From patchwork Thu Jun 20 10:28:30 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiejun Chen X-Patchwork-Id: 252863 X-Patchwork-Delegate: scottwood@freescale.com Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 18A0B2C0A35 for ; Thu, 20 Jun 2013 20:33:03 +1000 (EST) Received: from mail.windriver.com (mail.windriver.com [147.11.1.11]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mail.windriver.com", Issuer "Intel External Basic Issuing CA 3A" (not verified)) by ozlabs.org (Postfix) with ESMTPS id F32CC2C033D for ; Thu, 20 Jun 2013 20:28:54 +1000 (EST) Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail.windriver.com (8.14.5/8.14.3) with ESMTP id r5KASp1L027899 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Thu, 20 Jun 2013 03:28:51 -0700 (PDT) Received: from Linux.corp.ad.wrs.com (128.224.162.191) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server id 14.2.342.3; Thu, 20 Jun 2013 03:28:50 -0700 From: Tiejun Chen To: Subject: [v5][PATCH 6/6] book3e/kgdb: Fix a single stgep case of lazy IRQ Date: Thu, 20 Jun 2013 18:28:30 +0800 Message-ID: <1371724110-8250-7-git-send-email-tiejun.chen@windriver.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1371724110-8250-1-git-send-email-tiejun.chen@windriver.com> References: <1371724110-8250-1-git-send-email-tiejun.chen@windriver.com> MIME-Version: 1.0 Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" When we're in kgdb_singlestep(), we have to work around to get thread_info by copying from the kernel stack before calling kgdb_handle_exception(), then copying it back afterwards. But for PPC64, we have a lazy interrupt implementation. So after copying thread info frome kernle stack, if we need to replay an interrupt, we shouldn't restore that previous backup thread info to make sure we can replay an interrupt lately with a proper thread info. This patch use __check_irq_replay() to guarantee this process. Signed-off-by: Tiejun Chen --- arch/powerpc/kernel/irq.c | 10 ++++++++++ arch/powerpc/kernel/kgdb.c | 3 ++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index ea185e0..3625453 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -339,7 +339,17 @@ bool prep_irq_for_idle(void) return true; } +notrace unsigned int check_irq_replay(void) +{ + return __check_irq_replay(); +} +#else +notrace unsigned int check_irq_replay(void) +{ + return 0; +} #endif /* CONFIG_PPC64 */ +EXPORT_SYMBOL(check_irq_replay); int arch_show_interrupts(struct seq_file *p, int prec) { diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index cde7818..5b30408 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -152,6 +152,7 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs) } static DEFINE_PER_CPU(struct thread_info, kgdb_thread_info); +extern notrace unsigned int check_irq_replay(void); static int kgdb_singlestep(struct pt_regs *regs) { struct thread_info *thread_info, *exception_thread_info; @@ -181,7 +182,7 @@ static int kgdb_singlestep(struct pt_regs *regs) kgdb_handle_exception(0, SIGTRAP, 0, regs); - if (thread_info != exception_thread_info) + if ((thread_info != exception_thread_info) && (!check_irq_replay())) /* Restore current_thread_info lastly. */ memcpy(exception_thread_info, backup_current_thread_info, sizeof *thread_info);