From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-183.mta0.migadu.com (out-183.mta0.migadu.com [91.218.175.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1D69F2F3C26; Sun, 17 May 2026 09:16:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.183 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779009375; cv=none; b=EayUW6b9AgpafBS9cr5Ib2+T+U1aQXXaiDRHRpoeSOZPzFJHIFQn8cAYFuzfL2rNVTHEUcHUD2PzZYbcDVBNW6wAVIHIeMdfquF2/G8qWtgodJA2l8fhP3ZrhUwQhkuRd7ihPasYG2ztg0wWPtGAGAoyvBKTJy5EylCslGcmd8E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779009375; c=relaxed/simple; bh=lEeKAVs+A7htvBIMxaKefADK2RaRnc7+HdLBfkRha/s=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=gAxhpjkBk4r8lMDiHPi5+xO7t2ljBrxQGeWKdr/gTpmX2AqQaHYbpaEq4qWMj1JH1AwQEXDA3U/VyRPpTolOHRPlCn/FndVKHNNF6Hynp8bNP+kkPT2lT77YhxFU43AELBVDCgoZE52AWxZ5H9EvsmfK/nfPyPZwc3qngoVqfuE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=EkwhRdRx; arc=none smtp.client-ip=91.218.175.183 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="EkwhRdRx" Message-ID: <4c623c63-682d-495c-86e6-6ed8832d3480@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1779009371; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Y3P8wZuJ7kjlEfC+TU2NCo0rq1vzU1BYH9e7NhsM3IE=; b=EkwhRdRxjc9xd+lurr1cgyzGOeDzmvjtYndRqzm+lM16Pd7AiVTmv2F1aphfRkQzcuijAj zs7V0MH7z3Mrd5t9cU4IAyH+gE7TtrUVimpCF9HaV7imd/fwAwCo//cMGtl6CFn33PQ0+t VFaCuZOdOzDVN/G7JU9AT+gHddM+2b8= Date: Sun, 17 May 2026 17:15:50 +0800 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH 7/9] rv: Do not rely on clean monitor when initialising HA To: Gabriele Monaco , linux-kernel@vger.kernel.org, Steven Rostedt , Masami Hiramatsu , Nam Cao , linux-trace-kernel@vger.kernel.org References: <20260512140250.262190-1-gmonaco@redhat.com> <20260512140250.262190-8-gmonaco@redhat.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Wen Yang In-Reply-To: <20260512140250.262190-8-gmonaco@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT The ha_mon_initializing flag correctly guards the init path against stale monitoring=1 (from either a previous different monitor type or a race during teardown of the previous instance). Reviewed-by: Wen Yang On 5/12/26 22:02, Gabriele Monaco wrote: > Hybrid Automata monitors hook into the DA implementation when doing > da_monitor_reset(). This function is called both on initialisation and > teardown, HA monitors try to cancel a timer only when it's initialised > relying on the da_mon->monitoring flag. This flag could however be > corrupted during initialisation. This happens for instance on per-task > monitors that share the same storage with different type of monitors > like LTL or in case of races during a previous teardown. > > Stop relying on the monitoring flag during initialisation, assume that > can have any value, so skip timer cancellation in any case when a local > flag is set. New monitors (e.g. new tasks) are always zero-initialised > so they are safe. > > Reported-by: Wen Yang > Closes: https://lore.kernel.org/lkml/d02c656aada7d071f083460a5c9a454363669b61.1778522945.git.wen.yang@linux.dev > Fixes: f5587d1b6ec9 ("rv: Add Hybrid Automata monitor type") > Signed-off-by: Gabriele Monaco > --- > include/rv/ha_monitor.h | 31 ++++++++++++++++++- > kernel/trace/rv/monitors/nomiss/nomiss.c | 4 +-- > kernel/trace/rv/monitors/opid/opid.c | 4 +-- > kernel/trace/rv/monitors/stall/stall.c | 4 +-- > .../rvgen/rvgen/templates/dot2k/main.c | 4 +-- > 5 files changed, 38 insertions(+), 9 deletions(-) > > diff --git a/include/rv/ha_monitor.h b/include/rv/ha_monitor.h > index 47ff1a41febe..11ae85bad492 100644 > --- a/include/rv/ha_monitor.h > +++ b/include/rv/ha_monitor.h > @@ -116,6 +116,35 @@ static enum hrtimer_restart ha_monitor_timer_callback(struct hrtimer *hrtimer); > #define ha_get_ns() 0 > #endif /* HA_CLK_NS */ > > +static bool ha_mon_initializing; > + > +static int