cmd/cgo: jobject is not mapped to uintptr if building with the Android NDK #26213

eliasnaur · 2018-07-04T07:54:05Z

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

go version devel +36c623046b Wed Jul 4 00:22:11 2018 +0000 linux/amd64

Does this issue reproduce with the latest release?

With tip.

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

GOARCH="amd64"
GOBIN=""
GOCACHE="/home/elias/.cache/go-build"
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/elias/dev/go"
GOPROXY=""
GORACE=""
GOROOT="/home/elias/dev/go-tip"
GOTMPDIR=""
GOTOOLDIR="/home/elias/dev/go-tip/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
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-build267724991=/tmp/go-build -gno-record-gcc-switches"
VGOMODROOT=""

What did you do?

Compiled the program

package blah

/*
#include <jni.h>
*/
import "C"

var blah C.jobject = 0

with the Android NDK:

$ CC=/path/to/ndk-standalone-x86_64/bin/clang CGO_ENABLED=1 GOOS=android go build program.go

What did you expect to see?

No error.

What did you see instead?

# command-line-arguments
./program.go:8: cannot use 0 (type int) as type _Ctype_jobject in assignment

The short program is a condensed version of the gomobile internal/mobileinit/ctx_android.go file. There is no direct assignment to a jobject variables in gomobile; I found out because I was alerted to a write barrier related crash in the function SetContext that operates on jobject values.

Note that the program successfully builds with my system's JNI headers:

$ CGO_CFLAGS="-I/usr/lib/jvm/java/include/ -I/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.172-9.b11.fc28.x86_64/include/linux" CGO_ENABLED=1 go build program.go

The text was updated successfully, but these errors were encountered:

eliasnaur · 2018-07-04T07:56:35Z

I'm marking this release-blocker since it causes crashes in the wild.

eliasnaur · 2018-07-04T08:01:24Z

CC @randall77 who did CL 81876.

steeve · 2018-07-04T08:02:22Z

Here is a stack trace:

