x/sys/unix: missing SIGSTKFLT for mips64le

[ydcool]

What version of Go are you using (go version)?

$ go version
go version go1.12.5 linux/mips64le

Does this issue reproduce with the latest release?

Yes.

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GOARCH="mips64le"
GOBIN=""
GOCACHE="/root/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="mips64le"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/opt/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/lib/go-go1.12.5"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go-go1.12.5/pkg/tool/linux_mips64le"
GCCGO="gccgo"
GOMIPS64="hardfloat"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -mabi=64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build457678816=/tmp/go-build -gno-record-gcc-switches"

What did you do?

git clone -b v18.09.8-ce https://github.com/docker/docker-ce "$GOPATH/src/github.com/docker/"
cd $GOPATH/src/github.com/docker
ln -s $GOPATH/src/github.com/docker/docker-ce/components/engine docker
cd $GOPATH/src/github.com/docker/docker
sh -x ./hack/make.sh dynbinary

What did you expect to see?

build docker without error related to golang.org/x/sys

What did you see instead?

# github.com/docker/docker/pkg/signal
pkg/signal/signal_linux.go:35:14: undefined: unix.SIGSTKFLT

[ydcool]

I wonder if I could submit a PR for golang.org/x/sys/unix/zerros_linux_mips64le.go, just adding the code like this:

SIGSTKFLT = syscall.Signal(0x16)

And this works for me.

[ianlancetaylor]

As far as I can tell, the x/sys/unix package is correct. MIPS64le GNU/Linux does not have a SIGSTKFLT signal. Signal number 0x16 is SIGIO aka SIGPOLL. You would see the same error compiling an equivalent C program on MIPS64le GNU/Linux. Note that in the x86 header file SIGSTKFLT is marked as obsolete.

This needs to be fixed in Docker itself.