Commit 32bfa5bf authored by Alexandre Truong's avatar Alexandre Truong Committed by Arnaldo Carvalho de Melo
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perf machine: Add a mechanism to inject stack frames 



Add a mechanism for platforms to inject stack frames for the leaf
frame caller if there is enough information to determine a frame
is missing from dwarf or other post processing mechanisms.

Reviewed-by: default avatarJames Clark <james.clark@arm.com>
Signed-off-by: default avatarAlexandre Truong <alexandre.truong@arm.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211217154521.80603-3-german.gomez@arm.com


Signed-off-by: default avatarGerman Gomez <german.gomez@arm.com>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 7248e308

tools/perf/util/machine.c

+36 −1
Original line number Diff line number Diff line
@@ -2710,6 +2710,12 @@ static int find_prev_cpumode(struct ip_callchain *chain, struct thread *thread, 
	return err;

}



static u64 get_leaf_frame_caller(struct perf_sample *sample __maybe_unused,

		struct thread *thread __maybe_unused, int usr_idx __maybe_unused)

{

	return 0;

}



static int thread__resolve_callchain_sample(struct thread *thread,

					    struct callchain_cursor *cursor,

					    struct evsel *evsel,
@@ -2723,9 +2729,10 @@ static int thread__resolve_callchain_sample(struct thread *thread, 
	struct ip_callchain *chain = sample->callchain;

	int chain_nr = 0;

	u8 cpumode = PERF_RECORD_MISC_USER;

	int i, j, err, nr_entries;

	int i, j, err, nr_entries, usr_idx;

	int skip_idx = -1;

	int first_call = 0;

	u64 leaf_frame_caller;



	if (chain)

		chain_nr = chain->nr;
@@ -2850,6 +2857,34 @@ static int thread__resolve_callchain_sample(struct thread *thread, 
			continue;

		}



		/*

		 * PERF_CONTEXT_USER allows us to locate where the user stack ends.

		 * Depending on callchain_param.order and the position of PERF_CONTEXT_USER,

		 * the index will be different in order to add the missing frame

		 * at the right place.

		 */



		usr_idx = callchain_param.order == ORDER_CALLEE ? j-2 : j-1;



		if (usr_idx >= 0 && chain->ips[usr_idx] == PERF_CONTEXT_USER) {



			leaf_frame_caller = get_leaf_frame_caller(sample, thread, usr_idx);



			/*

			 * check if leaf_frame_Caller != ip to not add the same

			 * value twice.

			 */



			if (leaf_frame_caller && leaf_frame_caller != ip) {



				err = add_callchain_ip(thread, cursor, parent,

					       root_al, &cpumode, leaf_frame_caller,

					       false, NULL, NULL, 0);

				if (err)

					return (err < 0) ? err : 0;

			}

		}



		err = add_callchain_ip(thread, cursor, parent,

				       root_al, &cpumode, ip,

				       false, NULL, NULL, 0);