Commit ae39ba16 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf inject: Fix build ID injection 



Build ID injection wasn't inserting a sample ID and aligning events to
64 bytes rather than 8. No sample ID means events are unordered and two
different build_id events for the same path, as happens when a file is
replaced, can't be differentiated.

Add in sample ID insertion for the build_id events alongside some
refactoring. The refactoring better aligns the function arguments for
different use cases, such as synthesizing build_id events without
needing to have a dso. The misc bits are explicitly passed as with
callchains the maps/dsos may span user and kernel land, so using
sample->cpumode isn't good enough.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Anne Macedo <retpolanne@posteo.net>
Cc: Casey Chen <cachen@purestorage.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sun Haiyong <sunhaiyong@loongson.cn>
Link: https://lore.kernel.org/r/20240909203740.143492-2-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 02648783

tools/perf/builtin-inject.c

+131 −39
Original line number Diff line number Diff line
@@ -130,6 +130,7 @@ struct perf_inject { 
	struct perf_file_section secs[HEADER_FEAT_BITS];

	struct guest_session	guest_session;

	struct strlist		*known_build_ids;

	const struct evsel	*mmap_evsel;

};



struct event_entry {
@@ -138,8 +139,13 @@ struct event_entry { 
	union perf_event event[];

};



static int dso__inject_build_id(struct dso *dso, const struct perf_tool *tool,

				struct machine *machine, u8 cpumode, u32 flags);

static int tool__inject_build_id(const struct perf_tool *tool,

				 struct perf_sample *sample,

				 struct machine *machine,

				 const struct evsel *evsel,

				 __u16 misc,

				 const char *filename,

				 struct dso *dso, u32 flags);



static int output_bytes(struct perf_inject *inject, void *buf, size_t sz)

{
@@ -422,6 +428,28 @@ static struct dso *findnew_dso(int pid, int tid, const char *filename, 
	return dso;

}



/*

 * The evsel used for the sample ID for mmap events. Typically stashed when

 * processing mmap events. If not stashed, search the evlist for the first mmap

 * gathering event.

 */

static const struct evsel *inject__mmap_evsel(struct perf_inject *inject)

{

	struct evsel *pos;



	if (inject->mmap_evsel)

		return inject->mmap_evsel;



	evlist__for_each_entry(inject->session->evlist, pos) {

		if (pos->core.attr.mmap) {

			inject->mmap_evsel = pos;

			return pos;

		}

	}

	pr_err("No mmap events found\n");

	return NULL;

}



static int perf_event__repipe_common_mmap(const struct perf_tool *tool,

					  union perf_event *event,

					  struct perf_sample *sample,
@@ -469,12 +497,28 @@ static int perf_event__repipe_common_mmap(const struct perf_tool *tool, 
		}



		if (dso && !dso__hit(dso)) {

			struct evsel *evsel = evlist__event2evsel(inject->session->evlist, event);



			if (evsel) {

				dso__set_hit(dso);

			dso__inject_build_id(dso, tool, machine, sample->cpumode, flags);

				tool__inject_build_id(tool, sample, machine, evsel,

						      /*misc=*/sample->cpumode,

						      filename, dso, flags);

			}

		}

	} else {

		int err;



		/*

		 * Remember the evsel for lazy build id generation. It is used

		 * for the sample id header type.

		 */

		if (inject->build_id_style == BID_RWS__INJECT_HEADER_LAZY &&

		    !inject->mmap_evsel)

			inject->mmap_evsel = evlist__event2evsel(inject->session->evlist, event);



		/* Create the thread, map, etc. Not done for the unordered inject all case. */

		int err = perf_event_process(tool, event, sample, machine);

		err = perf_event_process(tool, event, sample, machine);



		if (err) {

			dso__put(dso);
@@ -667,16 +711,20 @@ static bool perf_inject__lookup_known_build_id(struct perf_inject *inject, 
	return false;

