plugin: add test (was encoding/asn1 error when using plugin) #18584

fsenart · 2017-01-09T22:38:25Z

Please answer these questions before submitting your issue. Thanks!

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

go version go1.8beta2 linux/amd64

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

GOARCH="amd64"
GOBIN=""
GOEXE=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/fsenart/projects"
GORACE=""
GOROOT="/home/fsenart/tools/go"
GOTOOLDIR="/home/fsenart/tools/go/pkg/tool/linux_amd64"
GCCGO="gccgo"
CC="gcc"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build746500890=/tmp/go-build -gno-record-gcc-switches"
CXX="g++"
CGO_ENABLED="1"
PKG_CONFIG="pkg-config"
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"

What did you do?

If possible, provide a recipe for reproducing the error.
A complete runnable program is good.
A link on play.golang.org is best.

// main.go

package main

import (
	"plugin"
	"reflect"
)

func main() {
	p, err := plugin.Open("plugin.so")
	if err != nil {
		panic(err)
	}
	f, err := p.Lookup("F")
	if err != nil {
		panic(err)
	}

	// f.(func())()
	reflect.ValueOf(f).Call(nil)
}

// plugin.go

package main

import "C"
import "net/http"

func F() {
	_, err := http.Get("https://example.com")
	if err != nil {
		panic(err)
	}
}

# Makefile

test: build
	@./main

build: clean
	@go build -buildmode=plugin -o plugin.so plugin.go
	@go build -o main main.go

clean:
	@rm -rf main *.so

What did you expect to see?

I don't expect any panic to happen.

What did you see instead?

I see a panic happen.

panic: Get https://example.com: tls: failed to parse certificate from server: asn1: structure error: tags don't match (4 vs {class:0 tag:16 length:1242 isCompound:true}) {optional:false explicit:false application:false defaultValue:<nil> tag:<nil> stringType:0 timeType:0 set:false omitEmpty:false} RawContent @4

goroutine 1 [running]:
plugin/unnamed-4ad3198f73971e7223d350ce7ae956cd80d817d9.F()
	/home/fsenart/projects/src/github.com/alsanium/issue_asn1/plugin.go:9 +0x65
reflect.Value.call(0x4d3820, 0xc42000f728, 0x13, 0x4ef099, 0x4, 0x0, 0x0, 0x0, 0xc42000c2e0, 0x4d3820, ...)
	/home/fsenart/tools/go/src/reflect/value.go:434 +0x91f
reflect.Value.Call(0x4d3820, 0xc42000f728, 0x13, 0x0, 0x0, 0x0, 0xc42004df68, 0x4be551, 0x0)
	/home/fsenart/tools/go/src/reflect/value.go:302 +0xa4
main.main()
	/home/fsenart/projects/src/github.com/alsanium/issue_asn1/main.go:19 +0xed
Makefile:2: recipe for target 'test' failed

Observations

If I don't use the reflect package, and instead make type assertion manually, then no error happens.
```
f.(func())()
// reflect.ValueOf(f).Call(nil)
```

If I don't use the plugin package, then no error happens.

package main

import (
    "net/http"
    "reflect"
)

var f interface{} = func() {
    _, err := http.Get("https://example.com")
    if err != nil {
        panic(err)
    }
}

func main() {
    //f.(func())()
    reflect.ValueOf(f).Call(nil)
}

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

bradfitz · 2017-01-09T22:41:38Z

/cc @crawshaw @ianlancetaylor

bradfitz · 2017-01-09T22:41:54Z

Probably too late for a Go 1.8 fix, but maybe a point release.

CAT: #doc REF: golang/go#18584

fsenart · 2017-01-10T00:49:27Z

OK. THIS IS WEIRD.

After more investigation, it seems not even related to the reflect package.

The error happens if you import any package when using the plugin package.
For example (plugin.go as above):

// main.go

package main

import (
	"fmt" // you can import any package (fails with fmt, log, json, etc.)
	"plugin"
)

func main() {
	fmt.Print() // dummy print for the import statement

	p, err := plugin.Open("plugin.so")
	if err != nil {
		panic(err)
	}
	f, err := p.Lookup("F")
	if err != nil {
		panic(err)
	}

	f.(func())()
}

PS: I don't know what should be the issue title!

stefanahman · 2017-01-10T14:01:54Z

Getting the same error using https://github.com/eawsy/aws-lambda-go-shim library.
After more investigation and reading this thread, I noticed the plugin import in this file.

fsenart · 2017-01-10T15:52:00Z

@stefanahman we effectively use go plugins in this project and the issue is related to the fact that we have other imports than plugin in the referenced file (cf. above comment).

@bradfitz at the time I've opened the issue, I agree with you that the problem was very special and happen in rare cases and Go1.8Maybe milestone was ok.
But considering my last comment, you must notice that as soon as any package is imported along with the plugin package then all SSL requests fail. Isn't it a major issue to be fixed before the release of 1.8? Can you please reconsider the milestone, taking into account the new elements?

crawshaw · 2017-01-10T16:03:03Z

Importing package plugin into a binary switches the linker to the dynamic linking codepath. Presumably that is triggering something which causes type-handling problems.

