(&machine->kmaps, event->ksymbol_event.addr);
+	if (map)
+		map_groups__remove(&machine->kmaps, map);
+
+	return 0;
+}
+
+int machine__process_ksymbol(struct machine *machine __maybe_unused,
+			     union perf_event *event,
+			     struct perf_sample *sample)
+{
+	if (dump_trace)
+		perf_event__fprintf_ksymbol(event, stderr);
+
+	if (event->ksymbol_event.flags & PERF_RECORD_KSYMBOL_FLAGS_UNREGISTER)
+		return machine__process_ksymbol_unregister(machine, event,
+							   sample);
+	return machine__process_ksymbol_register(machine, event, sample);
+}
+
 static void dso__adjust_kmod_long_name(struct dso *dso, const char *filename)
 {
 	const char *dup_filename;
@@ -1812,6 +1867,8 @@  int machine__process_event(struct machine *machine, union perf_event *event,
 	case PERF_RECORD_SWITCH:
 	case PERF_RECORD_SWITCH_CPU_WIDE:
 		ret = machine__process_switch_event(machine, event); break;
+	case PERF_RECORD_KSYMBOL:
+		ret = machine__process_ksymbol(machine, event, sample); break;
 	default:
 		ret = -1;
 		break;
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index a5d1da60f751..4ecd380ce1b4 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -130,6 +130,9 @@  int machine__process_mmap_event(struct machine *machine, union perf_event *event
 				struct perf_sample *sample);
 int machine__process_mmap2_event(struct machine *machine, union perf_event *event,
 				 struct perf_sample *sample);
+int machine__process_ksymbol(struct machine *machine,
+			     union perf_event *event,
+			     struct perf_sample *sample);
 int machine__process_event(struct machine *machine, union perf_event *event,
 				struct perf_sample *sample);
 
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 78a067777144..a9c98c3914ed 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -376,6 +376,8 @@  void perf_tool__fill_defaults(struct perf_tool *tool)
 		tool->itrace_start = perf_event__process_itrace_start;
 	if (tool->context_switch == NULL)
 		tool->context_switch = perf_event__process_switch;
+	if (tool->ksymbol == NULL)
+		tool->ksymbol = perf_event__process_ksymbol;
 	if (tool->read == NULL)
 		tool->read = process_event_sample_stub;
 	if (tool->throttle == NULL)
@@ -1305,6 +1307,8 @@  static int machines__deliver_event(struct machines *machines,
 	case PERF_RECORD_SWITCH:
 	case PERF_RECORD_SWITCH_CPU_WIDE:
 		return tool->context_switch(tool, event, sample, machine);
+	case PERF_RECORD_KSYMBOL:
+		return tool->ksymbol(tool, event, sample, machine);
 	default:
 		++evlist->stats.nr_unknown_events;
 		return -1;
diff --git a/tools/perf/util/tool.h b/tools/perf/util/tool.h
index 56e4ca54020a..9c81ca2f3cf7 100644
--- a/tools/perf/util/tool.h
+++ b/tools/perf/util/tool.h
@@ -53,7 +53,9 @@  struct perf_tool {
 			itrace_start,
 			context_switch,
 			throttle,
-			unthrottle;
+			unthrottle,
+			ksymbol;
+
 	event_attr_op	attr;
 	event_attr_op	event_update;
 	event_op2	tracing_data;