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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Tue, 29 Oct 2019 16:34:53 -0000 Received: from d06av23.portsmouth.uk.ibm.com (d06av23.portsmouth.uk.ibm.com [9.149.105.59]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x9TGYquB44433852 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 29 Oct 2019 16:34:52 GMT Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4B77FA4051; Tue, 29 Oct 2019 16:34:52 +0000 (GMT) Received: from d06av23.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DD884A4040; Tue, 29 Oct 2019 16:34:51 +0000 (GMT) Received: from osiris (unknown [9.152.212.85]) by d06av23.portsmouth.uk.ibm.com (Postfix) with ESMTPS; Tue, 29 Oct 2019 16:34:51 +0000 (GMT) Date: Tue, 29 Oct 2019 17:34:50 +0100 From: Heiko Carstens To: Miroslav Benes Cc: gor@linux.ibm.com, borntraeger@de.ibm.com, jpoimboe@redhat.com, joe.lawrence@redhat.com, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, jikos@kernel.org, pmladek@suse.com, nstange@suse.de, live-patching@vger.kernel.org Subject: Re: [PATCH v2 0/3] s390/livepatch: Implement reliable stack tracing for the consistency model References: <20191029143904.24051-1-mbenes@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191029143904.24051-1-mbenes@suse.cz> X-TM-AS-GCONF: 00 x-cbid: 19102916-0016-0000-0000-000002BED94E X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19102916-0017-0000-0000-000033203281 Message-Id: <20191029163450.GI5646@osiris> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-10-29_05:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=486 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1908290000 definitions=main-1910290145 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 29, 2019 at 03:39:01PM +0100, Miroslav Benes wrote: > - I tried to use the existing infrastructure as much as possible with > one exception. I kept unwind_next_frame_reliable() next to the > ordinary unwind_next_frame(). I did not come up with a nice solution > how to integrate it. The reliable unwinding is executed on a task > stack only, which leads to a nice simplification. My integration > attempts only obfuscated the existing unwind_next_frame() which is > already not easy to read. Ideas are definitely welcome. Ah, now I see. So patch 2 seems to be leftover(?). Could you just send how the result would look like? I'd really like to have only one function, since some of the sanity checks you added also make sense for what we already have - so code would diverge from the beginning.