rtla: Avoid record NULL pointer dereference

Fix the following null/deref_null.cocci errors:
./tools/tracing/rtla/src/osnoise_hist.c:870:31-36: ERROR: record is NULL but dereferenced.
./tools/tracing/rtla/src/osnoise_top.c:650:31-36: ERROR: record is NULL but dereferenced.
./tools/tracing/rtla/src/timerlat_hist.c:905:31-36: ERROR: record is NULL but dereferenced.
./tools/tracing/rtla/src/timerlat_top.c:700:31-36: ERROR: record is NULL but dereferenced.

"record" is NULL before calling osnoise_init_trace_tool.
Add a tag "out_free" to avoid dereferring a NULL pointer.

Link: https://lkml.kernel.org/r/ae0e4500d383db0884eb2820286afe34ca303778.1651247710.git.bristot@kernel.org
Link: https://lore.kernel.org/r/20220408151406.34823-1-wanjiabing@vivo.com/

Cc: kael_w@yeah.net
Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Fixes: 51d64c3 ("rtla: Add -e/--event support")
Acked-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tools/tracing/rtla/src/osnoise_hist.c

@@ -809,7 +809,7 @@ int osnoise_hist_main(int argc, char *argv[])
 		retval = set_comm_sched_attr("osnoise/", &params->sched_param);
 		if (retval) {
 			err_msg("Failed to set sched parameters\n");
-			goto out_hist;
+			goto out_free;
 		}
 	}
 
@@ -819,7 +819,7 @@ int osnoise_hist_main(int argc, char *argv[])
 		record = osnoise_init_trace_tool("osnoise");
 		if (!record) {
 			err_msg("Failed to enable the trace instance\n");
-			goto out_hist;
+			goto out_free;
 		}
 
 		if (params->events) {
@@ -869,6 +869,7 @@ int osnoise_hist_main(int argc, char *argv[])
 out_hist:
 	trace_events_destroy(&record->trace, params->events);
 	params->events = NULL;
+out_free:
 	osnoise_free_histogram(tool->data);
 out_destroy:
 	osnoise_destroy_tool(record);

tools/tracing/rtla/src/osnoise_top.c

@@ -572,22 +572,22 @@ int osnoise_top_main(int argc, char **argv)
 	retval = osnoise_top_apply_config(tool, params);
 	if (retval) {
 		err_msg("Could not apply config\n");
-		goto out_top;
+		goto out_free;
 	}
 
 	trace = &tool->trace;
 
 	retval = enable_osnoise(trace);
 	if (retval) {
 		err_msg("Failed to enable osnoise tracer\n");
-		goto out_top;
+		goto out_free;
 	}
 
 	if (params->set_sched) {
 		retval = set_comm_sched_attr("osnoise/", &params->sched_param);
 		if (retval) {
 			err_msg("Failed to set sched parameters\n");
-			goto out_top;
+			goto out_free;
 		}
 	}
 
@@ -597,7 +597,7 @@ int osnoise_top_main(int argc, char **argv)
 		record = osnoise_init_trace_tool("osnoise");
 		if (!record) {
 			err_msg("Failed to enable the trace instance\n");
-			goto out_top;
+			goto out_free;
 		}
 
 		if (params->events) {
@@ -649,6 +649,7 @@ int osnoise_top_main(int argc, char **argv)
 out_top:
 	trace_events_destroy(&record->trace, params->events);
 	params->events = NULL;
+out_free:
 	osnoise_free_top(tool->data);
 	osnoise_destroy_tool(record);
 	osnoise_destroy_tool(tool);

tools/tracing/rtla/src/timerlat_hist.c

@@ -821,30 +821,30 @@ int timerlat_hist_main(int argc, char *argv[])
 	retval = timerlat_hist_apply_config(tool, params);
 	if (retval) {
 		err_msg("Could not apply config\n");
-		goto out_hist;
+		goto out_free;
 	}
 
 	trace = &tool->trace;
 
 	retval = enable_timerlat(trace);
 	if (retval) {
 		err_msg("Failed to enable timerlat tracer\n");
-		goto out_hist;
+		goto out_free;
 	}
 
 	if (params->set_sched) {
 		retval = set_comm_sched_attr("timerlat/", &params->sched_param);
 		if (retval) {
 			err_msg("Failed to set sched parameters\n");
-			goto out_hist;
+			goto out_free;
 		}
 	}
 
 	if (params->dma_latency >= 0) {
 		dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
 		if (dma_latency_fd < 0) {
 			err_msg("Could not set /dev/cpu_dma_latency.\n");
-			goto out_hist;
+			goto out_free;
 		}
 	}
 
@@ -854,7 +854,7 @@ int timerlat_hist_main(int argc, char *argv[])
 		record = osnoise_init_trace_tool("timerlat");
 		if (!record) {
 			err_msg("Failed to enable the trace instance\n");
-			goto out_hist;
+			goto out_free;
 		}
 
 		if (params->events) {
@@ -904,6 +904,7 @@ int timerlat_hist_main(int argc, char *argv[])
 		close(dma_latency_fd);
 	trace_events_destroy(&record->trace, params->events);
 	params->events = NULL;
+out_free:
 	timerlat_free_histogram(tool->data);
 	osnoise_destroy_tool(record);
 	osnoise_destroy_tool(tool);

tools/tracing/rtla/src/timerlat_top.c

@@ -612,30 +612,30 @@ int timerlat_top_main(int argc, char *argv[])
 	retval = timerlat_top_apply_config(top, params);
 	if (retval) {
 		err_msg("Could not apply config\n");
-		goto out_top;
+		goto out_free;
 	}
 
 	trace = &top->trace;
 
 	retval = enable_timerlat(trace);
 	if (retval) {
 		err_msg("Failed to enable timerlat tracer\n");
-		goto out_top;
+		goto out_free;
 	}
 
 	if (params->set_sched) {
 		retval = set_comm_sched_attr("timerlat/", &params->sched_param);
 		if (retval) {
 			err_msg("Failed to set sched parameters\n");
-			goto out_top;
+			goto out_free;
 		}
 	}
 
 	if (params->dma_latency >= 0) {
 		dma_latency_fd = set_cpu_dma_latency(params->dma_latency);
 		if (dma_latency_fd < 0) {
 			err_msg("Could not set /dev/cpu_dma_latency.\n");
-			goto out_top;
+			goto out_free;
 		}
 	}
 
@@ -645,7 +645,7 @@ int timerlat_top_main(int argc, char *argv[])
 		record = osnoise_init_trace_tool("timerlat");
 		if (!record) {
 			err_msg("Failed to enable the trace instance\n");
-			goto out_top;
+			goto out_free;
 		}
 
 		if (params->events) {
@@ -699,6 +699,7 @@ int timerlat_top_main(int argc, char *argv[])
 		close(dma_latency_fd);
 	trace_events_destroy(&record->trace, params->events);
 	params->events = NULL;
+out_free:
 	timerlat_free_top(top->data);
 	osnoise_destroy_tool(record);
 	osnoise_destroy_tool(top);