LXR linux/arch/x86/um/vdso/um

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
   4 *
   5 * This vDSO turns all calls into a syscall so that UML can trap them.
   6 */
   7
   8
   9/* Disable profiling for userspace code */
  10#define DISABLE_BRANCH_PROFILING
  11
  12#include <linux/time.h>
  13#include <linux/getcpu.h>
  14#include <asm/unistd.h>
  15
  16int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
  17{
  18        long ret;
  19
  20        asm("syscall" : "=a" (ret) :
  21                "0" (__NR_clock_gettime), "D" (clock), "S" (ts) : "memory");
  22
  23        return ret;
  24}
  25int clock_gettime(clockid_t, struct __kernel_old_timespec *)
  26        __attribute__((weak, alias("__vdso_clock_gettime")));
  27
  28int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
  29{
  30        long ret;
  31
  32        asm("syscall" : "=a" (ret) :
  33                "0" (__NR_gettimeofday), "D" (tv), "S" (tz) : "memory");
  34
  35        return ret;
  36}
  37int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
  38        __attribute__((weak, alias("__vdso_gettimeofday")));
  39
  40__kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
  41{
  42        long secs;
  43
  44        asm volatile("syscall"
  45                : "=a" (secs)
  46                : "0" (__NR_time), "D" (t) : "cc", "r11", "cx", "memory");
  47
  48        return secs;
  49}
  50__kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__vdso_time")));
  51
  52long
  53__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
  54{
  55        /*
  56         * UML does not support SMP, we can cheat here. :)
  57         */
  58
  59        if (cpu)
  60                *cpu = 0;
  61        if (node)
  62                *node = 0;
  63
  64        return 0;
  65}
  66
  67long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
  68        __attribute__((weak, alias("__vdso_getcpu")));
  69