cmd/dist,runtime: support cgo on openbsd/mips64

Add support for cgo on openbsd/mips64.

Fixes #43005

Change-Id: I2386204f53fa984a01a9d89f0b6c96455768f326
Reviewed-on: https://go-review.googlesource.com/c/go/+/275896
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Joel Sing <joel@sing.id.au>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

diff --git a/src/cmd/dist/build.go b/src/cmd/dist/build.go
index c81fe6a586f2e53b0586d24e4d6864ae23e57551..00e23ef179e65ce91ba01a23f945c63819ba6044 100644 (file)
--- a/src/cmd/dist/build.go
+++ b/src/cmd/dist/build.go
@@ -1590,7 +1590,7 @@ var cgoEnabled = map[string]bool{
        "openbsd/amd64":   true,
        "openbsd/arm":     true,
        "openbsd/arm64":   true,
-       "openbsd/mips64":  false,
+       "openbsd/mips64":  true,
        "plan9/386":       false,
        "plan9/amd64":     false,
        "plan9/arm":       false,

diff --git a/src/cmd/link/internal/mips64/asm.go b/src/cmd/link/internal/mips64/asm.go
index 55b4ba2fc84a329ea773e753ee90b1df983c2c97..f7f91d1e8b2c8b98ed6eaf14f33c43eee4c1ec64 100644 (file)
--- a/src/cmd/link/internal/mips64/asm.go
+++ b/src/cmd/link/internal/mips64/asm.go
@@ -52,6 +52,8 @@ func elfreloc1(ctxt *ld.Link, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym,
        //              type    uint8
        //              addend  int64
 
+       addend := r.Xadd
+
        out.Write64(uint64(sectoff))
 
        elfsym := ld.ElfSymForReloc(ctxt, r.Xsym)
@@ -77,11 +79,17 @@ func elfreloc1(ctxt *ld.Link, out *ld.OutBuf, ldr *loader.Loader, s loader.Sym,
                out.Write8(uint8(elf.R_MIPS_HI16))
        case objabi.R_ADDRMIPSTLS:
                out.Write8(uint8(elf.R_MIPS_TLS_TPREL_LO16))
+               if ctxt.Target.IsOpenbsd() {
+                       // OpenBSD mips64 does not currently offset TLS by 0x7000,
+                       // as such we need to add this back to get the correct offset
+                       // via the external linker.
+                       addend += 0x7000
+               }
        case objabi.R_CALLMIPS,
                objabi.R_JMPMIPS:
                out.Write8(uint8(elf.R_MIPS_26))
        }
-       out.Write64(uint64(r.Xadd))
+       out.Write64(uint64(addend))
 
        return true
 }
@@ -124,6 +132,11 @@ func archreloc(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, r loade
        case objabi.R_ADDRMIPSTLS:
                // thread pointer is at 0x7000 offset from the start of TLS data area
                t := ldr.SymValue(rs) + r.Add() - 0x7000
+               if target.IsOpenbsd() {
+                       // OpenBSD mips64 does not currently offset TLS by 0x7000,
+                       // as such we need to add this back to get the correct offset.
+                       t += 0x7000
+               }
                if t < -32768 || t >= 32678 {
                        ldr.Errorf(s, "TLS offset out of range %d", t)
                }

diff --git a/src/cmd/nm/nm_cgo_test.go b/src/cmd/nm/nm_cgo_test.go
index d0937904a2a81a69a3df4f2c324a448d6ceca5a8..1544be041a8174eee4b2849d354ecd0274f8cb76 100644 (file)
--- a/src/cmd/nm/nm_cgo_test.go
+++ b/src/cmd/nm/nm_cgo_test.go
@@ -30,7 +30,7 @@ func canInternalLink() bool {
                }
        case "openbsd":
                switch runtime.GOARCH {
-               case "arm64":
+               case "arm64", "mips64":
                        return false
                }
        case "windows":

diff --git a/src/runtime/cgo/gcc_openbsd_mips64.c b/src/runtime/cgo/gcc_openbsd_mips64.c
new file mode 100644 (file)
index 0000000..79f039a
--- /dev/null
+++ b/src/runtime/cgo/gcc_openbsd_mips64.c
@@ -0,0 +1,67 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include <sys/types.h>
+#include <pthread.h>
+#include <signal.h>
+#include <string.h>
+#include "libcgo.h"
+#include "libcgo_unix.h"
+
+static void* threadentry(void*);
+static void (*setg_gcc)(void*);
+
+void
+x_cgo_init(G *g, void (*setg)(void*))
+{
+       pthread_attr_t attr;
+       size_t size;
+
+       setg_gcc = setg;
+       pthread_attr_init(&attr);
+       pthread_attr_getstacksize(&attr, &size);
+       g->stacklo = (uintptr)&attr - size + 4096;
+       pthread_attr_destroy(&attr);
+}
+
+void
+_cgo_sys_thread_start(ThreadStart *ts)
+{
+       pthread_attr_t attr;
+       sigset_t ign, oset;
+       pthread_t p;
+       size_t size;
+       int err;
+
+       sigfillset(&ign);
+       pthread_sigmask(SIG_SETMASK, &ign, &oset);
+
+       pthread_attr_init(&attr);
+       pthread_attr_getstacksize(&attr, &size);
+
+       // Leave stacklo=0 and set stackhi=size; mstart will do the rest.
+       ts->g->stackhi = size;
+       err = _cgo_try_pthread_create(&p, &attr, threadentry, ts);
+
+       pthread_sigmask(SIG_SETMASK, &oset, nil);
+
+       if (err != 0) {
+               fprintf(stderr, "runtime/cgo: pthread_create failed: %s\n", strerror(err));
+               abort();
+       }
+}
+
+extern void crosscall1(void (*fn)(void), void (*setg_gcc)(void*), void *g);
+
+static void*
+threadentry(void *v)
+{
+       ThreadStart ts;
+
+       ts = *(ThreadStart*)v;
+       free(v);
+
+       crosscall1(ts.fn, setg_gcc, (void*)ts.g);
+       return nil;
+}