[Crash-utility] Question about crashkernel parameter on cmdline

Hi, list. I am running kexec-tools on ARM soc to dump vmcore file. In my case, the crashkernel parameter of crash kernel 's cmdline is "crashkernel=20M@10M". Then in bash of crash kernel, "echo c > /proc/sysrq-trigger", and the capture kernel launches. But it will fail on initializing /proc/vmcore. Because it trigger "WARN_ON(pfn_valid(pfn))" in __arm_ioremap_pfn_caller() @arch/arm/mm/ioremap.c. I check the reason as follows. #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) To my case, pfn:x01d00, ARCH_PFN_OFFSET:0, max_mapnr:0x1300. So pfn-ARCH_PFN_OFFSET is less than max_mapnr, and the WARN_ON(pfn_valid(pfn)) is triggered on. I want to know, to ignore this warning, whether I should comment this WARN_ON() in kernel source code for my case. And another doubt, will this warning corrupt my dumpfile? Because, when I use the crash utility to analyse this vmcore, many errors throw. Any suggestion will be appreciate. Thanks.