perf tools: Allow using PERF_RECORD_MMAP2 to synthesize the kernel modules maps

Allow using PERF_RECORD_MMAP2 to synthesize the kernel modules maps so
that we can use PERF_RECORD_MMAP2 to encode the kernel modules build ids
in the following csets.

It's enabled by a new symbol_conf.buildid_mmap2 bool field, which will
be switchable in following changes.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-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: Alexei Budankov <abudankov@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201214105457.543111-10-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/util/synthetic-events.c b/tools/perf/util/synthetic-events.c
index 746f35bc2e76616ac0f17719446f736c39a8d0e1..126446de7bdddc100961cf92c1c6b111ea575f3f 100644 (file)
--- a/tools/perf/util/synthetic-events.c
+++ b/tools/perf/util/synthetic-events.c
@@ -596,16 +596,17 @@ int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t
        int rc = 0;
        struct map *pos;
        struct maps *maps = machine__kernel_maps(machine);
-       union perf_event *event = zalloc((sizeof(event->mmap) +
-                                         machine->id_hdr_size));
+       union perf_event *event;
+       size_t size = symbol_conf.buildid_mmap2 ?
+                       sizeof(event->mmap2) : sizeof(event->mmap);
+
+       event = zalloc(size + machine->id_hdr_size);
        if (event == NULL) {
                pr_debug("Not enough memory synthesizing mmap event "
                         "for kernel modules\n");
                return -1;
        }
 
-       event->header.type = PERF_RECORD_MMAP;
-
        /*
         * kernel uses 0 for user space maps, see kernel/perf_event.c
         * __perf_event_mmap
@@ -616,23 +617,37 @@ int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t
                event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
 
        maps__for_each_entry(maps, pos) {
-               size_t size;
-
                if (!__map__is_kmodule(pos))
                        continue;
 
-               size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
-               event->mmap.header.type = PERF_RECORD_MMAP;
-               event->mmap.header.size = (sizeof(event->mmap) -
-                                       (sizeof(event->mmap.filename) - size));
-               memset(event->mmap.filename + size, 0, machine->id_hdr_size);
-               event->mmap.header.size += machine->id_hdr_size;
-               event->mmap.start = pos->start;
-               event->mmap.len   = pos->end - pos->start;
-               event->mmap.pid   = machine->pid;
+               if (symbol_conf.buildid_mmap2) {
+                       size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
+                       event->mmap2.header.type = PERF_RECORD_MMAP2;
+                       event->mmap2.header.size = (sizeof(event->mmap2) -
+                                               (sizeof(event->mmap2.filename) - size));
+                       memset(event->mmap2.filename + size, 0, machine->id_hdr_size);
+                       event->mmap2.header.size += machine->id_hdr_size;
+                       event->mmap2.start = pos->start;
+                       event->mmap2.len   = pos->end - pos->start;
+                       event->mmap2.pid   = machine->pid;
+
+                       memcpy(event->mmap2.filename, pos->dso->long_name,
+                              pos->dso->long_name_len + 1);
+               } else {
+                       size = PERF_ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
+                       event->mmap.header.type = PERF_RECORD_MMAP;
+                       event->mmap.header.size = (sizeof(event->mmap) -
+                                               (sizeof(event->mmap.filename) - size));
+                       memset(event->mmap.filename + size, 0, machine->id_hdr_size);
+                       event->mmap.header.size += machine->id_hdr_size;
+                       event->mmap.start = pos->start;
+                       event->mmap.len   = pos->end - pos->start;
+                       event->mmap.pid   = machine->pid;
+
+                       memcpy(event->mmap.filename, pos->dso->long_name,
+                              pos->dso->long_name_len + 1);
+               }
 
-               memcpy(event->mmap.filename, pos->dso->long_name,
-                      pos->dso->long_name_len + 1);
                if (perf_tool__process_synth_event(tool, event, machine, process) != 0) {
                        rc = -1;
                        break;