From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45420 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751787AbbGaTiE (ORCPT ); Fri, 31 Jul 2015 15:38:04 -0400 Subject: Patch "ARM64: smp: Fix suspicious RCU usage with ipi tracepoints" has been added to the 4.1-stable tree To: sboyd@codeaurora.org, catalin.marinas@arm.com, gregkh@linuxfoundation.org, john.stultz@linaro.org, nicolas.pitre@linaro.org, paulmck@linux.vnet.ibm.com, rostedt@goodmis.org Cc: , From: Date: Fri, 31 Jul 2015 12:38:02 -0700 Message-ID: <1438371482191125@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ARM64: smp: Fix suspicious RCU usage with ipi tracepoints to the 4.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arm64-smp-fix-suspicious-rcu-usage-with-ipi-tracepoints.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From be081d9bf3e163a9ed1ca2f0f14f08424c7f9016 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Wed, 24 Jun 2015 13:14:18 -0700 Subject: ARM64: smp: Fix suspicious RCU usage with ipi tracepoints From: Stephen Boyd commit be081d9bf3e163a9ed1ca2f0f14f08424c7f9016 upstream. John Stultz reported an RCU splat on ARM with ipi trace events enabled. It looks like the same problem exists on ARM64. At this point in the IPI handling path we haven't called irq_enter() yet, so RCU doesn't know that we're about to exit idle and properly warns that we're using RCU from an idle CPU. Use trace_ipi_entry_rcuidle() instead of trace_ipi_entry() so that RCU is informed about our exit from idle. Cc: John Stultz Cc: Nicolas Pitre Acked-by: Steven Rostedt Reviewed-by: Paul E. McKenney Fixes: 45ed695ac10a ("ARM64: add IPI tracepoints") Signed-off-by: Stephen Boyd Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/smp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -569,7 +569,7 @@ void handle_IPI(int ipinr, struct pt_reg struct pt_regs *old_regs = set_irq_regs(regs); if ((unsigned)ipinr < NR_IPI) { - trace_ipi_entry(ipi_types[ipinr]); + trace_ipi_entry_rcuidle(ipi_types[ipinr]); __inc_irq_stat(cpu, ipi_irqs[ipinr]); } @@ -612,7 +612,7 @@ void handle_IPI(int ipinr, struct pt_reg } if ((unsigned)ipinr < NR_IPI) - trace_ipi_exit(ipi_types[ipinr]); + trace_ipi_exit_rcuidle(ipi_types[ipinr]); set_irq_regs(old_regs); } Patches currently in stable-queue which might be from sboyd@codeaurora.org are queue-4.1/arm-8393-1-smp-fix-suspicious-rcu-usage-with-ipi-tracepoints.patch queue-4.1/clk-qcom-use-parent-rate-when-set-rate-to-pixel-rcg-clock.patch queue-4.1/clk-fix-json-output-in-debugfs.patch queue-4.1/clk-ti-dra7-atl-clock-fix-possible-err_ptr-dereference.patch queue-4.1/arm64-smp-fix-suspicious-rcu-usage-with-ipi-tracepoints.patch