kernel/linux.git/tools/tracing/rtla/src, branch v6.18.48

rtla/actions: Restore continue flag in actions_perform()

2026-07-24T14:15:54+00:00

[ Upstream commit dd520daffbc901f10d49a51a58313547d417b506 ] Currently, actions_perform() only ever sets the continue flag (when performing the continue action), but never resets it. That leads to RTLA continuing tracing even if the continue action was not performed in the current iteration. For example, the following command: $ rtla timerlat hist -T 100 --on-threshold shell,command=' echo Spike! if [ -f /tmp/a ] then exit 1 else touch /tmp/a fi' --on-threshold continue should print Spike! at most once, because after hitting the threshold for the first time, /tmp/a exists, the shell action will fail, and the continue action is not performed. However, unless /tmp/a exists before the measurement, it will print Spike! until stopped, as the continue flag stays set. Set the continue flag to false in the beginning of actions_perform() to make RTLA continue only if the action was actually performed. Fixes: 8d933d5c89e8 ("rtla/timerlat: Add continue action") Link: https://lore.kernel.org/r/20260526102523.2662391-1-tglozar@redhat.com [ correct Fixes tag to include 12 characters of hash ] Signed-off-by: Tomas Glozar Signed-off-by: Sasha Levin

rtla: Introduce for_each_action() helper

2026-07-24T14:15:54+00:00

[ Upstream commit 648634d17c813b35da775982662e56ea8ce750de ] The for loop to iterate over the list of actions is used in more than one place. To avoid code duplication and improve readability, introduce a for_each_action() helper macro. Replace the open-coded for loops with the new helper. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-4-wander@redhat.com Signed-off-by: Tomas Glozar Stable-dep-of: dd520daffbc9 ("rtla/actions: Restore continue flag in actions_perform()") Signed-off-by: Sasha Levin

rtla: Fix parse_cpu_set() bug introduced by strtoi()

2026-05-23T11:07:14+00:00

[ Upstream commit 6ea8a206108fe8b5940c2797afc54ae9f5a7bbdd ] The patch 'Replace atoi() with a robust strtoi()' introduced a bug in parse_cpu_set(), which relies on partial parsing of the input string. The function parses CPU specifications like '0-3,5' by incrementing a pointer through the string. strtoi() rejects strings with trailing characters, causing parse_cpu_set() to fail on any CPU list with multiple entries. Restore the original use of atoi() in parse_cpu_set(). Fixes: 7e9dfccf8f11 ("rtla: Replace atoi() with a robust strtoi()") Signed-off-by: Costa Shulyupin Reviewed-by: Masami Hiramatsu (Google) Link: https://lore.kernel.org/r/20260112192642.212848-2-costa.shul@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Sasha Levin

rtla/utils: Fix resource leak in set_comm_sched_attr()

2026-05-23T11:06:43+00:00

[ Upstream commit 5b6dc659ad792c72b3ff1be8039ae2945e030928 ] The set_comm_sched_attr() function opens the /proc directory via opendir() but fails to call closedir() on its successful exit path. If the function iterates through all processes without error, it returns 0 directly, leaking the DIR stream pointer. Fix this by refactoring the function to use a single exit path. A retval variable is introduced to track the success or failure status. All exit points now jump to a unified out label that calls closedir() before the function returns, ensuring the resource is always freed. Fixes: dada03db9bb19 ("rtla: Remove procps-ng dependency") Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260309195040.1019085-18-wander@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Sasha Levin

rtla: Replace atoi() with a robust strtoi()

2026-05-23T11:06:43+00:00

[ Upstream commit 7e9dfccf8f11c26208211457c4597a466135b56a ] The atoi() function does not perform error checking, which can lead to undefined behavior when parsing invalid or out-of-range strings. This can cause issues when parsing user-provided numerical inputs, such as signal numbers, PIDs, or CPU lists. To address this, introduce a new strtoi() helper function that safely converts a string to an integer. This function validates the input and checks for overflows, returning a negative value on failure. Replace all calls to atoi() with the new strtoi() function and add proper error handling to make the parsing more robust and prevent potential issues. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-5-wander@redhat.com Signed-off-by: Tomas Glozar Stable-dep-of: 5b6dc659ad79 ("rtla/utils: Fix resource leak in set_comm_sched_attr()") Signed-off-by: Sasha Levin

