On Mon, Jun 29, 2020 at 5:28 PM Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > On Thu, Jun 18, 2020 at 3:33 PM Andrii Nakryiko > <andrii.nakryiko@xxxxxxxxx> wrote: > > > + * > > > + * int bpf_copy_from_user(void *dst, u32 size, const void *user_ptr) > > > > Can we also add bpf_copy_str_from_user (or bpf_copy_from_user_str, > > whichever makes more sense) as well? > > Those would have to wait. I think strings need better long term design. > That would be separate patches. I agree that it would be nice to have better support for strings, long term, but that's beside the point. I think bpf_copy_from_user_str() is a must have right now as a sleepable counterpart to bpf_probe_read_user_str(), just like bpf_copy_from_user() is a sleepable variant of bpf_probe_read_user(). Look at progs/strobemeta.h, it does bpf_probe_read_user_str() to get user-space zero-terminated strings. It's well defined interface and behavior. There is nothing extra needed beyond a sleepable variant of bpf_probe_read_user_str() to allow Strobemeta reliably fetch data from user-space from inside a sleepable BPF program.
