Re: Self-XORing BPF registers is undefined behavior

On 02/06/2020 18:32, Alexei Starovoitov wrote:

The target for bpf codegen is JITs.
bpf interpreter is simulating hw.
For now if you want UB fuzzer running in your environment please add
_out_of_tree_ patch that inits all interpreter registers to zero.

+1 to all the above.

Also, note that you can still fuzz BPF JITs by building the kernel
 without the interpreter: CONFIG_BPF_JIT_ALWAYS_ON.