On 20 October 2017 at 17:12, Daniel Borkmann <dan...@iogearbox.net> wrote: > On 10/20/2017 05:50 PM, Quentin Monnet wrote: > [...] >> >> The remaining four bytes are taken from the "immediate" field of the >> second >> instruction, which leaves the first four fields (offset, source and >> destination >> registers, and in particular opcode) unused. As far as I know, these >> fields >> remain at zero, and this makes it the only “instruction” to have a null >> code >> (although I am not sure this is a strict requirement, because I did not >> find >> the code in the verifier that would reject a program having a non-null >> opcode >> right after a "load double word immediate" instruction). > > > It's in replace_map_fd_with_map_ptr(), invalid insns for the 2nd part > are rejected there, they have to be otherwise it's not extendable anymore > from abi pov; check also 'test1* ld_imm64' in the verifier test cases. > > Cheers, > Daniel
Indeed, thanks Daniel! Quentin
