kernel/linux.git/tools/tracing/rtla/src/trace.c, branch v6.19.11

rtla: Fix segfault in save_trace_to_file call

2025-03-26T14:35:20+00:00

Running rtla with exit on threshold, but without saving trace leads to a segmenetation fault: $ rtla timerlat hist -T 10 ... Max timerlat IRQ latency from idle: 4.29 us in cpu 0 Segmentation fault This is caused by null pointer deference in the call of save_trace_to_file, which attempts to dereference an uninitialized osnoise_tool variable: save_trace_to_file(record->trace.inst, params->trace_output); ^ this is uninitialized if params->trace_output is not set Fix this by not attempting to dereference "record" if it is NULL and passing NULL instead. As a safety measure, the first field is also checked for NULL inside save_trace_to_file. Cc: John Kacur Cc: Luis Goncalves Cc: Costa Shulyupin Link: https://lore.kernel.org/20250313141034.299117-1-tglozar@redhat.com Fixes: dc4d4e7c72d1 ("rtla: Refactor save_trace_to_file") Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla: Refactor save_trace_to_file

2025-03-04T19:17:19+00:00

The functions osnoise_hist_main(), osnoise_top_main(), timerlat_hist_main(), and timerlat_top_main() are lengthy and contain duplicated code. Refactor by consolidating the duplicate lines into the save_trace_to_file() function. Cc: Daniel Bristot de Oliveira Cc: John Kacur Cc: "Luis Claudio R. Goncalves" Cc: Eder Zulian Cc: Dan Carpenter Cc: Gabriele Monaco Link: https://lore.kernel.org/20250219115138.406075-1-costa.shul@redhat.com Signed-off-by: Costa Shulyupin Reviewed-by: Tomas Glozar Tested-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla: Count all processed events

2025-01-24T18:46:24+00:00

Add a field processed_events to struct trace_instance and increment it in collect_registered_events, regardless of whether a handler is registered for the event. The purpose is to calculate the percentage of events that were missed due to tracefs buffer overflow. Cc: John Kacur Cc: Luis Goncalves Cc: Gabriele Monaco Link: https://lore.kernel.org/20250123142339.990300-3-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla: Count missed trace events

2025-01-24T18:46:16+00:00

Add function collect_missed_events to trace.c to act as a callback for tracefs_follow_missed_events, summing the number of total missed events into a new field missing_events of struct trace_instance. In case record->missed_events is negative, trace->missed_events is set to UINT64_MAX to signify an unknown number of events was missed. The callback is activated on initialization of the trace instance. Cc: John Kacur Cc: Luis Goncalves Cc: Gabriele Monaco Link: https://lore.kernel.org/20250123142339.990300-2-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

tools/rtla: Add osnoise_trace_is_off()

2025-01-24T18:46:11+00:00

All of the users of trace_is_off() passes in &record->trace as the second parameter, where record is a pointer to a struct osnoise_tool. This record could be NULL and there is a hidden dependency that the trace field is the first field to allow &record->trace to work with a NULL record pointer. In order to make this code a bit more robust, as record shouldn't be dereferenced if it is NULL, even if the code does work, create a new function called osnoise_trace_is_off() that takes the pointer to a struct osnoise_tool as its second parameter. This way it can properly test if it is NULL before it dereferences it. The old function trace_is_off() is removed and the function osnoise_trace_is_off() is added into osnoise.c which is what the struct osnoise_tool is associated with. Cc: John Kacur Cc: "Luis Claudio R. Goncalves" Cc: Eder Zulian Cc: Dan Carpenter Cc: Tomas Glozar Cc: Gabriele Monaco Link: https://lore.kernel.org/20250115180055.2136815-1-costa.shul@redhat.com Signed-off-by: Costa Shulyupin Signed-off-by: Steven Rostedt (Google)

rtla: Add trace_instance_stop

2025-01-24T18:45:02+00:00

Support not only turning trace on for the timerlat tracer, but also turning it off. This will be used in subsequent patches to stop the timerlat tracer without also wiping the trace buffer. Cc: stable@vger.kernel.org Cc: John Kacur Cc: Luis Goncalves Cc: Gabriele Monaco Link: https://lore.kernel.org/20250116144931.649593-2-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Steven Rostedt (Google)

rtla: Add --trace-buffer-size option

2024-05-16T14:44:34+00:00

Add the option allow the users to set a different buffer size for the trace. For example, in large systems, the user might be interested on reducing the trace buffer to avoid large tracing files. The buffer size is specified in kB, and it is only affecting the tracing instance. The function trace_set_buffer_size() appears on libtracefs v1.6, so increase the minimum required version on Makefile.config. Link: https://lkml.kernel.org/r/e7c9ca5b3865f28e131a49ec3b984fadf2d056c6.1715860611.git.bristot@kernel.org Cc: Jonathan Corbet Cc: Juri Lelli Cc: John Kacur Signed-off-by: Daniel Bristot de Oliveira

rtla: Fix double free

2022-07-31T21:03:38+00:00

Avoid double free by making trace_instance_destroy indempotent. When trace_instance_init fails, it calls trace_instance_destroy, but its only caller osnoise_destroy_tool calls it again. Link: https://lkml.kernel.org/r/mvmilnlkyzx.fsf_-_@suse.de Fixes: 0605bf009f18 ("rtla: Add osnoise tool") Signed-off-by: Andreas Schwab Acked-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla: Check for trace off also in the trace instance

2022-03-15T18:36:50+00:00

With the addition of --trigger option, it is also possible to stop the trace from the -t tracing instance using the traceoff trigger. Make rtla tools to check if the trace is stopped also in the trace instance, stopping the execution of the tool. Link: https://lkml.kernel.org/r/59fc7c6f23dddd5c8b7ef1782cf3da51ea2ce0f5.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira Cc: Clark Williams Cc: Juri Lelli Cc: Jonathan Corbet Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)

rtla/trace: Save event histogram output to a file

2022-03-15T18:36:50+00:00

The hist: trigger generates a histogram in the file sys/event/hist. If the hist: trigger is used, automatically save the histogram output of the event sys:event in the sys_event_hist.txt file. Link: https://lkml.kernel.org/r/b5c906af31d4e022ffe87fb0848fac5c089087c8.1646247211.git.bristot@kernel.org Cc: Daniel Bristot de Oliveira Cc: Clark Williams Cc: Juri Lelli Cc: Jonathan Corbet Signed-off-by: Daniel Bristot de Oliveira Signed-off-by: Steven Rostedt (Google)