From c2fabf1a268f0480d78bede82fc6a9d3a63fcace Mon Sep 17 00:00:00 2001 From: Michael Pratt Date: Thu, 8 Jan 2026 18:36:45 -0500 Subject: os/signal: completely ignore bogus signals signal.Notify should ignore bogus signals (syscall.Signals with invalid signal numbers). Ignoring means Notify/Stop/Reset all work fine, but the channel will never receive any events. Today, Stop hangs if Notify has only ever been called with bogus signals because Stop assumes that runtime.signal_recv is running if a handler is present. Notify unconditionally registers the handler, but only starts signal_recv if the signal was valid. Address this by avoiding registering the handler at all if the signal is bogus. We additionally add a bogus signal check to cancel (used by Ignore/Reset). Currently those are calling into the runtime signal_ignore and signal_disable, which do ignore bogus signals, but is now inconsistent with the rest of the package. For #77076. Change-Id: I6a6a636c27c41a158e203bbf470be5f1f3f631bd Reviewed-on: https://go-review.googlesource.com/c/go/+/735040 Reviewed-by: Cherry Mui LUCI-TryBot-Result: Go LUCI Reviewed-by: Alex Brainman Auto-Submit: Michael Pratt --- src/runtime/testdata/testprog/signal_bogus.go | 29 +++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 src/runtime/testdata/testprog/signal_bogus.go (limited to 'src/runtime/testdata') diff --git a/src/runtime/testdata/testprog/signal_bogus.go b/src/runtime/testdata/testprog/signal_bogus.go new file mode 100644 index 0000000000..a372277d41 --- /dev/null +++ b/src/runtime/testdata/testprog/signal_bogus.go @@ -0,0 +1,29 @@ +// Copyright 2026 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build !plan9 + +package main + +import ( + "os" + "os/signal" + "syscall" +) + +func init() { + register("SignalBogus", SignalBogus) +} + +// signal.Notify should effectively ignore bogus signal numbers. Never writing +// to the channel, but otherwise allowing Notify/Stop as normal. +// +// This is a regression test for https://go.dev/issue/77076, where bogus +// signals used to make Stop hang if there were no real signals installed. +func SignalBogus() { + ch := make(chan os.Signal, 1) + signal.Notify(ch, syscall.Signal(0xdead)) + signal.Stop(ch) + println("OK") +} -- cgit v1.3