Bug 1486379

Summary:	binfmt config for ppc64le is incorrect
Product:	[Fedora] Fedora	Reporter:	Jason DeTiberus <jdetiber>
Component:	qemu	Assignee:	Fedora Virtualization Maintainers <virt-maint>
Status:	CLOSED RAWHIDE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	rawhide	CC:	amit, berrange, cfergeau, crobinso, dwmw2, itamar, npmccallum, pbonzini, rjones, virt-maint
Target Milestone:	---	Keywords:	Reopened
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:
Clones:	1500526 (view as bug list)		Environment:
Last Closed:	2017-10-11 10:18:10 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1500526

Description Jason DeTiberus 2017-08-29 15:29:36 UTC

Description of problem:
The binfmt config configured for ppc64le uses \x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x15 as the magic number rather than \x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x15\x00

The former is the magic number for ppc64.

Version-Release number of selected component (if applicable):
qemu-2.10.0-0.4.rc4.fc27 (and all earlier versions that included a binfmt config for ppc64le)

How reproducible:
100%

Steps to Reproduce:
1. Install qemu-user-static and docker on an x86_64 host
2. docker run -it -v /usr/bin/qemu-ppc64le-static:/usr/bin/qemu-ppc64le-static ppc64le/centos:7 /bin/bash

Actual results:
panic: standard_init_linux.go:178: exec user process caused "exec format error" [recovered]
	panic: standard_init_linux.go:178: exec user process caused "exec format error"

goroutine 1 [running, locked to thread]:
github.com/urfave/cli.HandleAction.func1(0xc4200e57a0)
	/builddir/build/BUILD/docker-0fdc77886ccc101a28b11ce63e87a935c936d2ef/runc-79c3939053c870fbb4de5484d98640d5ba028ef4/Godeps/_workspace/src/github.com/urfave/cli/app.go:478 +0x23f
panic(0x6f0c00, 0xc420169030)
	/usr/lib/golang/src/runtime/panic.go:489 +0x2cf
github.com/opencontainers/runc/libcontainer.(*LinuxFactory).StartInitialization.func1(0xc4200e5208, 0xc42000e040, 0xc4200e52a8)
	/builddir/build/BUILD/docker-0fdc77886ccc101a28b11ce63e87a935c936d2ef/runc-79c3939053c870fbb4de5484d98640d5ba028ef4/Godeps/_workspace/src/github.com/opencontainers/runc/libcontainer/factory_linux.go:259 +0xc1
github.com/opencontainers/runc/libcontainer.(*LinuxFactory).StartInitialization(0xc4200d0280, 0xaa88e0, 0xc420169030)
	/builddir/build/BUILD/docker-0fdc77886ccc101a28b11ce63e87a935c936d2ef/runc-79c3939053c870fbb4de5484d98640d5ba028ef4/Godeps/_workspace/src/github.com/opencontainers/runc/libcontainer/factory_linux.go:277 +0x353
main.glob..func8(0xc4200b2780, 0x0, 0x0)
	/builddir/build/BUILD/docker-0fdc77886ccc101a28b11ce63e87a935c936d2ef/runc-79c3939053c870fbb4de5484d98640d5ba028ef4/main_unix.go:26 +0x66
reflect.Value.call(0x6d9b20, 0x7502a8, 0x13, 0x73b882, 0x4, 0xc4200e5760, 0x1, 0x1, 0xc4200e56f0, 0x731360, ...)
	/usr/lib/golang/src/reflect/value.go:434 +0x91f
reflect.Value.Call(0x6d9b20, 0x7502a8, 0x13, 0xc4200e5760, 0x1, 0x1, 0x665a76, 0x73ba0e, 0x4)
	/usr/lib/golang/src/reflect/value.go:302 +0xa4
github.com/urfave/cli.HandleAction(0x6d9b20, 0x7502a8, 0xc4200b2780, 0x0, 0x0)
	/builddir/build/BUILD/docker-0fdc77886ccc101a28b11ce63e87a935c936d2ef/runc-79c3939053c870fbb4de5484d98640d5ba028ef4/Godeps/_workspace/src/github.com/urfave/cli/app.go:487 +0x18f
github.com/urfave/cli.Command.Run(0x73ba2e, 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x74d2ea, 0x51, 0x0, ...)
	/builddir/build/BUILD/docker-0fdc77886ccc101a28b11ce63e87a935c936d2ef/runc-79c3939053c870fbb4de5484d98640d5ba028ef4/Godeps/_workspace/src/github.com/urfave/cli/command.go:191 +0xac8
github.com/urfave/cli.(*App).Run(0xc420114000, 0xc42008c060, 0x2, 0x2, 0x0, 0x0)
	/builddir/build/BUILD/docker-0fdc77886ccc101a28b11ce63e87a935c936d2ef/runc-79c3939053c870fbb4de5484d98640d5ba028ef4/Godeps/_workspace/src/github.com/urfave/cli/app.go:240 +0x5d6
main.main()
	/builddir/build/BUILD/docker-0fdc77886ccc101a28b11ce63e87a935c936d2ef/runc-79c3939053c870fbb4de5484d98640d5ba028ef4/main.go:137 +0xbd2


