1#include <time.h> 2#include <errno.h> 3#include <stdint.h> 4#include "syscall.h" 5#include "atomic.h" 6 7#ifdef VDSO_CGT_SYM 8 9static void *volatile vdso_func; 10 11#ifdef VDSO_CGT32_SYM 12static void *volatile vdso_func_32; 13static int cgt_time32_wrap(clockid_t clk, struct timespec *ts) 14{ 15 long ts32[2]; 16 int (*f)(clockid_t, long[2]) = 17 (int (*)(clockid_t, long[2]))vdso_func_32; 18 int r = f(clk, ts32); 19 if (!r) { 20 /* Fallback to syscalls if time32 overflowed. Maybe 21 * we lucked out and somehow migrated to a kernel with 22 * time64 syscalls available. */ 23 if (ts32[0] < 0) { 24 a_cas_p(&vdso_func, (void *)cgt_time32_wrap, 0); 25 return -ENOSYS; 26 } 27 ts->tv_sec = ts32[0]; 28 ts->tv_nsec = ts32[1]; 29 } 30 return r; 31} 32#endif 33 34static int cgt_init(clockid_t clk, struct timespec *ts) 35{ 36#ifndef __LITEOS__ 37 __get_vdso_info(); 38 void *p = __get_vdso_addr(VDSO_CGT_VER, VDSO_CGT_SYM); 39#else 40 void *p = __vdsosym(VDSO_CGT_VER, VDSO_CGT_SYM); 41#endif 42#ifdef VDSO_CGT32_SYM 43 if (!p) { 44#ifndef __LITEOS__ 45 void *q = __get_vdso_addr(VDSO_CGT32_VER, VDSO_CGT32_SYM); 46#else 47 void *q = __vdsosym(VDSO_CGT32_VER, VDSO_CGT32_SYM); 48#endif 49 if (q) { 50 a_cas_p(&vdso_func_32, 0, q); 51 p = cgt_time32_wrap; 52 } 53 } 54#ifdef VDSO_CGT_WORKAROUND 55#ifndef __LITEOS__ 56 if (!__get_vdso_addr(VDSO_CGT32_VER, VDSO_CGT32_SYM)) p = 0; 57#else 58 if (!__vdsosym(VDSO_CGT32_VER, VDSO_CGT32_SYM)) p = 0; 59#endif 60#endif 61#endif 62 int (*f)(clockid_t, struct timespec *) = 63 (int (*)(clockid_t, struct timespec *))p; 64 a_cas_p(&vdso_func, (void *)cgt_init, p); 65 return f ? f(clk, ts) : -ENOSYS; 66} 67 68static void *volatile vdso_func = (void *)cgt_init; 69 70#endif 71 72int __clock_gettime(clockid_t clk, struct timespec *ts) 73{ 74 int r; 75 76#ifdef VDSO_CGT_SYM 77 int (*f)(clockid_t, struct timespec *) = 78 (int (*)(clockid_t, struct timespec *))vdso_func; 79 if (f) { 80 r = f(clk, ts); 81 if (!r) return r; 82 if (r == -EINVAL) return __syscall_ret(r); 83 /* Fall through on errors other than EINVAL. Some buggy 84 * vdso implementations return ENOSYS for clocks they 85 * can't handle, rather than making the syscall. This 86 * also handles the case where cgt_init fails to find 87 * a vdso function to use. */ 88 } 89#endif 90 91#ifdef SYS_clock_gettime64 92 r = -ENOSYS; 93 if (sizeof(time_t) > 4) 94 r = __syscall(SYS_clock_gettime64, clk, ts); 95 if (SYS_clock_gettime == SYS_clock_gettime64 || r!=-ENOSYS) 96 return __syscall_ret(r); 97 long ts32[2]; 98 r = __syscall(SYS_clock_gettime, clk, ts32); 99#ifdef SYS_gettimeofday 100 if (r==-ENOSYS && clk==CLOCK_REALTIME) { 101 r = __syscall(SYS_gettimeofday, ts32, 0); 102 ts32[1] *= 1000; 103 } 104#endif 105 if (!r) { 106 ts->tv_sec = ts32[0]; 107 ts->tv_nsec = ts32[1]; 108 return r; 109 } 110 return __syscall_ret(r); 111#else 112 r = __syscall(SYS_clock_gettime, clk, ts); 113#ifdef SYS_gettimeofday 114 if (r == -ENOSYS) { 115 if (clk == CLOCK_REALTIME) { 116 __syscall(SYS_gettimeofday, ts, 0); 117 ts->tv_nsec = (int)ts->tv_nsec * 1000; 118 return 0; 119 } 120 r = -EINVAL; 121 } 122#endif 123 return __syscall_ret(r); 124#endif 125} 126 127weak_alias(__clock_gettime, clock_gettime); 128