Unable to build kernel

[dnffabs]

Hello, I tried to build libtea on the kali system of Raspberry PI 4B(ARM-v8A), but when I used make operation to build the kernel in the module folder, I got the following error:

make -C /lib/modules/5.15.44-Re4son-v8l+/build M=/home/kali/Desktop/frameworks-master/libtea/module clean make[1]: Entering directory '/usr/src/linux-headers-5.15.44-Re4son-v8l+' make[1]: Leaving directory '/usr/src/linux-headers-5.15.44-Re4son-v8l+' make -C /lib/modules/5.15.44-Re4son-v8l+/build M=/home/kali/Desktop/frameworks-master/libtea/module modules make[1]: Entering directory '/usr/src/linux-headers-5.15.44-Re4son-v8l+' warning: the compiler differs from the one used to build the kernel The kernel was built by: gcc (Debian 11.2.0-19) 11.2.0 You are using: gcc (Debian 10.2.0-16) 10.2.0 CC [M] /home/kali/Desktop/frameworks-master/libtea/module/libtea.o /home/kali/Desktop/frameworks-master/libtea/module/libtea.c:10:49: warning: "LIBTEA_WINDOWS" is not defined, evaluates to 0 [-Wundef] 10 | #if defined(i386) || defined(x86_64) || LIBTEA_WINDOWS | ^~~~~~~~~~~~~~ /home/kali/Desktop/frameworks-master/libtea/module/libtea.c: In function ‘get_system_reg’: /home/kali/Desktop/frameworks-master/libtea/module/libtea.c:123:7: warning: unused variable ‘err’ [-Wunused-variable] 123 | int err; | ^~~ /home/kali/Desktop/frameworks-master/libtea/module/libtea.c:122:22: warning: unused variable ‘msr_val’ [-Wunused-variable] 122 | unsigned long long msr_val; | ^~~~~~~ /home/kali/Desktop/frameworks-master/libtea/module/libtea.c: In function ‘set_system_reg’: /home/kali/Desktop/frameworks-master/libtea/module/libtea.c:152:7: warning: unused variable ‘err’ [-Wunused-variable] 152 | int err; | ^~~ /home/kali/Desktop/frameworks-master/libtea/module/libtea.c: In function ‘libtea_ioctl’: /home/kali/Desktop/frameworks-master/libtea/module/libtea.c:744:13: warning: "LIBTEA_ARM" is not defined, evaluates to 0 [-Wundef] 744 | #elif LIBTEA_ARM | ^~~~~~~~~~ /home/kali/Desktop/frameworks-master/libtea/module/libtea.c:589:8: warning: unused variable ‘ret’ [-Wunused-variable] 589 | long ret; | ^~~ /home/kali/Desktop/frameworks-master/libtea/module/libtea.c:588:11: warning: unused variable ‘handler’ [-Wunused-variable] 588 | ioctl_t handler = NULL; | ^~~~~~~ /home/kali/Desktop/frameworks-master/libtea/module/libtea.c:587:8: warning: unused variable ‘data’ [-Wunused-variable] 587 | char data[256]; | ^~~~ libtea.c: Assembler messages: libtea.c:481: Error: constant expression required /tmp/ccV9l290.s:483: Info: macro invoked from here libtea.c:650: Error: constant expression required /tmp/ccV9l290.s:652: Info: macro invoked from here make[2]: *** [scripts/Makefile.build:288: /home/kali/Desktop/frameworks-master/libtea/module/libtea.o] Error 1 make[1]: *** [Makefile:1868: /home/kali/Desktop/frameworks-master/libtea/module] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-5.15.44-Re4son-v8l+' make: *** [Makefile:13: linux] Error 2

[cattius]

Hi, did you run make directly in the kernel module folder, or did you use one of the AArch64 make commands in the README (running it in the top-level libtea folder)? There are different files used in the build process for each architecture (including the headers that define LIBTEA_WINDOWS and LIBTEA_ARM). The commands are libtea-aarch64-basic, libtea-aarch64-cache, and libtea-aarch64-paging - all three will build the kernel module together with the libtea header, but with different features included. The paging command will compile the most-feature complete version.

Some other tips:

• If you get 'file not found' errors for the kernel development headers, you'll need to install them - I'm not sure which package they're in for Kali, but you should find them by searching in your package manager (or Googling). This is distro-specific - I just tried this on an EC2 instance running Amazon Linux, for example, and needed to run sudo yum install -y wget kernel-devel-$(uname -r) kernel-headers-$(uname -r) ($(uname -r) gets your current kernel version).
• The Makefile assumes that the main use case for AArch64 will be cross-compiling for Android devices, so to compile to run directly on your Raspberry Pi, comment out the AARCH64_RECIPE = android line near the top of the Makefile.