diff options
Diffstat (limited to 'arch/x86_64/kernel/head64.c')
| -rw-r--r-- | arch/x86_64/kernel/head64.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/arch/x86_64/kernel/head64.c b/arch/x86_64/kernel/head64.c index 5c529c1e3d6..6c34bdd22e2 100644 --- a/arch/x86_64/kernel/head64.c +++ b/arch/x86_64/kernel/head64.c @@ -18,8 +18,16 @@ #include <asm/setup.h> #include <asm/desc.h> #include <asm/pgtable.h> +#include <asm/tlbflush.h> #include <asm/sections.h> +static void __init zap_identity_mappings(void) +{ + pgd_t *pgd = pgd_offset_k(0UL); + pgd_clear(pgd); + __flush_tlb(); +} + /* Don't add a printk in there. printk relies on the PDA which is not initialized yet. */ static void __init clear_bss(void) @@ -57,18 +65,15 @@ void __init x86_64_start_kernel(char * real_mode_data) /* clear bss before set_intr_gate with early_idt_handler */ clear_bss(); + /* Make NULL pointers segfault */ + zap_identity_mappings(); + for (i = 0; i < IDT_ENTRIES; i++) set_intr_gate(i, early_idt_handler); asm volatile("lidt %0" :: "m" (idt_descr)); early_printk("Kernel alive\n"); - /* - * switch to init_level4_pgt from boot_level4_pgt - */ - memcpy(init_level4_pgt, boot_level4_pgt, PTRS_PER_PGD*sizeof(pgd_t)); - asm volatile("movq %0,%%cr3" :: "r" (__pa_symbol(&init_level4_pgt))); - for (i = 0; i < NR_CPUS; i++) cpu_pda(i) = &boot_cpu_pda[i]; |