On 2/24/21 8:54 PM, Luigi Rizzo wrote:
I prepared a BPF version of kstats[1] https://github.com/luigirizzo/lr-cstats that uses fentry/fexit hooks to monitor the execution time of a kernel function. I hoped to have it working on ARM64 too, but it looks like arch_prepare_bpf_trampoline() only exists for x86. Is there any outstanding patch for this function on ARM64, or any similar function I could look at to implement it myself ?
Not that I'm currently aware of, arm64 support would definitely be great to have. From x86 side, the underlying arch dependency was basically on text_poke_bp() to patch instructions on a live kernel. Haven't checked recently whether an equivalent exists on arm64 yet, but perhaps Will might know.
[1] kstats is an in-kernel also in the above repo and previously discussed at https://lwn.net/Articles/813303/
