On 19/08/16 09:00, Pratyush Anand wrote: > On 17/08/2016:04:33:31 PM, James Morse wrote: >> copy_oldmem_page() and mmap_vmcore() provide two ways for userspace to read >> from /proc/vmcore. Neither of these check with memblock to see if the page >> they are accessing is nomap. On Seattle this causes: > > Thanks for the patch.It did resolve the kernel crash issue with makedumpfile, > however neither there was any data in vmcore-dmesg nor crash utility was able to > work the saved vmcore. vmcore-dmesg doesn't work for me, but crash did once I'd rebuilt it from the most recent source. The most recent commit I have is: b349598bb755 ("Fix for the ARM64 "bt -R <symbol>" option if the only reference") Are you using an older version? Thanks, James [0] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-August/447597.html