perf: add perf-inject builtin

Currently, perf 'live mode' writes build-ids at the end of the
session, which isn't actually useful for processing live mode events.

What would be better would be to have the build-ids sent before any of
the samples that reference them, which can be done by processing the
event stream and retrieving the build-ids on the first hit.  Doing
that in perf-record itself, however, is off-limits.

This patch introduces perf-inject, which does the same job while
leaving perf-record untouched.  Normal mode perf still records the
build-ids at the end of the session as it should, but for live mode,
perf-inject can be injected in between the record and report steps
e.g.:

perf record -o - ./hackbench 10 | perf inject -v -b | perf report -v -i -

perf-inject reads a perf-record event stream and repipes it to stdout.
At any point the processing code can inject other events into the
event stream - in this case build-ids (-b option) are read and
injected as needed into the event stream.

Build-ids are just the first user of perf-inject - potentially
anything that needs userspace processing to augment the trace stream
with additional information could make use of this facility.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1272696080-16435-3-git-send-email-tzanussi@gmail.com>
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

20 files changed, 293 insertions, 24 deletions

diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index c5ac0a991565..0ef5cfe52f2d 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -490,6 +490,7 @@ BUILTIN_OBJS += $(OUTPUT)builtin-kmem.o
 BUILTIN_OBJS += $(OUTPUT)builtin-lock.o
 BUILTIN_OBJS += $(OUTPUT)builtin-kvm.o
 BUILTIN_OBJS += $(OUTPUT)builtin-test.o
+BUILTIN_OBJS += $(OUTPUT)builtin-inject.o
 
 PERFLIBS = $(LIB_FILE)
 
diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index b57dbcf62af3..ee154b58772b 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -554,7 +554,7 @@ static int __cmd_annotate(void)
         int ret;
         struct perf_session *session;
 
-        session = perf_session__new(input_name, O_RDONLY, force);
+        session = perf_session__new(input_name, O_RDONLY, force, false);
         if (session == NULL)
                 return -ENOMEM;
 
diff --git a/tools/perf/builtin-buildid-list.c b/tools/perf/builtin-buildid-list.c
index 7dc3b2e7a5e4..44a47e13bd67 100644
--- a/tools/perf/builtin-buildid-list.c
+++ b/tools/perf/builtin-buildid-list.c
@@ -39,7 +39,7 @@ static int __cmd_buildid_list(void)
         int err = -1;
         struct perf_session *session;
 
-        session = perf_session__new(input_name, O_RDONLY, force);
+        session = perf_session__new(input_name, O_RDONLY, force, false);
         if (session == NULL)
                 return -1;
 
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index 207e860591e2..4cce68f23686 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -156,8 +156,8 @@ static int __cmd_diff(void)
         int ret, i;
         struct perf_session *session[2];
 
-        session[0] = perf_session__new(input_old, O_RDONLY, force);
-        session[1] = perf_session__new(input_new, O_RDONLY, force);
+        session[0] = perf_session__new(input_old, O_RDONLY, force, false);
+        session[1] = perf_session__new(input_new, O_RDONLY, force, false);
         if (session[0] == NULL || session[1] == NULL)
                 return -ENOMEM;
 
