From 68c983919ecfa75a8216d93b85baaefcb7b6e51c Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sun, 28 Jul 2019 17:05:47 -0400 Subject: sigtimedwait: add time64 syscall support, decouple 32-bit time_t time64 syscall is used only if it's the only one defined for the arch, or if the requested timeout length does not fit in 32 bits. on current 32-bit archs where time_t is a 32-bit type, this makes it statically unreachable. on 64-bit archs, there are only superficial changes to the code after preprocessing. on current 32-bit archs, the timeout is passed via an intermediate copy to remove the assumption that time_t is a 32-bit type. --- src/signal/sigtimedwait.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/src/signal/sigtimedwait.c b/src/signal/sigtimedwait.c index 7bcfe720..1287174e 100644 --- a/src/signal/sigtimedwait.c +++ b/src/signal/sigtimedwait.c @@ -2,11 +2,31 @@ #include #include "syscall.h" +#define IS32BIT(x) !((x)+0x80000000ULL>>32) +#define CLAMP(x) (int)(IS32BIT(x) ? (x) : 0x7fffffffU+((0ULL+(x))>>63)) + +static int do_sigtimedwait(const sigset_t *restrict mask, siginfo_t *restrict si, const struct timespec *restrict ts) +{ +#ifdef SYS_rt_sigtimedwait_time64 + time_t s = ts ? ts->tv_sec : 0; + long ns = ts ? ts->tv_nsec : 0; + int r = -ENOSYS; + if (SYS_rt_sigtimedwait == SYS_rt_sigtimedwait_time64 || !IS32BIT(s)) + r = __syscall_cp(SYS_rt_sigtimedwait_time64, mask, si, + ts ? ((long long[]){s, ns}) : 0, _NSIG/8); + if (SYS_rt_sigtimedwait == SYS_rt_sigtimedwait_time64 || r!=-ENOSYS) + return r; + return __syscall_cp(SYS_rt_sigtimedwait, mask, si, + ts ? ((long[]){CLAMP(s), ns}) : 0, _NSIG/8);; +#else + return __syscall_cp(SYS_rt_sigtimedwait, mask, si, ts, _NSIG/8); +#endif +} + int sigtimedwait(const sigset_t *restrict mask, siginfo_t *restrict si, const struct timespec *restrict timeout) { int ret; - do ret = syscall_cp(SYS_rt_sigtimedwait, mask, - si, timeout, _NSIG/8); - while (ret<0 && errno==EINTR); - return ret; + do ret = do_sigtimedwait(mask, si, timeout); + while (ret==-EINTR); + return __syscall_ret(ret); } -- cgit v1.2.1