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authorMichael Munday <mike.munday@ibm.com>2020-08-10 08:01:21 -0700
committerDmitri Shuralyov <dmitshur@golang.org>2020-09-10 18:29:56 +0000
commitbbee5236cd64a11a2bfd194eb9f809f51cae0870 (patch)
treebbe74d2a1687ca9ebe69ba69db57d08758b37f39
parent9706f510a5e2754595d716bd64be8375997311fb (diff)
downloadgo-bbee5236cd64a11a2bfd194eb9f809f51cae0870.tar.gz
go-bbee5236cd64a11a2bfd194eb9f809f51cae0870.zip
[release-branch.go1.15] 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 #40693. Change-Id: I4eb570de13165cde342d5fb2ee3218945ddf4b52 Reviewed-on: https://go-review.googlesource.com/c/go/+/248478 Run-TryBot: Michael Munday <mike.munday@ibm.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
-rw-r--r--src/cmd/internal/obj/s390x/objz.go11
1 files changed, 0 insertions, 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