diff --git a/tools/perf/builtin-inject.c b/tools/perf/builtin-inject.c
new file mode 100644
index 000000000000..a5902a3eadd3
--- /dev/null
+++ b/tools/perf/builtin-inject.c
@@ -0,0 +1,228 @@
+/*
+ * builtin-inject.c
+ *
+ * Builtin inject command: Examine the live mode (stdin) event stream
+ * and repipe it to stdout while optionally injecting additional
+ * events into it.
+ */
+#include "builtin.h"
+
+#include "perf.h"
+#include "util/session.h"
+#include "util/debug.h"
+
+#include "util/parse-options.h"
+
+static char             const *input_name = "-";
+static bool             inject_build_ids;
+
+static int event__repipe(event_t *event __used,
+                         struct perf_session *session __used)
+{
+        uint32_t size;
+        void *buf = event;
+
+        size = event->header.size;
+
+        while (size) {
+                int ret = write(STDOUT_FILENO, buf, size);
+                if (ret < 0)
+                        return -errno;
+
+                size -= ret;
+                buf += ret;
+        }
+
+        return 0;
+}
+
+static int event__repipe_mmap(event_t *self, struct perf_session *session)
+{
+        int err;
+
+        err = event__process_mmap(self, session);
+        event__repipe(self, session);
+
+        return err;
+}
+
+static int event__repipe_task(event_t *self, struct perf_session *session)
+{
+        int err;
+
+        err = event__process_task(self, session);
+        event__repipe(self, session);
+
+        return err;
+}
+
+static int event__repipe_tracing_data(event_t *self,
+                                      struct perf_session *session)
+{
+        int err;
+
+        event__repipe(self, session);
+        err = event__process_tracing_data(self, session);
+
+        return err;
+}
+
+static int read_buildid(struct map *self, struct perf_session *session)
+{
+        const char *name = self->dso->long_name;
+        int err;
+
+        if (filename__read_build_id(self->dso->long_name, self->dso->build_id,
+                                    sizeof(self->dso->build_id)) > 0) {
+                char sbuild_id[BUILD_ID_SIZE * 2 + 1];
+
+                self->dso->has_build_id = true;
+
+                build_id__sprintf(self->dso->build_id,
+                                  sizeof(self->dso->build_id),
+                                  sbuild_id);
+                pr_debug("build id found for %s: %s\n", self->dso->long_name,
+                         sbuild_id);
+        }
+
+        if (self->dso->has_build_id) {
+                u16 misc = PERF_RECORD_MISC_USER;
+                struct machine *machine;
+
+                misc = self->dso->kernel ? PERF_RECORD_MISC_KERNEL : misc;
+
+                machine = perf_session__find_host_machine(session);
+                if (!machine) {
+                        pr_err("Can't find machine for session\n");
+                        return -1;
+                }
+
+                err = event__synthesize_build_id(self->dso, misc,
+                                                 event__repipe, machine,
+                                                 session);
+                if (err) {
+                        pr_err("Can't synthesize build_id event for %s\n",
+                               name);
+                        return -1;
+                }
+        } else {
+                pr_debug("no build_id found for %s\n", name);
+                return -1;
+        }
+
+        return 0;
+}
+
+static int event__inject_buildid(event_t *event, struct perf_session *session)
+{
+        struct addr_location al;
+        struct thread *thread;
+        u8 cpumode;
+        int err = 0;
+
+        cpumode = event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
+
+        thread = perf_session__findnew(session, event->ip.pid);
+        if (thread == NULL) {
+                pr_err("problem processing %d event, skipping it.\n",
+                       event->header.type);
+                err = -1;
+                goto repipe;
+        }
+
+        thread__find_addr_map(thread, session, cpumode, MAP__FUNCTION,
+                              event->ip.pid, event->ip.ip, &al);
+
+        if (al.map != NULL) {
+                if (!al.map->dso->hit) {
+                        al.map->dso->hit = 1;
+                        if (map__load(al.map, NULL) >= 0)
+                                read_buildid(al.map, session);
+                        else
+                                pr_warning("no symbols found in %s, maybe "
+                                           "install a debug package?\n",
+                                           al.map->dso->long_name);
+                }
+        }
+
+repipe:
+        event__repipe(event, session);
+        return err;
+}
+
+struct perf_event_ops inject_ops = {
+        .sample         = event__repipe,
+        .mmap           = event__repipe,
+        .comm           = event__repipe,
+        .fork           = event__repipe,
+        .exit           = event__repipe,
+        .lost           = event__repipe,
+        .read           = event__repipe,
+        .throttle       = event__repipe,
+        .unthrottle     = event__repipe,
+        .attr           = event__repipe,
+        .event_type     = event__repipe,
+        .tracing_data   = event__repipe,
+        .build_id       = event__repipe,
+};
+
+extern volatile int session_done;
+
+static void sig_handler(int sig __attribute__((__unused__)))
+{
+        session_done = 1;
+}
+
+static int __cmd_inject(void)
+{
+        struct perf_session *session;
+        int ret = -EINVAL;
+
+        signal(SIGINT, sig_handler);
+
+        if (inject_build_ids) {
+                inject_ops.sample       = event__inject_buildid;
+                inject_ops.mmap         = event__repipe_mmap;
+                inject_ops.fork         = event__repipe_task;
+                inject_ops.tracing_data = event__repipe_tracing_data;
+        }
+
+        session = perf_session__new(input_name, O_RDONLY, false, true);
+        if (session == NULL)
+                return -ENOMEM;
+
+        ret = perf_session__process_events(session, &inject_ops);
+
+        perf_session__delete(session);
+
+        return ret;
+}
+
+static const char * const report_usage[] = {
+        "perf inject [<options>]",
+        NULL
+};
+
+static const struct option options[] = {
+        OPT_BOOLEAN('b', "inject build-ids", &inject_build_ids,
+                    "Inject build-ids into the output stream"),
+        OPT_INCR('v', "verbose", &verbose,
+                 "be more verbose (show build ids, etc)"),
+        OPT_END()
+};
+
+int cmd_inject(int argc, const char **argv, const char *prefix __used)
+{
+        argc = parse_options(argc, argv, options, report_usage, 0);
+
+        /*
+         * Any (unrecognized) arguments left?
+         */
+        if (argc)
+                usage_with_options(report_usage, options);
+
+        if (symbol__init() < 0)
+                return -1;
+
+        return __cmd_inject();
+}
diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index ee05dba9609a..31f60a2535e0 100644
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -492,7 +492,7 @@ static void sort_result(void)
 static int __cmd_kmem(void)
 {
         int err = -EINVAL;
-        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0);
+        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0, false);
         if (session == NULL)
                 return -ENOMEM;
 
