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Message-ID: <CAP-5=fX9bmzn51DPHoeGVMbY=LLux2_JKGwFHNek7Je1h8qPBg@mail.gmail.com>
Date: Wed, 28 Aug 2024 08:15:10 -0700
From: Ian Rogers <irogers@...gle.com>
To: Arnaldo Carvalho de Melo <acme@...nel.org>
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 Mon, Aug 19, 2024 at 12:54 PM Ian Rogers <irogers@...gle.com> wrote:
>
> On Mon, Aug 19, 2024 at 11:01 AM Arnaldo Carvalho de Melo
> <acme@...nel.org> wrote:
> >
> > 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.
>
> Maybe we should rename the function? We can get the build ID from
> mmap2 events now, not just stored away in the dso by build_id events.
> Reordering the arguments isn't a problem, I was just aiming for
> consistency between the caller, perf_event__synthesize_build_id and
> eventually the call to process that all take the arguments in this
> order.
Arnaldo, did you have any more thoughts on this?
Thanks,
Ian
>
> > - 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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