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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 6BEE0C3A5A2 for ; Fri, 23 Aug 2019 14:51:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 357D021848 for ; Fri, 23 Aug 2019 14:51:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566571896; bh=aVchjuHWTXOaTDZuWT4rE8xKpWB6QsFxLg6BDqrPMBU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=SpqM9jkycYngtv3OuTwomWz0sXNkMgJUEYJkubFBVeZ8SXekIFTdOTERkIa4GyvxU 4qSdofpOVZA17tB5Wbg2orb7oXiFAqzKYXbCWg78a3dtBI8fPPAPdmnOTfxYzYEZtV vwKBCF5P8EQiPdi+27MdKMJjr6sXS288HWNSVo2o= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2395412AbfHWOvf (ORCPT ); Fri, 23 Aug 2019 10:51:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:34322 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388352AbfHWOvf (ORCPT ); Fri, 23 Aug 2019 10:51:35 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 97BFE2166E; Fri, 23 Aug 2019 14:51:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566571894; bh=aVchjuHWTXOaTDZuWT4rE8xKpWB6QsFxLg6BDqrPMBU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lOhadIdBCMKhZZkWRsZKTsc0dnSKABUI8r7IDxP9auoTwL6cq9VHHquL4sgCddJ6+ i1Jq9+dVh+hxyozPx0IO9InPMe2+rO8hPvYEdx76EdJfBrs/UVH85CpxjJtTRN9YbF 4CjkRdbiWquBWBZNXw5KcjOc4pDLb86Dt8FmvwSE= Date: Fri, 23 Aug 2019 23:51:27 +0900 From: Masami Hiramatsu To: Jisheng Zhang Cc: Thomas Gleixner , Catalin Marinas , Jonathan Corbet , Will Deacon , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "x86@kernel.org" , "Naveen N. Rao" , Anil S Keshavamurthy , "David S. Miller" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH v2 1/3] kprobes/x86: use instruction_pointer and instruction_pointer_set Message-Id: <20190823235127.6b1ab6bdb3a280b64ca8585e@kernel.org> In-Reply-To: <20190821095527.729b2b0d@xhacker.debian> References: <20190820113928.1971900c@xhacker.debian> <20190820114109.4624d56b@xhacker.debian> <20190820165152.20275268@xhacker.debian> <20190821105247.f0236d2c04b2c0c4d4e1847e@kernel.org> <20190821095527.729b2b0d@xhacker.debian> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jisheng, On Wed, 21 Aug 2019 02:09:10 +0000 Jisheng Zhang wrote: > > > In v2, actually, the arm64 version's kprobe_ftrace_handler() is the same > > > as x86's, the only difference is comment, e.g > > > > > > /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ > > > > > > while in arm64 > > > > > > /* Kprobe handler expects regs->pc = ip + 1 as breakpoint hit */ > > > > As Peter pointed, on arm64, is that really 1 or 4 bytes? > > This part is heavily depends on the processor software-breakpoint > > implementation. > > Per my understanding, the "+1" here means "+ one kprobe_opcode_t". No, that is the size of INT3. It just emulates the software trap on x86. Thank you, -- Masami Hiramatsu 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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 8266FC3A5A2 for ; Fri, 23 Aug 2019 14:51:38 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 531912339D for ; Fri, 23 Aug 2019 14:51:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BIYt1E4z"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="lOhadIdB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 531912339D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Mime-Version:References:In-Reply-To: Message-Id:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ifdyPlszaoAkL0xRwfrm2tlQWgBu9ZcvRNnkyPXCcjY=; b=BIYt1E4zDUANM7 TLy+nZ4qq61dHBJ89PA6PBf9AL6x4hvq//TrixyjDPiaPwQkKd2yPjs4ducexKHCFQQ3V99VDVeWi VxbP/ZOIqNpOpTaOFHuVSaJK3jvWt4hvDQRdvd7F1xHixVvhAVZ0JyonpUFVIsj+b8tvJvXZfPVpy HkCQpNi4TuKOfYgH40Wk0QT8YRv/ZoA6RHNvPSyVn2Tax07gJ9aB3OFhC9Odp2VNplcFwK+xjEqI+ Ne30ZysKIzYEO6gkhvda8UJgY6Q6dQWZMQ6XByF+w+jLy8hP4AqkSujNzOKIu/hJ0hJ9JMP08OlPG 1srlg81S7W6a2aNE5NGQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i1Auf-0000nV-VP; Fri, 23 Aug 2019 14:51:37 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1i1Aud-0000n2-8G for linux-arm-kernel@lists.infradead.org; Fri, 23 Aug 2019 14:51:36 +0000 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 97BFE2166E; Fri, 23 Aug 2019 14:51:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566571894; bh=aVchjuHWTXOaTDZuWT4rE8xKpWB6QsFxLg6BDqrPMBU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lOhadIdBCMKhZZkWRsZKTsc0dnSKABUI8r7IDxP9auoTwL6cq9VHHquL4sgCddJ6+ i1Jq9+dVh+hxyozPx0IO9InPMe2+rO8hPvYEdx76EdJfBrs/UVH85CpxjJtTRN9YbF 4CjkRdbiWquBWBZNXw5KcjOc4pDLb86Dt8FmvwSE= Date: Fri, 23 Aug 2019 23:51:27 +0900 From: Masami Hiramatsu To: Jisheng Zhang Subject: Re: [PATCH v2 1/3] kprobes/x86: use instruction_pointer and instruction_pointer_set Message-Id: <20190823235127.6b1ab6bdb3a280b64ca8585e@kernel.org> In-Reply-To: <20190821095527.729b2b0d@xhacker.debian> References: <20190820113928.1971900c@xhacker.debian> <20190820114109.4624d56b@xhacker.debian> <20190820165152.20275268@xhacker.debian> <20190821105247.f0236d2c04b2c0c4d4e1847e@kernel.org> <20190821095527.729b2b0d@xhacker.debian> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190823_075135_309983_BE0CE9FB X-CRM114-Status: GOOD ( 12.52 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jonathan Corbet , Catalin Marinas , "x86@kernel.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Anil S Keshavamurthy , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "Naveen N. Rao" , Thomas Gleixner , Will Deacon , "David S. Miller" , "linux-arm-kernel@lists.infradead.org" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Jisheng, On Wed, 21 Aug 2019 02:09:10 +0000 Jisheng Zhang wrote: > > > In v2, actually, the arm64 version's kprobe_ftrace_handler() is the same > > > as x86's, the only difference is comment, e.g > > > > > > /* Kprobe handler expects regs->ip = ip + 1 as breakpoint hit */ > > > > > > while in arm64 > > > > > > /* Kprobe handler expects regs->pc = ip + 1 as breakpoint hit */ > > > > As Peter pointed, on arm64, is that really 1 or 4 bytes? > > This part is heavily depends on the processor software-breakpoint > > implementation. > > Per my understanding, the "+1" here means "+ one kprobe_opcode_t". No, that is the size of INT3. It just emulates the software trap on x86. Thank you, -- Masami Hiramatsu _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel