kernel_p4d 420 arch/x86/mm/pti.c p4d_t *kernel_p4d, *user_p4d; kernel_p4d 428 arch/x86/mm/pti.c kernel_p4d = p4d_offset(kernel_pgd, addr); kernel_p4d 429 arch/x86/mm/pti.c *user_p4d = *kernel_p4d;