SIGBUS error in TransferStatus on aarch64

[emul8ed]

Which version of the AzCopy was used?

10.3.3

Which platform are you using? (ex: Windows, Mac, Linux)

Linux/Ubuntu 18.04/AArch64

What command did you run?

./azcopy cp ./afile.bin "https://account.blob.core.windows.net/container?sas_token"

What problem was encountered?

Appears to be due to an atomic load from an unaligned address

Thread 13 "azcopy" received signal SIGBUS, Bus error.
[Switching to Thread 0xffffcaffd1e0 (LWP 21378)]
github.com/Azure/azure-storage-azcopy/ste.(*JobPartPlanTransfer).TransferStatus (jppt=0xfffff7ff61e5) at /root/go/src/github.com/Azure/azure-storage-azcopy/ste/JobPartPlan.go:321

(gdb) bt
#0 github.com/Azure/azure-storage-azcopy/ste.(*JobPartPlanTransfer).TransferStatus (jppt=0xfffff7ff61e5) at /root/go/src/github.com/Azure/azure-storage-azcopy/ste/JobPartPlan.go:321
#1 github.com/Azure/azure-storage-azcopy/ste.(*jobPartMgr).ScheduleTransfers (jpm=0x400103e000, jobCtx=...) at /root/go/src/github.com/Azure/azure-storage-azcopy/ste/mgr-JobPartMgr.go:349
#2 0x00000000004e424c in github.com/Azure/azure-storage-azcopy/ste.(*jobsAdmin).scheduleJobParts (ja=0x40000221a0) at /root/go/src/github.com/Azure/azure-storage-azcopy/ste/JobsAdmin.go:281
#3 0x000000000006bf3c in runtime.goexit () at /usr/lib/go-1.13/src/runtime/asm_arm64.s:1128

0x4f01c0 <github.com/Azure/azure-storage-azcopy/ste.(*jobPartMgr).ScheduleTransfers+1720> ldar w3, [x3]

(gdb) print $x3
$2 = 0xfffff7ff6221

How can we reproduce the problem in the simplest way?

See above

Have you found a mitigation/solution?

No. I had a quick skim through the code and found that the jppt pointer appears to come from here:

return (*JobPartPlanTransfer)(unsafe.Pointer((uintptr(unsafe.Pointer(jpph)) + unsafe.Sizeof(*jpph) + uintptr(jpph.CommandStringLength)) + (unsafe.Sizeof(JobPartPlanTransfer{}) * uintptr(transferIndex))))

If CommandStringLength or sizeof(JobPartPlanTransfer) isn't a multiple of the natural alignment of JobPartPlanTransfer, then I can see how we'd end up in this situation. Unfortunately I've never written nor debugged a line of Go in my life, and I don't particularly want to start now, so that's as far as I've got :).

[JohnRusk]

Thanks for logging this and looking up the likely cause.

[emul8ed]

You're welcome. I can provision an aarch64 VM on corp for testing if you need it. Otherwise, let me know if there's anything else I can do to help.