trace-bpfcc cannot trace the function in ./src directory?

[andyzhanged]

I build the nvidia.ko with flag NV_BUILD_TYPE=debug DEBUG=1，but trace-bpfcc report error:

open-gpu-kernel-modules # trace-bpfcc -K nvGpuOpsFreeDupedHandle
3 warnings generated.
cannot attach kprobe, Invalid argument
Failed to attach BPF program b'probe_nvGpuOpsFreeDupedHandle_1' to kprobe b'nvGpuOpsFreeDupedHandle'

The function nvGpuOpsFreeDupedHandle exist in /proc/kallsym.

open-gpu-kernel-modules # cat /proc/kallsyms | grep nvGpuOpsFreeDupedHandle
ffffffffc103488b t nvGpuOpsFreeDupedHandle      [nvidia]
open-gpu-kernel-modules #

The function nvUvmInterfaceFreeDupedHandle nv_dma_unmap_pages can be traceed. Seem list the functions defined in src directory cannot be traced , defined in kernel-open/nvidia can be traced. Someone know the reson?

[mtijanic]

This is probably because the modules don't inherit the kbuild flags properly. There is a patch in #675 that you can try.

I hope we can add a simpler makefile switch to include these flags in the future.

[andyzhanged]

Thank you very much, it works after apply the patch.