07-02 17:32:37.513 28901     0 E Go      : runtime: writebarrierptr *0x771bc8ac18 = 0x7ca
07-02 17:32:37.513 28901     0 E Go      : fatal error: bad pointer in write barrier
07-02 17:32:37.513 28901 28944 E GoLog   : runtime: writebarrierptr *0x771bc8ac18 = 0x7ca
07-02 17:32:37.519 28901     0 E Go      : 
07-02 17:32:37.519 28901     0 E Go      : runtime stack:
07-02 17:32:37.519 28901     0 E Go      : runtime.throw(0x771ac781b5, 0x1c)
07-02 17:32:37.519 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/panic.go:593 +0x58 fp=0x7fc8f384e0 sp=0x7fc8f384c0 pc=0x771a225408
07-02 17:32:37.519 28901     0 E Go      : runtime.writebarrierptr.func1()
07-02 17:32:37.519 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/mbarrier.go:215 +0x90 fp=0x7fc8f38510 sp=0x7fc8f384e0 pc=0x771a24c120
07-02 17:32:37.519 28901     0 E Go      : runtime.systemstack(0x782eb51671ac0e4e)
07-02 17:32:37.519 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:229 +0x8c fp=0x7fc8f38520 sp=0x7fc8f38510 pc=0x771a24ed3c
07-02 17:32:37.519 28901     0 E Go      : runtime.mstart()
07-02 17:32:37.519 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:1175 fp=0x7fc8f38520 sp=0x7fc8f38520 pc=0x771a2298a0
07-02 17:32:37.519 28901     0 E Go      : 
07-02 17:32:37.519 28901     0 E Go      : goroutine 17 [running, locked to thread]:
07-02 17:32:37.519 28901     0 E Go      : runtime.systemstack_switch()
07-02 17:32:37.519 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:178 +0x8 fp=0x4420074e60 sp=0x4420074e50 pc=0x771a24ec98
07-02 17:32:37.519 28901     0 E Go      : runtime.writebarrierptr(0x771bc8ac18, 0x7ca)
07-02 17:32:37.519 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/mbarrier.go:213 +0x7c fp=0x4420074e90 sp=0x4420074e60 pc=0x771a20cafc
07-02 17:32:37.520 28901     0 E Go      : golang.org/x/mobile/internal/mobileinit.SetCurrentContext(...)
07-02 17:32:37.520 28901     0 E Go      : 	/Users/administrator/go/src/golang.org/x/mobile/internal/mobileinit/ctx_android.go:83
07-02 17:32:37.520 28901     0 E Go      : golang.org/x/mobile/bind/java.setContext(...)
07-02 17:32:37.520 28901     0 E Go      : 	/Users/administrator/go/src/golang.org/x/mobile/bind/java/context_android.go:20
07-02 17:32:37.520 28901     0 E Go      : golang.org/x/mobile/bind/java._cgoexpwrap_720489891265_setContext(0x7748490080, 0x7ca)
07-02 17:32:37.520 28901     0 E Go      : 	_cgo_gotypes.go:61 +0x70 fp=0x4420074eb0 sp=0x4420074e90 pc=0x771ab9b960
07-02 17:32:37.520 28901     0 E Go      : runtime.call32(0x0, 0x7fc8f38578, 0x7fc8f38660)
07-02 17:32:37.520 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:411 +0x6c fp=0x4420074ee0 sp=0x4420074eb0 pc=0x771a24f10c
07-02 17:32:37.520 28901     0 E Go      : runtime.cgocallbackg1(0x0)
07-02 17:32:37.520 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/cgocall.go:316 +0x140 fp=0x4420074f60 sp=0x4420074ee0 pc=0x771a1fd880
07-02 17:32:37.520 28901     0 E Go      : runtime.cgocallbackg(0x0)
07-02 17:32:37.520 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/cgocall.go:194 +0x98 fp=0x4420074fc0 sp=0x4420074f60 pc=0x771a1fd6c8
07-02 17:32:37.520 28901     0 E Go      : runtime.cgocallback_gofunc(0x0, 0x0, 0x0, 0x0)
07-02 17:32:37.520 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:642 +0x90 fp=0x4420074fe0 sp=0x4420074fc0 pc=0x771a250ec0
07-02 17:32:37.520 28901     0 E Go      : runtime.goexit()
07-02 17:32:37.520 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:1037 +0x4 fp=0x4420074fe0 sp=0x4420074fe0 pc=0x771a251354
07-02 17:32:37.520 28901     0 E Go      : 
07-02 17:32:37.520 28901     0 E Go      : goroutine 2 [force gc (idle)]:
07-02 17:32:37.521 28901     0 E Go      : runtime.gopark(0x771b388050, 0x771bc68160, 0x771ac6a6a6, 0xf, 0x771b387f14, 0x1)
07-02 17:32:37.521 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:291 +0xe8 fp=0x4420062760 sp=0x4420062730 pc=0x771a226f78
07-02 17:32:37.521 28901     0 E Go      : runtime.goparkunlock(0x771bc68160, 0x771ac6a6a6, 0xf, 0x14, 0x1)
07-02 17:32:37.521 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:297 +0x4c fp=0x44200627a0 sp=0x4420062760 pc=0x771a22705c
07-02 17:32:37.521 28901     0 E Go      : runtime.forcegchelper()
07-02 17:32:37.521 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:248 +0xb8 fp=0x44200627d0 sp=0x44200627a0 pc=0x771a226df8
