From eebeca803d6df0d3434106d7f6ebb87229c54fd7 Mon Sep 17 00:00:00 2001 From: Richard Wang Date: Thu, 14 Sep 2023 05:13:40 +0000 Subject: [PATCH] runtime: clarify error when returning unpinned pointers With the introduction of runtime.Pinner, returning a pointer to a pinned struct that then points to an unpinned Go pointer is correctly caught. However, the error message remained as "cgo result has Go pointer", which should be updated to acknowledge that Go pointers to pinned memory are allowed. This also updates the comments for cgoCheckArg and cgoCheckResult to similarly clarify. Updates #46787 Change-Id: I147bb09e87dfb70a24d6d43e4cf84e8bcc2aff48 GitHub-Last-Rev: 706facb9f2bf28e1f6e575b7626f8feeca1187cf GitHub-Pull-Request: golang/go#62606 Reviewed-on: https://go-review.googlesource.com/c/go/+/527702 Reviewed-by: Michael Knyszek LUCI-TryBot-Result: Go LUCI Reviewed-by: Heschi Kreinick Auto-Submit: Michael Knyszek --- src/runtime/cgocall.go | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/src/runtime/cgocall.go b/src/runtime/cgocall.go index 73efd28491..6c2fd8f907 100644 --- a/src/runtime/cgocall.go +++ b/src/runtime/cgocall.go @@ -533,13 +533,13 @@ func cgoCheckPointer(ptr any, arg any) { } const cgoCheckPointerFail = "cgo argument has Go pointer to unpinned Go pointer" -const cgoResultFail = "cgo result has Go pointer" +const cgoResultFail = "cgo result is unpinned Go pointer or points to unpinned Go pointer" // cgoCheckArg is the real work of cgoCheckPointer. The argument p // is either a pointer to the value (of type t), or the value itself, // depending on indir. The top parameter is whether we are at the top // level, where Go pointers are allowed. Go pointers to pinned objects are -// always allowed. +// allowed as long as they don't reference other unpinned pointers. func cgoCheckArg(t *_type, p unsafe.Pointer, indir, top bool, msg string) { if t.PtrBytes == 0 || p == nil { // If the type has no pointers there is nothing to do. @@ -726,8 +726,8 @@ func cgoInRange(p unsafe.Pointer, start, end uintptr) bool { } // cgoCheckResult is called to check the result parameter of an -// exported Go function. It panics if the result is or contains a Go -// pointer. +// exported Go function. It panics if the result is or contains any +// other pointer into unpinned Go memory. func cgoCheckResult(val any) { if !goexperiment.CgoCheck2 && debug.cgocheck == 0 { return -- 2.44.0