From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by sourceware.org (Postfix) with ESMTPS id DB78D3858002 for ; Mon, 29 Mar 2021 13:27:16 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org DB78D3858002 Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 12TD5g99135065; Mon, 29 Mar 2021 09:27:14 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 37jpbvbqeq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Mar 2021 09:27:14 -0400 Received: from m0098421.ppops.net (m0098421.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.43/8.16.0.43) with SMTP id 12TD45gH124518; Mon, 29 Mar 2021 09:27:14 -0400 Received: from ppma04dal.us.ibm.com (7a.29.35a9.ip4.static.sl-reverse.com [169.53.41.122]) by mx0a-001b2d01.pphosted.com with ESMTP id 37jpbvbqef-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Mar 2021 09:27:14 -0400 Received: from pps.filterd (ppma04dal.us.ibm.com [127.0.0.1]) by ppma04dal.us.ibm.com (8.16.0.43/8.16.0.43) with SMTP id 12TDHuQc024759; Mon, 29 Mar 2021 13:27:13 GMT Received: from b03cxnp08028.gho.boulder.ibm.com (b03cxnp08028.gho.boulder.ibm.com [9.17.130.20]) by ppma04dal.us.ibm.com with ESMTP id 37hvb928xq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 29 Mar 2021 13:27:13 +0000 Received: from b03ledav005.gho.boulder.ibm.com (b03ledav005.gho.boulder.ibm.com [9.17.130.236]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 12TDRC1621954996 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 29 Mar 2021 13:27:12 GMT Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 25710BE054; Mon, 29 Mar 2021 13:27:12 +0000 (GMT) Received: from b03ledav005.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C7630BE053; Mon, 29 Mar 2021 13:27:10 +0000 (GMT) Received: from TP480.linux.ibm.com (unknown [9.65.241.79]) by b03ledav005.gho.boulder.ibm.com (Postfix) with ESMTPS; Mon, 29 Mar 2021 13:27:10 +0000 (GMT) References: <20210322142035.183915-1-msc@linux.ibm.com> <87k0pzmeqh.fsf@igel.home> User-agent: mu4e 1.4.10; emacs 27.1 From: Matheus Castanho To: Andreas Schwab Cc: Matheus Castanho via Libc-alpha , tuliom@linux.ibm.com, npiggin@gmail.com Subject: Re: [PATCH] powerpc: Add missing registers to clobbers list for syscalls [BZ #27623] In-reply-to: <87k0pzmeqh.fsf@igel.home> Date: Mon, 29 Mar 2021 10:27:08 -0300 Message-ID: <87v99aks43.fsf@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-GUID: gMS5Cv3UwDCEy8fsYxHTnjfho46IgiZE X-Proofpoint-ORIG-GUID: oBD5Zr_wrtj20WoOtHIckW4w0IJiUi-N X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.369, 18.0.761 definitions=2021-03-29_09:2021-03-26, 2021-03-29 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 mlxscore=0 suspectscore=0 priorityscore=1501 malwarescore=0 clxscore=1011 spamscore=0 lowpriorityscore=0 bulkscore=0 impostorscore=0 adultscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2103250000 definitions=main-2103290097 X-Spam-Status: No, score=-4.5 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 29 Mar 2021 13:27:18 -0000 Andreas Schwab writes: > On M=C3=A4r 22 2021, Matheus Castanho via Libc-alpha wrote: > >> Some registers that can be clobbered by the kernel during a syscall are = not >> listed on the clobbers list in sysdeps/unix/sysv/linux/powerpc/sysdep.h. >> >> For syscalls using sc: >> - XER is zeroed by the kernel on exit >> >> For syscalls using scv: >> - XER is zeroed by the kernel on exit >> - Different from the sc case, most CR fields can be clobbered (accor= ding to >> the ELF ABI and the Linux kernel's syscall ABI for powerpc >> (linux/Documentation/powerpc/syscall64-abi.rst) >> >> These are likely not causing issues today, but they should be added to t= he >> clobbers list just in case things change on the kernel side in the futur= e. > > What about INTERNAL_VSYSCALL_CALL_TYPE? Doesn't that clobber XER[CA] > and CR1/5/6/7 like ordinary function calls? > > Andreas. Yes, looks like they should be added to the clobbers list there too. I'll s= end a v2 shortly. -- Matheus Castanho