kernel/arch/x86/um/vdso/um_vdso.c
2024-07-22 17:22:30 +08:00

73 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
*
* This vDSO turns all calls into a syscall so that UML can trap them.
*/
/* Disable profiling for userspace code */
#define DISABLE_BRANCH_PROFILING
#include <linux/time.h>
#include <linux/getcpu.h>
#include <asm/unistd.h>
int __vdso_clock_gettime(clockid_t clock, struct __kernel_old_timespec *ts)
{
long ret;
asm("syscall"
: "=a" (ret)
: "0" (__NR_clock_gettime), "D" (clock), "S" (ts)
: "rcx", "r11", "memory");
return ret;
}
int clock_gettime(clockid_t, struct __kernel_old_timespec *)
__attribute__((weak, alias("__vdso_clock_gettime")));
int __vdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
{
long ret;
asm("syscall"
: "=a" (ret)
: "0" (__NR_gettimeofday), "D" (tv), "S" (tz)
: "rcx", "r11", "memory");
return ret;
}
int gettimeofday(struct __kernel_old_timeval *, struct timezone *)
__attribute__((weak, alias("__vdso_gettimeofday")));
__kernel_old_time_t __vdso_time(__kernel_old_time_t *t)
{
long secs;
asm volatile("syscall"
: "=a" (secs)
: "0" (__NR_time), "D" (t) : "cc", "r11", "cx", "memory");
return secs;
}
__kernel_old_time_t time(__kernel_old_time_t *t) __attribute__((weak, alias("__vdso_time")));
long
__vdso_getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *unused)
{
/*
* UML does not support SMP, we can cheat here. :)
*/
if (cpu)
*cpu = 0;
if (node)
*node = 0;
return 0;
}
long getcpu(unsigned *cpu, unsigned *node, struct getcpu_cache *tcache)
__attribute__((weak, alias("__vdso_getcpu")));