From f8892147bdfd16fe7ef04eccf59c4abf774550f1 Mon Sep 17 00:00:00 2001 From: Cherry Zhang Date: Mon, 19 Apr 2021 13:58:07 -0400 Subject: [PATCH] runtime: open up space for callee's arg spill slot in mcall (regabi version) mcall calls fn with an argument. Currently, in the regabi version of mcall it does not reserve space for that argument's spill slot. If the callee spills its argument, it may clobber things on the g0 stack at 0(SP) (e.g. the old SP saved in cgocallback). Reserve the space. Change-Id: I85a314273cd996c7fac8fd0b03cd9033faae9c5a Reviewed-on: https://go-review.googlesource.com/c/go/+/311489 Trust: Cherry Zhang Reviewed-by: Michael Knyszek --- src/runtime/asm_amd64.s | 2 ++ 1 file changed, 2 insertions(+) diff --git a/src/runtime/asm_amd64.s b/src/runtime/asm_amd64.s index ca6b1501d1..1e6d8189c9 100644 --- a/src/runtime/asm_amd64.s +++ b/src/runtime/asm_amd64.s @@ -302,8 +302,10 @@ goodm: get_tls(CX) // Set G in TLS MOVQ R14, g(CX) MOVQ (g_sched+gobuf_sp)(R14), SP // sp = g0.sched.sp + PUSHQ AX // open up space for fn's arg spill slot MOVQ 0(DX), R12 CALL R12 // fn(g) + POPQ AX JMP runtime·badmcall2(SB) RET #else -- 2.50.0