From patchwork Thu Dec 20 09:08:28 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tiejun Chen X-Patchwork-Id: 207628 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 A2E4C2C0868 for ; Thu, 20 Dec 2012 20:11:47 +1100 (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 0EB0C2C0338 for ; Thu, 20 Dec 2012 20:08:48 +1100 (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 qBK98iBc018581 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=FAIL); Thu, 20 Dec 2012 01:08:44 -0800 (PST) Received: from work.corp.ad.wrs.com (128.224.162.71) by ALA-HCA.corp.ad.wrs.com (147.11.189.50) with Microsoft SMTP Server id 14.2.318.4; Thu, 20 Dec 2012 01:08:44 -0800 From: Tiejun Chen To: Subject: [v1][PATCH 4/6] book3e/kgdb: Fix a single stgep case of lazy IRQ Date: Thu, 20 Dec 2012 17:08:28 +0800 Message-ID: <1355994510-11934-5-git-send-email-tiejun.chen@windriver.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1355994510-11934-1-git-send-email-tiejun.chen@windriver.com> References: <1355994510-11934-1-git-send-email-tiejun.chen@windriver.com> MIME-Version: 1.0 Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, jason.wessel@windriver.com 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 71413f4..30a9cb0 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -332,7 +332,17 @@ 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 516b44b..6a48db9 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -151,6 +151,7 @@ static int kgdb_handle_breakpoint(struct pt_regs *regs) return 1; } +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);