darling-mach fails to build on Linux 5.1

[mrtino]

Hi all. make and sudo make install are doing fine, however, when I try to build the kernel module, the compilation almost stops immediately. Here's the complete build log:

$ make lkm                                                                                                                                                       
Built target migcom
Built target migexe
Built target lkm_generate
Building the Linux kernel module
make[4]: Entering directory '/home/leia/darling/src/lkm'
Running kernel version is 5.1.2-arch1-1-ARCH
rm -f darling-mach.mod.o
make -C /lib/modules/5.1.2-arch1-1-ARCH/build M=/home/leia/darling/src/lkm modules
make[5]: Entering directory '/usr/lib/modules/5.1.2-arch1-1-ARCH/build'
Running kernel version is 5.1.2-arch1-1-ARCH
Invoked by kernel build system, building for 5.1.2-arch1-1-ARCH
  CC [M]  /home/leia/darling/src/lkm/darling/traps.o
In file included from /home/leia/darling/src/lkm/osfmk/i386/user_ldt.h:72,
                 from /home/leia/darling/src/lkm/osfmk/i386/task.h:61,
                 from /home/leia/darling/src/lkm/osfmk/machine/task.h:32,
                 from /home/leia/darling/src/lkm/osfmk/kern/task.h:108,
                 from /home/leia/darling/src/lkm/osfmk/kern/thread.h:123,
                 from /home/leia/darling/src/lkm/bsd/kern/ast.h:37,
                 from /home/leia/darling/src/lkm/osfmk/kern/processor.h:75,
                 from /home/leia/darling/src/lkm/osfmk/i386/cpu_data.h:41,
                 from /home/leia/darling/src/lkm/osfmk/i386/cpu_number.h:75,
                 from /home/leia/darling/src/lkm/osfmk/machine/cpu_number.h:34,
                 from /home/leia/darling/src/lkm/osfmk/kern/wait_queue.h:48,
                 from /home/leia/darling/src/lkm/osfmk/ipc/ipc_mqueue.h:77,
                 from /home/leia/darling/src/lkm/osfmk/ipc/ipc_port.h:91,
                 from /home/leia/darling/src/lkm/darling/traps.c:42:
/home/leia/darling/src/lkm/osfmk/i386/seg.h:213: warning: "SZ_64" redefined
 #define SZ_64  0x2   /* 64-bit segment */

In file included from ./include/linux/mm.h:29,
                 from /home/leia/darling/src/lkm/osfmk/duct/duct.h:54,
                 from /home/leia/darling/src/lkm/darling/traps.c:20:
./include/linux/sizes.h:19: note: this is the location of the previous definition
 #define SZ_64    0x00000040

In file included from /home/leia/darling/src/lkm/osfmk/i386/user_ldt.h:72,
                 from /home/leia/darling/src/lkm/osfmk/i386/task.h:61,
                 from /home/leia/darling/src/lkm/osfmk/machine/task.h:32,
                 from /home/leia/darling/src/lkm/osfmk/kern/task.h:108,
                 from /home/leia/darling/src/lkm/osfmk/kern/thread.h:123,
                 from /home/leia/darling/src/lkm/bsd/kern/ast.h:37,
                 from /home/leia/darling/src/lkm/osfmk/kern/processor.h:75,
                 from /home/leia/darling/src/lkm/osfmk/i386/cpu_data.h:41,
                 from /home/leia/darling/src/lkm/osfmk/i386/cpu_number.h:75,
                 from /home/leia/darling/src/lkm/osfmk/machine/cpu_number.h:34,
                 from /home/leia/darling/src/lkm/osfmk/kern/wait_queue.h:48,
                 from /home/leia/darling/src/lkm/osfmk/ipc/ipc_mqueue.h:77,
                 from /home/leia/darling/src/lkm/osfmk/ipc/ipc_port.h:91,
                 from /home/leia/darling/src/lkm/darling/traps.c:42:
/home/leia/darling/src/lkm/osfmk/i386/seg.h:214: warning: "SZ_32" redefined
 #define SZ_32  0x4   /* 32-bit segment */

In file included from ./include/linux/mm.h:29,
                 from /home/leia/darling/src/lkm/osfmk/duct/duct.h:54,
                 from /home/leia/darling/src/lkm/darling/traps.c:20:
./include/linux/sizes.h:18: note: this is the location of the previous definition
 #define SZ_32    0x00000020

In file included from /home/leia/darling/src/lkm/osfmk/duct/duct.h:105,
                 from /home/leia/darling/src/lkm/darling/traps.c:20:
/home/leia/darling/src/lkm/osfmk/duct/duct__pre_xnu_types.h:99:33: warning: ‘struct xnu_rlimit’ declared inside parameter list will not be visible outside of this definition or declaration
 #define rlimit                  xnu_rlimit
                                 ^~~~~~~~~~
./include/linux/sched/mm.h:129:14: note: in expansion of macro ‘rlimit’
       struct rlimit *rlim_stack);
              ^~~~~~
/home/leia/darling/src/lkm/darling/traps.c: In function ‘mach_init’:
/home/leia/darling/src/lkm/darling/traps.c:201:1: warning: label ‘fail’ defined but not used [-Wunused-label]
 fail:
 ^~~~
/home/leia/darling/src/lkm/darling/traps.c: At top level:
/home/leia/darling/src/lkm/darling/traps.c:408:16: error: initialization of ‘vm_fault_t (*)(struct vm_fault *)’ {aka ‘unsigned int (*)(struct vm_fault *)’} from incompatible pointer type ‘int (*)(struct vm_fault *)’ [-Werror=incompatible-pointer-types]
  .fault      = mach_mmap_fault,
                ^~~~~~~~~~~~~~~
/home/leia/darling/src/lkm/darling/traps.c:408:16: note: (near initialization for ‘mach_mmap_ops.fault’)
cc1: some warnings being treated as errors
make[6]: *** [scripts/Makefile.build:276: /home/leia/darling/src/lkm/darling/traps.o] Error 1
make[5]: *** [Makefile:1571: _module_/home/leia/darling/src/lkm] Error 2
make[5]: Leaving directory '/usr/lib/modules/5.1.2-arch1-1-ARCH/build'
make[4]: *** [Makefile:292: default] Error 2
make[4]: Leaving directory '/home/leia/darling/src/lkm'
make[3]: *** [src/lkm/CMakeFiles/lkm.dir/build.make:58: src/lkm/CMakeFiles/lkm] Error 2
make[2]: *** [CMakeFiles/Makefile2:54343: src/lkm/CMakeFiles/lkm.dir/all] Error 2
make[1]: *** [CMakeFiles/Makefile2:54350: src/lkm/CMakeFiles/lkm.dir/rule] Error 2
make: *** [Makefile:15036: lkm] Error 2

I'm running the latest kernel version provided by Arch Linux, and the latest versions of software listed on the wiki.
Thanks for this project and (hopefully) for solving this issue!

[bugaevc]

It's not Arch, it's just that vm_fault_t has changed from int to unsigned int in Linux 5.1; I would say the fix is to use vm_fault_t directly rather than what it's typedefed to.

Would you like to submit a PR? 😀

[mrtino]

Submitted.

[ahyattdev]

Thanks to some PRs this has been fixed, thanks @mrtino and @jamesbrink