1 #include <pthread.h>
2 #include <time.h>
3 #include <errno.h>
4 #include "futex.h"
5 #include "syscall.h"
6 #include "pthread_impl.h"
7
8 #define IS32BIT(x) !((x)+0x80000000ULL>>32)
9 #define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63))
10
__futex4_cp(volatile void * addr,int op,int val,const struct timespec * to)11 static int __futex4_cp(volatile void *addr, int op, int val, const struct timespec *to)
12 {
13 int r;
14 #ifdef SYS_futex_time64
15 time_t s = to ? to->tv_sec : 0;
16 long ns = to ? to->tv_nsec : 0;
17 r = -ENOSYS;
18 if (SYS_futex == SYS_futex_time64 || !IS32BIT(s))
19 r = __syscall_cp(SYS_futex_time64, addr, op, val,
20 to ? ((long long[]){s, ns}) : 0);
21 if (SYS_futex == SYS_futex_time64 || r!=-ENOSYS) return r;
22 to = to ? (void *)(long[]){CLAMP(s), ns} : 0;
23 #endif
24 r = __syscall_cp(SYS_futex, addr, op, val, to);
25 if (r != -ENOSYS) return r;
26 return __syscall_cp(SYS_futex, addr, op & ~FUTEX_PRIVATE, val, to);
27 }
28
29 static volatile int dummy = 0;
30 weak_alias(dummy, __eintr_valid_flag);
31
__timedwait_cp(volatile int * addr,int val,clockid_t clk,const struct timespec * at,int priv)32 int __timedwait_cp(volatile int *addr, int val,
33 clockid_t clk, const struct timespec *at, int priv)
34 {
35 int r;
36 struct timespec to, *top=0;
37
38 if (priv) priv = FUTEX_PRIVATE;
39
40 if (at) {
41 if (at->tv_nsec >= 1000000000UL) return EINVAL;
42 if (__clock_gettime(clk, &to)) return EINVAL;
43 to.tv_sec = at->tv_sec - to.tv_sec;
44 if ((to.tv_nsec = at->tv_nsec - to.tv_nsec) < 0) {
45 to.tv_sec--;
46 to.tv_nsec += 1000000000;
47 }
48 if (to.tv_sec < 0) return ETIMEDOUT;
49 top = &to;
50 }
51
52 r = -__futex4_cp(addr, FUTEX_WAIT|priv, val, top);
53 if (r != EINTR && r != ETIMEDOUT && r != ECANCELED) r = 0;
54 /* Mitigate bug in old kernels wrongly reporting EINTR for non-
55 * interrupting (SA_RESTART) signal handlers. This is only practical
56 * when NO interrupting signal handlers have been installed, and
57 * works by sigaction tracking whether that's the case. */
58 if (r == EINTR && !__eintr_valid_flag) r = 0;
59
60 return r;
61 }
62
__timedwait(volatile int * addr,int val,clockid_t clk,const struct timespec * at,int priv)63 int __timedwait(volatile int *addr, int val,
64 clockid_t clk, const struct timespec *at, int priv)
65 {
66 int cs, r;
67 __pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
68 r = __timedwait_cp(addr, val, clk, at, priv);
69 __pthread_setcancelstate(cs, 0);
70 return r;
71 }
72