07-02 17:32:37.521 28901     0 E Go      : runtime.goexit()
07-02 17:32:37.521 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:1037 +0x4 fp=0x44200627d0 sp=0x44200627d0 pc=0x771a251354
07-02 17:32:37.521 28901     0 E Go      : created by runtime.init.3
07-02 17:32:37.521 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:237 +0x28
07-02 17:32:37.521 28901     0 E Go      : 
07-02 17:32:37.521 28901     0 E Go      : goroutine 3 [GC sweep wait]:
07-02 17:32:37.521 28901     0 E Go      : runtime.gopark(0x771b388050, 0x771bc68320, 0x771ac6837d, 0xd, 0x771a24cb14, 0x1)
07-02 17:32:37.521 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:291 +0xe8 fp=0x4420062f60 sp=0x4420062f30 pc=0x771a226f78
07-02 17:32:37.522 28901     0 E Go      : runtime.goparkunlock(0x771bc68320, 0x771ac6837d, 0xd, 0x14, 0x1)
07-02 17:32:37.522 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:297 +0x4c fp=0x4420062fa0 sp=0x4420062f60 pc=0x771a22705c
07-02 17:32:37.522 28901     0 E Go      : runtime.bgsweep(0x4420090000)
07-02 17:32:37.522 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/mgcsweep.go:71 +0x148 fp=0x4420062fd0 sp=0x4420062fa0 pc=0x771a219578
07-02 17:32:37.522 28901     0 E Go      : runtime.goexit()
07-02 17:32:37.522 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:1037 +0x4 fp=0x4420062fd0 sp=0x4420062fd0 pc=0x771a251354
07-02 17:32:37.522 28901     0 E Go      : created by runtime.gcenable
07-02 17:32:37.522 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/mgc.go:216 +0x4c
07-02 17:32:37.522 28901     0 E Go      : 
07-02 17:32:37.522 28901     0 E Go      : goroutine 4 [finalizer wait]:
07-02 17:32:37.522 28901     0 E Go      : runtime.gopark(0x771b388050, 0x771bc8af50, 0x771ac696ed, 0xe, 0x14, 0x1)
07-02 17:32:37.522 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:291 +0xe8 fp=0x44200636f0 sp=0x44200636c0 pc=0x771a226f78
07-02 17:32:37.522 28901     0 E Go      : runtime.goparkunlock(0x771bc8af50, 0x771ac696ed, 0xe, 0x14, 0x1)
07-02 17:32:37.522 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/proc.go:297 +0x4c fp=0x4420063730 sp=0x44200636f0 pc=0x771a22705c
07-02 17:32:37.522 28901     0 E Go      : runtime.runfinq()
07-02 17:32:37.522 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/mfinal.go:175 +0xa8 fp=0x44200637d0 sp=0x4420063730 pc=0x771a210a58
07-02 17:32:37.522 28901     0 E Go      : runtime.goexit()
07-02 17:32:37.522 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:1037 +0x4 fp=0x44200637d0 sp=0x44200637d0 pc=0x771a251354
07-02 17:32:37.522 28901     0 E Go      : created by runtime.createfing
07-02 17:32:37.523 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/mfinal.go:156 +0x64
07-02 17:32:37.523 28901     0 E Go      : 
07-02 17:32:37.523 28901     0 E Go      : goroutine 5 [runnable]:
07-02 17:32:37.523 28901     0 E Go      : runtime.cgocall(0x771abc59dc, 0x4420063e48, 0x29)
07-02 17:32:37.523 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/cgocall.go:128 +0x4c fp=0x4420063e10 sp=0x4420063de0 pc=0x771a1fd59c
07-02 17:32:37.523 28901     0 E Go      : golang.org/x/mobile/internal/mobileinit._Cfunc_free(0x773c80e4e0)
07-02 17:32:37.523 28901     0 E Go      : 	_cgo_gotypes.go:121 +0x38 fp=0x4420063e40 sp=0x4420063e10 pc=0x771a2c9358
07-02 17:32:37.523 28901     0 E Go      : golang.org/x/mobile/internal/mobileinit.lineLog.func1(0x773c80e4e0)
07-02 17:32:37.523 28901     0 E Go      : 	/Users/administrator/go/src/golang.org/x/mobile/internal/mobileinit/mobileinit_android.go:62 +0x44 fp=0x4420063e70 sp=0x4420063e40 pc=0x771a2c9944
07-02 17:32:37.523 28901     0 E Go      : golang.org/x/mobile/internal/mobileinit.lineLog(0x442000e028, 0x6)
07-02 17:32:37.523 28901     0 E Go      : 	/Users/administrator/go/src/golang.org/x/mobile/internal/mobileinit/mobileinit_android.go:62 +0x108 fp=0x4420063fc0 sp=0x4420063e70 pc=0x771a2c95c8
07-02 17:32:37.523 28901     0 E Go      : runtime.goexit()
07-02 17:32:37.523 28901     0 E Go      : 	/usr/local/Cellar/go/HEAD-896d263/libexec/src/runtime/asm_arm64.s:1037 +0x4 fp=0x4420063fc0 sp=0x4420063fc0 pc=0x771a251354
07-02 17:32:37.523 28901     0 E Go      : created by golang.org/x/mobile/internal/mobileinit.init.0
07-02 17:32:37.523 28901     0 E Go      : 	/Users/administrator/go/src/golang.org/x/mobile/internal/mobileinit/mobileinit_android.go:82 +0x100

