kext does not load on 10.16 Big Sur

[lundman]

Appears to be related to the Plugins/KernelDependencies.kext/ that we have to link against things we are not allowed to link against.

A straight load attempt fails with:

Error: Error Domain=KMErrorDomain Code=1 "Unable to resolve dependencies: 'net.lundman.zfs' names a 
dependency on 'net.lundman.kernel.dependencies.0.8.0', which was not found." UserInfo=
 {NSLocalizedDescription=Unable to resolve dependencies: 'net.lundman.zfs' names a dependency on
 'net.lundman.kernel.dependencies.0.8.0', which was not found.}

As if it doesn't look in Plugins anymore. However, when if I attempt to codesign the Plugins kext;

codesign_allocate: can't allocate code signature data for: 
/private/tmp/zfs.kext/Contents/PlugIns/KernelExports.kext/KernelExports (for architecture x86_64) because 
file does not have a __LINKEDIT segment

Which makes me think that they've made a slight change to the requirements of kexts, and kextsymboltool no
longer produces a valid object file.

Similarly, if I try to load the 1.9.4 signed/notarized kexts:

 "Error occurred while building cache:
in '/Library/Extensions/spl.kext/Contents/PlugIns/KernelExports.kext/KernelExports' missing __TEXT segment"

So I think we need to figure out how to make the output of kextsymboltool be accepted under Big Sur.

In addition, the output from kextload/kextutil is not exactly great - the real errors must go somewhere?

[lundman]

# file kernelexports
kernelexports: Mach-O universal binary with 2 architectures: [i386:Mach-O object i386] [x86_64:Mach-O 64-bit kext bundle x86_64]
kernelexports (for architecture i386):  Mach-O object i386
kernelexports (for architecture x86_64):        Mach-O 64-bit kext bundle x86_64


#  clang++ -g -O2 -Wl,-kext -nostdlib -o zfs ./kernelexports -lkmodc++ -lkmod -lcc_kext
ld: warning: ignoring file ./kernelexports, file is universal (2 slices) but does not contain the x86_64 architecture:
 ./kernelexports

and that's on Catalina even.

[lundman]

Hmm hey @meklort - you showed us this trickery the first time around, any ideas?

[meklort]

I haven't looked into the newer OSes much, so I can't really say. I'd suggest looking at the symbol kexts included by Apple and seeing how those have changed from before. I wouldn't be surprised if they are now either signed or have some changed to the plist.

There may also be an updated symbol tool that you'll need to use to generate the Mach-O binary with.

[lundman]

I think they changed kextsymboltool.c a fair bit, but unfortunately they don't release the XNU sources until a few months after the OS is out, and it would be nice if it worked before then. No other kexts on the OS has Plugins/ directory inside, so it is possible they removed the feature entirely, and we've had to sign the codeless plugin since 10.11.

I've asked Apple if I can have kextsymboltool.c , but it was met with silence.

[lundman]

Received DTK today, to also try to make it work for ARM64.
Homebrew isn't quite there, Homebrew/brew#7857
but they are making great progress.

Although even after compiling, we still have the kext loading issue.

[lundman]

OK, so exploring dynamically looking up the modules on kext init, which generally works, except the current way to lookup vm_kernel_slide is a bit off, +0c000 is needed in my example:

    vm_offset_t func_address = (vm_offset_t) vm_kernel_unslide_or_perm_external;
    vm_offset_t func_address_unslid = 0;
    vm_kernel_unslide_or_perm_external(func_address, &func_address_unslid);
    vm_kern_slide = func_address - func_address_unslid;
    printf("Kernel slide: %lx\n", vm_kern_slide);

Kernel slide: 0x0000000028400000

lldb:
KernelCache slide: 0x0000000028400000
KernelCache base:  0xffffff8028600000
Kernel slide:      0x000000002840c000
Kernel text base:  0xffffff802860c000
__HIB  text base: 0xffffff8028500000

However, hardcoding the difference:

    kern_base = KERN_TEXT_BASE + vm_kern_slide + 0xc000;

[   12.874118]: spl_loadsymbols: failed to locate '_fp_drop'
[   12.874759]: spl_loadsymbols: failed to locate '_fp_drop_written'
[   12.875355]: spl_loadsymbols: failed to locate '_fp_lookup'
[   12.875936]: spl_loadsymbols: failed to locate '_fo_read'
[   12.876511]: spl_loadsymbols: failed to locate '_fo_write'
[   12.877708]: spl_loadsymbols: Loaded 23, failed 5.

