From 77029b76b01fbb4dbeda57664ef62e98efbc2440 Mon Sep 17 00:00:00 2001 From: Michael Munday Date: Mon, 10 Aug 2020 08:01:21 -0700 Subject: [release-branch.go1.14] cmd/internal/obj: fix inline marker issue on s390x The optimization that replaces inline markers with pre-existing instructions assumes that 'Prog' values produced by the compiler are still reachable after the assembler has run. This was not true on s390x where the assembler was removing NOP instructions from the linked list of 'Prog' values. This led to broken inlining data which in turn caused an infinite loop in the runtime traceback code. Fix this by stopping the s390x assembler backend removing NOP values. It does not make any difference to the output of the assembler because NOP instructions are 0 bytes long anyway. Note: compiler check omitted from backport to reduce risk of change. Fixes #40694. Change-Id: I9f9bdbe895c3478549b5e7e623f9521f841e926a Reviewed-on: https://go-review.googlesource.com/c/go/+/248477 Run-TryBot: Michael Munday TryBot-Result: Gobot Gobot Reviewed-by: Dmitri Shuralyov Reviewed-by: Keith Randall --- src/cmd/internal/obj/s390x/objz.go | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/src/cmd/internal/obj/s390x/objz.go b/src/cmd/internal/obj/s390x/objz.go index b14dc810fa..ef6335d849 100644 --- a/src/cmd/internal/obj/s390x/objz.go +++ b/src/cmd/internal/obj/s390x/objz.go @@ -283,17 +283,6 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym, newprog obj.ProgAlloc) { ACMPUBNE: q = p p.Mark |= BRANCH - if p.Pcond != nil { - q := p.Pcond - for q.As == obj.ANOP { - q = q.Link - p.Pcond = q - } - } - - case obj.ANOP: - q.Link = p.Link /* q is non-nop */ - p.Link.Mark |= p.Mark default: q = p -- cgit v1.2.3-54-g00ecf