}



static int dso__inject_build_id(struct dso *dso, const struct perf_tool *tool,

				struct machine *machine, u8 cpumode, u32 flags)

static int tool__inject_build_id(const struct perf_tool *tool,

				 struct perf_sample *sample,

				 struct machine *machine,

				 const struct evsel *evsel,

				 __u16 misc,

				 const char *filename,

				 struct dso *dso, u32 flags)

{

	struct perf_inject *inject = container_of(tool, struct perf_inject,

						  tool);

	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);

	int err;



	if (is_anon_memory(dso__long_name(dso)) || flags & MAP_HUGETLB)

	if (is_anon_memory(filename) || flags & MAP_HUGETLB)

		return 0;

	if (is_no_dso_memory(dso__long_name(dso)))

	if (is_no_dso_memory(filename))

		return 0;



	if (inject->known_build_ids != NULL &&
@@ -684,24 +732,65 @@ static int dso__inject_build_id(struct dso *dso, const struct perf_tool *tool, 
		return 1;



	if (dso__read_build_id(dso) < 0) {

		pr_debug("no build_id found for %s\n", dso__long_name(dso));

		pr_debug("no build_id found for %s\n", filename);

		return -1;

	}



	err = perf_event__synthesize_build_id(tool, dso, cpumode,

					      perf_event__repipe, machine);

	err = perf_event__synthesize_build_id(tool, sample, machine,

					      perf_event__repipe,

					      evsel, misc, dso__bid(dso),

					      filename);

	if (err) {

		pr_err("Can't synthesize build_id event for %s\n", dso__long_name(dso));

		pr_err("Can't synthesize build_id event for %s\n", filename);

		return -1;

	}



	return 0;

}



static int mark_dso_hit(const struct perf_tool *tool,

			struct perf_sample *sample,

			struct machine *machine,

			const struct evsel *mmap_evsel,

			struct map *map, bool sample_in_dso)

{

	struct dso *dso;

	u16 misc = sample->cpumode;



	if (!map)

		return 0;



	if (!sample_in_dso) {

		u16 guest_mask = PERF_RECORD_MISC_GUEST_KERNEL |

			PERF_RECORD_MISC_GUEST_USER;



		if ((misc & guest_mask) != 0) {

			misc &= PERF_RECORD_MISC_HYPERVISOR;

			misc |= __map__is_kernel(map)

				? PERF_RECORD_MISC_GUEST_KERNEL

				: PERF_RECORD_MISC_GUEST_USER;

		} else {

			misc &= PERF_RECORD_MISC_HYPERVISOR;

			misc |= __map__is_kernel(map)

				? PERF_RECORD_MISC_KERNEL

				: PERF_RECORD_MISC_USER;

		}

	}

	dso = map__dso(map);

	if (dso && !dso__hit(dso)) {

		dso__set_hit(dso);

		tool__inject_build_id(tool, sample, machine,

				      mmap_evsel, misc, dso__long_name(dso), dso,

				      map__flags(map));

	}

	return 0;

}



struct mark_dso_hit_args {

	const struct perf_tool *tool;

	struct perf_sample *sample;

	struct machine *machine;

	u8 cpumode;

	const struct evsel *mmap_evsel;

};



static int mark_dso_hit_callback(struct callchain_cursor_node *node, void *data)
@@ -709,16 +798,8 @@ static int mark_dso_hit_callback(struct callchain_cursor_node *node, void *data) 
	struct mark_dso_hit_args *args = data;

	struct map *map = node->ms.map;



	if (map) {

		struct dso *dso = map__dso(map);



		if (dso && !dso__hit(dso)) {

			dso__set_hit(dso);

			dso__inject_build_id(dso, args->tool, args->machine,

					     args->cpumode, map__flags(map));

		}

	}

	return 0;

	return mark_dso_hit(args->tool, args->sample, args->machine,

			    args->mmap_evsel, map, /*sample_in_dso=*/false);

}



int perf_event__inject_buildid(const struct perf_tool *tool, union perf_event *event,
@@ -728,10 +809,16 @@ int perf_event__inject_buildid(const struct perf_tool *tool, union perf_event *e 
{

	struct addr_location al;

	struct thread *thread;

	struct perf_inject *inject = container_of(tool, struct perf_inject, tool);

	struct mark_dso_hit_args args = {

		.tool = tool,

		/*

		 * Use the parsed sample data of the sample event, which will

		 * have a later timestamp than the mmap event.

