runtime/race: race_linux_amd64.syso now depends on glibc 2.16

[Roguelazer]

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

$ go version
go version go1.13.8 linux/amd64

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
GO111MODULE=""
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/vagrant/.cache/go-build"
GOENV="/home/vagrant/.config/go/env"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GONOPROXY=""
GONOSUMDB=""
GOOS="linux"
GOPATH="/home/vagrant/go"
GOPRIVATE=""
GOPROXY="https://proxy.golang.org,direct"
GOROOT="/opt/golang1.13/lib/golang"
GOSUMDB="sum.golang.org"
GOTMPDIR=""
GOTOOLDIR="/opt/golang1.13/lib/golang/pkg/tool/linux_amd64"
GCCGO="gccgo"
AR="ar"
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-build152338807=/tmp/go-build"

What did you do?

I am attempting to build go 1.14 for our internal, EL6-based distribution. 1.12 and 1.13 work fine, but 1.14 fails any time it tries to build with -race with the following:

ld: race_linux_amd64.syso: in function `__sanitizer::ReExec()':
gotsan.cpp:(.text+0x1873c): undefined reference to `getauxval'
collect2: error: ld returned 1 exit status
FAIL	flag [build failed]
FAIL	net [build failed]
FAIL	os [build failed]
FAIL	os/exec [build failed]
FAIL	encoding/gob [build failed]
FAIL

It appears that race_linux_amd64.syso now has a dependency on glibc 2.16, whereas previous versions were built against glibc 2.12. This does not appear to be documented anywhere.

I do not have access to a system with the requisite LLVM dependencies to build a new race_linux_amd64.syso, but it would be great if that new dependency could be changed.

What did you expect to see?

A successful build

What did you see instead?

Failed self-tests

[bcmills]

CC @dvyukov @randall77 (see CL 201898 / #33309)

[dvyukov]

I see there is some logic not use getauxval:
https://github.com/llvm/llvm-project/blob/master/compiler-rt/lib/sanitizer_common/sanitizer_getauxval.h#L24
We probably need to include Go build in that condition.

[Roguelazer]

This is also broken in 1.14.1.

[gopherbot]

Change https://golang.org/cl/226981 mentions this issue: runtime/race: update some .syso files

[Roguelazer]

This is also broken in 1.14.2.

[randall77]

This should be fixed at tip (can you try tip? I've been told this issue has been fixed in compiler-rt but I haven't verified myself).
I don't think we've backported fixes like this before. We'll see if this qualifies for 1.14.3.

@gopherbot Please open a backport issue to 1.14.

[gopherbot]

Backport issue(s) opened: #38321 (for 1.14).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://golang.org/wiki/MinorReleases.

[FiloSottile]

Easiest way to test at tip is with golang.org/dl/gotip.

[Roguelazer]

@FiloSottile is there a way to run the test suite with gotip? For now, I'm muddling through trying to make it work with my regular build commands.