Revert "cmd/compile,runtime: allocate defer records on the stack"

This reverts commit fff4f599fe1c21e411a99de5c9b3777d06ce0ce6.

Reason for revert: Seems to still have issues around GC.

Fixes #32452

Change-Id: Ibe7af629f9ad6a3d5312acd7b066123f484da7f0
Reviewed-on: https://go-review.googlesource.com/c/go/+/180761
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/src/runtime/stack.go b/src/runtime/stack.go
index c32d9e8042..d5d09ba7d7 100644
--- a/src/runtime/stack.go
+++ b/src/runtime/stack.go
@@ -719,21 +719,16 @@ func adjustctxt(gp *g, adjinfo *adjustinfo) {
 }
 
 func adjustdefers(gp *g, adjinfo *adjustinfo) {
+	// Adjust defer argument blocks the same way we adjust active stack frames.
+	tracebackdefers(gp, adjustframe, noescape(unsafe.Pointer(adjinfo)))
+
 	// Adjust pointers in the Defer structs.
-	// We need to do this first because we need to adjust the
-	// defer.link fields so we always work on the new stack.
-	adjustpointer(adjinfo, unsafe.Pointer(&gp._defer))
+	// Defer structs themselves are never on the stack.
 	for d := gp._defer; d != nil; d = d.link {
 		adjustpointer(adjinfo, unsafe.Pointer(&d.fn))
 		adjustpointer(adjinfo, unsafe.Pointer(&d.sp))
 		adjustpointer(adjinfo, unsafe.Pointer(&d._panic))
-		adjustpointer(adjinfo, unsafe.Pointer(&d.link))
 	}
-
-	// Adjust defer argument blocks the same way we adjust active stack frames.
-	// Note: this code is after the loop above, so that if a defer record is
-	// stack allocated, we work on the copy in the new stack.
-	tracebackdefers(gp, adjustframe, noescape(unsafe.Pointer(adjinfo)))
 }
 
 func adjustpanics(gp *g, adjinfo *adjustinfo) {