		 */

		.sample = sample,

		.machine = machine,

		.cpumode = sample->cpumode,

		.mmap_evsel = inject__mmap_evsel(inject),

	};



	addr_location__init(&al);
@@ -743,13 +830,8 @@ int perf_event__inject_buildid(const struct perf_tool *tool, union perf_event *e 
	}



	if (thread__find_map(thread, sample->cpumode, sample->ip, &al)) {

		struct dso *dso = map__dso(al.map);



		if (!dso__hit(dso)) {

			dso__set_hit(dso);

			dso__inject_build_id(dso, tool, machine,

					     sample->cpumode, map__flags(al.map));

		}

		mark_dso_hit(tool, sample, machine, args.mmap_evsel, al.map,

			     /*sample_in_dso=*/true);

	}



	sample__for_each_callchain_node(thread, evsel, sample, PERF_MAX_STACK_DEPTH,
@@ -1159,17 +1241,27 @@ static int process_build_id(const struct perf_tool *tool, 
static int synthesize_build_id(struct perf_inject *inject, struct dso *dso, pid_t machine_pid)

{

	struct machine *machine = perf_session__findnew_machine(inject->session, machine_pid);

	u8 cpumode = dso__is_in_kernel_space(dso) ?

			PERF_RECORD_MISC_GUEST_KERNEL :

			PERF_RECORD_MISC_GUEST_USER;

	struct perf_sample synth_sample = {

		.pid	   = -1,

		.tid	   = -1,

		.time	   = -1,

		.stream_id = -1,

		.cpu	   = -1,

		.period	   = 1,

		.cpumode   = dso__is_in_kernel_space(dso)

		? PERF_RECORD_MISC_GUEST_KERNEL

		: PERF_RECORD_MISC_GUEST_USER,

	};



	if (!machine)

		return -ENOMEM;



	dso__set_hit(dso);



	return perf_event__synthesize_build_id(&inject->tool, dso, cpumode,

					       process_build_id, machine);

	return perf_event__synthesize_build_id(&inject->tool, &synth_sample, machine,

					       process_build_id, inject__mmap_evsel(inject),

					       /*misc=*/synth_sample.cpumode,

					       dso__bid(dso), dso__long_name(dso));

}



static int guest_session__add_build_ids_cb(struct dso *dso, void *data)

tools/perf/util/build-id.c

+3 −3
Original line number Diff line number Diff line
@@ -277,8 +277,8 @@ static int write_buildid(const char *name, size_t name_len, struct build_id *bid 
	struct perf_record_header_build_id b;

	size_t len;



	len = name_len + 1;

	len = PERF_ALIGN(len, NAME_ALIGN);

	len = sizeof(b) + name_len + 1;

	len = PERF_ALIGN(len, sizeof(u64));



	memset(&b, 0, sizeof(b));

	memcpy(&b.data, bid->data, bid->size);
@@ -286,7 +286,7 @@ static int write_buildid(const char *name, size_t name_len, struct build_id *bid 
	misc |= PERF_RECORD_MISC_BUILD_ID_SIZE;

	b.pid = pid;

	b.header.misc = misc;

	b.header.size = sizeof(b) + len;

	b.header.size = len;



	err = do_write(fd, &b, sizeof(b));

	if (err < 0)

tools/perf/util/synthetic-events.c

+32 −12
Original line number Diff line number Diff line
@@ -2225,28 +2225,48 @@ int perf_event__synthesize_tracing_data(const struct perf_tool *tool, int fd, st 
}

