cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

vdso.c (1996B)

      1/*
      2 *  Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE
      3 *  Copyright 2003 Andi Kleen, SuSE Labs.
      4 *
      5 *  Thanks to hpa@transmeta.com for some useful hint.
      6 *  Special thanks to Ingo Molnar for his early experience with
      7 *  a different vsyscall implementation for Linux/IA32 and for the name.
      8 */
      9
     10#include <linux/time.h>
     11#include <linux/timekeeper_internal.h>
     12
     13#include <asm/vvar.h>
     14
     15void update_vsyscall_tz(void)
     16{
     17	if (unlikely(vvar_data == NULL))
     18		return;
     19
     20	vvar_data->tz_minuteswest = sys_tz.tz_minuteswest;
     21	vvar_data->tz_dsttime = sys_tz.tz_dsttime;
     22}
     23
     24void update_vsyscall(struct timekeeper *tk)
     25{
     26	struct vvar_data *vdata = vvar_data;
     27
     28	if (unlikely(vdata == NULL))
     29		return;
     30
     31	vvar_write_begin(vdata);
     32	vdata->vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
     33	vdata->clock.cycle_last = tk->tkr_mono.cycle_last;
     34	vdata->clock.mask = tk->tkr_mono.mask;
     35	vdata->clock.mult = tk->tkr_mono.mult;
     36	vdata->clock.shift = tk->tkr_mono.shift;
     37
     38	vdata->wall_time_sec = tk->xtime_sec;
     39	vdata->wall_time_snsec = tk->tkr_mono.xtime_nsec;
     40
     41	vdata->monotonic_time_sec = tk->xtime_sec +
     42				    tk->wall_to_monotonic.tv_sec;
     43	vdata->monotonic_time_snsec = tk->tkr_mono.xtime_nsec +
     44				      (tk->wall_to_monotonic.tv_nsec <<
     45				       tk->tkr_mono.shift);
     46
     47	while (vdata->monotonic_time_snsec >=
     48	       (((u64)NSEC_PER_SEC) << tk->tkr_mono.shift)) {
     49		vdata->monotonic_time_snsec -=
     50				((u64)NSEC_PER_SEC) << tk->tkr_mono.shift;
     51		vdata->monotonic_time_sec++;
     52	}
     53
     54	vdata->wall_time_coarse_sec = tk->xtime_sec;
     55	vdata->wall_time_coarse_nsec =
     56			(long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
     57
     58	vdata->monotonic_time_coarse_sec =
     59		vdata->wall_time_coarse_sec + tk->wall_to_monotonic.tv_sec;
     60	vdata->monotonic_time_coarse_nsec =
     61		vdata->wall_time_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
     62
     63	while (vdata->monotonic_time_coarse_nsec >= NSEC_PER_SEC) {
     64		vdata->monotonic_time_coarse_nsec -= NSEC_PER_SEC;
     65		vdata->monotonic_time_coarse_sec++;
     66	}
     67
     68	vvar_write_end(vdata);
     69}