3 ms·
Isn't BPF execution constraints intentionally very tight, 4096 instruction, 512 bytes of stack, limited control flow? I don't think it's currently usable to imp
by Karliss 4y ago
Isn't BPF execution constraints intentionally very tight, 4096 instruction, 512 bytes of stack, limited control flow? I don't think it's currently usable to implement general purpose drivers. Only reason it could work for HID drivers is because a lot of them are doing nothing more than very simple byte substitution either in device descriptor or the actual data reports. So I am not too worried about closed source driver.
- mdaverde 4y agoeBPF has changed several of these constraints [0] - Verifier can explore up to 1million insns now instead of 4096 - 512 bytes of stack but with tail chaining you have up to 8k - Bounded loops have been added. Unbounded loops are prevented by design to not stall the kernel [0] https://docs.cilium.io/en/v1.12/bpf/ https://docs.cilium.io/en/v1.12/bpf/