From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH v3 47/51] cpuidle: Ensure ct_cpuidle_enter() is always called from noinstr/__cpuidle Date: Thu, 12 Jan 2023 20:44:01 +0100 Message-ID: <20230112195542.212914195@infradead.org> References: <20230112194314.845371875@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 48F2660FBF DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 0D55A60F3F DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 7DCD8411A8 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 423AB404BA DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=grsvYP38q4MnN8oBsFSgy8h24Veck5RfPmpq2ugRYPM=; b=sAS+cVfJZnxSjVZ+cWnQizLCZi uzGVUsOf3anafnENfDcz5DBxNwmF2u/05pvc6A0c+OdcaX2m7Qx3mQCWD2r8+RXAQmr6AABwQQUqG Xnn1+diWHWxMGA10WHWQkPrlviiLNwKR8l/igNBPuc/Urss/XPLwrgEzGEkTLbJF2i3zM2wEUdQId iXvs8/Thb5QmoGtDr5BpPsofdym80GCpPly/+P1kmFfpKKXI1eKi4k9Kt5ZS1McOXBTe8WNh0qvx1 Mira4VG3zNGY/eh9MdDKDjG1vDtIkJ7jl+e56WDxEl8scNd8fDZtJTeB77Tp7XyQzYbmD4z6YExxk sfEhC80A==; List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: peterz@infradead.org Cc: juri.lelli@redhat.com, rafael@kernel.org, catalin.marinas@arm.com, linus.walleij@linaro.org, nsekhar@ti.com, bsegall@google.com, guoren@kernel.org, pavel@ucw.cz, agordeev@linux.ibm.com, linux-arch@vger.kernel.org, linux-samsung-soc@vger.kernel.org, vincent.guittot@linaro.org, mpe@ellerman.id.au, chenhuacai@kernel.org, christophe.leroy@csgroup.eu, linux-acpi@vger.kernel.org, agross@kernel.org, geert@linux-m68k.org, linux-imx@nxp.com, vgupta@kernel.org, mattst88@gmail.com, mturquette@baylibre.com, sammy@sammy.net, pmladek@suse.com, linux-pm@vger.kernel.org, Sascha Hauer , linux-um@lists.infradead.org, npiggin@gmail.com, tglx@linutronix.de, linux-omap@vger.kernel.org, dietmar.eggemann@arm.com, andreyknvl@gmail.com, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, senozhatsky@chromium.org, svens@linux.ibm.com Tracing (kprobes included) and other compiler instrumentation relies on a normal kernel runtime. Therefore all functions that disable RCU should be noinstr, as should all functions that are called while RCU is disabled. Signed-off-by: Peter Zijlstra (Intel) --- drivers/cpuidle/cpuidle.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -137,11 +137,13 @@ int cpuidle_find_deepest_state(struct cp } #ifdef CONFIG_SUSPEND -static void enter_s2idle_proper(struct cpuidle_driver *drv, - struct cpuidle_device *dev, int index) +static noinstr void enter_s2idle_proper(struct cpuidle_driver *drv, + struct cpuidle_device *dev, int index) { - ktime_t time_start, time_end; struct cpuidle_state *target_state = &drv->states[index]; + ktime_t time_start, time_end; + + instrumentation_begin(); time_start = ns_to_ktime(local_clock()); @@ -152,13 +154,18 @@ static void enter_s2idle_proper(struct c * suspended is generally unsafe. */ stop_critical_timings(); - if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) + if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) { ct_cpuidle_enter(); + /* Annotate away the indirect call */ + instrumentation_begin(); + } target_state->enter_s2idle(dev, drv, index); if (WARN_ON_ONCE(!irqs_disabled())) raw_local_irq_disable(); - if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) + if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) { + instrumentation_end(); ct_cpuidle_exit(); + } tick_unfreeze(); start_critical_timings(); @@ -166,6 +173,7 @@ static void enter_s2idle_proper(struct c dev->states_usage[index].s2idle_time += ktime_us_delta(time_end, time_start); dev->states_usage[index].s2idle_usage++; + instrumentation_end(); } /** @@ -200,8 +208,9 @@ int cpuidle_enter_s2idle(struct cpuidle_ * @drv: cpuidle driver for this cpu * @index: index into the states table in @drv of the state to enter */ -int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv, - int index) +noinstr int cpuidle_enter_state(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) { int entered_state; @@ -209,6 +218,8 @@ int cpuidle_enter_state(struct cpuidle_d bool broadcast = !!(target_state->flags & CPUIDLE_FLAG_TIMER_STOP); ktime_t time_start, time_end; + instrumentation_begin(); + /* * Tell the time framework to switch to a broadcast timer because our * local timer will be shut down. If a local timer is used from another @@ -235,15 +246,21 @@ int cpuidle_enter_state(struct cpuidle_d time_start = ns_to_ktime(local_clock()); stop_critical_timings(); - if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) + if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) { ct_cpuidle_enter(); + /* Annotate away the indirect call */ + instrumentation_begin(); + } entered_state = target_state->enter(dev, drv, index); + if (WARN_ONCE(!irqs_disabled(), "%ps leaked IRQ state", target_state->enter)) raw_local_irq_disable(); - if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) + if (!(target_state->flags & CPUIDLE_FLAG_RCU_IDLE)) { + instrumentation_end(); ct_cpuidle_exit(); + } start_critical_timings(); sched_clock_idle_wakeup_event(); @@ -306,6 +323,8 @@ int cpuidle_enter_state(struct cpuidle_d dev->states_usage[index].rejected++; } + instrumentation_end(); + return entered_state; }