[dev.link] cmd/link: refer to .got instead of .got.plt on S390X

S390X uses .got instead of .got.plt. It is changed accidentally
in CL 222977. This CL fixes it.

Also, on S390X, we need to set the relocation "variant" of
R_PCREL relocation. In the old code AddPCRelPlus has the magic.
Here we use the equivalent R_PCRELDBL, as the loader doesn't
have variant.

Fix S390X build.

Change-Id: I388e16f02a0568d70287aa9a132fd42b442e3905
Reviewed-on: https://go-review.googlesource.com/c/go/+/223143
Run-TryBot: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Than McIntosh <thanm@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/cmd/link/internal/ld/elf.go b/src/cmd/link/internal/ld/elf.go
index b0710892546279daa0810faf0ce13808cb08bb8a..078b0a55db283e0d31890e9157ac4c722266ef6d 100644 (file)
--- a/src/cmd/link/internal/ld/elf.go
+++ b/src/cmd/link/internal/ld/elf.go
@@ -1645,6 +1645,10 @@ func (ctxt *Link) doelf() {
                dynamic.SetReachable(true)
                dynamic.SetType(sym.SELFSECT) // writable
 
+               if ctxt.IsS390X() {
+                       // S390X uses .got instead of .got.plt
+                       gotplt = got
+               }
                thearch.Elfsetupplt(ctxt, plt, gotplt, dynamic.Sym())
 
                /*
@@ -1678,8 +1682,6 @@ func (ctxt *Link) doelf() {
 
                if ctxt.IsPPC64() {
                        elfwritedynentsym2(ctxt, dynamic, DT_PLTGOT, plt.Sym())
-               } else if ctxt.IsS390X() {
-                       elfwritedynentsym2(ctxt, dynamic, DT_PLTGOT, got.Sym())
                } else {
                        elfwritedynentsym2(ctxt, dynamic, DT_PLTGOT, gotplt.Sym())
                }

diff --git a/src/cmd/link/internal/s390x/asm.go b/src/cmd/link/internal/s390x/asm.go
index c5060fa02c9eb34a90eba8042604b2c1f5b3c58a..57437f2f4e1a81058c7034b438a075f2e39c16ad 100644 (file)
--- a/src/cmd/link/internal/s390x/asm.go
+++ b/src/cmd/link/internal/s390x/asm.go
@@ -346,7 +346,7 @@ func elfsetupplt(ctxt *ld.Link, plt, got *loader.SymbolBuilder, dynamic loader.S
                // larl    %r1,_GLOBAL_OFFSET_TABLE_
                plt.AddUint8(0xc0)
                plt.AddUint8(0x10)
-               plt.AddPCRelPlus(ctxt.Arch, got.Sym(), 6)
+               plt.AddSymRef(ctxt.Arch, got.Sym(), 6, objabi.R_PCRELDBL, 4)
                // mvc     48(8,%r15),8(%r1)
                plt.AddUint8(0xd2)
                plt.AddUint8(0x07)