[PATCH v5 8/8] tracing/osnoise: Refuse timerlat fd open if tracer inactive
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WARM3d
From: Crystal Wood <hidden>
Date: 2026-10-24 01:56:31
Subsystem:
the rest, tracing, tracing os noise / latency tracers · Maintainers:
Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Revision v5 (4 revisions archived).
Revisions (4)
Besides being generally bad, allowing an fd open when there are no active instances means that osnoise_options_write() and osnoise_cpus_write() will leave it active during reconfiguration, causing at least WARN splats. Signed-off-by: Crystal Wood <redacted> --- v2: new patch --- kernel/trace/trace_osnoise.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 2bc23a4c1b06..5835b9d77bb8 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c@@ -2507,7 +2507,8 @@ static int timerlat_fd_open(struct inode *inode, struct file *file) * This file is accessible only if timerlat is enabled, and * NO_OSNOISE_WORKLOAD is set. */ - if (!timerlat_enabled() || test_bit(OSN_WORKLOAD, &osnoise_options)) + if (!osnoise_has_registered_instances() || !timerlat_enabled() || + test_bit(OSN_WORKLOAD, &osnoise_options)) return -EINVAL; guard(migrate)();
--
2.54.0