From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 65426B70D7 for ; Mon, 27 Jul 2009 10:18:42 +1000 (EST) Received: from e28smtp08.in.ibm.com (e28smtp08.in.ibm.com [59.145.155.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e28smtp08.in.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 3C077DDD01 for ; Mon, 27 Jul 2009 10:18:40 +1000 (EST) Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by e28smtp08.in.ibm.com (8.14.3/8.13.1) with ESMTP id n6R0G5Be002397 for ; Mon, 27 Jul 2009 05:46:05 +0530 Received: from d28av04.in.ibm.com (d28av04.in.ibm.com [9.184.220.66]) by d28relay04.in.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id n6R0IWKS2719860 for ; Mon, 27 Jul 2009 05:48:32 +0530 Received: from d28av04.in.ibm.com (loopback [127.0.0.1]) by d28av04.in.ibm.com (8.13.1/8.13.3) with ESMTP id n6R0IVvf016648 for ; Mon, 27 Jul 2009 10:18:31 +1000 Date: Mon, 27 Jul 2009 05:48:27 +0530 From: "K.Prasad" To: David Gibson , linuxppc-dev@ozlabs.org Subject: [Patch 3/6] Modify ptrace code to use Hardware Breakpoint interfaces Message-ID: <20090727001324.GD13562@in.ibm.com> References: <20090726235854.574539012@prasadkr_t60p.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Michael Neuling , Benjamin Herrenschmidt , paulus@samba.org, Alan Stern , "K.Prasad" , Roland McGrath List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Modify the ptrace code to use the hardware breakpoint interfaces for user-space. Signed-off-by: K.Prasad --- arch/powerpc/kernel/ptrace.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) Index: linux-2.6-tip.hbkpt/arch/powerpc/kernel/ptrace.c =================================================================== --- linux-2.6-tip.hbkpt.orig/arch/powerpc/kernel/ptrace.c +++ linux-2.6-tip.hbkpt/arch/powerpc/kernel/ptrace.c @@ -37,6 +37,7 @@ #include #include #include +#include /* * does not yet catch signals sent when the child dies. @@ -757,11 +758,24 @@ void user_disable_single_step(struct tas void ptrace_triggered(struct hw_breakpoint *bp, struct pt_regs *regs) { + /* + * Unregister the breakpoint request here since ptrace has defined a + * one-shot behaviour for breakpoint exceptions in PPC64. + * The SIGTRAP signal is generated automatically for us in do_dabr(). + * We don't have to do anything here + */ + unregister_user_hw_breakpoint(current, bp); + kfree(bp); } int ptrace_set_debugreg(struct task_struct *task, unsigned long addr, unsigned long data) { +#ifdef CONFIG_PPC64 + struct thread_struct *thread = &(task->thread); + struct hw_breakpoint *bp; + int ret; +#endif /* For ppc64 we support one DABR and no IABR's at the moment (ppc64). * For embedded processors we support one DAC and no IAC's at the * moment. @@ -791,6 +805,35 @@ int ptrace_set_debugreg(struct task_stru if (data && !(data & DABR_TRANSLATION)) return -EIO; +#ifdef CONFIG_PPC64 + bp = thread->hbp[0]; + if (data == 0) { + if (bp) { + unregister_user_hw_breakpoint(task, bp); + kfree(bp); + } + return 0; + } + + if (bp) { + bp->info.type = data & HW_BREAKPOINT_RW; + task->thread.dabr = bp->info.address = data; + return modify_user_hw_breakpoint(task, bp); + } + bp = kzalloc(sizeof(struct hw_breakpoint), GFP_KERNEL); + if (!bp) + return -ENOMEM; + + /* Store the type of breakpoint */ + bp->info.type = data & HW_BREAKPOINT_RW; + bp->triggered = ptrace_triggered; + task->thread.dabr = bp->info.address = data; + + ret = register_user_hw_breakpoint(task, bp); + if (ret) + return ret; +#endif /* CONFIG_PPC64 */ + /* Move contents to the DABR register */ task->thread.dabr = data;