diff options
Diffstat (limited to 'src/reflect/value.go')
| -rw-r--r-- | src/reflect/value.go | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/reflect/value.go b/src/reflect/value.go index 9ea95bc1d9..6daeb65b0f 100644 --- a/src/reflect/value.go +++ b/src/reflect/value.go @@ -577,6 +577,13 @@ func callReflect(ctxt *makeFuncImpl, frame unsafe.Pointer, retValid *bool) { // Convert v to type typ if v is assignable to a variable // of type t in the language spec. // See issue 28761. + if typ.Kind() == Interface { + // We must clear the destination before calling assignTo, + // in case assignTo writes (with memory barriers) to the + // target location used as scratch space. See issue 39541. + *(*uintptr)(addr) = 0 + *(*uintptr)(add(addr, ptrSize, "typ.size == 2*ptrSize")) = 0 + } v = v.assignTo("reflect.MakeFunc", typ, addr) // We are writing to stack. No write barrier. @@ -2367,6 +2374,7 @@ func NewAt(typ Type, p unsafe.Pointer) Value { // assignTo returns a value v that can be assigned directly to typ. // It panics if v is not assignable to typ. // For a conversion to an interface type, target is a suggested scratch space to use. +// target must be initialized memory (or nil). func (v Value) assignTo(context string, dst *rtype, target unsafe.Pointer) Value { if v.flag&flagMethod != 0 { v = makeMethodValue(context, v) |