diff options
Diffstat (limited to 'library/std/src/thread/mod.rs')
| -rw-r--r-- | library/std/src/thread/mod.rs | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs index 6d6be8560aa..8c353e2484e 100644 --- a/library/std/src/thread/mod.rs +++ b/library/std/src/thread/mod.rs @@ -144,6 +144,7 @@ //! [`with`]: LocalKey::with #![stable(feature = "rust1", since = "1.0.0")] +#![deny(unsafe_op_in_unsafe_fn)] #[cfg(all(test, not(target_os = "emscripten")))] mod tests; @@ -456,14 +457,23 @@ impl Builder { imp::Thread::set_name(name); } - thread_info::set(imp::guard::current(), their_thread); + // SAFETY: the stack guard passed is the one for the current thread. + // This means the current thread's stack and the new thread's stack + // are properly set and protected from each other. + thread_info::set(unsafe { imp::guard::current() }, their_thread); let try_result = panic::catch_unwind(panic::AssertUnwindSafe(|| { crate::sys_common::backtrace::__rust_begin_short_backtrace(f) })); - *their_packet.get() = Some(try_result); + // SAFETY: `their_packet` as been built just above and moved by the + // closure (it is an Arc<...>) and `my_packet` will be stored in the + // same `JoinInner` as this closure meaning the mutation will be + // safe (not modify it and affect a value far away). + unsafe { *their_packet.get() = Some(try_result) }; }; Ok(JoinHandle(JoinInner { + // SAFETY: + // // `imp::Thread::new` takes a closure with a `'static` lifetime, since it's passed // through FFI or otherwise used with low-level threading primitives that have no // notion of or way to enforce lifetimes. @@ -475,12 +485,14 @@ impl Builder { // Similarly, the `sys` implementation must guarantee that no references to the closure // exist after the thread has terminated, which is signaled by `Thread::join` // returning. - native: Some(imp::Thread::new( - stack_size, - mem::transmute::<Box<dyn FnOnce() + 'a>, Box<dyn FnOnce() + 'static>>(Box::new( - main, - )), - )?), + native: unsafe { + Some(imp::Thread::new( + stack_size, + mem::transmute::<Box<dyn FnOnce() + 'a>, Box<dyn FnOnce() + 'static>>( + Box::new(main), + ), + )?) + }, thread: my_thread, packet: Packet(my_packet), })) |