From 43fef1dae66e581309d62bb4421df4d07683a49c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Tue, 5 Aug 2025 23:20:42 +0800
Subject: [PATCH] android: Add workaround for tailscale pidfd crash

---
 cmd/internal/build_libbox/main.go    |  2 ++
 experimental/libbox/pidfd_android.go | 19 +++++++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 experimental/libbox/pidfd_android.go

diff --git a/cmd/internal/build_libbox/main.go b/cmd/internal/build_libbox/main.go
index 2b81ff36..de470eb3 100644
--- a/cmd/internal/build_libbox/main.go
+++ b/cmd/internal/build_libbox/main.go
@@ -112,6 +112,8 @@ func buildAndroid() {
 		args = append(args, debugFlags...)
 	}
 
+	args = append(args, "-ldflags", "-checklinkname=0")
+
 	tags := append(sharedTags, memcTags...)
 	if debugEnabled {
 		tags = append(tags, debugTags...)
diff --git a/experimental/libbox/pidfd_android.go b/experimental/libbox/pidfd_android.go
new file mode 100644
index 00000000..cc7cdd7a
--- /dev/null
+++ b/experimental/libbox/pidfd_android.go
@@ -0,0 +1,19 @@
+package libbox
+
+import (
+	"os"
+	_ "unsafe"
+)
+
+// https://github.com/SagerNet/sing-box/issues/3233
+// https://github.com/golang/go/issues/70508
+// https://github.com/tailscale/tailscale/issues/13452
+
+//go:linkname checkPidfdOnce os.checkPidfdOnce
+var checkPidfdOnce func() error
+
+func init() {
+	checkPidfdOnce = func() error {
+		return os.ErrInvalid
+	}
+}