diff options
| -rw-r--r-- | src/tools/miri/src/shims/unix/unnamed_socket.rs | 160 |
1 files changed, 74 insertions, 86 deletions
diff --git a/src/tools/miri/src/shims/unix/unnamed_socket.rs b/src/tools/miri/src/shims/unix/unnamed_socket.rs index 86ebe95762a..7f35838e9d7 100644 --- a/src/tools/miri/src/shims/unix/unnamed_socket.rs +++ b/src/tools/miri/src/shims/unix/unnamed_socket.rs @@ -96,26 +96,7 @@ impl FileDescription for AnonSocket { dest: &MPlaceTy<'tcx>, ecx: &mut MiriInterpCx<'tcx>, ) -> InterpResult<'tcx> { - // Always succeed on read size 0. - if len == 0 { - return ecx.return_read_success(ptr, &[], 0, dest); - } - - let Some(readbuf) = &self.readbuf else { - // FIXME: This should return EBADF, but there's no nice way to do that as there's no - // corresponding ErrorKind variant. - throw_unsup_format!("reading from the write end of a pipe"); - }; - - if readbuf.borrow().buf.is_empty() && self.is_nonblock { - // Non-blocking socketpair with writer and empty buffer. - // https://linux.die.net/man/2/read - // EAGAIN or EWOULDBLOCK can be returned for socket, - // POSIX.1-2001 allows either error to be returned for this case. - // Since there is no ErrorKind for EAGAIN, WouldBlock is used. - return ecx.set_last_error_and_return(ErrorKind::WouldBlock, dest); - } - anonsocket_read(self_ref.downgrade(), len, ptr, dest.clone(), ecx) + anonsocket_read(self_ref, len, ptr, dest, ecx) } fn write<'tcx>( @@ -127,31 +108,7 @@ impl FileDescription for AnonSocket { dest: &MPlaceTy<'tcx>, ecx: &mut MiriInterpCx<'tcx>, ) -> InterpResult<'tcx> { - // Always succeed on write size 0. - // ("If count is zero and fd refers to a file other than a regular file, the results are not specified.") - if len == 0 { - return ecx.return_write_success(0, dest); - } - - // We are writing to our peer's readbuf. - let Some(peer_fd) = self.peer_fd().upgrade() else { - // If the upgrade from Weak to Rc fails, it indicates that all read ends have been - // closed. - return ecx.set_last_error_and_return(ErrorKind::BrokenPipe, dest); - }; - - let Some(writebuf) = &peer_fd.downcast::<AnonSocket>().unwrap().readbuf else { - // FIXME: This should return EBADF, but there's no nice way to do that as there's no - // corresponding ErrorKind variant. - throw_unsup_format!("writing to the reading end of a pipe"); - }; - let available_space = - MAX_SOCKETPAIR_BUFFER_CAPACITY.strict_sub(writebuf.borrow().buf.len()); - if available_space == 0 && self.is_nonblock { - // Non-blocking socketpair with a full buffer. - return ecx.set_last_error_and_return(ErrorKind::WouldBlock, dest); - } - anonsocket_write(self_ref.downgrade(), ptr, len, dest.clone(), ecx) + anonsocket_write(self_ref, ptr, len, dest, ecx) } fn as_unix(&self) -> &dyn UnixFileDescription { @@ -161,50 +118,66 @@ impl FileDescription for AnonSocket { /// Write to AnonSocket based on the space available and return the written byte size. fn anonsocket_write<'tcx>( - weak_self_ref: WeakFileDescriptionRef, + self_ref: &FileDescriptionRef, ptr: Pointer, len: usize, - dest: MPlaceTy<'tcx>, + dest: &MPlaceTy<'tcx>, ecx: &mut MiriInterpCx<'tcx>, ) -> InterpResult<'tcx> { - let Some(self_ref) = weak_self_ref.upgrade() else { - // FIXME: We should raise a deadlock error if the self_ref upgrade failed. - throw_unsup_format!("This will be a deadlock error in future") - }; let self_anonsocket = self_ref.downcast::<AnonSocket>().unwrap(); + + // Always succeed on write size 0. + // ("If count is zero and fd refers to a file other than a regular file, the results are not specified.") + if len == 0 { + return ecx.return_write_success(0, dest); + } + + // We are writing to our peer's readbuf. let Some(peer_fd) = self_anonsocket.peer_fd().upgrade() else { // If the upgrade from Weak to Rc fails, it indicates that all read ends have been - // closed. - return ecx.set_last_error_and_return(ErrorKind::BrokenPipe, &dest); + // closed. It is an error to write even if there would be space. + return ecx.set_last_error_and_return(ErrorKind::BrokenPipe, dest); }; + let Some(writebuf) = &peer_fd.downcast::<AnonSocket>().unwrap().readbuf else { - // FIXME: This should return EBADF, but there's no nice way to do that as there's no - // corresponding ErrorKind variant. - throw_unsup_format!