From: Crystal Wood <crwood@redhat.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Tomas Glozar <tglozar@redhat.com>, John Kacur <jkacur@redhat.com>,
linux-trace-kernel@vger.kernel.org,
Crystal Wood <crwood@redhat.com>
Subject: [PATCH v2 9/9] tracing/osnoise: Refuse timerlat fd open if tracer inactive
Date: Fri, 9 Oct 2026 21:23:38 -0500 [thread overview]
Message-ID: <20261010022338.2507589-10-crwood@redhat.com> (raw)
In-Reply-To: <20261010022338.2507589-1-crwood@redhat.com>
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 <crwood@redhat.com>
---
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
prev parent reply other threads:[~2026-10-10 2:24 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-10 2:23 [PATCH v2 0/9] tracing/osnoise: Synchronization fixes Crystal Wood
2026-10-10 2:23 ` [PATCH v2 1/9] tracing/osnoise: Variable cleanup Crystal Wood
2026-10-10 2:23 ` [PATCH v2 2/9] tracing/osnoise: Hold a ref on osn->kthread Crystal Wood
2026-10-10 2:23 ` [PATCH v2 3/9] tracing/osnoise: Per-cpu mutexes and fd detachment Crystal Wood
2026-10-10 2:35 ` sashiko-bot
2026-10-10 2:23 ` [PATCH v2 4/9] tracing/osnoise: kthreads: Verify CPU after migrate_disable() Crystal Wood
2026-10-10 2:23 ` [PATCH v2 5/9] tracing/osnoise: start_kthread: Always check OSN_WORKLOAD Crystal Wood
2026-10-10 2:34 ` sashiko-bot
2026-10-10 2:23 ` [PATCH v2 6/9] tracing/osnoise: Take trace_types_lock in timerlat_fd_open Crystal Wood
2026-10-10 2:23 ` [PATCH v2 7/9] tracing/osnoise: Split out per-cpu variable resets Crystal Wood
2026-10-10 2:36 ` sashiko-bot
2026-10-10 2:23 ` [PATCH v2 8/9] tracing/osnoise: Print taint message for timerlat Crystal Wood
2026-10-10 2:23 ` Crystal Wood [this message]
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