[PATCH v2 1/1] perf cs-etm: Add warnings for missing DSOs

[James Clark <james.clark@arm.com>]

Currently decode will silently fail if no binary data is available for
the decode. This is made worse if only partial data is available because
the decode will appear to work, but any trace from that missing DSO will
silently not be generated.

Add a UI popup once if there is any data missing, and then warn in the
bottom left for each individual DSO that's missing.

Signed-off-by: James Clark <james.clark@arm.com>
---
 tools/perf/util/cs-etm.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index f4b2bff533f3..b59d234e437d 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -716,8 +716,17 @@ static u32 cs_etm__mem_access(struct cs_etm_queue *etmq, u8 trace_chan_id,
 
 	len = dso__data_read_offset(al.map->dso, machine, offset, buffer, size);
 
-	if (len <= 0)
+	if (len <= 0) {
+		ui__warning_once("CS ETM Trace: Missing DSO. Use 'perf archive' or debuginfod to export data from the traced system.\n"
+				 "              Enable CONFIG_PROC_KCORE or use option '-k /path/to/vmlinux' for kernel symbols.\n");
+		if (!al.map->dso->auxtrace_warned) {
+			pr_err("CS ETM Trace: Debug data not found for address %#"PRIx64" in %s\n",
+				    address,
+				    al.map->dso->long_name ? al.map->dso->long_name : "Unknown");
+			al.map->dso->auxtrace_warned = true;
+		}
 		return 0;
+	}
 
 	return len;
 }
-- 
2.23.0