[lundman]

The Intel Big Sur VM does start the kext without those functions, obviously with some features missing.

DTK loading does not yet work.

[lundman]

There is now a Big Sur x64 build, no missing features. No arm64 yet.
https://twitter.com/JorgenLundman/status/1283602297344258053

[lin7sh]

Will Kext support eventually remove by Apple, Is it possible for zfs on Mac switch to Apple System extension like DriverKit?

[captain-haddock17]

Hi all !

Did some searching about VFS (kext) and FileProvider (userland) on macOS Catalina & 'Big Sur'.
Found that FileProvider (macOS) will/(will only be ?) on macOS.11 'Big Sur', but is not yet stable/complete...
:-(
Although with Apple's security concern, I'm guessing FileProvider [Extension] will be the only way to make ZFS "drives" appear on our next macOS.11 Big Sur.
https://developer.apple.com/documentation/fileprovider/macos_support

See Apple Dev Forum Cannot launch new FileProvider extension on macOS 10.15

After checking it out in macOS 11 Beta 4 and Xcode 12 Beta 4:
There is no option to add a File Provider extension target to a macOS app
The documentation has a macOS support section but lacks actual documentation on how it should be used
The documentation says the NSFileProviderExtension class is only available on iOS

and

NSFileProviderExtension' is unavailable in macOS.
Confirmed in macOS 11 Beta 4(Xcode 12 Beta 4)

@lundman : did you already submit a dev feedback ?
HTH
William

[yurikoles]

There is now a Big Sur x64 build, no missing features. No arm64 yet.
https://twitter.com/JorgenLundman/status/1283602297344258053

I have a KP with this build on Big Sur 11.0.1.

[cabrinha]

There is now a Big Sur x64 build, no missing features. No arm64 yet.
https://twitter.com/JorgenLundman/status/1283602297344258053

I have a KP with this build on Big Sur 11.0.1.

I downloaded the package from the tweet. How did you install/load this up?

When trying to import, I get:

dyld: Symbol not found: _aok
  Referenced from: /Users/yuppie/Downloads/openzfsonosx-bigsur/usr/local/sbin/zpool
  Expected in: /usr/local/lib/libuutil.1.dylib
 in /Users/yuppie/Downloads/openzfsonosx-bigsur/usr/local/sbin/zpool

[yurikoles]

I downloaded the package from the tweet. How did you install/load this up?

When trying to import, I get:

dyld: Symbol not found: _aok
  Referenced from: /Users/yuppie/Downloads/openzfsonosx-bigsur/usr/local/sbin/zpool
  Expected in: /usr/local/lib/libuutil.1.dylib
 in /Users/yuppie/Downloads/openzfsonosx-bigsur/usr/local/sbin/zpool

The contents of this zip archive is intended to be extracted to the root of your system/boot volume.

[cabrinha]

I downloaded the package from the tweet. How did you install/load this up?
When trying to import, I get:

dyld: Symbol not found: _aok
  Referenced from: /Users/yuppie/Downloads/openzfsonosx-bigsur/usr/local/sbin/zpool
  Expected in: /usr/local/lib/libuutil.1.dylib
 in /Users/yuppie/Downloads/openzfsonosx-bigsur/usr/local/sbin/zpool

The contents of this zip archive is intended to be extracted to the root of your system/boot volume.

Does this mean that I can install OpenZFS 1.9.4 and just extract this zip to /System?

I see that there is a 2.0.0 release and also branches for big-sur, but I don't see any 2.0.0 DMG installer.

I'm currently running Big Sur and can't import my volumes.

Any instructions on how to get this working would be very helpful.

[glessard]

The openzfs-on-osx forums are a better place to get releases:
https://openzfsonosx.org/forum/viewtopic.php?f=20&t=3478

That topic has links to proper installer files since earlier this week.

[gssdromen]

xxx@xxx-Air  ~  sudo zpool import -f disk
Password:
The ZFS modules are not loaded.
Try running '/sbin/kextload zfs.kext' as root to load them.
✘ xxx@xxx-Air  ~  sudo su
sh-3.2# /sbin/kextload zfs.kext
Executing: /usr/bin/kmutil load -p /Users/xxx/zfs.kext
Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"

No such file or directory after install 2.0 openzfs for big sur

[lundman]

The openzfs-2.0 installer requires you to set "keepsyms=1" for it to load. This was the only work-around for this issue that we could find so far.

[lundman]

pure is about to be pushed.