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index ce276750b140..6605000ed73d 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -818,7 +818,7 @@ static struct perf_event_ops eops = {
 
 static int read_events(void)
 {
-        session = perf_session__new(input_name, O_RDONLY, 0);
+        session = perf_session__new(input_name, O_RDONLY, 0, false);
         if (!session)
                 die("Initializing perf session failed\n");
 
diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c
index 1a7379674c29..e382d93d369c 100644
--- a/tools/perf/builtin-record.c
+++ b/tools/perf/builtin-record.c
@@ -548,7 +548,7 @@ static int __cmd_record(int argc, const char **argv)
         }
 
         session = perf_session__new(output_name, O_WRONLY,
-                                    write_mode == WRITE_FORCE);
+                                    write_mode == WRITE_FORCE, false);
         if (session == NULL) {
                 pr_err("Not enough memory for reading perf file header\n");
                 return -1;
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index f1b46eb7ef9a..0152b5412cc3 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -289,7 +289,7 @@ static int __cmd_report(void)
 
         signal(SIGINT, sig_handler);
 
-        session = perf_session__new(input_name, O_RDONLY, force);
+        session = perf_session__new(input_name, O_RDONLY, force, false);
         if (session == NULL)
                 return -ENOMEM;
 
diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 94453f1e4e01..aef6ed0e119c 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1660,7 +1660,7 @@ static struct perf_event_ops event_ops = {
 static int read_events(void)
 {
         int err = -EINVAL;
-        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0);
+        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0, false);
         if (session == NULL)
                 return -ENOMEM;
 
diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
index c35aa44f82ba..5a52ed9fc10b 100644
--- a/tools/perf/builtin-timechart.c
+++ b/tools/perf/builtin-timechart.c
@@ -936,7 +936,7 @@ static struct perf_event_ops event_ops = {
 
 static int __cmd_timechart(void)
 {
-        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0);
+        struct perf_session *session = perf_session__new(input_name, O_RDONLY, 0, false);
         int ret = -EINVAL;
 
         if (session == NULL)
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index d95281f588d2..3de397764cb3 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1287,7 +1287,7 @@ static int __cmd_top(void)
          * FIXME: perf_session__new should allow passing a O_MMAP, so that all this
          * mmap reading, etc is encapsulated in it. Use O_WRONLY for now.
          */
-        struct perf_session *session = perf_session__new(NULL, O_WRONLY, false);
+        struct perf_session *session = perf_session__new(NULL, O_WRONLY, false, false);
         if (session == NULL)
                 return -ENOMEM;
 
diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 77f556f7604c..9c483e92e8db 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -661,7 +661,7 @@ int cmd_trace(int argc, const char **argv, const char *prefix __used)
         if (!script_name)
                 setup_pager();
 