steeve · 2018-07-04T08:12:34Z

This is how jobject is defined in Android's jni.h:

#ifdef __cplusplus

class _jobject {};
typedef _jobject*       jobject;

#else /* not __cplusplus */

typedef void*           jobject;

#endif

steeve · 2018-07-04T08:15:15Z

This check then fails:
https://github.com/golang/go/blob/master/src/cmd/cgo/gcc.go#L2707-L2716

steeve · 2018-07-04T10:57:19Z

We have a fix that we'll upstream today or tomorrow if you guys want: https://github.com/znly/go/commit/6319b41464636ec173958c08b4b39611c677bb0e

That said, I fail to understand why test22906 did not catch this. My guess is probably differences in the NDK environment.

eliasnaur · 2018-07-04T11:29:09Z

I think test22906 uses its own definition of JNI types to avoid depending on jni.h.

steeve · 2018-07-04T12:22:23Z

Ah you're right.

eliasnaur · 2018-07-04T17:38:22Z

This is a candidate for back-porting as well.

steeve · 2018-07-04T17:55:13Z

After fighting with the auth on Gerrit, I bailed and submitted a PR at #26221

gopherbot · 2018-07-04T17:55:41Z

Change https://golang.org/cl/122217 mentions this issue: cmd/cgo: update JNI's jobject to uintptr check for newer Android NDKs

eliasnaur added the release-blocker label Jul 4, 2018

steeve mentioned this issue Jul 4, 2018

cmd/cgo: update JNI's jobject to uintptr check for newer Android NDKs #26221

Closed

ianlancetaylor added the NeedsInvestigation label Jul 11, 2018

ianlancetaylor added this to the Go1.11 milestone Jul 11, 2018

gopherbot closed this as completed in 5419e7a Jul 17, 2018

golang locked and limited conversation to collaborators Jul 17, 2019

gopherbot added the FrozenDueToAge label Jul 17, 2019

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cmd/cgo: jobject is not mapped to uintptr if building with the Android NDK #26213

cmd/cgo: jobject is not mapped to uintptr if building with the Android NDK #26213

eliasnaur commented Jul 4, 2018 •

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eliasnaur commented Jul 4, 2018

steeve commented Jul 4, 2018

steeve commented Jul 4, 2018 •

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steeve commented Jul 4, 2018

eliasnaur commented Jul 4, 2018 •

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eliasnaur commented Jul 4, 2018

steeve commented Jul 4, 2018 •

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gopherbot commented Jul 4, 2018

cmd/cgo: jobject is not mapped to uintptr if building with the Android NDK #26213

cmd/cgo: jobject is not mapped to uintptr if building with the Android NDK #26213

Comments

eliasnaur commented Jul 4, 2018 • edited Loading

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

Does this issue reproduce with the latest release?

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

What did you do?

What did you expect to see?

What did you see instead?

eliasnaur commented Jul 4, 2018 • edited Loading

eliasnaur commented Jul 4, 2018

steeve commented Jul 4, 2018

steeve commented Jul 4, 2018 • edited Loading

steeve commented Jul 4, 2018 • edited Loading

steeve commented Jul 4, 2018

eliasnaur commented Jul 4, 2018 • edited Loading

steeve commented Jul 4, 2018

eliasnaur commented Jul 4, 2018

steeve commented Jul 4, 2018 • edited Loading

gopherbot commented Jul 4, 2018

eliasnaur commented Jul 4, 2018 •

edited

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

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

eliasnaur commented Jul 4, 2018 •

edited

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steeve commented Jul 4, 2018 •

edited

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steeve commented Jul 4, 2018 •

edited

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eliasnaur commented Jul 4, 2018 •

edited

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steeve commented Jul 4, 2018 •

edited

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