Re: [PATCH bpf-next v10 0/4] bpf: Add bpf_rcu_read_lock() support

patchwork-bot+netdevbpf
2022-11-24T21:10:20Z

Hello:

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

On Wed, 23 Nov 2022 21:32:01 -0800 you wrote:
> Currently, without rcu attribute info in BTF, the verifier treats
> rcu tagged pointer as a normal pointer. This might be a problem
> for sleepable program where rcu_read_lock()/unlock() is not available.
> For example, for a sleepable fentry program, if rcu protected memory
> access is interleaved with a sleepable helper/kfunc, it is possible
> the memory access after the sleepable helper/kfunc might be invalid
> since the object might have been freed then. Even without
> a sleepable helper/kfunc, without rcu_read_lock() protection,
> it is possible that the rcu protected object might be release
> in the middle of bpf program execution which may cause incorrect
> result.
>
> [...]

Here is the summary with links:
- [bpf-next,v10,1/4] compiler_types: Define __rcu as __attribute__((btf_type_tag("rcu")))
https://git.kernel.org/bpf/bpf-next/c/5a0f663f0189
- [bpf-next,v10,2/4] bpf: Introduce might_sleep field in bpf_func_proto
https://git.kernel.org/bpf/bpf-next/c/01685c5bddaa
- [bpf-next,v10,3/4] bpf: Add kfunc bpf_rcu_read_lock/unlock()
https://git.kernel.org/bpf/bpf-next/c/9bb00b2895cb
- [bpf-next,v10,4/4] selftests/bpf: Add tests for bpf_rcu_read_lock()
https://git.kernel.org/bpf/bpf-next/c/48671232fcb8

You are awesome, thank you!
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