-        session = perf_session__new(input_name, O_RDONLY, 0);
+        session = perf_session__new(input_name, O_RDONLY, 0, false);
         if (session == NULL)
                 return -ENOMEM;
 
diff --git a/tools/perf/builtin.h b/tools/perf/builtin.h
index 34a8a9ab9617..921245b28583 100644
--- a/tools/perf/builtin.h
+++ b/tools/perf/builtin.h
@@ -34,5 +34,6 @@ extern int cmd_kmem(int argc, const char **argv, const char *prefix);
 extern int cmd_lock(int argc, const char **argv, const char *prefix);
 extern int cmd_kvm(int argc, const char **argv, const char *prefix);
 extern int cmd_test(int argc, const char **argv, const char *prefix);
+extern int cmd_inject(int argc, const char **argv, const char *prefix);
 
 #endif
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index 5ff9b5b46970..08e0e5d2b50e 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -309,6 +309,7 @@ static void handle_internal_command(int argc, const char **argv)
                 { "lock",       cmd_lock,       0 },
                 { "kvm",        cmd_kvm,        0 },
                 { "test",       cmd_test,       0 },
+                { "inject",     cmd_inject,     0 },
         };
         unsigned int i;
         static const char ext[] = STRIP_EXTENSION;
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 2d1d97e0746d..79da0e50ef8f 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -713,10 +713,18 @@ static int __event_process_build_id(struct build_id_event *bev,
 
         dso = __dsos__findnew(head, filename);
         if (dso != NULL) {
+                char sbuild_id[BUILD_ID_SIZE * 2 + 1];
+
                 dso__set_build_id(dso, &bev->build_id);
-                        if (filename[0] == '[')
-                                dso->kernel = dso_type;
-                }
+
+                if (filename[0] == '[')
+                        dso->kernel = dso_type;
+
+                build_id__sprintf(dso->build_id, sizeof(dso->build_id),
+                                  sbuild_id);
+                pr_debug("build id event received for %s: %s\n",
+                         dso->long_name, sbuild_id);
+        }
 
         err = 0;
 out:
@@ -767,7 +775,7 @@ static int perf_file_section__process(struct perf_file_section *self,
 
         switch (feat) {
         case HEADER_TRACE_INFO:
-                trace_report(fd);
+                trace_report(fd, false);
                 break;
 
         case HEADER_BUILD_ID:
@@ -782,12 +790,16 @@ static int perf_file_section__process(struct perf_file_section *self,
 }
 
 static int perf_file_header__read_pipe(struct perf_pipe_file_header *self,
-                                       struct perf_header *ph, int fd)
+                                       struct perf_header *ph, int fd,
+                                       bool repipe)
 {
         if (do_read(fd, self, sizeof(*self)) <= 0 ||
             memcmp(&self->magic, __perf_magic, sizeof(self->magic)))
                 return -1;
 
+        if (repipe && do_write(STDOUT_FILENO, self, sizeof(*self)) < 0)
+                return -1;
+
         if (self->size != sizeof(*self)) {
                 u64 size = bswap_64(self->size);
 
@@ -805,7 +817,8 @@ static int perf_header__read_pipe(struct perf_session *session, int fd)
         struct perf_header *self = &session->header;
         struct perf_pipe_file_header f_header;
 
-        if (perf_file_header__read_pipe(&f_header, self, fd) < 0) {
+        if (perf_file_header__read_pipe(&f_header, self, fd,
+                                        session->repipe) < 0) {
                 pr_debug("incompatible file format\n");
                 return -EINVAL;
         }
@@ -1096,12 +1109,17 @@ int event__process_tracing_data(event_t *self,
         lseek(session->fd, offset + sizeof(struct tracing_data_event),
               SEEK_SET);
 
-        size_read = trace_report(session->fd);
+        size_read = trace_report(session->fd, session->repipe);
 
         padding = ALIGN(size_read, sizeof(u64)) - size_read;
 
         if (read(session->fd, buf, padding) < 0)
                 die("reading input file");
+        if (session->repipe) {
+                int retw = write(STDOUT_FILENO, buf, padding);
+                if (retw <= 0 || retw != padding)
+                        die("repiping tracing data padding");
+        }
 
         if (size_read + padding != size)
                 die("tracing data size mismatch");
@@ -1110,7 +1128,8 @@ int event__process_tracing_data(event_t *self,
 }
 
 int event__synthesize_build_id(struct dso *pos, u16 misc,
-                               event__handler_t process, struct machine *machine,
+                               event__handler_t process,
+                               struct machine *machine,
                                struct perf_session *session)
 {
         event_t ev;
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index a8dd73ed1581..5d353e70fe26 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -77,7 +77,7 @@ int perf_session__create_kernel_maps(struct perf_session *self)
         return ret;
 }
 
