Commit e0dbf18f authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
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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: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarIan Rogers <irogers@google.com>
Acked-by: default avatarNamhyung 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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 978410ff

tools/perf/util/synthetic-events.c

+32 −17
Original line number Diff line number Diff line
@@ -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
@@ -616,11 +617,23 @@ 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;



		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) -
@@ -633,6 +646,8 @@ int perf_event__synthesize_modules(struct perf_tool *tool, perf_event__handler_t 


			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;