diff options
Diffstat (limited to 'arch/x86_64/kernel/vsyscall.c')
| -rw-r--r-- | arch/x86_64/kernel/vsyscall.c | 226 |
1 files changed, 0 insertions, 226 deletions
diff --git a/arch/x86_64/kernel/vsyscall.c b/arch/x86_64/kernel/vsyscall.c deleted file mode 100644 index 2e573442594..00000000000 --- a/arch/x86_64/kernel/vsyscall.c +++ /dev/null @@ -1,226 +0,0 @@ -/* - * linux/arch/x86_64/kernel/vsyscall.c - * - * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE - * Copyright 2003 Andi Kleen, SuSE Labs. - * - * Thanks to hpa@transmeta.com for some useful hint. - * Special thanks to Ingo Molnar for his early experience with - * a different vsyscall implementation for Linux/IA32 and for the name. - * - * vsyscall 1 is located at -10Mbyte, vsyscall 2 is located - * at virtual address -10Mbyte+1024bytes etc... There are at max 4 - * vsyscalls. One vsyscall can reserve more than 1 slot to avoid - * jumping out of line if necessary. We cannot add more with this - * mechanism because older kernels won't return -ENOSYS. - * If we want more than four we need a vDSO. - * - * Note: the concept clashes with user mode linux. If you use UML and - * want per guest time just set the kernel.vsyscall64 sysctl to 0. - */ - -#include <linux/time.h> -#include <linux/init.h> -#include <linux/kernel.h> -#include <linux/timer.h> -#include <linux/seqlock.h> -#include <linux/jiffies.h> -#include <linux/sysctl.h> - -#include <asm/vsyscall.h> -#include <asm/pgtable.h> -#include <asm/page.h> -#include <asm/fixmap.h> -#include <asm/errno.h> -#include <asm/io.h> - -#define __vsyscall(nr) __attribute__ ((unused,__section__(".vsyscall_" #nr))) -#define force_inline __attribute__((always_inline)) inline - -int __sysctl_vsyscall __section_sysctl_vsyscall = 1; -seqlock_t __xtime_lock __section_xtime_lock = SEQLOCK_UNLOCKED; - -#include <asm/unistd.h> - -static force_inline void timeval_normalize(struct timeval * tv) -{ - time_t __sec; - - __sec = tv->tv_usec / 1000000; - if (__sec) { - tv->tv_usec %= 1000000; - tv->tv_sec += __sec; - } -} - -static force_inline void do_vgettimeofday(struct timeval * tv) -{ - long sequence, t; - unsigned long sec, usec; - - do { - sequence = read_seqbegin(&__xtime_lock); - - sec = __xtime.tv_sec; - usec = (__xtime.tv_nsec / 1000) + - (__jiffies - __wall_jiffies) * (1000000 / HZ); - - if (__vxtime.mode != VXTIME_HPET) { - sync_core(); - rdtscll(t); - if (t < __vxtime.last_tsc) - t = __vxtime.last_tsc; - usec += ((t - __vxtime.last_tsc) * - __vxtime.tsc_quot) >> 32; - /* See comment in x86_64 do_gettimeofday. */ - } else { - usec += ((readl((void *)fix_to_virt(VSYSCALL_HPET) + 0xf0) - - __vxtime.last) * __vxtime.quot) >> 32; - } - } while (read_seqretry(&__xtime_lock, sequence)); - - tv->tv_sec = sec + usec / 1000000; - tv->tv_usec = usec % 1000000; -} - -/* RED-PEN may want to readd seq locking, but then the variable should be write-once. */ -static force_inline void do_get_tz(struct timezone * tz) -{ - *tz = __sys_tz; -} - -static force_inline int gettimeofday(struct timeval *tv, struct timezone *tz) -{ - int ret; - asm volatile("vsysc2: syscall" - : "=a" (ret) - : "0" (__NR_gettimeofday),"D" (tv),"S" (tz) : __syscall_clobber ); - return ret; -} - -static force_inline long time_syscall(long *t) -{ - long secs; - asm volatile("vsysc1: syscall" - : "=a" (secs) - : "0" (__NR_time),"D" (t) : __syscall_clobber); - return secs; -} - -static int __vsyscall(0) vgettimeofday(struct timeval * tv, struct timezone * tz) -{ - if (unlikely(!__sysctl_vsyscall)) - return gettimeofday(tv,tz); - if (tv) - do_vgettimeofday(tv); - if (tz) - do_get_tz(tz); - return 0; -} - -/* This will break when the xtime seconds get inaccurate, but that is - * unlikely */ -static time_t __vsyscall(1) vtime(time_t *t) -{ - if (unlikely(!__sysctl_vsyscall)) - return time_syscall(t); - else if (t) - *t = __xtime.tv_sec; - return __xtime.tv_sec; -} - -static long __vsyscall(2) venosys_0(void) -{ - return -ENOSYS; -} - -static long __vsyscall(3) venosys_1(void) -{ - return -ENOSYS; -} - -#ifdef CONFIG_SYSCTL - -#define SYSCALL 0x050f -#define NOP2 0x9090 - -/* - * NOP out syscall in vsyscall page when not needed. - */ -static int vsyscall_sysctl_change(ctl_table *ctl, int write, struct file * filp, - void __user *buffer, size_t *lenp, loff_t *ppos) -{ - extern u16 vsysc1, vsysc2; - u16 *map1, *map2; - int ret = proc_dointvec(ctl, write, filp, buffer, lenp, ppos); - if (!write) - return ret; - /* gcc has some trouble with __va(__pa()), so just do it this - way. */ - map1 = ioremap(__pa_symbol(&vsysc1), 2); - if (!map1) - return -ENOMEM; - map2 = ioremap(__pa_symbol(&vsysc2), 2); - if (!map2) { - ret = -ENOMEM; - goto out; - } - if (!sysctl_vsyscall) { - *map1 = SYSCALL; - *map2 = SYSCALL; - } else { - *map1 = NOP2; - *map2 = NOP2; - } - iounmap(map2); -out: - iounmap(map1); - return ret; -} - -static int vsyscall_sysctl_nostrat(ctl_table *t, int __user *name, int nlen, - void __user *oldval, size_t __user *oldlenp, - void __user *newval, size_t newlen, - void **context) -{ - return -ENOSYS; -} - -static ctl_table kernel_table2[] = { - { .ctl_name = 99, .procname = "vsyscall64", - .data = &sysctl_vsyscall, .maxlen = sizeof(int), .mode = 0644, - .strategy = vsyscall_sysctl_nostrat, - .proc_handler = vsyscall_sysctl_change }, - { 0, } -}; - -static ctl_table kernel_root_table2[] = { - { .ctl_name = CTL_KERN, .procname = "kernel", .mode = 0555, - .child = kernel_table2 }, - { 0 }, -}; - -#endif - -static void __init map_vsyscall(void) -{ - extern char __vsyscall_0; - unsigned long physaddr_page0 = __pa_symbol(&__vsyscall_0); - - __set_fixmap(VSYSCALL_FIRST_PAGE, physaddr_page0, PAGE_KERNEL_VSYSCALL); -} - -static int __init vsyscall_init(void) -{ - BUG_ON(((unsigned long) &vgettimeofday != - VSYSCALL_ADDR(__NR_vgettimeofday))); - BUG_ON((unsigned long) &vtime != VSYSCALL_ADDR(__NR_vtime)); - BUG_ON((VSYSCALL_ADDR(0) != __fix_to_virt(VSYSCALL_FIRST_PAGE))); - map_vsyscall(); -#ifdef CONFIG_SYSCTL - register_sysctl_table(kernel_root_table2, 0); -#endif - return 0; -} - -__initcall(vsyscall_init); |