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 5954C12DD97; Tue, 23 Jan 2024 00:58:15 +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=1705971495; cv=none; b=RIw0stjWWxSYIhCl4mloGycIlfC+JH1D3fNk52UENHlJu7ajJsxNx1iJgN/uHUfMuhravww3EroEg8YMHtnR5tgo2RkAMVIX5KIgkXe+9mPOWjJM5V7lqXdQ1/q8diJSMF4izga4knUqc3cJBgJYT5nCObTodCbnafV+VjafnYg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705971495; c=relaxed/simple; bh=KpVzk19zAxz2dwFDbWJZMt3hUgo+6RRV4YgeGoLi/jw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Qhj14/sqWAALCVjaYQmrwY1mnCWPcqrnUvt0rleE3h4PnJC+1lrLt1bnFHAwVMpLX+W4VEyAJcN0Af83ua/Vc7iLyuanZf2zUVB7OqSlA1yTcK/lrzIIZ32hIE5VrZI9cLrPLHMPXgoeIg3WYXMPaYAKo9Bhne9IOUFoNswSdi0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=u96iSaUg; 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="u96iSaUg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02B8EC433C7; Tue, 23 Jan 2024 00:58:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1705971495; bh=KpVzk19zAxz2dwFDbWJZMt3hUgo+6RRV4YgeGoLi/jw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u96iSaUgn12dwkl+8aHTZMTfBHe311c2EOb8jLEwftEVvCaZzhiM7pPYKF4ueYUov A11CdydTKOOCbVSqLHvHqI+dwuo2JVYtOLWC0oGCYg1yw+lqXLYYB6H+YRJNoxKSIa i5bUTxB6jSd3V34xBULJp3amNQ8fHquqW+kUjxgY= 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 6.1 252/417] mips/smp: Call rcutree_report_cpu_starting() earlier Date: Mon, 22 Jan 2024 15:57:00 -0800 Message-ID: <20240122235800.607332620@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240122235751.480367507@linuxfoundation.org> References: <20240122235751.480367507@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 6.1-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 @@ -333,10 +333,11 @@ 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(); @@ -348,7 +349,6 @@ asmlinkage void start_secondary(void) */ calibrate_delay(); - cpu = smp_processor_id(); cpu_data[cpu].udelay_val = loops_per_jiffy; set_cpu_sibling_map(cpu);