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 4A6356BB56; Tue, 23 Jan 2024 02:03:08 +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=1705975388; cv=none; b=UDjNYON5xGLYBuZ4xbL4NIbWz9kekO3m/Z4D+dJ35bQQXJuLXSR4T1EjJRbhzA6ZOIc/0pgpmAqZkTz5C1mWK5LyOdRQBlMQqdrn1hieAPxfkNaKgAap5I//ZQJlIcHFsSqU4I6PjgVlb4HndmPee9L0yMbJH+w46+Gh9+/eGdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705975388; c=relaxed/simple; bh=UdAN5tBOYok4x/v652DxjaxyJdVa6wJYwdwQVNJb9Pg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=H+X8PD3+JE7eJbpzY3JxjpdZ8N6hPHjQBdXAUgdAqGIvSs0wex6G1jz2ZNiv3n0FiGzD2gWEaQDo9N2rHRoNnOdraGbSOvciEu9exCXkgGy7boN3eaeo9LNWMGLyLaAtvyhu6cj5J0gcnE4/E4OSJcuW02m9kApsh2V70yHsCRE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Za9Og3SA; 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="Za9Og3SA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09A50C43390; Tue, 23 Jan 2024 02:03:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705975388; bh=UdAN5tBOYok4x/v652DxjaxyJdVa6wJYwdwQVNJb9Pg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Za9Og3SAYJ0XQ0FeukJMBpjoOdQSVF54f7WXw6Op+dWSLuoTiRHvBEJQfE2AEBK69 kthmhx2wchyoNTzBCAOzHdb/zdt4P9gAJExsWsjr3xpsy0nw8iLCgYpNBQg5oXDAu5 Yj2innCnPGu7Q8FzYoTlfFWQeJZtBXBF05c3tsB8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stefan Wiehler , Huacai Chen , Thomas Bogendoerfer Subject: [PATCH 6.6 348/583] mips/smp: Call rcutree_report_cpu_starting() earlier Date: Mon, 22 Jan 2024 15:56:39 -0800 Message-ID: <20240122235822.670349324@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235812.238724226@linuxfoundation.org> References: <20240122235812.238724226@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 commit 55702ec9603ebeffb15e6f7b113623fe1d8872f4 upstream. 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: Greg Kroah-Hartman --- arch/mips/kernel/smp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- 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); + rcu_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);