Re: [PATCH 17/39] bpf: resolve_pseudo_ldimm64(): take handling of a single ldimm64 insn into helper

Andrii Nakryiko
2024-08-13T03:32:48Z

On Mon, Aug 12, 2024 at 7:06 PM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> On Mon, Aug 12, 2024 at 01:05:19PM -0700, Andrii Nakryiko wrote:
> > On Fri, Aug 9, 2024 at 8:29???PM Al Viro <viro@zeniv.linux.org.uk> wrote:
> > >
> > > On Thu, Aug 08, 2024 at 09:51:34AM -0700, Alexei Starovoitov wrote:
> > >
> > > > The bpf changes look ok and Andrii's approach is easier to grasp.
> > > > It's better to route bpf conversion to CLASS(fd,..) via bpf-next,
> > > > so it goes through bpf CI and our other testing.
> > > >
> > > > bpf patches don't seem to depend on newly added CLASS(fd_pos, ...
> > > > and fderr, so pretty much independent from other patches.
> > >
> > > Representation change and switch to accessors do matter, though.
> > > OTOH, I can put just those into never-rebased branch (basically,
> > > "introduce fd_file(), convert all accessors to it" +
> > > "struct fd representation change" + possibly "add struct fd constructors,
> > > get rid of __to_fd()", for completeness sake), so you could pull it.
> > > Otherwise you'll get textual conflicts on all those f.file vs. fd_file(f)...
> >
> > Yep, makes sense. Let's do that, we can merge that branch into
> > bpf-next/master and I will follow up with my changes on top of that.
> >
> > Let's just drop the do_one_ldimm64() extraction, and keep fdput(f)
> > logic, plus add fd_file() accessor changes. I'll then add a switch to
> > CLASS(fd) after a bit more BPF-specific clean ups. This code is pretty
> > sensitive, so I'd rather have all the non-trivial refactoring done
> > separately. Thanks!
>
> Done (#stable-struct_fd);

great, thanks, I'll look at this tomorrow

> BTW, which tree do you want "convert __bpf_prog_get()
> to CLASS(fd)" to go through?

So we seem to have the following for BPF-related stuff:

[PATCH 16/39] convert __bpf_prog_get() to CLASS(fd, ...)

This looks to be ready to go in.

[PATCH 17/39] bpf: resolve_pseudo_ldimm64(): take handling of a single
ldimm64 insn into helper

This one I'd like to rework differently and land it through bpf-next.

[PATCH 18/39] bpf maps: switch to CLASS(fd, ...)

This one touches __bpf_map_get() which I'm going to remove or refactor
as part of the abovementioned refactoring, so there will be conflicts.

[PATCH 19/39] fdget_raw() users: switch to CLASS(fd_raw, ...)

This one touches a bunch of cases across multiple systems, including
BPF's kernel/bpf/bpf_inode_storage.c.

So how about this. We take #16 as is through bpf-next, change how #17
is done, take 18 mostly as is but adjust as necessary. As for #19, if
you could split out changes in bpf_inode_storage.c to a separate
patch, we can also apply it in bpf-next as one coherent set. I'll send
all that as one complete patch set for you to do the final review.

WDYT?