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Message-ID: <ZsOIkMEf3l6e-mdX@x1>
Date: Mon, 19 Aug 2024 15:01:52 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Ian Rogers <irogers@...gle.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
Namhyung Kim <namhyung@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...nel.org>,
Adrian Hunter <adrian.hunter@...el.com>,
Kan Liang <kan.liang@...ux.intel.com>,
Masahiro Yamada <masahiroy@...nel.org>,
Arnd Bergmann <arnd@...db.de>, Jann Horn <jannh@...gle.com>,
Colin Ian King <colin.i.king@...il.com>,
Casey Chen <cachen@...estorage.com>,
Athira Rajeev <atrajeev@...ux.vnet.ibm.com>,
Chaitanya S Prakash <chaitanyas.prakash@....com>,
James Clark <james.clark@...aro.org>, Ze Gao <zegao2021@...il.com>,
Yang Jihong <yangjihong1@...wei.com>,
Yunseong Kim <yskelg@...il.com>,
Weilin Wang <weilin.wang@...el.com>,
Dominique Martinet <asmadeus@...ewreck.org>,
Anne Macedo <retpolanne@...teo.net>,
Sun Haiyong <sunhaiyong@...ngson.cn>,
linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 10/13] perf inject: Fix build ID injection
On Fri, Aug 16, 2024 at 11:44:39PM -0700, Ian Rogers wrote:
> 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: Ian Rogers <irogers@...gle.com>
> ---
> tools/perf/builtin-inject.c | 170 ++++++++++++++++++++++-------
> tools/perf/util/build-id.c | 6 +-
> tools/perf/util/synthetic-events.c | 44 ++++++--
> tools/perf/util/synthetic-events.h | 10 +-
> 4 files changed, 175 insertions(+), 55 deletions(-)
>
> diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
> index a7c859db2e15..84a4bdb5cb0a 100644
> --- a/tools/perf/builtin-inject.c
> +++ b/tools/perf/builtin-inject.c
> @@ -131,6 +131,7 @@ 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 {
> @@ -139,8 +140,13 @@ 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 dso__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);
So in the end the dso was needed, the name of the function remains
dso__something(), so first arg would be a 'struct dso *'
I processed the patches up to 9/13, so that they can get tested now.
- Arnaldo
>
> 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)) {
> - dso__set_hit(dso);
> - dso__inject_build_id(dso, tool, machine, sample->cpumode, flags);
> + struct evsel *evsel = evlist__event2evsel(inject->session->evlist, event);
> +
> + if (evsel) {
> + dso__set_hit(dso);
> + dso__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 dso__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);
> + dso__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)
> diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> index 451d145fa4ed..8982f68e7230 100644
> --- a/tools/perf/util/build-id.c
> +++ b/tools/perf/util/build-id.c
> @@ -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)
> diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
> index 0a7f93ae76fb..6bb62e4e2d5d 100644
> --- a/tools/perf/util/synthetic-events.c
> +++ b/tools/perf/util/synthetic-events.c
> @@ -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;
>
> - return process(tool, &ev, NULL, machine);
> + array += ev.header.size;
> + ret = perf_event__synthesize_id_sample(array, evsel->core.attr.sample_type, sample);
> + if (ret < 0)
> + return ret;
> +
> + 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,
> diff --git a/tools/perf/util/synthetic-events.h b/tools/perf/util/synthetic-events.h
> index 31df7653677f..795bf3e18396 100644
> --- a/tools/perf/util/synthetic-events.h
> +++ b/tools/perf/util/synthetic-events.h
> @@ -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);
> --
> 2.46.0.184.g6999bdac58-goog
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