/* Stores the physical address of elf header of crash image. */
unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX;
+static inline bool is_crashed_pfn_valid(unsigned long pfn)
+{
+#ifndef CONFIG_X86_PAE
+ /*
+ * non-PAE kdump kernel executed from a PAE one will crop high pte
+ * bits and poke unwanted space counting again from address 0, we
+ * don't want that. pte must fit into unsigned long. In fact the
+ * test checks high 12 bits for being zero (pfn will be shifted left
+ * by PAGE_SHIFT).
+ */
+ return pte_pfn(pfn_pte(pfn, __pgprot(0))) == pfn;
+#else
+ return true;
+#endif
+}
+
/**
* copy_oldmem_page - copy one page from "oldmem"
* @pfn: page frame number to be copied
if (!csize)
return 0;
+ if (!is_crashed_pfn_valid(pfn))
+ return -EFAULT;
+
vaddr = kmap_atomic_pfn(pfn, KM_PTE0);
if (!userbuf) {