-struct perf_session *perf_session__new(const char *filename, int mode, bool force)
+struct perf_session *perf_session__new(const char *filename, int mode, bool force, bool repipe)
 {
         size_t len = filename ? strlen(filename) + 1 : 0;
         struct perf_session *self = zalloc(sizeof(*self) + len);
@@ -97,6 +97,7 @@ struct perf_session *perf_session__new(const char *filename, int mode, bool forc
         self->cwdlen = 0;
         self->unknown_events = 0;
         self->machines = RB_ROOT;
+        self->repipe = repipe;
         self->ordered_samples.flush_limit = ULLONG_MAX;
         INIT_LIST_HEAD(&self->ordered_samples.samples_head);
 
diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index 61ca92e58ad4..f2b2c6a3a49d 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -34,6 +34,7 @@ struct perf_session {
         u64                     sample_type;
         int                     fd;
         bool                    fd_pipe;
+        bool                    repipe;
         int                     cwdlen;
         char                    *cwd;
         struct ordered_samples  ordered_samples;
@@ -59,7 +60,7 @@ struct perf_event_ops {
         bool    ordered_samples;
 };
 
-struct perf_session *perf_session__new(const char *filename, int mode, bool force);
+struct perf_session *perf_session__new(const char *filename, int mode, bool force, bool repipe);
 void perf_session__delete(struct perf_session *self);
 
 void perf_event_header__bswap(struct perf_event_header *self);
diff --git a/tools/perf/util/trace-event-read.c b/tools/perf/util/trace-event-read.c
index 44889c9b5630..43f19c1fed3a 100644
--- a/tools/perf/util/trace-event-read.c
+++ b/tools/perf/util/trace-event-read.c
@@ -51,6 +51,7 @@ static int long_size;
 static unsigned long    page_size;
 
 static ssize_t calc_data_size;
+static bool repipe;
 
 static int do_read(int fd, void *buf, int size)
 {
@@ -62,6 +63,13 @@ static int do_read(int fd, void *buf, int size)
                 if (ret <= 0)
                         return -1;
 
+                if (repipe) {
+                        int retw = write(STDOUT_FILENO, buf, ret);
+
+                        if (retw <= 0 || retw != ret)
+                                die("repiping input file");
+                }
+
                 size -= ret;
                 buf += ret;
         }
@@ -116,6 +124,13 @@ static char *read_string(void)
                 if (!r)
                         die("no data");
 
+                if (repipe) {
+                        int retw = write(STDOUT_FILENO, &c, 1);
+
+                        if (retw <= 0 || retw != r)
+                                die("repiping input file string");
+                }
+
                 buf[size++] = c;
 
                 if (!c)
@@ -454,7 +469,7 @@ struct record *trace_read_data(int cpu)
         return data;
 }
 
-ssize_t trace_report(int fd)
+ssize_t trace_report(int fd, bool __repipe)
 {
         char buf[BUFSIZ];
         char test[] = { 23, 8, 68 };
@@ -465,6 +480,7 @@ ssize_t trace_report(int fd)
         ssize_t size;
 
         calc_data_size = 1;
+        repipe = __repipe;
 
         input_fd = fd;
 
@@ -499,6 +515,7 @@ ssize_t trace_report(int fd)
 
         size = calc_data_size - 1;
         calc_data_size = 0;
+        repipe = false;
 
         if (show_funcs) {
                 print_funcs();
diff --git a/tools/perf/util/trace-event.h b/tools/perf/util/trace-event.h
index 1f45d468fd9a..ebfee80e4a07 100644
--- a/tools/perf/util/trace-event.h
+++ b/tools/perf/util/trace-event.h
@@ -163,7 +163,7 @@ struct record *trace_read_data(int cpu);
 
 void parse_set_info(int nr_cpus, int long_sz);
 
-ssize_t trace_report(int fd);
+ssize_t trace_report(int fd, bool repipe);
 
 void *malloc_or_die(unsigned int size);