Hello Bhupesh, On Thu, Oct 25, 2018 at 03:00:08AM +0530, Bhupesh Sharma wrote: > External Email > > Hello Vadim, > > On Wed, Oct 24, 2018 at 6:23 PM Lomovtsev, Vadim > <Vadim.Lomovtsev@xxxxxxxxxx> wrote: > > > > Hi all, > > > > Following issue has been found for vmcore-dmesg app with latest release (94159bc3c264fa26395e56302072276a139d18af 2.0.18-rc1) of kexec-tools at CentOS 7.5 distro: > > > > While having systems with large number of CPUs (e.g. Cavium ThunderX2 has 224) the log_buf gets reallocated by memblock_virt_alloc() at the setup_log_buf routine (https://elixir.bootlin.com/linux/v4.16.18/source/kernel/printk/printk.c#L1108). > > > > Then while dumping vmcore the vmcore-dmesg can't find dmesg log at /proc/vmcore file and exits with following message: > > Failed to read log text of size 0 bytes: Bad address > > > > However it (vmcore-dmesg app) reads properly the log_buf symbol, it's address and eventually it's value from /proc/vmcore but fails to find dmesg data then. > > > > In the same time the makedumpfile is able to find and extract dmesg buffer from /proc/vmcore. > > The makedumpfile comes with kexec-tools-2.0.15-13.el7_5.2.aarch64 package. > > > > The issue is not reproduced for systems with small number of CPUs and log_buf not reallocated to memblock section. > > Seems like you are hitting a known issue we saw on qualcomm amberwing > platforms as well. > I have sent a patch-series titled 'kexec-tools/arm64: Add support to > read PHYS_OFFSET from vmcoreinfo inside '/proc/kcore' to this list > just a few minutes back. > > I have Cc'ed you to the patchset as I think it might fix the issue for > you. Got them, thank you. > Kindly try the patchset on your platform (cavium?) and let me > know if this fixes the issue for you. Sure, I'd like to check them at my side, but.. I fall into merge conflicts while trying to apply them onto https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/ master, kexec-tools 2.0.18-rc1 94159bc3c264fa26395e56302072276a139d18af Are there any specific branch/revision for them to be applied ? (or it might be my mail server issues with formatting emails). WBR, Vadim > > Thanks, > Bhupesh _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
