Re: [PATCH bpf-next v5 0/5] writable contexts for bpf raw tracepoints

From: Alexei Starovoitov
Date: Fri Apr 26 2019 - 22:15:35 EST


On Fri, Apr 26, 2019 at 11:50 AM Matt Mullins <mmullins@xxxxxx> wrote:
>
> This adds an opt-in interface for tracepoints to expose a writable context to
> BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE programs that are attached, while
> supporting read-only access from existing BPF_PROG_TYPE_RAW_TRACEPOINT
> programs, as well as from non-BPF-based tracepoints.
>
> The initial motivation is to support tracing that can be observed from the
> remote end of an NBD socket, e.g. by adding flags to the struct nbd_request
> header. Earlier attempts included adding an NBD-specific tracepoint fd, but in
> code review, I was recommended to implement it more generically -- as a result,
> this patchset is far simpler than my initial try.
>
> v4->v5:
> * rebased onto bpf-next/master and fixed merge conflicts
> * "tools: sync bpf.h" also syncs comments that have previously changed
> in bpf-next

Applied. Thanks!