On Fri, Oct 05, 2018 at 10:46:19AM +0100, Russell King - ARM Linux wrote: > On Fri, Oct 05, 2018 at 11:09:40AM +0200, Marek Szyprowski wrote: > > This patch causes lots of kernel 'BUG' messages on all Samsung Exynos > > boards. It started to appear since it has been merged to linux-next > > on 20181002. I wonder if this issue is Exynos specific or there are > > some patches missing in linux-next, which should fix those 'BUGS'. > > If this is Exynos specific, please let us know what should be changed > > in Exynos platform code to avoid this issue. > > Thanks for the report. > > It looks like my solution for big.Little isn't possible... back to > the drawing board, and big.Little will have to remain vulnerable to > Spectre for another release cycle. I've pushed out a new version in my build branch for the autobuilders to chew on, but I've little confidence in validating that the problem is fixed because the boot results are completely unreliable. It really doesn't help that kernelci.org flags boot logs as "green" and "successful" when they contain such stuff as: 01:08:40.181846 [ 9.309984] Unable to handle kernel paging request at virtual address e7fddef0 which is the kernel hitting a BUG() - for the full log, see: https://storage.kernelci.org/rmk/to-build/v4.16-38-g9fa10446d304/arm/multi_v7_defconfig/lab-collabora/boot-exynos5800-peach-pi.html This means the only way to check is to _manually_ go through reading each and every boot log - to see if your reported BUG: messages are there - no thanks. If kernelci thinks that a boot which hits a kernel BUG(), but still manages to get to a shell prompt is successful, it's giving very misleading boot results. What about a WARN_ON() or an oops that still allows it to reach a shell prompt. Yes, these may be "successful" in so far as reaching the shell prompt, but they should at least be flagged for further inspection, not effectively marked as "there is nothing wrong here". -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up