rtla: Fix -C/--cgroup interface

2026-05-23T11:06:43+00:00

[ Upstream commit 7b71f3a6986c93defbb72bb6c143e04122720cb1 ] Currently, user can only specify cgroup to the tracer's thread the following ways: `-C[cgroup]` `-C[=cgroup]` `--cgroup[=cgroup]` If user tries to specify cgroup as `-C [cgroup]` or `--cgroup [cgroup]`, the parser silently fails and rtla's cgroup is used for the tracer threads. To make interface more user-friendly, allow user to specify cgroup in the aforementioned way, i.e. `-C [cgroup]` and `--cgroup [cgroup]`. Refactor identical logic between -t/--trace and -C/--cgroup into a common function. Change documentation to reflect this user interface change. Fixes: a957cbc02531 ("rtla: Add -C cgroup support") Signed-off-by: Ivan Pravdin Reviewed-by: Tomas Glozar Link: https://lore.kernel.org/r/16132f1565cf5142b5fbd179975be370b529ced7.1762186418.git.ipravdin.official@gmail.com [ use capital letter in subject, as required by tracing subsystem ] Signed-off-by: Tomas Glozar Stable-dep-of: 5b6dc659ad79 ("rtla/utils: Fix resource leak in set_comm_sched_attr()") Signed-off-by: Sasha Levin

rtla: Fix NULL pointer dereference in actions_parse

2026-03-04T12:20:13+00:00

[ Upstream commit a0890f9dbd24b302d327fe7dad9b9c5be0e278aa ] The actions_parse() function uses strtok() to tokenize the trigger string, but does not check if the returned token is NULL before passing it to strcmp(). If the trigger parameter is an empty string or contains only delimiter characters, strtok() returns NULL, causing strcmp() to dereference a NULL pointer and crash the program. This issue can be triggered by malformed user input or edge cases in trigger string parsing. Add a NULL check immediately after the strtok() call to validate that a token was successfully extracted before using it. If no token is found, the function now returns -1 to indicate a parsing error. Signed-off-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20260106133655.249887-13-wander@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Sasha Levin

rtla/timerlat_bpf: Stop tracing on user latency

2026-01-02T11:57:29+00:00

commit e4240db9336c25826a2d6634adcca86d5ee01bde upstream. rtla-timerlat allows a *thread* latency threshold to be set via the -T/--thread option. However, the timerlat tracer calls this *total* latency (stop_tracing_total_us), and stops tracing also when the return-to-user latency is over the threshold. Change the behavior of the timerlat BPF program to reflect what the timerlat tracer is doing, to avoid discrepancy between stopping collecting data in the BPF program and stopping tracing in the timerlat tracer. Cc: stable@vger.kernel.org Fixes: e34293ddcebd ("rtla/timerlat: Add BPF skeleton to collect samples") Reviewed-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20251006143100.137255-1-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Greg Kroah-Hartman

rtla: Fix -a overriding -t argument

2025-12-18T13:03:10+00:00

[ Upstream commit ddb6e42494e5c48c17e64f29b7674b9add486a19 ] When running rtla as `rtla -t custom_file.txt -a 100` -a options override trace output filename specified by -t option. Running the command above will create _trace.txt file instead of custom_file.txt. Fix this by making sure that -a option does not override trace output filename even if it's passed after trace output filename is specified. Fixes: 173a3b014827 ("rtla/timerlat: Add the automatic trace option") Signed-off-by: Ivan Pravdin Reviewed-by: Tomas Glozar Link: https://lore.kernel.org/r/b6ae60424050b2c1c8709e18759adead6012b971.1762186418.git.ipravdin.official@gmail.com [ use capital letter in subject, as required by tracing subsystem ] Signed-off-by: Tomas Glozar Signed-off-by: Sasha Levin

tools/rtla: Fix --on-threshold always triggering

2025-12-18T13:03:07+00:00

[ Upstream commit 417bd0d502f90a2e785e7299dae4f248b5ac0292 ] Commit 8d933d5c89e8 ("rtla/timerlat: Add continue action") moved the code performing on-threshold actions (enabled through --on-threshold option) to inside the RTLA main loop. The condition in the loop does not check whether the threshold was actually exceeded or if stop tracing was requested by the user through SIGINT or duration. This leads to a bug where on-threshold actions are always performed, even when the threshold was not hit. (BPF mode is not affected, since it uses a different condition in the while loop.) Add a condition that checks for !stop_tracing before executing the actions. Also, fix incorrect brackets in hist_main_loop to match the semantics of top_main_loop. Fixes: 8d933d5c89e8 ("rtla/timerlat: Add continue action") Fixes: 2f3172f9dd58 ("tools/rtla: Consolidate code between osnoise/timerlat and hist/top") Reviewed-by: Crystal Wood Reviewed-by: Wander Lairson Costa Link: https://lore.kernel.org/r/20251007095341.186923-1-tglozar@redhat.com Signed-off-by: Tomas Glozar Signed-off-by: Sasha Levin