From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jpmlD-0001mX-1p for kexec@lists.infradead.org; Mon, 29 Jun 2020 05:55:19 +0000 Subject: Re: [PATCH 04/11] ppc64/kexec_file: avoid stomping memory used by special regions References: <159319825403.16351.7253978047621755765.stgit@hbathini.in.ibm.com> <159319831192.16351.17443438699302756548.stgit@hbathini.in.ibm.com> <9cfda789-0747-a67a-b825-5ea6f15099b8@redhat.com> From: Hari Bathini Message-ID: Date: Mon, 29 Jun 2020 11:25:02 +0530 MIME-Version: 1.0 In-Reply-To: <9cfda789-0747-a67a-b825-5ea6f15099b8@redhat.com> Content-Language: en-US List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: piliu , Michael Ellerman , Andrew Morton Cc: Kexec-ml , Petr Tesarik , Mahesh J Salgaonkar , Sourabh Jain , lkml , linuxppc-dev , Mimi Zohar , Thiago Jung Bauermann , Dave Young , Vivek Goyal , Eric Biederman On 28/06/20 7:44 am, piliu wrote: > Hi Hari, Hi Pingfan, > > After a quick through for this series, I have a few question/comment on > this patch for the time being. Pls see comment inline. > > On 06/27/2020 03:05 AM, Hari Bathini wrote: >> crashkernel region could have an overlap with special memory regions >> like opal, rtas, tce-table & such. These regions are referred to as >> exclude memory ranges. Setup this ranges during image probe in order >> to avoid them while finding the buffer for different kdump segments. [...] >> + /* >> + * Use the locate_mem_hole logic in kexec_add_buffer() for regular >> + * kexec_file_load syscall >> + */ >> + if (kbuf->image->type != KEXEC_TYPE_CRASH) >> + return 0; > Can the ranges overlap [crashk_res.start, crashk_res.end]? Otherwise > there is no requirement for @exclude_ranges. The ranges like rtas, opal are loaded by f/w. They almost always overlap with crashkernel region. So, @exclude_ranges is required to support kdump. > I guess you have a design for future. If not true, then it is better to > fold the condition "if (kbuf->image->type != KEXEC_TYPE_CRASH)" into the > caller and rename this function to better distinguish use cases between > kexec and kdump Yeah, this condition will be folded. I have a follow-up patch for that explaining why kexec case should also be folded. Will try to add that to this series for v2. Thanks Hari _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec