perf inject: Fix build ID injection
authorIan Rogers <irogers@google.com>
Mon, 9 Sep 2024 20:37:37 +0000 (13:37 -0700)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Tue, 10 Sep 2024 20:32:47 +0000 (17:32 -0300)
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@google.com>
Acked-by: Namhyung 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: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/builtin-inject.c
tools/perf/util/build-id.c
tools/perf/util/synthetic-events.c
tools/perf/util/synthetic-events.h

index 0ccf80fe8399bf3363a8369df16fb1e9a733d9e4..24470c57527dec58640c867c83dce5a7aab5672c 100644 (file)
@@ -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)) {
-                       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);
+                               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)
index 451d145fa4ed3339a66aa288b5c929925d09f3fd..8982f68e7230cd6433b59f3e1abe2cdd1643304c 100644 (file)
@@ -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)
index 0a7f93ae76fbb6364c1ac145c2a7dc07c2cee771..6bb62e4e2d5d80e845cc9677cf05b0167c64d37e 100644 (file)
@@ -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,
index 31df7653677f815dd3b6d034a64a9adfc6c5e35e..795bf3e183969d94a992aece2c6cc6f8f882f1c8 100644 (file)
@@ -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);