#endif



int perf_event__synthesize_build_id(const struct perf_tool *tool, struct dso *pos, u16 misc,

				    perf_event__handler_t process, struct machine *machine)

int perf_event__synthesize_build_id(const struct perf_tool *tool,

				    struct perf_sample *sample,

				    struct machine *machine,

				    perf_event__handler_t process,

				    const struct evsel *evsel,

				    __u16 misc,

				    const struct build_id *bid,

				    const char *filename)

{

	union perf_event ev;

	size_t len;



	if (!dso__hit(pos))

		return 0;

	len = sizeof(ev.build_id) + strlen(filename) + 1;

	len = PERF_ALIGN(len, sizeof(u64));



	memset(&ev, 0, sizeof(ev));

	memset(&ev, 0, len);



	len = dso__long_name_len(pos) + 1;

	len = PERF_ALIGN(len, NAME_ALIGN);

	ev.build_id.size = min(dso__bid(pos)->size, sizeof(dso__bid(pos)->data));

	memcpy(&ev.build_id.build_id, dso__bid(pos)->data, ev.build_id.size);

	ev.build_id.size = min(bid->size, sizeof(ev.build_id.build_id));

	memcpy(ev.build_id.build_id, bid->data, ev.build_id.size);

	ev.build_id.header.type = PERF_RECORD_HEADER_BUILD_ID;

	ev.build_id.header.misc = misc | PERF_RECORD_MISC_BUILD_ID_SIZE;

	ev.build_id.pid = machine->pid;

	ev.build_id.header.size = sizeof(ev.build_id) + len;

	memcpy(&ev.build_id.filename, dso__long_name(pos), dso__long_name_len(pos));

	ev.build_id.header.size = len;

	strcpy(ev.build_id.filename, filename);



	if (evsel) {

		void *array = &ev;

		int ret;



		array += ev.header.size;

		ret = perf_event__synthesize_id_sample(array, evsel->core.attr.sample_type, sample);

		if (ret < 0)

			return ret;



	return process(tool, &ev, NULL, machine);

		if (ret & 7) {

			pr_err("Bad id sample size %d\n", ret);

			return -EINVAL;

		}



		ev.header.size += ret;

	}

	return process(tool, &ev, sample, machine);

}



int perf_event__synthesize_stat_events(struct perf_stat_config *config, const struct perf_tool *tool,

tools/perf/util/synthetic-events.h

+9 −1
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <perf/cpumap.h>



struct auxtrace_record;

struct build_id;

struct dso;

struct evlist;

struct evsel;
@@ -45,7 +46,14 @@ typedef int (*perf_event__handler_t)(const struct perf_tool *tool, union perf_ev 


int perf_event__synthesize_attrs(const struct perf_tool *tool, struct evlist *evlist, perf_event__handler_t process);

int perf_event__synthesize_attr(const struct perf_tool *tool, struct perf_event_attr *attr, u32 ids, u64 *id, perf_event__handler_t process);

int perf_event__synthesize_build_id(const struct perf_tool *tool, struct dso *pos, u16 misc, perf_event__handler_t process, struct machine *machine);

int perf_event__synthesize_build_id(const struct perf_tool *tool,

				    struct perf_sample *sample,

				    struct machine *machine,

				    perf_event__handler_t process,

				    const struct evsel *evsel,

				    __u16 misc,

				    const struct build_id *bid,

				    const char *filename);

int perf_event__synthesize_cpu_map(const struct perf_tool *tool, const struct perf_cpu_map *cpus, perf_event__handler_t process, struct machine *machine);

int perf_event__synthesize_event_update_cpus(const struct perf_tool *tool, struct evsel *evsel, perf_event__handler_t process);

int perf_event__synthesize_event_update_name(const struct perf_tool *tool, struct evsel *evsel, perf_event__handler_t process);