From: Michael Anthony Knyszek <mknyszek@google.com>
Date: Mon, 3 Nov 2025 22:29:36 +0000 (+0000)
Subject: runtime: don't panic in castogscanstatus
X-Git-Tag: go1.26rc1~391
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=b5353fd90a;p=gostls13.git

runtime: don't panic in castogscanstatus

The panic calls gopanic which may have write barriers, but
castogscanstatus is called from //go:nowritebarrier contexts.

The panic is dead code anyway, and appears immediately before a call to
'throw'.

Change-Id: I4a8e296b71bf002295a3aa1db4f723c305ed939a
Reviewed-on: https://go-review.googlesource.com/c/go/+/717406
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
---

diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index ef3a0b7a0e..91740d1fa6 100644
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -1254,8 +1254,8 @@ func castogscanstatus(gp *g, oldval, newval uint32) bool {
 		}
 	}
 	print("runtime: castogscanstatus oldval=", hex(oldval), " newval=", hex(newval), "\n")
-	throw("castogscanstatus")
-	panic("not reached")
+	throw("bad oldval passed to castogscanstatus")
+	return false
 }
 
 // casgstatusAlwaysTrack is a debug flag that causes casgstatus to always track