From: Joe Tsai <joetsai@digital-static.net>
Date: Thu, 13 Feb 2025 23:59:32 +0000 (-0800)
Subject: runtime: respect GOTRACEBACK for user-triggered runtime panics
X-Git-Tag: go1.26rc1~149
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=02d1f3a06b;p=gostls13.git

runtime: respect GOTRACEBACK for user-triggered runtime panics

The documentation for GOTRACEBACK says that "single" is the default
where the stack trace for only a single routine is printed except
that it prints all stack traces if:

	there is no current goroutine or
	the failure is internal to the run-time.

In the runtime, there are two types of panics:
throwTypeUser and throwTypeRuntime.
The latter more clearly corresponds to a
"failure [that] is internal to the run-time",
while the former corresponds to a
problem trigger due to a user mistake.

Thus, a user-triggered panic (e.g., concurrent map access)
should not result in a dump of all stack traces.

Fixes #68019

Change-Id: I9b02f82535ddb9fd666f7158e2e4ee10f235646a
Reviewed-on: https://go-review.googlesource.com/c/go/+/649535
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
---

diff --git a/src/runtime/runtime1.go b/src/runtime/runtime1.go
index 43e4c14236..64ee4c8d2e 100644
--- a/src/runtime/runtime1.go
+++ b/src/runtime/runtime1.go
@@ -39,7 +39,7 @@ func gotraceback() (level int32, all, crash bool) {
 	gp := getg()
 	t := atomic.Load(&traceback_cache)
 	crash = t&tracebackCrash != 0
-	all = gp.m.throwing >= throwTypeUser || t&tracebackAll != 0
+	all = gp.m.throwing > throwTypeUser || t&tracebackAll != 0
 	if gp.m.traceback != 0 {
 		level = int32(gp.m.traceback)
 	} else if gp.m.throwing >= throwTypeRuntime {