(I won't have access to a linux machine to investigate this until tomorrow.)

cristim · 2017-01-10T16:25:19Z

@fsenart, @bradfitz IMHO having the new plugin feature break TLS when there are any other imports makes it pretty useless for a lot of web backend use cases, so I think 1.8 shouldn't be released before this issue is fixed.

bradfitz · 2017-01-10T16:48:08Z

If we stopped the release train for every bug, we'd never ship.

Plugins are a new part of Go 1.8 anyway. Expect some rough edges. For instance, we disabled them entirely on Mac at the last second, and they don't work on Windows. A few more bugs are expected. That's what point releases are for.

cristim · 2017-01-10T17:17:33Z

@bradfitz if you mentioned all that it sounds reasonable, I was just under the impression that the plugin feature was a bit more mature than that.

schickling · 2017-01-10T17:45:11Z

Same issue here. Thanks for investigating @fsenart 👍

fsenart · 2017-01-10T23:51:56Z

The issue (or at least its visible symptoms) is resolved with the release of go1.8rc1 3de6e96. /cc @crawshaw @bradfitz
PS: I let you close the issue or remain it open for deep investigations.

bradfitz · 2017-01-11T00:01:03Z

@crawshaw, @ianlancetaylor do you know what might've fixed this between beta2 and rc1?

ianlancetaylor · 2017-01-11T01:20:43Z

It was fixed by the fix to #18252.

But we should add a test for this in misc/cgo/testplugin.

stefanahman · 2017-01-11T13:04:29Z

Can confirm that my issue has been resolved with v1.8rc1 😃 🎉

gopherbot · 2017-09-29T15:42:34Z

Change https://golang.org/cl/67150 mentions this issue: misc/cgo/testplugin: add test for issue 18584

fsenart changed the title ~~encoding/asn1 side effects when using reflect to call plugin methods.~~ encoding/asn1 side effects when using reflect to call plugin methods. Jan 9, 2017

bradfitz added this to the Go1.8Maybe milestone Jan 9, 2017

fsenart mentioned this issue Jan 9, 2017

SSL certificates cannot be loaded lifadev/archive_aws-lambda-go-shim#1

Closed

fsenart added a commit to lifadev/archive_aws-lambda-go that referenced this issue Jan 9, 2017

Delete migration message due to go1.8 bug

1230e8b

CAT: #doc REF: golang/go#18584

ianlancetaylor changed the title ~~encoding/asn1 side effects when using reflect to call plugin methods.~~ plugin: encoding/asn1 error when using plugin Jan 10, 2017

ianlancetaylor modified the milestones: Go1.9, Go1.8Maybe Jan 11, 2017

ianlancetaylor assigned crawshaw Jan 11, 2017

jefferai mentioned this issue Jan 12, 2017

encoding/asn1: tags don't match parsing certificate #18634

Closed

fsenart mentioned this issue Jan 20, 2017

reflect: duplicate reflect.Type values under dynamic linking #18729

Closed

bradfitz changed the title ~~plugin: encoding/asn1 error when using plugin~~ plugin: add test (was encoding/asn1 error when using plugin) Jan 23, 2017

bradfitz modified the milestones: Go1.9, Go1.10 Jun 7, 2017

gopherbot closed this as completed in 046c658 Sep 29, 2017

golang locked and limited conversation to collaborators Sep 29, 2018

gopherbot added the FrozenDueToAge label Sep 29, 2018

rsc unassigned crawshaw Jun 23, 2022

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plugin: add test (was encoding/asn1 error when using plugin) #18584

plugin: add test (was encoding/asn1 error when using plugin) #18584

fsenart commented Jan 9, 2017

bradfitz commented Jan 9, 2017

bradfitz commented Jan 9, 2017

fsenart commented Jan 10, 2017 •

edited

stefanahman commented Jan 10, 2017

fsenart commented Jan 10, 2017

crawshaw commented Jan 10, 2017

cristim commented Jan 10, 2017

bradfitz commented Jan 10, 2017

cristim commented Jan 10, 2017

schickling commented Jan 10, 2017

fsenart commented Jan 10, 2017 •

edited

bradfitz commented Jan 11, 2017

ianlancetaylor commented Jan 11, 2017

stefanahman commented Jan 11, 2017

gopherbot commented Sep 29, 2017

plugin: add test (was encoding/asn1 error when using plugin) #18584

plugin: add test (was encoding/asn1 error when using plugin) #18584

Comments

fsenart commented Jan 9, 2017

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

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?

Observations

bradfitz commented Jan 9, 2017

bradfitz commented Jan 9, 2017

fsenart commented Jan 10, 2017 • edited

stefanahman commented Jan 10, 2017

fsenart commented Jan 10, 2017

crawshaw commented Jan 10, 2017

cristim commented Jan 10, 2017

bradfitz commented Jan 10, 2017

cristim commented Jan 10, 2017

schickling commented Jan 10, 2017

fsenart commented Jan 10, 2017 • edited

bradfitz commented Jan 11, 2017

ianlancetaylor commented Jan 11, 2017

stefanahman commented Jan 11, 2017

gopherbot commented Sep 29, 2017

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

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

fsenart commented Jan 10, 2017 •

edited

fsenart commented Jan 10, 2017 •

edited