Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752359AbWCPKz7 (ORCPT ); Thu, 16 Mar 2006 05:55:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752360AbWCPKz7 (ORCPT ); Thu, 16 Mar 2006 05:55:59 -0500 Received: from e5.ny.us.ibm.com ([32.97.182.145]:9446 "EHLO e5.ny.us.ibm.com") by vger.kernel.org with ESMTP id S1752358AbWCPKz6 (ORCPT ); Thu, 16 Mar 2006 05:55:58 -0500 Date: Thu, 16 Mar 2006 16:26:17 +0530 From: Prasanna S Panchamukhi To: akpm@osdl.org, Andi Kleen , davem@davemloft.net Cc: linux-kernel@vger.kernel.org, ananth@in.ibm.com, anil.s.keshavamurthy@intel.com Subject: Re: [4/5 PATCH] Kprobes-fix-broken-fault-handling-for-ia64 Message-ID: <20060316105617.GE16392@in.ibm.com> Reply-To: prasanna@in.ibm.com References: <20060316105236.GB16392@in.ibm.com> <20060316105404.GC16392@in.ibm.com> <20060316105509.GD16392@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060316105509.GD16392@in.ibm.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2866 Lines: 90 This patch fixes the broken kprobes fault handling similar to i386 architecture. Signed-off-by: Prasanna S Panchamukhi Acked-by: Anil S Keshavamurthy arch/ia64/kernel/kprobes.c | 48 ++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 43 insertions(+), 5 deletions(-) diff -puN arch/ia64/kernel/kprobes.c~kprobes-ia64-pagefault-handling arch/ia64/kernel/kprobes.c --- linux-2.6.16-rc6-mm1/arch/ia64/kernel/kprobes.c~kprobes-ia64-pagefault-handling 2006-03-16 16:13:38.000000000 +0530 +++ linux-2.6.16-rc6-mm1-prasanna/arch/ia64/kernel/kprobes.c 2006-03-16 16:13:38.000000000 +0530 @@ -34,6 +34,7 @@ #include #include #include +#include extern void jprobe_inst_return(void); @@ -722,13 +723,50 @@ static int __kprobes kprobes_fault_handl struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) - return 1; - if (kcb->kprobe_status & KPROBE_HIT_SS) { - resume_execution(cur, regs); - reset_current_kprobe(); + switch(kcb->kprobe_status) { + case KPROBE_HIT_SS: + case KPROBE_REENTER: + /* + * We are here because the instruction being single + * stepped caused a page fault. We reset the current + * kprobe and the instruction pointer points back to + * the probe address and allow the page fault handler + * to continue as a normal page fault. + */ + regs->cr_iip = ((unsigned long)cur->addr) & ~0xFULL; + ia64_psr(regs)->ri = ((unsigned long)cur->addr) & 0xf; + if (kcb->kprobe_status == KPROBE_REENTER) + restore_previous_kprobe(kcb); + else + reset_current_kprobe(); preempt_enable_no_resched(); + break; + case KPROBE_HIT_ACTIVE: + case KPROBE_HIT_SSDONE: + /* + * We increment the nmissed count for accounting, + * we can also use npre/npostfault count for accouting + * these specific fault cases. + */ + kprobes_inc_nmissed_count(cur); + + /* + * We come here because instructions in the pre/post + * handler caused the page_fault, this could happen + * if handler tries to access user space by + * copy_from_user(), get_user() etc. Let the + * user-specified handler try to fix it first. + */ + if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) + return 1; + + /* + * Let ia64_do_page_fault() fix it. + */ + break; + default: + break; } return 0; _ -- Prasanna S Panchamukhi Linux Technology Center India Software Labs, IBM Bangalore Email: prasanna@in.ibm.com Ph: 91-80-51776329 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/