From 485f882d7713b0e0b864fc8b21368910e5b8b0a7 Mon Sep 17 00:00:00 2001 From: Mara Bos Date: Sun, 20 Sep 2020 00:17:05 +0200 Subject: [PATCH] Check conversion from Duration to timespec in futex_wait. --- library/std/src/sys/unix/futex.rs | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) diff --git a/library/std/src/sys/unix/futex.rs b/library/std/src/sys/unix/futex.rs index 6af06aa5f7e..e6f0c48c59b 100644 --- a/library/std/src/sys/unix/futex.rs +++ b/library/std/src/sys/unix/futex.rs @@ -1,27 +1,26 @@ #![cfg(any(target_os = "linux", target_os = "android"))] +use crate::convert::TryInto; +use crate::ptr::null; use crate::sync::atomic::AtomicI32; use crate::time::Duration; pub fn futex_wait(futex: &AtomicI32, expected: i32, timeout: Option) { - let timespec; - let timespec_ptr = match timeout { - Some(timeout) => { - timespec = libc::timespec { - tv_sec: timeout.as_secs() as _, - tv_nsec: timeout.subsec_nanos() as _, - }; - ×pec as *const libc::timespec - } - None => crate::ptr::null(), - }; + let timespec = timeout.and_then(|d| { + Some(libc::timespec { + // Sleep forever if the timeout is longer than fits in a timespec. + tv_sec: d.as_secs().try_into().ok()?, + // This conversion never truncates, as subsec_nanos is always <1e9. + tv_nsec: d.subsec_nanos() as _, + }) + }); unsafe { libc::syscall( libc::SYS_futex, futex as *const AtomicI32, libc::FUTEX_WAIT | libc::FUTEX_PRIVATE_FLAG, expected, - timespec_ptr, + timespec.as_ref().map_or(null(), |d| d as *const libc::timespec), ); } } -- 2.44.0