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 <[email protected]> --- 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 912ff5f5e490..fc55ef8e7204 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