ha_monitor_init(void) > +{ > + int ret; > + > + ha_mon_initializing = true; > + ret = da_monitor_init(); > + ha_mon_initializing = false; > + return ret; > +} > + > +static void ha_monitor_destroy(void) > +{ > + da_monitor_destroy(); > +} > + > +/* > + * ha_monitor_uninitialized - are fields like the timer initialized? > + * > + * On a clean monitor, we can assume an active monitor (monitoring) is > + * initialized, however the monitoring field cannot be trusted during > + * initialization. > + */ > +static inline bool ha_monitor_uninitialized(struct da_monitor *da_mon) > +{ > + return ha_mon_initializing || !da_monitoring(da_mon); > +} > + > /* Should be supplied by the monitor */ > static u64 ha_get_env(struct ha_monitor *ha_mon, enum envs env, u64 time_ns); > static bool ha_verify_constraint(struct ha_monitor *ha_mon, > @@ -160,7 +189,7 @@ static inline void ha_monitor_reset_env(struct da_monitor *da_mon) > struct ha_monitor *ha_mon = to_ha_monitor(da_mon); > > /* Initialisation resets the monitor before initialising the timer */ > - if (likely(da_monitoring(da_mon))) > + if (likely(!ha_monitor_uninitialized(da_mon))) > ha_cancel_timer(ha_mon); > } > > diff --git a/kernel/trace/rv/monitors/nomiss/nomiss.c b/kernel/trace/rv/monitors/nomiss/nomiss.c > index 31f90f3638d8..8ead8783c29f 100644 > --- a/kernel/trace/rv/monitors/nomiss/nomiss.c > +++ b/kernel/trace/rv/monitors/nomiss/nomiss.c > @@ -227,7 +227,7 @@ static int enable_nomiss(void) > { > int retval; > > - retval = da_monitor_init(); > + retval = ha_monitor_init(); > if (retval) > return retval; > > @@ -263,7 +263,7 @@ static void disable_nomiss(void) > rv_detach_trace_probe("nomiss", sched_switch, handle_sched_switch); > rv_detach_trace_probe("nomiss", sched_wakeup, handle_sched_wakeup); > > - da_monitor_destroy(); > + ha_monitor_destroy(); > } > > static struct rv_monitor rv_this = { > diff --git a/kernel/trace/rv/monitors/opid/opid.c b/kernel/trace/rv/monitors/opid/opid.c > index 4594c7c46601..2922318c6112 100644 > --- a/kernel/trace/rv/monitors/opid/opid.c > +++ b/kernel/trace/rv/monitors/opid/opid.c > @@ -73,7 +73,7 @@ static int enable_opid(void) > { > int retval; > > - retval = da_monitor_init(); > + retval = ha_monitor_init(); > if (retval) > return retval; > > @@ -90,7 +90,7 @@ static void disable_opid(void) > rv_detach_trace_probe("opid", sched_set_need_resched_tp, handle_sched_need_resched); > rv_detach_trace_probe("opid", sched_waking, handle_sched_waking); > > - da_monitor_destroy(); > + ha_monitor_destroy(); > } > > /* > diff --git a/kernel/trace/rv/monitors/stall/stall.c b/kernel/trace/rv/monitors/stall/stall.c > index 9ccfda6b0e73..3c38fb1a0159 100644 > --- a/kernel/trace/rv/monitors/stall/stall.c > +++ b/kernel/trace/rv/monitors/stall/stall.c > @@ -103,7 +103,7 @@ static int enable_stall(void) > { > int retval; > > - retval = da_monitor_init(); > + retval = ha_monitor_init(); > if (retval) > return retval; > > @@ -120,7 +120,7 @@ static void disable_stall(void) > rv_detach_trace_probe("stall", sched_switch, handle_sched_switch); > rv_detach_trace_probe("stall", sched_wakeup, handle_sched_wakeup); > > - da_monitor_destroy(); > + ha_monitor_destroy(); > } > > static struct rv_monitor rv_this = { > diff --git a/tools/verification/rvgen/rvgen/templates/dot2k/main.c b/tools/verification/rvgen/rvgen/templates/dot2k/main.c > index bf0999f6657a..889446760e3c 100644 > --- a/tools/verification/rvgen/rvgen/templates/dot2k/main.c > +++ b/tools/verification/rvgen/rvgen/templates/dot2k/main.c > @@ -35,7 +35,7 @@ static int enable_%%MODEL_NAME%%(void) > { > int retval; > > - retval = da_monitor_init(); > + retval = %%MONITOR_CLASS%%_monitor_init(); > if (retval) > return retval; > > @@ -50,7 +50,7 @@ static void disable_%%MODEL_NAME%%(void) > > %%TRACEPOINT_DETACH%% > > - da_monitor_destroy(); > + %%MONITOR_CLASS%%_monitor_destroy(); > } > > /*