("writing to the reading end of a pipe") + // Writing to the read end of a pipe. + return ecx.set_last_error_and_return(IoError::LibcError("EBADF"), dest); }; + // Let's see if we can write. let available_space = MAX_SOCKETPAIR_BUFFER_CAPACITY.strict_sub(writebuf.borrow().buf.len()); - if available_space == 0 { - // Blocking socketpair with a full buffer. - let dest = dest.clone(); - self_anonsocket.blocked_write_tid.borrow_mut().push(ecx.active_thread()); - ecx.block_thread( - BlockReason::UnnamedSocket, - None, - callback!( - @capture<'tcx> { - weak_self_ref: WeakFileDescriptionRef, - ptr: Pointer, - len: usize, - dest: MPlaceTy<'tcx>, - } - @unblock = |this| { - anonsocket_write(weak_self_ref, ptr, len, dest, this) - } - ), - ); + if self_anonsocket.is_nonblock { + // Non-blocking socketpair with a full buffer. + return ecx.set_last_error_and_return(ErrorKind::WouldBlock, dest); + } else { + // Blocking socketpair with a full buffer. + // Block the current thread; only keep a weak ref for this. + let weak_self_ref = self_ref.downgrade(); + let dest = dest.clone(); + self_anonsocket.blocked_write_tid.borrow_mut().push(ecx.active_thread()); + ecx.block_thread( + BlockReason::UnnamedSocket, + None, + callback!( + @capture<'tcx> { + weak_self_ref: WeakFileDescriptionRef, + ptr: Pointer, + len: usize, + dest: MPlaceTy<'tcx>, + } + @unblock = |this| { + let Some(self_ref) = weak_self_ref.upgrade() else { + // FIXME: We should raise a deadlock error if the self_ref upgrade failed. + throw_unsup_format!("This will be a deadlock error in future") + }; + anonsocket_write(&self_ref, ptr, len, &dest, this) + } + ), + ); + } } else { + // There is space to write! let mut writebuf = writebuf.borrow_mut(); // Remember this clock so `read` can synchronize with us. ecx.release_clock(|clock| { @@ -229,25 +202,26 @@ fn anonsocket_write<'tcx>( ecx.unblock_thread(thread_id, BlockReason::UnnamedSocket)?; } - return ecx.return_write_success(actual_write_size, &dest); + return ecx.return_write_success(actual_write_size, dest); } interp_ok(()) } /// Read from AnonSocket and return the number of bytes read. fn anonsocket_read<'tcx>( - weak_self_ref: WeakFileDescriptionRef, + self_ref: &FileDescriptionRef, len: usize, ptr: Pointer, - dest: MPlaceTy<'tcx>, + dest: &MPlaceTy<'tcx>, ecx: &mut MiriInterpCx<'tcx>, ) -> InterpResult<'tcx> { - let Some(self_ref) = weak_self_ref.upgrade() else { - // FIXME: We should raise a deadlock error if the self_ref upgrade failed. - throw_unsup_format!("This will be a deadlock error in future") - }; let self_anonsocket = self_ref.downcast::<AnonSocket>().unwrap(); + // Always succeed on read size 0. + if len == 0 { + return ecx.return_read_success(ptr, &[], 0, dest); + } + let Some(readbuf) = &self_anonsocket.readbuf else { // FIXME: This should return EBADF, but there's no nice way to do that as there's no // corresponding ErrorKind variant. @@ -258,10 +232,19 @@ fn anonsocket_read<'tcx>( if self_anonsocket.peer_fd().upgrade().is_none() { // Socketpair with no peer and empty buffer. // 0 bytes successfully read indicates end-of-file. - return ecx.return_read_success(ptr, &[], 0, &dest); + return ecx.return_read_success(ptr, &[], 0, dest); + } else if self_anonsocket.is_nonblock { + // Non-blocking socketpair with writer and empty buffer. + // https://linux.die.net/man/2/read + // EAGAIN or EWOULDBLOCK can be returned for socket, + // POSIX.1-2001 allows either error to be returned for this case. + // Since there is no ErrorKind for EAGAIN, WouldBlock is used. + return ecx.set_last_error_and_return(ErrorKind::WouldBlock, dest); } else { // Blocking socketpair with writer and empty buffer. - let weak_self_ref = weak_self_ref.clone(); + // Block the current thread; only keep a weak ref for this. + let weak_self_ref = self_ref.downgrade(); + let dest = dest.clone(); self_anonsocket.blocked_read_tid.borrow_mut().push(ecx.active_thread()); ecx.block_thread( BlockReason::UnnamedSocket, @@ -274,12 +257,17 @@ fn anonsocket_read<'tcx>( dest: MPlaceTy<'tcx>, } @unblock = |this| { - anonsocket_read(weak_self_ref, len, ptr, dest, this) + let Some(self_ref) = weak_self_ref.upgrade() else { + // FIXME: We should raise a deadlock error if the self_ref upgrade failed. + throw_unsup_format!("This will be a deadlock error in future") + }; + anonsocket_read(&self_ref, len, ptr, &dest, this) } ), ); } } else { + // There's data to be read! let mut bytes = vec![0; len]; let mut readbuf = readbuf.borrow_mut(); // Synchronize with all previous writes to this buffer. @@ -313,7 +301,7 @@ fn anonsocket_read<'tcx>( } }; - return ecx.return_read_success(ptr, &bytes, actual_read_size, &dest); + return ecx.return_read_success(ptr, &bytes, actual_read_size, dest); } interp_ok(()) } |