Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64...

[cascardo/linux.git] / arch / arm64 / kernel / setup.c

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 450987d..9dc6776 100644 (file)
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -62,6 +62,7 @@
 #include <asm/memblock.h>
 #include <asm/efi.h>
 #include <asm/xen/hypervisor.h>
+#include <asm/mmu_context.h>
 
 phys_addr_t __fdt_pointer __initdata;
 
@@ -313,6 +314,12 @@ void __init setup_arch(char **cmdline_p)
         */
        local_async_enable();
 
+       /*
+        * TTBR0 is only used for the identity mapping at this stage. Make it
+        * point to zero page to avoid speculatively fetching new entries.
+        */
+       cpu_uninstall_idmap();
+
        efi_init();
        arm64_memblock_init();
 
@@ -381,3 +388,32 @@ static int __init topology_init(void)
        return 0;
 }
 subsys_initcall(topology_init);
+
+/*
+ * Dump out kernel offset information on panic.
+ */
+static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
+                             void *p)
+{
+       u64 const kaslr_offset = kimage_vaddr - KIMAGE_VADDR;
+
+       if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset > 0) {
+               pr_emerg("Kernel Offset: 0x%llx from 0x%lx\n",
+                        kaslr_offset, KIMAGE_VADDR);
+       } else {
+               pr_emerg("Kernel Offset: disabled\n");
+       }
+       return 0;
+}
+
+static struct notifier_block kernel_offset_notifier = {
+       .notifier_call = dump_kernel_offset
+};
+
+static int __init register_kernel_offset_dumper(void)
+{
+       atomic_notifier_chain_register(&panic_notifier_list,
+                                      &kernel_offset_notifier);
+       return 0;
+}
+__initcall(register_kernel_offset_dumper);