// Copyright 2018 The gVisor Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // System call support for the VDSO. // // Provides fallback system call interfaces for getcpu() // and clock_gettime(). #ifndef VDSO_SYSCALLS_H_ #define VDSO_SYSCALLS_H_ #include <asm/unistd.h> #include <errno.h> #include <fcntl.h> #include <stddef.h> #include <sys/types.h> #define __stringify_1(x...) #x #define __stringify(x...) __stringify_1(x) namespace vdso { #if __x86_64__ struct getcpu_cache; static inline int sys_clock_gettime(clockid_t clock, struct timespec* ts) { int num = __NR_clock_gettime; asm volatile("syscall\n" : "+a"(num) : "D"(clock), "S"(ts) : "rcx", "r11", "memory"); return num; } static inline int sys_getcpu(unsigned* cpu, unsigned* node, struct getcpu_cache* cache) { int num = __NR_getcpu; asm volatile("syscall\n" : "+a"(num) : "D"(cpu), "S"(node), "d"(cache) : "rcx", "r11", "memory"); return num; } static inline void sys_rt_sigreturn(void) { asm volatile("movl $" __stringify(__NR_rt_sigreturn)", %eax \n" "syscall \n"); } #elif __aarch64__ static inline int sys_clock_gettime(clockid_t _clkid, struct timespec* _ts) { register struct timespec* ts asm("x1") = _ts; register clockid_t clkid asm("x0") = _clkid; register long ret asm("x0"); register long nr asm("x8") = __NR_clock_gettime; asm volatile("svc #0\n" : "=r"(ret) : "r"(clkid), "r"(ts), "r"(nr) : "memory"); return ret; } static inline int sys_clock_getres(clockid_t _clkid, struct timespec* _ts) { register struct timespec* ts asm("x1") = _ts; register clockid_t clkid asm("x0") = _clkid; register long ret asm("x0"); register long nr asm("x8") = __NR_clock_getres; asm volatile("svc #0\n" : "=r"(ret) : "r"(clkid), "r"(ts), "r"(nr) : "memory"); return ret; } static inline void sys_rt_sigreturn(void) { asm volatile("mov x8, #" __stringify(__NR_rt_sigreturn)" \n" "svc #0 \n"); } #else #error "unsupported architecture" #endif } // namespace vdso #endif // VDSO_SYSCALLS_H_