[PATCH v1] rtla: Fix implicit NULL dereference

Costa Shulyupin
2025-01-09T21:14:31Z

The `record` variable is NULL when tracing is not requested:

struct osnoise_tool *record = NULL;

if (params->trace_output) {
record = osnoise_init_trace_tool("osnoise");
....

Value of `&record->trace` in this case is NULL just because
the `trace` member is the first member `struct osnoise_tool` with offset 0.
`&record->trace` just returns the offset.

Explicit dereference `record->trace' would cause segmentation fault.

Add explicit check for zero `record`.

Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
---
tools/tracing/rtla/src/osnoise_hist.c | 4 ++--
tools/tracing/rtla/src/osnoise_top.c | 4 ++--
tools/tracing/rtla/src/timerlat_hist.c | 4 ++--
tools/tracing/rtla/src/timerlat_top.c | 6 +++---
4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/tools/tracing/rtla/src/osnoise_hist.c b/tools/tracing/rtla/src/osnoise_hist.c
index 214e2c93fde01..46add229967b1 100644
--- a/tools/tracing/rtla/src/osnoise_hist.c
+++ b/tools/tracing/rtla/src/osnoise_hist.c
@@ -970,7 +970,7 @@ int osnoise_hist_main(int argc, char *argv[])
goto out_hist;
}

- if (trace_is_off(&tool->trace, &record->trace))
+ if (trace_is_off(&tool->trace, record ? &record->trace : NULL))
break;
}

@@ -980,7 +980,7 @@ int osnoise_hist_main(int argc, char *argv[])

return_value = 0;

- if (trace_is_off(&tool->trace, &record->trace)) {
+ if (trace_is_off(&tool->trace, record ? &record->trace : NULL)) {
printf("rtla osnoise hit stop tracing\n");
if (params->trace_output) {
printf(" Saving trace to %s\n", params->trace_output);
diff --git a/tools/tracing/rtla/src/osnoise_top.c b/tools/tracing/rtla/src/osnoise_top.c
index 45647495ce3bd..a0302b30da122 100644
--- a/tools/tracing/rtla/src/osnoise_top.c
+++ b/tools/tracing/rtla/src/osnoise_top.c
@@ -801,7 +801,7 @@ int osnoise_top_main(int argc, char **argv)
if (!params->quiet)
osnoise_print_stats(params, tool);

- if (trace_is_off(&tool->trace, &record->trace))
+ if (trace_is_off(&tool->trace, record ? &record->trace : NULL))
break;

}
@@ -810,7 +810,7 @@ int osnoise_top_main(int argc, char **argv)

return_value = 0;

- if (trace_is_off(&tool->trace, &record->trace)) {
+ if (trace_is_off(&tool->trace, record ? &record->trace : NULL)) {
printf("osnoise hit stop tracing\n");
if (params->trace_output) {
printf(" Saving trace to %s\n", params->trace_output);
diff --git a/tools/tracing/rtla/src/timerlat_hist.c b/tools/tracing/rtla/src/timerlat_hist.c
index 4403cc4eba302..d92a894fecc00 100644
--- a/tools/tracing/rtla/src/timerlat_hist.c
+++ b/tools/tracing/rtla/src/timerlat_hist.c
@@ -1342,7 +1342,7 @@ int timerlat_hist_main(int argc, char *argv[])
goto out_hist;
}

- if (trace_is_off(&tool->trace, &record->trace))
+ if (trace_is_off(&tool->trace, record ? &record->trace : NULL))
break;

/* is there still any user-threads ? */
@@ -1363,7 +1363,7 @@ int timerlat_hist_main(int argc, char *argv[])

return_value = 0;

- if (trace_is_off(&tool->trace, &record->trace)) {
+ if (trace_is_off(&tool->trace, record ? &record->trace : NULL)) {
printf("rtla timerlat hit stop tracing\n");

if (!params->no_aa)
diff --git a/tools/tracing/rtla/src/timerlat_top.c b/tools/tracing/rtla/src/timerlat_top.c
index 059b468981e4d..f05ef7aadf515 100644
--- a/tools/tracing/rtla/src/timerlat_top.c
+++ b/tools/tracing/rtla/src/timerlat_top.c
@@ -1093,7 +1093,7 @@ int timerlat_top_main(int argc, char *argv[])
while (!stop_tracing) {
sleep(params->sleep_time);

- if (params->aa_only && !trace_is_off(&top->trace, &record->trace))
+ if (params->aa_only && !trace_is_off(&top->trace, record ? &record->trace : NULL))
continue;

retval = tracefs_iterate_raw_events(trace->tep,
@@ -1110,7 +1110,7 @@ int timerlat_top_main(int argc, char *argv[])
if (!params->quiet)
timerlat_print_stats(params, top);

- if (trace_is_off(&top->trace, &record->trace))
+ if (trace_is_off(&top->trace, record ? &record->trace : NULL))
break;

/* is there still any user-threads ? */
@@ -1131,7 +1131,7 @@ int timerlat_top_main(int argc, char *argv[])

return_value = 0;

- if (trace_is_off(&top->trace, &record->trace)) {
+ if (trace_is_off(&top->trace, record ? &record->trace : NULL)) {
printf("rtla timerlat hit stop tracing\n");

if (!params->no_aa)
--
2.47.0