From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120] helo=us-smtp-1.mimecast.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1icvnp-00034W-Qh for kexec@lists.infradead.org; Thu, 05 Dec 2019 18:24:39 +0000 Received: by mail-lf1-f71.google.com with SMTP id f16so648291lfc.2 for ; Thu, 05 Dec 2019 10:24:34 -0800 (PST) MIME-Version: 1.0 References: <1573556939-17803-1-git-send-email-bhsharma@redhat.com> <1573556939-17803-5-git-send-email-bhsharma@redhat.com> <4AE2DC15AC0B8543882A74EA0D43DBEC035971D4@BPXM09GP.gisp.nec.co.jp> In-Reply-To: <4AE2DC15AC0B8543882A74EA0D43DBEC035971D4@BPXM09GP.gisp.nec.co.jp> From: Bhupesh Sharma Date: Thu, 5 Dec 2019 23:54:20 +0530 Message-ID: Subject: Re: [PATCH v4 4/4] makedumpfile: Mark --mem-usage option unsupported for arm64 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: Kazuhito Hagio Cc: John Donnelly , "bhupesh.linux@gmail.com" , "kexec@lists.infradead.org" Hi Kazu, On Wed, Dec 4, 2019 at 11:20 PM Kazuhito Hagio wrote: > > > -----Original Message----- > > This patch marks '--mem-usage' option as unsupported for arm64 > > architecture. > > > > With the newer arm64 kernels supporting 48-bit/52-bit VA address spaces > > and keeping a single binary for supporting the same, the address of > > kernel symbols like _stext which could be earlier used to determine > > VA_BITS value, can no longer to determine whether VA_BITS is set to 48 > > or 52 in the kernel space. > > The --mem-usage option works with older arm64 kernels, so we should not > mark it unsupported for all arm64 kernels. > > (If we use ELF note vmcoreinfo in kcore, is it possible to support the > option? Let's think about it later..) Ok, I am in the process of discussing this with arm64 maintainers in detail as _stext symbol address can no longer be used to separate 48-bit v/s 52-bit kernel VA space configurations. Also other user-space utilities like 'kexec-tools' also face a similar problem with the 52-bit change (as the vmcore-dmesg stops working). I am currently caught up with another high priority issue. Will come back with more thoughts on this in a couple of days. Thanks, Bhupesh > > Hence for now, it makes sense to mark '--mem-usage' option as > > unsupported for arm64 architecture until we have more clarity from arm64 > > kernel maintainers on how to manage the same in future > > kernel/makedumpfile versions. > > > > Cc: John Donnelly > > Cc: Kazuhito Hagio > > Cc: kexec@lists.infradead.org > > Signed-off-by: Bhupesh Sharma > > --- > > makedumpfile.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/makedumpfile.c b/makedumpfile.c > > index baf559e4d74e..ae60466a1e9c 100644 > > --- a/makedumpfile.c > > +++ b/makedumpfile.c > > @@ -11564,6 +11564,11 @@ main(int argc, char *argv[]) > > MSG("\n"); > > MSG("The dmesg log is saved to %s.\n", info->name_dumpfile); > > } else if (info->flag_mem_usage) { > > +#ifdef __aarch64__ > > + MSG("mem-usage not supported for arm64 architecure.\n"); > > + goto out; > > +#endif > > + > > if (!check_param_for_creating_dumpfile(argc, argv)) { > > MSG("Commandline parameter is invalid.\n"); > > MSG("Try `makedumpfile --help' for more information.\n"); > > -- > > 2.7.4 > > > > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec