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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 918DAC433B4 for ; Sat, 15 May 2021 10:35:21 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 1FA4B61355 for ; Sat, 15 May 2021 10:35:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1FA4B61355 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45980 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lhrde-0001YE-Pf for qemu-devel@archiver.kernel.org; Sat, 15 May 2021 06:35:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37450) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lhrZX-0004JG-Lt for qemu-devel@nongnu.org; Sat, 15 May 2021 06:31:03 -0400 Received: from indium.canonical.com ([91.189.90.7]:52500) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lhrZR-0006Dp-1c for qemu-devel@nongnu.org; Sat, 15 May 2021 06:31:03 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.93 #5 (Debian)) id 1lhrZO-0004Ck-Tg for ; Sat, 15 May 2021 10:30:54 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id DF1292E8188 for ; Sat, 15 May 2021 10:30:54 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Sat, 15 May 2021 10:23:22 -0000 From: Thomas Huth <1922773@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Incomplete; importance=Undecided; assignee=None; X-Launchpad-Bug-Tags: riscv32 X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: mehrdadhe th-huth X-Launchpad-Bug-Reporter: Mehrdad Hessar (mehrdadhe) X-Launchpad-Bug-Modifier: Thomas Huth (th-huth) References: <161772848102.29247.5138127903263010821.malonedeb@gac.canonical.com> Message-Id: <162107420287.21341.10547864525499442661.malone@soybean.canonical.com> Subject: [Bug 1922773] Re: RISCV32 illegal instruction exception X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="5321c3f40fa4d4b847f4e47fb766e7b95ed5036c"; Instance="production" X-Launchpad-Hash: 989f1de0a36dd0930a6e73817fd327ec94332eb3 Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -65 X-Spam_score: -6.6 X-Spam_bar: ------ X-Spam_report: (-6.6 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.248, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1922773 <1922773@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The QEMU project is currently moving its bug tracking to another system. For this we need to know which bugs are still valid and which could be closed already. Thus we are setting the bug state to "Incomplete" now. If the bug has already been fixed in the latest upstream version of QEMU, then please close this ticket as "Fix released". If it is not fixed yet and you think that this bug report here is still valid, then you have two options: 1) If you already have an account on gitlab.com, please open a new ticket for this problem in our new tracker here: https://gitlab.com/qemu-project/qemu/-/issues and then close this ticket here on Launchpad (or let it expire auto- matically after 60 days). Please mention the URL of this bug ticket on Launchpad in the new ticket on GitLab. 2) If you don't have an account on gitlab.com and don't intend to get one, but still would like to keep this ticket opened, then please switch the state back to "New" or "Confirmed" within the next 60 days (other- wise it will get closed as "Expired"). We will then eventually migrate the ticket automatically to the new system (but you won't be the reporter of the bug in the new system and thus you won't get notified on changes anymore). Thank you and sorry for the inconvenience. ** Changed in: qemu Status: New =3D> Incomplete -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1922773 Title: RISCV32 illegal instruction exception Status in QEMU: Incomplete Bug description: I'm running a machine learning model on qemu riscv32 and I ran into illegal instruction exception for some reason. I wasn't sure if this is a bug and if so whether it is related to zephyr or qemu, however I'll try to provide as much as information to get a better understanding. Here is the assembly code that I'm running: 0x8000bd74 <+0>: lw a4,0(a0) 0x8000bd76 <+2>: lw a5,8(a0) 0x8000bd78 <+4>: lw a0,0(a4) 0x8000bd7a <+6>: lw a1,0(a5) 0x8000bd7c <+8>: li a3,0 0x8000bd7e <+10>: j 0x8000bda4 0x8000bd80 <+12>: addi a5,a3,-2 0x8000bd84 <+16>: li a2,27 0x8000bd86 <+18>: bgeu a2,a5,0x8000bdae =3D> 0x8000bd8a <+22>: fmv.w.x fa5,zero 0x8000bd8e <+26>: slli a5,a3,0x5 0x8000bd92 <+30>: add a5,a5,a4 0x8000bd94 <+32>: slli a5,a5,0x2 0x8000bd96 <+34>: add a5,a5,a1 0x8000bd98 <+36>: fsw fa5,0(a5) 0x8000bd9a <+38>: addi a4,a4,1 0x8000bd9c <+40>: li a5,31 0x8000bd9e <+42>: bge a5,a4,0x8000bd80 0x8000bda2 <+46>: addi a3,a3,1 0x8000bda4 <+48>: li a5,31 0x8000bda6 <+50>: blt a5,a3,0x8000bde0 0x8000bdaa <+54>: li a4,0 0x8000bdac <+56>: j 0x8000bd9c 0x8000bdae <+58>: li a5,1 0x8000bdb0 <+60>: bge a5,a4,0x8000bdd4 0x8000bdb4 <+64>: li a5,29 0x8000bdb6 <+66>: blt a5,a4,0x8000bdda 0x8000bdba <+70>: li a5,28 0x8000bdbc <+72>: mul a5,a3,a5 0x8000bdc0 <+76>: add a5,a5,a4 0x8000bdc2 <+78>: lui a2,0x40000 0x8000bdc6 <+82>: addi a2,a2,-58 # 0x3fffffc6 0x8000bdca <+86>: add a5,a5,a2 0x8000bdcc <+88>: slli a5,a5,0x2 0x8000bdce <+90>: add a5,a5,a0 0x8000bdd0 <+92>: flw fa5,0(a5) 0x8000bdd2 <+94>: j 0x8000bd8e 0x8000bdd4 <+96>: fmv.w.x fa5,zero 0x8000bdd8 <+100>: j 0x8000bd8e 0x8000bdda <+102>: fmv.w.x fa5,zero 0x8000bdde <+106>: j 0x8000bd8e 0x8000bde0 <+108>: li a0,0 0x8000bde2 <+110>: ret My code breaks on line 0x8000bd8a and then the mcause register is loaded with value 0x02 which translates to illegal instruction. Please let me know if you need more information about this. I also posted this on ZephyrProject in case it is related to the Zephyr: https://github.com/zephyrproject-rtos/zephyr/issues/34026 I have tested on both QEMU 5.1.0 and 5.2.0 versions. I ran the same code on qemu riscv64 and didn't have the same problem. Here is the assembly code that is generated for the same operation: =3D> 0x000000008000b446 <+0>: ld a4,0(a0) 0x000000008000b448 <+2>: ld a5,8(a0) 0x000000008000b44a <+4>: ld a0,0(a4) 0x000000008000b44c <+6>: ld a1,0(a5) 0x000000008000b44e <+8>: li a3,0 0x000000008000b450 <+10>: j 0x8000b476 0x000000008000b452 <+12>: addiw a5,a3,-2 0x000000008000b456 <+16>: li a2,27 0x000000008000b458 <+18>: bgeu a2,a5,0x8000b480 0x000000008000b45c <+22>: li a2,0 0x000000008000b460 <+26>: slliw a5,a3,0x5 0x000000008000b464 <+30>: addw a5,a5,a4 0x000000008000b466 <+32>: slli a5,a5,0x2 0x000000008000b468 <+34>: add a5,a5,a1 0x000000008000b46a <+36>: sw a2,0(a5) 0x000000008000b46c <+38>: addiw a4,a4,1 0x000000008000b46e <+40>: li a5,31 0x000000008000b470 <+42>: bge a5,a4,0x8000b452 0x000000008000b474 <+46>: addiw a3,a3,1 0x000000008000b476 <+48>: li a5,31 0x000000008000b478 <+50>: blt a5,a3,0x8000b4ac 0x000000008000b47c <+54>: li a4,0 0x000000008000b47e <+56>: j 0x8000b46e 0x000000008000b480 <+58>: li a5,1 0x000000008000b482 <+60>: bge a5,a4,0x8000b4a0 0x000000008000b486 <+64>: li a5,29 0x000000008000b488 <+66>: blt a5,a4,0x8000b4a6 0x000000008000b48c <+70>: li a5,28 0x000000008000b48e <+72>: mulw a5,a5,a3 0x000000008000b492 <+76>: addw a5,a5,a4 0x000000008000b494 <+78>: addiw a5,a5,-58 0x000000008000b498 <+82>: slli a5,a5,0x2 0x000000008000b49a <+84>: add a5,a5,a0 0x000000008000b49c <+86>: lw a2,0(a5) 0x000000008000b49e <+88>: j 0x8000b460 0x000000008000b4a0 <+90>: li a2,0 0x000000008000b4a4 <+94>: j 0x8000b460 0x000000008000b4a6 <+96>: li a2,0 0x000000008000b4aa <+100>: j 0x8000b460 0x000000008000b4ac <+102>: li a0,0 0x000000008000b4ae <+104>: ret To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1922773/+subscriptions