/* * linux/arch/i386/kernel/sysenter.c * * (C) Copyright 2002 Linus Torvalds * * This file contains the needed initializations to support sysenter. */ #include <linux/init.h> #include <linux/smp.h> #include <linux/thread_info.h> #include <linux/sched.h> #include <linux/gfp.h> #include <linux/string.h> #include <linux/elf.h> #include <asm/cpufeature.h> #include <asm/msr.h> #include <asm/pgtable.h> #include <asm/unistd.h> extern asmlinkage void sysenter_entry(void); void enable_sep_cpu(void) { int cpu = get_cpu(); struct tss_struct *tss = &per_cpu(init_tss, cpu); if (!boot_cpu_has(X86_FEATURE_SEP)) { put_cpu(); return; } tss->ss1 = __KERNEL_CS; tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss; wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0); wrmsr(MSR_IA32_SYSENTER_ESP, tss->esp1, 0); wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) sysenter_entry, 0); put_cpu(); } /* * These symbols are defined by vsyscall.o to mark the bounds * of the ELF DSO images included therein. */ extern const char vsyscall_int80_start, vsyscall_int80_end; extern const char vsyscall_sysenter_start, vsyscall_sysenter_end; int __init sysenter_setup(void) { void *page = (void *)get_zeroed_page(GFP_ATOMIC); __set_fixmap(FIX_VSYSCALL, __pa(page), PAGE_READONLY_EXEC); if (!boot_cpu_has(X86_FEATURE_SEP)) { memcpy(page, &vsyscall_int80_start, &vsyscall_int80_end - &vsyscall_int80_start); return 0; } memcpy(page, &vsyscall_sysenter_start, &vsyscall_sysenter_end - &vsyscall_sysenter_start); return 0; }