runtime: go compiler with PIE enabled by default race segv

[jsimonetti]

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

$ go version
go version go1.12.3 linux/amd64

Does this issue reproduce with the latest release?

Yes

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

ArchLinux 5.0.7-arch1-1-ARCH #1 SMP PREEMPT

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/jsimonetti/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/jsimonetti/go"
GOPROXY=""
GORACE=""
GOROOT="/usr/lib/go"
GOTMPDIR=""
GOTOOLDIR="/usr/lib/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
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 -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build181627555=/tmp/go-build -gno-record-gcc-switches"

What did you do?

Testing code using -race on a go version with PIE enabled by default I get a segv and a ENOMEM error from the ThreadSanitizer.

What did you expect to see?

An error message similar to one when using the normal go compiler but with -buildmode=pie flag:

% go test -buildmode=pie  -race -count 1 .
-buildmode=pie not supported when -race is enabled

What did you see instead?

=7219==ERROR: ThreadSanitizer failed to allocate 0x2711000 (40964096) bytes at address 176bdd04c0000 (errno: 12)
unexpected fault address 0x0
fatal error: fault
unexpected fault address 0x55af73e8b59c
fatal error: fault
unexpected fault address 0x55af74aefbea
fatal error: fault
[signal SIGSEGV: segmentation violation code=0x2 addr=0x55af74aefbea pc=0x55af74aefbea]

goroutine 1 [running, locked to thread]:
runtime: unexpected return pc for runtime.throw called from 0x55af73e8b1bc
stack: frame={sp:0x7ffdc4bfcfd0, fp:0x7ffdc4bfd000} stack=[0xc000044000,0xc000044800)

runtime.throw(0x3, 0x3)
	/usr/lib/go/src/runtime/panic.go:617 +0x74 fp=0x7ffdc4bfd000 sp=0x7ffdc4bfcfd0 pc=0x55af73c42c14

Edit:
Package managers' patch applied to default source:
https://git.archlinux.org/svntogit/community.git/tree/trunk/default-buildmode-pie.patch?h=packages/go

BTW, feel free to flag this as WONTFIX as this probably it not your problem.

[ianlancetaylor]

This is a problem with the patch you are applying to the sources, not with the Go source code. There isn't anything we can do to fix this.