From 3e7abf82e3e0614f7d8163053d944dc59d8b9247 Mon Sep 17 00:00:00 2001 From: Lynn Boger Date: Tue, 8 Aug 2017 13:45:41 -0400 Subject: [PATCH] cmd/go,cmd/link: support buildmode c-shared on ppc64le This change enables buildmode c-shared on ppc64le. A bug was fixed in runtime/rt0_linux_ppc64le.s that was necessary to make this work. In _rt0_ppc64le_linux_lib, there is code to store the value of r2 onto the caller's stack. However, if this file is compiled using a build mode that maintains the TOC address in r2, then instructions will be inserted at the beginning of this function to generate the r2 value for the callee, not the caller. That means the r2 value for the callee is stored onto the caller's stack. If caller and callee don't have the same r2 values, then the caller will restore the wrong r2 value after it returns. This situation can happen when using dlopen since the caller of this function will be in ld64.so and will definitely have a different TOC. Updates #20756 Change-Id: I6e165e0d0716e73721bbbcc520e8302e4856e3ba Reviewed-on: https://go-review.googlesource.com/53890 Reviewed-by: Ian Lance Taylor --- src/cmd/dist/test.go | 2 +- src/cmd/go/internal/work/build.go | 2 +- src/cmd/link/internal/ld/config.go | 2 +- src/runtime/rt0_linux_ppc64le.s | 2 -- 4 files changed, 3 insertions(+), 5 deletions(-) diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go index 73432d31ea..6052904cbf 100644 --- a/src/cmd/dist/test.go +++ b/src/cmd/dist/test.go @@ -824,7 +824,7 @@ func (t *tester) supportedBuildmode(mode string) bool { return false case "c-shared": switch pair { - case "linux-386", "linux-amd64", "linux-arm", "linux-arm64", + case "linux-386", "linux-amd64", "linux-arm", "linux-arm64", "linux-ppc64le", "darwin-amd64", "darwin-386", "android-arm", "android-arm64", "android-386": return true diff --git a/src/cmd/go/internal/work/build.go b/src/cmd/go/internal/work/build.go index 7d667ff552..8ac4f75985 100644 --- a/src/cmd/go/internal/work/build.go +++ b/src/cmd/go/internal/work/build.go @@ -293,7 +293,7 @@ func BuildModeInit() { codegenArg = "-fPIC" } else { switch platform { - case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", + case "linux/amd64", "linux/arm", "linux/arm64", "linux/386", "linux/ppc64le", "android/amd64", "android/arm", "android/arm64", "android/386": codegenArg = "-shared" case "darwin/amd64", "darwin/386": diff --git a/src/cmd/link/internal/ld/config.go b/src/cmd/link/internal/ld/config.go index 342351b4bc..aae2a43723 100644 --- a/src/cmd/link/internal/ld/config.go +++ b/src/cmd/link/internal/ld/config.go @@ -63,7 +63,7 @@ func (mode *BuildMode) Set(s string) error { *mode = BuildmodeCArchive case "c-shared": switch objabi.GOARCH { - case "386", "amd64", "arm", "arm64": + case "386", "amd64", "arm", "arm64", "ppc64le": default: return badmode() } diff --git a/src/runtime/rt0_linux_ppc64le.s b/src/runtime/rt0_linux_ppc64le.s index 81b991349a..134858bff8 100644 --- a/src/runtime/rt0_linux_ppc64le.s +++ b/src/runtime/rt0_linux_ppc64le.s @@ -10,7 +10,6 @@ TEXT _rt0_ppc64le_linux_lib(SB),NOSPLIT,$-8 MOVD R0, 16(R1) // Save LR in caller's frame. MOVW CR, R0 // Save CR in caller's frame MOVD R0, 8(R1) - MOVD R2, 24(R1) // Save TOC in caller's frame. MOVDU R1, -320(R1) // Allocate frame. // Preserve callee-save registers. @@ -121,7 +120,6 @@ done: FMOVD 304(R1), F31 ADD $320, R1 - MOVD 24(R1), R2 MOVD 8(R1), R0 MOVFL R0, $0xff MOVD 16(R1), R0 -- 2.48.1