From 8bf94b92316c44a3110667d52bcb92f22f6c2923 Mon Sep 17 00:00:00 2001 From: Ayke van Laethem Date: Wed, 22 Feb 2023 17:44:34 +0100 Subject: [PATCH] internal/task: disallow blocking inside an interrupt Blocking inside an interrupt is always unsafe and will lead to all kinds of bad behavior (even if it might appear to work sometimes). So disallow it, just like allocating heap memory inside an interrupt is not allowed. I suspect this will usually be caused by channel sends, like this: ch <- someValue The easy workaround is to make it a non-blocking send instead: select { case ch <- someValue: default: } This does mean the application might become a bit more complex to be able to deal with this case, but the alternative (undefined behavior) is IMHO much worse. --- src/internal/task/task_stack.go | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/src/internal/task/task_stack.go b/src/internal/task/task_stack.go index ed938a63..81e0f9ad 100644 --- a/src/internal/task/task_stack.go +++ b/src/internal/task/task_stack.go @@ -2,7 +2,10 @@ package task -import "unsafe" +import ( + "runtime/interrupt" + "unsafe" +) //go:linkname runtimePanic runtime.runtimePanic func runtimePanic(str string) @@ -45,6 +48,9 @@ func Pause() { if *currentTask.state.canaryPtr != stackCanary { runtimePanic("goroutine stack overflow") } + if interrupt.In() { + runtimePanic("blocked inside interrupt") + } currentTask.state.pause() }