Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> writes: > On Fri, Sep 11, 2020 at 3:00 AM Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: >> >> From: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> >> >> The check_attach_btf_id() function really does three things: >> >> 1. It performs a bunch of checks on the program to ensure that the >> attachment is valid. >> >> 2. It stores a bunch of state about the attachment being requested in >> the verifier environment and struct bpf_prog objects. >> >> 3. It allocates a trampoline for the attachment. >> >> This patch splits out (1.) and (3.) into separate functions in preparation >> for reusing them when the actual attachment is happening (in the >> raw_tracepoint_open syscall operation), which will allow tracing programs >> to have multiple (compatible) attachments. >> >> No functional change is intended with this patch. >> >> Signed-off-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx> >> --- > > I can't tell if there are any functional changes or not, tbh. The > logic is quite complicated and full of intricate details. I did leave > some suggestions on hopefully simplifying code flow in some places > (and ensuring it's harder to break it on future changes), but I hope > Alexei will give it a very thorough review and check that none of the > subtle details broke. Yeah, totally agree this is gnarly... :/ Which is also why I chickened out of doing any further changes in an attempt to simplify the flow, but rather kept as much as the existing structure as possible (with somewhat mixed results, I suppose). Let's see what Alexei thinks. I guess I can take another crack at it, in which case, thank you for the suggestions for simplifying things! -Toke
