commit 3141bba98af302e2a7c5e2a19203bb8a40b6aa63
Author: Dave Anderson <anderson@redhat.com>
Date:   Wed Oct 10 09:15:42 2018 -0400

    Fix the calculation of the vmalloc memory region size to account for
    Linux 4.17 commit a7412546d8cb5ad578805060b4006f2a021b5868, titled
    "x86/mm: Adjust vmalloc base and size at boot-time", which increases
    the region's size from 32TB to 1280TB when 5-level pagetables are
    enabled.  Also presume that virtual addresses above the end of the
    vmalloc space up to the beginning of vmemmap space are translatable
    via 5-level page tables.  Without the patch, mapped virtual addresses
    may fail translation in whatever command accesses them, with errors
    indicating "seek error: kernel virtual address: <mapped-address>
    type: <type-string>"
    (anderson@redhat.com)

diff --git a/x86_64.c b/x86_64.c
index 6f547e8..345122c 100644
--- a/x86_64.c
+++ b/x86_64.c
@@ -393,8 +393,12 @@ x86_64_init(int when)
 				readmem(symbol_value("vmalloc_base"), KVADDR,
 					&machdep->machspec->vmalloc_start_addr,
 					sizeof(ulong), "vmalloc_base", FAULT_ON_ERROR);
-				machdep->machspec->vmalloc_end =
-					machdep->machspec->vmalloc_start_addr + TERABYTES(32) - 1;
+				if (machdep->flags & VM_5LEVEL)
+					machdep->machspec->vmalloc_end =
+						machdep->machspec->vmalloc_start_addr + TERABYTES(1280) - 1;
+				else
+					machdep->machspec->vmalloc_end =
+						machdep->machspec->vmalloc_start_addr + TERABYTES(32) - 1;
 				if (kernel_symbol_exists("vmemmap_base")) {
 					readmem(symbol_value("vmemmap_base"), KVADDR,
 						&machdep->machspec->vmemmap_vaddr, sizeof(ulong),
@@ -1626,7 +1630,8 @@ x86_64_IS_VMALLOC_ADDR(ulong vaddr)
 		(vaddr >= VSYSCALL_START && vaddr < VSYSCALL_END) ||
 		(machdep->machspec->cpu_entry_area_start && 
 		 vaddr >= machdep->machspec->cpu_entry_area_start &&
-		 vaddr <= machdep->machspec->cpu_entry_area_end));
+		 vaddr <= machdep->machspec->cpu_entry_area_end) ||
+		((machdep->flags & VM_5LEVEL) && vaddr > VMALLOC_END && vaddr < VMEMMAP_VADDR));
 }
 
 static int