runtime: mark morestack_noctxt SPWRITE for linux/loong64

ref. CL 425396 Updates golang#54332. Change-Id: I1a235b0cca4dbf79cf61cf5f40b594fc2d940857 Reviewed-on: https://go-review.googlesource.com/c/go/+/446895 Reviewed-by: Cherry Mui <[email protected]> Reviewed-by: WANG Xuerui <[email protected]> Run-TryBot: Wayne Zuo <[email protected]> TryBot-Result: Gopher Robot <[email protected]> Reviewed-by: Ian Lance Taylor <[email protected]> Reviewed-by: xiaodong liu <[email protected]>
xen0n · Mar 15, 2023 · b5c8ae9 · b5c8ae9
1 parent 574c620
commit b5c8ae9
Showing 1 changed file with 7 additions and 0 deletions.
diff --git a/src/runtime/asm_loong64.s b/src/runtime/asm_loong64.s
@@ -266,6 +266,13 @@ TEXT runtime·morestack(SB),NOSPLIT|NOFRAME,$0-0
 	UNDEF
 
 TEXT runtime·morestack_noctxt(SB),NOSPLIT|NOFRAME,$0-0
+	// Force SPWRITE. This function doesn't actually write SP,
+	// but it is called with a special calling convention where
+	// the caller doesn't save LR on stack but passes it as a
+	// register (R5), and the unwinder currently doesn't understand.
+	// Make it SPWRITE to stop unwinding. (See issue 54332)
+	MOVV    R3, R3
+
 	MOVV	R0, REGCTXT
 	JMP	runtime·morestack(SB)