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

From: Arnaldo Carvalho de Melo
Date: Tue Jan 15 2019 - 14:12:31 EST

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In reply to: Arnaldo Carvalho de Melo: "Re: [PATCH v7 perf, bpf-next 6/8] perf util: handle PERF_RECORD_KSYMBOL"
Next in thread: Song Liu: "Re: [PATCH v7 perf, bpf-next 6/8] perf util: handle PERF_RECORD_KSYMBOL"
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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@xxxxxx>
> ---
> 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

--

- Arnaldo

Next message: Koenig, Christian: "Re: [PATCH] lib/scatterlist: Provide a DMA page iterator"
Previous message: Laura Abbott: "Re: [PATCH 14/14] staging: android: ion: Add UNMAPPED heap type and helper"
In reply to: Arnaldo Carvalho de Melo: "Re: [PATCH v7 perf, bpf-next 6/8] perf util: handle PERF_RECORD_KSYMBOL"
Next in thread: Song Liu: "Re: [PATCH v7 perf, bpf-next 6/8] perf util: handle PERF_RECORD_KSYMBOL"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]