From dcdee153cd61de47d0cabd6729a17673536b0418 Mon Sep 17 00:00:00 2001 From: Cherry Zhang Date: Wed, 18 Dec 2019 15:19:05 -0500 Subject: [PATCH] runtime: use innermost frame's func name for async preemption check We don't asynchronously preempt if we are in the runtime. We do this by checking the function name. However, it failed to take inlining into account. If a runtime function gets inlined into a non-runtime function, it can be preempted, and bad things can happen. One instance of this is dounlockOSThread inlined into UnlockOSThread which is in turn inlined into a non-runtime function. Fix this by using the innermost frame's function name. Change-Id: Ifa036ce1320700aaaefd829b4bee0d04d05c395d Reviewed-on: https://go-review.googlesource.com/c/go/+/211978 Run-TryBot: Cherry Zhang TryBot-Result: Gobot Gobot Reviewed-by: Austin Clements --- src/runtime/preempt.go | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/src/runtime/preempt.go b/src/runtime/preempt.go index 2c38ac02f5..420a7f96e0 100644 --- a/src/runtime/preempt.go +++ b/src/runtime/preempt.go @@ -411,9 +411,17 @@ func isAsyncSafePoint(gp *g, pc, sp, lr uintptr) bool { // locals pointer map, like empty frame functions? return false } - if hasPrefix(funcname(f), "runtime.") || - hasPrefix(funcname(f), "runtime/internal/") || - hasPrefix(funcname(f), "reflect.") { + name := funcname(f) + if inldata := funcdata(f, _FUNCDATA_InlTree); inldata != nil { + inltree := (*[1 << 20]inlinedCall)(inldata) + ix := pcdatavalue(f, _PCDATA_InlTreeIndex, pc, nil) + if ix >= 0 { + name = funcnameFromNameoff(f, inltree[ix].func_) + } + } + if hasPrefix(name, "runtime.") || + hasPrefix(name, "runtime/internal/") || + hasPrefix(name, "reflect.") { // For now we never async preempt the runtime or // anything closely tied to the runtime. Known issues // include: various points in the scheduler ("don't -- 2.50.0