Hi Vadim, On Fri, Oct 26, 2018 at 6:49 PM Vadim Lomovtsev <Vadim.Lomovtsev@xxxxxxxxxxxxxxxxxx> wrote: > > Hi Bhupesh, > > On Fri, Oct 26, 2018 at 03:49:11PM +0530, Bhupesh Sharma wrote: > > > > Hi Vadim, > > On Fri, Oct 26, 2018 at 3:41 PM Vadim Lomovtsev > > <Vadim.Lomovtsev@xxxxxxxxxxxxxxxxxx> wrote: > > > > > > Hi Bhupesh, > > > > > > On Fri, Oct 26, 2018 at 12:25:17PM +0530, Bhupesh Sharma wrote: > > > > > > > > ease p > > > > before seiHi Vadim, > > > > > > > > On Thu, Oct 25, 2018 at 4:10 PM Vadim Lomovtsev > > > > <Vadim.Lomovtsev@xxxxxxxxxxxxxxxxxx> wrote: > > > > > > > > > > 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 > > > > > > > > Hmm.. that's strange as I rebased them on kexec-tools 2.0.18-rc1 > > > > (94159bc3c264fa26395e56302072276a139d18af) > > > > before sending out the patchset. > > > > > > > > > Are there any specific branch/revision for them to be applied ? > > > > > (or it might be my mail server issues with formatting emails). > > > > > > > > > > > > > Can you please try picking them up from my public github tree instead? > > > > Here you can find the same: > > > > https://github.com/bhupesh-sharma/kexec-tools/tree/read-phys-offset-from-kcore-upstream-v1 > > > > > > > > Please pick the top 2 commit from here. > > > > > > Applied them onto commit '94159bc kexec-tools 2.0.18-rc1'. > > > > > > Still having following error while saving dmesg by vmcore-dmesg: > > > > > > kdump: saving vmcore-dmesg.txt > > > Failed to read log text of size 0 bytes: Bad address > > > kdump: saving vmcore-dmesg.txt failed > > > > > > So far tried kernels 4.14.78, 4.16.18. > > > > You would need kernel 4.19-rc5 or above as the same exposes VMCOREINFO > > as '/proc/kcore'. > > So far with 4.19-rc6 (and updated kexec, vmcore-dmesg but having kdump scripts from CentOS) > the crashkernel can't found sysroot and thus it can't dump anything, so it timeouts and reboot system. > > > If you are having issues while switching to newer kernel, please share > > the output(s) of following on your platform: > > > > # kexec -p /boot/vmlinuz-`uname -r` --initrd=/boot/initramfs-`uname > > -r`.img --reuse-cmdline -d > > > > attached as kexec-start.log.xz > > > and, > > > > # readelf -l vmcore > > [root@2sgbt-53 vlomovts]# readelf -l vmcore > readelf: vmcore: Error: No such file > [root@2sgbt-53 vlomovts]# uname -r > 4.19.0-rc6+ > > > > > and, > > > > # cat /proc/iomem > > attached as cat-proc-iomem.log.xz Just to confirm: these logs are after your apply my kexec-tools patches, right? It looks likely that we are seeing differences in the value of 'phys_offset' on your platforms: From, '/proc/iomem', we can see that phys_offset is 0x01400000: 01400000-ffedffff : System RAM while the 'kexec -p -d' logs indicate that it is 0: image_arm64_load: phys_offset: 0000000000000000 This tells me that the phys_offset value is not correctly calculated in kexec-tools which should be fixed after my patches. BTW , by '# readelf -l vmcore', I meant the 'vmcore' dump file you have obtained via 'kexec'. It might be that you are saving it on some different location (something /var/crash?). Can you please try sharing the output of the same as well? Regards, Bhupesh > > > > And then I can suggest a hack, which you can try and test on your > > platform and then we can take it forward from there. > > > > Thanks, > > Bhupesh > > > > > > > > > > Thanks, > > > > Bhupesh > > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > Bhupesh _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
