From mboxrd@z Thu Jan 1 00:00:00 1970 From: Will Deacon Subject: Re: [PATCH] arm64: replace read_lock to rcu lock in call_step_hook Date: Tue, 9 Feb 2016 14:54:26 +0000 Message-ID: <20160209145426.GR22874@arm.com> References: <1454971764-30720-1-git-send-email-yang.shi@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: rostedt@goodmis.org, catalin.marinas@arm.com, bigeasy@linutronix.de, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linaro-kernel@lists.linaro.org To: Yang Shi Return-path: Received: from foss.arm.com ([217.140.101.70]:40751 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752934AbcBIOyY (ORCPT ); Tue, 9 Feb 2016 09:54:24 -0500 Content-Disposition: inline In-Reply-To: <1454971764-30720-1-git-send-email-yang.shi@linaro.org> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On Mon, Feb 08, 2016 at 02:49:24PM -0800, Yang Shi wrote: > BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:917 > in_atomic(): 1, irqs_disabled(): 128, pid: 383, name: sh > Preemption disabled at:[] kgdb_cpu_enter+0x158/0x6b8 > > CPU: 3 PID: 383 Comm: sh Tainted: G W 4.1.13-rt13 #2 > Hardware name: Freescale Layerscape 2085a RDB Board (DT) > Call trace: > [] dump_backtrace+0x0/0x128 > [] show_stack+0x24/0x30 > [] dump_stack+0x80/0xa0 > [] ___might_sleep+0x18c/0x1a0 > [] __rt_spin_lock+0x2c/0x40 > [] rt_read_lock+0x40/0x58 > [] single_step_handler+0x38/0xd8 > [] do_debug_exception+0x58/0xb8 > Exception stack(0xffff80834a1e7c80 to 0xffff80834a1e7da0) > 7c80: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7e40 ffff8083 001bfcc4 ffff8000 > 7ca0: f2000400 00000000 00000000 00000000 4a1e7d80 ffff8083 0049501c ffff8000 > 7cc0: 00005402 00000000 00aaa210 ffff8000 4a1e7ea0 ffff8083 000833f4 ffff8000 > 7ce0: ffffff9c ffffffff 92c23ba0 0000ffff 4a1e7ea0 ffff8083 001bfcc0 ffff8000 > 7d00: 4a0fc400 ffff8083 00005402 00000000 4a1e7d40 ffff8083 00490324 ffff8000 > 7d20: ffffff9c 00000000 92c23ba0 0000ffff 000a0000 00000000 00000000 00000000 > 7d40: 00000008 00000000 00080000 00000000 92c23b8b 0000ffff 92c23b8e 0000ffff > 7d60: 00000038 00000000 00001cb2 00000000 00000005 00000000 92d7b498 0000ffff > 7d80: 01010101 01010101 92be9000 0000ffff 00000000 00000000 00000030 00000000 > [] el1_dbg+0x18/0x6c > > This issue is similar with 62c6c61("arm64: replace read_lock to rcu lock in > call_break_hook"), but comes to single_step_handler. > > This also solves kgdbts boot test silent hang issue on 4.4 -rt kernel. > > Signed-off-by: Yang Shi Acked-by: Will Deacon Will