Expected results:
An active shell in the ppc64le container

Additional info:
Modifying /usr/lib/binfmt.d/qemu-ppc64le-static.conf with the following contents resolves the issue:
:qemu-ppc64le:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x15\x00:\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\xff\xfe\xff\xff:/usr/bin/qemu-ppc64le-static:

Comment 1 Cole Robinson 2017-08-29 16:02:52 UTC

npmccallum you added ppc64le binfmt, does this sound correct?

Comment 2 Nathaniel McCallum 2017-08-29 16:54:39 UTC

As I understand the problem, I failed to change the byte order for the ELF e_machine field when I made all the PPC64 binfmts. If that understanding is correct, then yes, this looks like a valid issue and valid fix to me.

Jason, as an aside, there is no reason to mount the qemu binary into the chroot if you are running a recent kernel in the host. The kernel now has the F flag in binfmt for this purpose.

Comment 3 Nathaniel McCallum 2017-08-29 17:01:47 UTC

https://src.fedoraproject.org/rpms/qemu/c/3b6c813012ab11076e8fb1440dfeae7415db1d98?branch=master

I pushed the above fix. It should be available whenever Cole Robinson makes the next Fedora build.

Comment 4 Jason DeTiberus 2017-08-30 16:10:11 UTC

Nathaniel, I'm running a backported version of qemu-user-static on RHEL 7, so unfortunately I can't take advantage of the F flag, but thanks for the quick turnaround.

Comment 5 Cole Robinson 2017-09-07 22:05:26 UTC

This is in qemu-2.10.0-1.fc28 now, f27 build in progress

Comment 6 Jason DeTiberus 2017-09-14 00:54:49 UTC

Nathaniel,

I'm just getting back around to doing further testing on this, I believe there still needs to be an update to switch the fields for the e_type field as well as the corresponding mask fields. In my previous testing I had swapped the fields for the e_type field, but neglected to also switch the corresponding mask fields, which allowed static binaries to work, but not dynamically linked binaries.

The following are the contents of the working /usr/lib/binfmt.d/qemu-ppc64le-static.conf:
:qemu-ppc64le:M::\x7fELF\x02\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02\x00\x15\x00:\xff\xff\xff\xff\xff\xff\xff\x00\x00\x00\x00\x00\x00\x00\x00\x00\xfe\xff\xff\xff:/usr/bin/qemu-ppc64le-static:F

Comment 7 Nathaniel McCallum 2017-09-18 20:23:29 UTC

Yup, you're right. Working on a fix now.

Comment 8 Nathaniel McCallum 2017-09-18 20:29:41 UTC

Cole, I have fixed and pushed this to rawhide. Like before, I have not built it. Please cherry pick this to whatever branches you want (preferably f26 and f27).

Comment 9 Cole Robinson 2017-09-19 22:22:08 UTC

Thanks, pushed to f26/f27 branches as well