From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 411B9C3A5A9 for ; Tue, 5 May 2020 01:43:11 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 81E8A206B9 for ; Tue, 5 May 2020 01:43:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81E8A206B9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=popple.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 49GMtg6Pc1zDqdV for ; Tue, 5 May 2020 11:43:07 +1000 (AEST) Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 49GMs02W2hzDqPn for ; Tue, 5 May 2020 11:41:40 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=popple.id.au Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 49GMry07nYz9sSs; Tue, 5 May 2020 11:41:37 +1000 (AEST) From: Alistair Popple To: Jordan Niethe Subject: Re: [PATCH v7 15/28] powerpc/kprobes: Use patch_instruction() Date: Tue, 05 May 2020 11:41:36 +1000 Message-ID: <1746162.D6oU1Leszo@townsend> In-Reply-To: <20200501034220.8982-16-jniethe5@gmail.com> References: <20200501034220.8982-1-jniethe5@gmail.com> <20200501034220.8982-16-jniethe5@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: npiggin@gmail.com, bala24@linux.ibm.com, naveen.n.rao@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, dja@axtens.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Without CONFIG_STRICT_KERNEL_RWX this boils down to doing the same thing (although with a few more safety checks along the way), and with CONFIG_STRICT_KERNEL_RWX this should make it actually work (although perhaps there was some other mechanism that made it work anyway). Reviewed-by: Alistair Popple On Friday, 1 May 2020 1:42:07 PM AEST Jordan Niethe wrote: > Instead of using memcpy() and flush_icache_range() use > patch_instruction() which not only accomplishes both of these steps but > will also make it easier to add support for prefixed instructions. > > Signed-off-by: Jordan Niethe > --- > v6: New to series. > --- > arch/powerpc/kernel/kprobes.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c > index f64312dca84f..a72c8e1a42ad 100644 > --- a/arch/powerpc/kernel/kprobes.c > +++ b/arch/powerpc/kernel/kprobes.c > @@ -125,11 +125,8 @@ int arch_prepare_kprobe(struct kprobe *p) > } > > if (!ret) { > - memcpy(p->ainsn.insn, p->addr, > - MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); > + patch_instruction((struct ppc_inst *)p->ainsn.insn, insn); > p->opcode = ppc_inst_val(insn); > - flush_icache_range((unsigned long)p->ainsn.insn, > - (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t)); > } > > p->ainsn.boostable = 0;