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runtime: use innermost frame's func name for async preemption check

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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 <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
This commit is contained in:
Cherry Zhang 2019-12-18 15:19:05 -05:00
parent 87a546776b
commit dcdee153cd
1 changed files with 11 additions and 3 deletions
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14
src/runtime/preempt.go
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@ -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