Re: [PATCH bpf-next v5 00/16] Fix some arena paper cuts

[patchwork-bot+netdevbpf@kernel.org]

Hello:

This series was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:

On Mon, 19 Oct 2026 15:21:42 +0200 you wrote:
> Kernel code that shares arena memory with BPF programs runs into two
> paper cuts, both visible in sched_ext's cid-form schedulers today.
> 
> A kernel struct cannot publish an arena pointer: a pointer member reaches
> the program typed as a kernel pointer, so sched_ext hands out a plain u64
> holding a pre-translated arena address and every program casts it before
> use. __arena and __nullable become BTF type tags, defined in a header of
> their own, bpf_compiler_types.h, that the code tagging a member includes.
> A load through an __arena member of a kernel struct yields PTR_TO_ARENA:
> the member holds the kernel address and the fixup pass appends the
> conversion to the arena pointer form that the struct_ops trampoline
> applies to __arena arguments, with a NULL test for __nullable members.
> A __nullable member on its own yields PTR_MAYBE_NULL where NULL would
> otherwise be assumed away, on trusted, RCU and per-CPU results, and the
> program checks it; through a plain or an untrusted pointer the member is
> probed and tolerates NULL, as the BTF_TYPE_SAFE_*_OR_NULL lists never
> applied there either. libbpf renders the arena tag with its address
> space, so the member arrives in a program built against vmlinux.h ready
> to use, without a cast.
> 
> [...]

Here is the summary with links:
  - [bpf-next,v5,01/16] bpf: Check exclusive maps once the program digest is final
    https://git.kernel.org/bpf/bpf-next/c/55f17779d649
  - [bpf-next,v5,02/16] selftests/bpf: Bind an exclusive map through a continuous fd_array
    https://git.kernel.org/bpf/bpf-next/c/c2e56c88f14a
  - [bpf-next,v5,03/16] libbpf: Keep the fd_array fill index out of bpf_program__clone()
    https://git.kernel.org/bpf/bpf-next/c/b1eaee8b9a95
  - [bpf-next,v5,04/16] selftests/bpf: Clone a program that calls a module kfunc
    https://git.kernel.org/bpf/bpf-next/c/d837f008bfe6
  - [bpf-next,v5,05/16] bpf: Add the __arena and __nullable BTF type tags
    https://git.kernel.org/bpf/bpf-next/c/10832993c941
  - [bpf-next,v5,06/16] bpf: Recognize __nullable on pointer members of kernel structs
    https://git.kernel.org/bpf/bpf-next/c/bc7c2824682b
  - [bpf-next,v5,07/16] bpf: Turn loads of __arena pointer members into arena pointers
    https://git.kernel.org/bpf/bpf-next/c/7efe1d4e1139
  - [bpf-next,v5,08/16] selftests/bpf: Test __nullable pointer members
    https://git.kernel.org/bpf/bpf-next/c/9278bedb22de
  - [bpf-next,v5,09/16] selftests/bpf: Test __arena pointer members
    https://git.kernel.org/bpf/bpf-next/c/1dad22de9c03
  - [bpf-next,v5,10/16] selftests/bpf: Move the no-arena tests out of objects with an arena map
    https://git.kernel.org/bpf/bpf-next/c/bc4a327d5b87
  - [bpf-next,v5,11/16] libbpf: Bind the arena of an object to every program in it
    https://git.kernel.org/bpf/bpf-next/c/cd7a395838cb
  - [bpf-next,v5,12/16] selftests/bpf: Test arena binding by libbpf
    https://git.kernel.org/bpf/bpf-next/c/8911d7766073
  - [bpf-next,v5,13/16] bpf: Set up the arena base only in functions that use it
    https://git.kernel.org/bpf/bpf-next/c/a8471eb0747f
  - [bpf-next,v5,14/16] libbpf: Render the arena type tag with its address space
    https://git.kernel.org/bpf/bpf-next/c/7418d9291c57
  - [bpf-next,v5,15/16] selftests/bpf: Test the address space rendering of the arena type tag
    https://git.kernel.org/bpf/bpf-next/c/31ef8ab6dfc7
  - [bpf-next,v5,16/16] selftests/bpf: Test an arena kfunc argument passed from a subprogram
    https://git.kernel.org/bpf/bpf-next/c/fb854e2e54a7

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html