From mboxrd@z Thu Jan 1 00:00:00 1970 From: oleg@redhat.com (Oleg Nesterov) Date: Fri, 9 Jan 2015 18:59:36 +0100 Subject: [RFC 8/8] ARM64: Add uprobe support In-Reply-To: <0694af6935f9c6873ef8d25ad51630a40a74a116.1420038188.git.panand@redhat.com> References: <0694af6935f9c6873ef8d25ad51630a40a74a116.1420038188.git.panand@redhat.com> Message-ID: <20150109175936.GB13161@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12/31, Pratyush Anand wrote: > > +int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, > + unsigned long addr) > +{ > + probe_opcode_t insn; > + > + insn = *(probe_opcode_t *)(&auprobe->insn[0]); > + > + switch (arm_probe_decode_insn(insn, &auprobe->ainsn)) { > + case INSN_REJECTED: > + return -EINVAL; > + > + case INSN_GOOD_NO_SLOT: > + auprobe->simulate = true; > + if (auprobe->ainsn.prepare) > + auprobe->ainsn.prepare(insn, &auprobe->ainsn); > + break; > + > + case INSN_GOOD: > + default: > + break; > + } > + > + return 0; > +} forgot to mention... shouldn't it also check IS_ALIGNED(addr, AARCH64_INSN_SIZE) ? I do not know if unaligned insn address is valid on arm64 or not, but please note that at least it should not cross the page boundary, set_swbp() needs to write AARCH64_INSN_SIZE == UPROBE_SWBP_INSN bytes and it assumes that this should fit the single page. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758109AbbAISBI (ORCPT ); Fri, 9 Jan 2015 13:01:08 -0500 Received: from mx1.redhat.com ([209.132.183.28]:56968 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750976AbbAISBG (ORCPT ); Fri, 9 Jan 2015 13:01:06 -0500 Date: Fri, 9 Jan 2015 18:59:36 +0100 From: Oleg Nesterov To: Pratyush Anand Cc: linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, tixy@linaro.org, ananth@in.ibm.com, sandeepa.prabhu@linaro.org, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, anil.s.keshavamurthy@intel.com, masami.hiramatsu.pt@hitachi.com, wcohen@redhat.com Subject: Re: [RFC 8/8] ARM64: Add uprobe support Message-ID: <20150109175936.GB13161@redhat.com> References: <0694af6935f9c6873ef8d25ad51630a40a74a116.1420038188.git.panand@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0694af6935f9c6873ef8d25ad51630a40a74a116.1420038188.git.panand@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/31, Pratyush Anand wrote: > > +int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, > + unsigned long addr) > +{ > + probe_opcode_t insn; > + > + insn = *(probe_opcode_t *)(&auprobe->insn[0]); > + > + switch (arm_probe_decode_insn(insn, &auprobe->ainsn)) { > + case INSN_REJECTED: > + return -EINVAL; > + > + case INSN_GOOD_NO_SLOT: > + auprobe->simulate = true; > + if (auprobe->ainsn.prepare) > + auprobe->ainsn.prepare(insn, &auprobe->ainsn); > + break; > + > + case INSN_GOOD: > + default: > + break; > + } > + > + return 0; > +} forgot to mention... shouldn't it also check IS_ALIGNED(addr, AARCH64_INSN_SIZE) ? I do not know if unaligned insn address is valid on arm64 or not, but please note that at least it should not cross the page boundary, set_swbp() needs to write AARCH64_INSN_SIZE == UPROBE_SWBP_INSN bytes and it assumes that this should fit the single page. Oleg.