From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A99A1C678D4 for ; Tue, 7 Mar 2023 17:49:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232135AbjCGRt0 (ORCPT ); Tue, 7 Mar 2023 12:49:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36728 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232251AbjCGRsz (ORCPT ); Tue, 7 Mar 2023 12:48:55 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CAE498EA3 for ; Tue, 7 Mar 2023 09:43:43 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D4070614DF for ; Tue, 7 Mar 2023 17:38:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CDCBDC433D2; Tue, 7 Mar 2023 17:38:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678210721; bh=UWfoVHCIMcXXZEC4WkYEzU9xMqbxy+hmF9ARRDEdT9Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t9swFMedz+/hPsexdfMzvafTFqL8LkUoiyKXCkO0bRvgF8IW332LYiBNxGLYW8UVu Zzqiq74d8+PRi6itiIZo3LdcOFerr/LuWNBufmn+NDT0HUekoYYiXp2hMnu7kkpDNk R7YGsTSlC7tFnghp7socyvPg8P/Cc9xJSIquIoes= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mark Rutland , "Peter Zijlstra (Intel)" , Ingo Molnar , Sasha Levin Subject: [PATCH 6.2 0633/1001] cpuidle: drivers: firmware: psci: Dont instrument suspend code Date: Tue, 7 Mar 2023 17:56:45 +0100 Message-Id: <20230307170049.049972903@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170022.094103862@linuxfoundation.org> References: <20230307170022.094103862@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mark Rutland [ Upstream commit 393e2ea30aec634b37004d401863428e120d5e1b ] The PSCI suspend code is currently instrumentable, which is not safe as instrumentation (e.g. ftrace) may try to make use of RCU during idle periods when RCU is not watching. To fix this we need to ensure that psci_suspend_finisher() and anything it calls are not instrumented. We can do this fairly simply by marking psci_suspend_finisher() and the psci*_cpu_suspend() functions as noinstr, and the underlying helper functions as __always_inline. When CONFIG_DEBUG_VIRTUAL=y, __pa_symbol() can expand to an out-of-line instrumented function, so we must use __pa_symbol_nodebug() within psci_suspend_finisher(). The raw SMCCC invocation functions are written in assembly, and are not subject to compiler instrumentation. Signed-off-by: Mark Rutland Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20230126151323.349423061@infradead.org Signed-off-by: Sasha Levin --- drivers/firmware/psci/psci.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index 447ee4ea5c903..f78249fe2512a 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c @@ -108,9 +108,10 @@ bool psci_power_state_is_valid(u32 state) return !(state & ~valid_mask); } -static unsigned long __invoke_psci_fn_hvc(unsigned long function_id, - unsigned long arg0, unsigned long arg1, - unsigned long arg2) +static __always_inline unsigned long +__invoke_psci_fn_hvc(unsigned long function_id, + unsigned long arg0, unsigned long arg1, + unsigned long arg2) { struct arm_smccc_res res; @@ -118,9 +119,10 @@ static unsigned long __invoke_psci_fn_hvc(unsigned long function_id, return res.a0; } -static unsigned long __invoke_psci_fn_smc(unsigned long function_id, - unsigned long arg0, unsigned long arg1, - unsigned long arg2) +static __always_inline unsigned long +__invoke_psci_fn_smc(unsigned long function_id, + unsigned long arg0, unsigned long arg1, + unsigned long arg2) { struct arm_smccc_res res; @@ -128,7 +130,7 @@ static unsigned long __invoke_psci_fn_smc(unsigned long function_id, return res.a0; } -static int psci_to_linux_errno(int errno) +static __always_inline int psci_to_linux_errno(int errno) { switch (errno) { case PSCI_RET_SUCCESS: @@ -169,7 +171,8 @@ int psci_set_osi_mode(bool enable) return psci_to_linux_errno(err); } -static int __psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point) +static __always_inline int +__psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point) { int err; @@ -177,13 +180,15 @@ static int __psci_cpu_suspend(u32 fn, u32 state, unsigned long entry_point) return psci_to_linux_errno(err); } -static int psci_0_1_cpu_suspend(u32 state, unsigned long entry_point) +static __always_inline int +psci_0_1_cpu_suspend(u32 state, unsigned long entry_point) { return __psci_cpu_suspend(psci_0_1_function_ids.cpu_suspend, state, entry_point); } -static int psci_0_2_cpu_suspend(u32 state, unsigned long entry_point) +static __always_inline int +psci_0_2_cpu_suspend(u32 state, unsigned long entry_point) { return __psci_cpu_suspend(PSCI_FN_NATIVE(0_2, CPU_SUSPEND), state, entry_point); @@ -450,10 +455,12 @@ late_initcall(psci_debugfs_init) #endif #ifdef CONFIG_CPU_IDLE -static int psci_suspend_finisher(unsigned long state) +static noinstr int psci_suspend_finisher(unsigned long state) { u32 power_state = state; - phys_addr_t pa_cpu_resume = __pa_symbol(cpu_resume); + phys_addr_t pa_cpu_resume; + + pa_cpu_resume = __pa_symbol_nodebug((unsigned long)cpu_resume); return psci_ops.cpu_suspend(power_state, pa_cpu_resume); } -- 2.39.2