There is a problem with building the linux kernel.

[yunekorea]

Hello. I'm trying to implement this project in our system with DaisyPlus.
I was trying to build the kernel and downgrade from kernel version 5.15.0-101-generic to 5.10.21 which you have suggested.
But an error saying that there is no lio.h header file in linux directory.

So I copied a file with the same name from "uebf-rt/include/" to the specified directory and built it.
The system says that it was successful but after installing the built kernel and running the "eval-one" program you provided,
another error occurs saying that seems to be failing at the function "set_back_file".

So, I'm wondering if there was a misbehavior of me when building the kernel.
I suspect that the reason was copying the lio.h from the other directory.
If it is true, can you provide me with a correct solution for getting the lio.h file?

[yzim]

Hello. Apart from building and using the kernel source, please also compile and install the kernel module in the kmod folder. "set_back_file" relies on it.

[rookiewwj]

kernel/bpf/core.c:36:10: fatal error: linux/lio.h: no such file or directory exists
36 | #include <linux/lio.h>
| ^~~~~~~~~~~~~
compilation terminated.
I also encountered this problem while compiling the kernel, I copied linux-lio/ into the linux source and compiled with this error. Do I need to copy the kmod together with the linux source and then execute make?

[yzim]

Sorry I missed the header file. Maybe the header file does not take effect? What will happen if you remove "#include <linux/lio.h" from the source code?

The error during set_back_file seems not related to linux/lio.h. Could you provide more details or logs?

[rookiewwj]

now i have removed "#include<linux/lio.h>" from core.c ,then i got another error
kernel/bpf/core.c: In function ‘bpf_prog_select_runtime’:
kernel/bpf/core.c:1810:3: error: implicit declaration of function ‘lio_pr’ [-Werror=implicit-function-declaration]
1810 | lio_pr(info, "prog_name=%s", fp->aux->name);
| ^~~~~~
kernel/bpf/core.c:1810:10: error: ‘info’ undeclared (first use in this function)
1810 | lio_pr(info, "prog_name=%s", fp->aux->name);
| ^~~~
kernel/bpf/core.c:1810:10: note: each undeclared identifier is reported only once for each function it appears in
cc1: some warnings being treated as errors
make[2]: *** [scripts/Makefile.build:279：kernel/bpf/core.o] 错误 1
make[1]: *** [scripts/Makefile.build:496：kernel/bpf] 错误 2
make[1]: *** 正在等待未完成的任务....
make: *** [Makefile:1801：kernel] 错误 2
make: *** 正在等待未完成的任务....

[yzim]

A simple workaround is using uebpf-rt/include/lio.h. It disables lio_pr.