From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 86A9C1B96D; Thu, 18 Jan 2024 10:54:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705575254; cv=none; b=RvlFTjZnhFNzuirh0oRjyLBYeHirwREAJqbLPBhpPFx2wVoDg66RqVYboYsXhKq1ElhamyDwFH3o6OFV3F7REOmvlKkp5OHzxt/B8kfnhSE8XObsgVIV21QF8LL8gyo5qmCjCXMTqS2xh5z21ZWPujGsSppB9Oty7zuygaPCxAY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705575254; c=relaxed/simple; bh=R3pO/0ga0StjT1ANvtodmGK1rxtbYl+XGVenC8OU2uw=; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID: X-Mailer:In-Reply-To:References:User-Agent:X-stable: X-Patchwork-Hint:MIME-Version:Content-Transfer-Encoding; b=ORYjSOt2GojfDw+gfpxca+WG31sCeuYQlo2wXThQebT6bjlqQ34S9czO1KV1Rmw9BedeT4cTW1vq+HM4U9J6Zq/yWrIkAo0iTdQ9A1Y+F21EPk8UTFPSiauSyivMDUM6zkCMC/UCz84cFwLI6H94Y5ZspejriUszQotY31ByQJo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=16jFt9w1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="16jFt9w1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0ADA0C43390; Thu, 18 Jan 2024 10:54:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705575254; bh=R3pO/0ga0StjT1ANvtodmGK1rxtbYl+XGVenC8OU2uw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=16jFt9w1pMQU4GNG0BynCA6/dlOP0gpxkSymwTdtSS2POgclW0q7YKd5LnzLc6FRV /2q+44mCENbyzsXtOhtIBsfTbV6DwtouAqWkkKXboNxf7EjYH7h57t5dHOcZux2uGB IOLUDWbzezvNFLfWqjW8mKqCeoDeXQ1hRtd5tLd0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stefan Wiehler , Huacai Chen , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 6.6 059/150] mips/smp: Call rcutree_report_cpu_starting() earlier Date: Thu, 18 Jan 2024 11:48:01 +0100 Message-ID: <20240118104322.716905144@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240118104320.029537060@linuxfoundation.org> References: <20240118104320.029537060@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefan Wiehler [ Upstream commit 55702ec9603ebeffb15e6f7b113623fe1d8872f4 ] rcutree_report_cpu_starting() must be called before clockevents_register_device() to avoid the following lockdep splat triggered by calling list_add() when CONFIG_PROVE_RCU_LIST=y: WARNING: suspicious RCU usage ... ----------------------------- kernel/locking/lockdep.c:3680 RCU-list traversed in non-reader section!! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/1/0. ... Call Trace: [] show_stack+0x64/0x158 [] dump_stack_lvl+0x90/0xc4 [] __lock_acquire+0x1404/0x2940 [] lock_acquire+0x14c/0x448 [] _raw_spin_lock_irqsave+0x50/0x88 [] clockevents_register_device+0x60/0x1e8 [] r4k_clockevent_init+0x220/0x3a0 [] start_secondary+0x50/0x3b8 raw_smp_processor_id() is required in order to avoid calling into lockdep before RCU has declared the CPU to be watched for readers. See also commit 29368e093921 ("x86/smpboot: Move rcu_cpu_starting() earlier"), commit de5d9dae150c ("s390/smp: move rcu_cpu_starting() earlier") and commit 99f070b62322 ("powerpc/smp: Call rcu_cpu_starting() earlier"). Signed-off-by: Stefan Wiehler Reviewed-by: Huacai Chen Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/kernel/smp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c index 8fbef537fb88..82e2e051b416 100644 --- a/arch/mips/kernel/smp.c +++ b/arch/mips/kernel/smp.c @@ -351,10 +351,11 @@ early_initcall(mips_smp_ipi_init); */ asmlinkage void start_secondary(void) { - unsigned int cpu; + unsigned int cpu = raw_smp_processor_id(); cpu_probe(); per_cpu_trap_init(false); + rcutree_report_cpu_starting(cpu); mips_clockevent_init(); mp_ops->init_secondary(); cpu_report(); @@ -366,7 +367,6 @@ asmlinkage void start_secondary(void) */ calibrate_delay(); - cpu = smp_processor_id(); cpu_data[cpu].udelay_val = loops_per_jiffy; set_cpu_sibling_map(cpu); -- 2.43.0