RE: [PATCH bpf-next 0/5] libbpf: error reporting changes for v1.0

[John Fastabend <john.fastabend@gmail.com>]

Andrii Nakryiko wrote:
> Implement error reporting changes discussed in "Libbpf: the road to v1.0"
> ([0]) document.
> 
> Libbpf gets a new API, libbpf_set_strict_mode() which accepts a set of flags
> that turn on a set of libbpf 1.0 changes, that might be potentially breaking.
> It's possible to opt-in into all current and future 1.0 features by specifying
> LIBBPF_STRICT_ALL flag.
> 
> When some of the 1.0 "features" are requested, libbpf APIs might behave
> differently. In this patch set a first set of changes are implemented, all
> related to the way libbpf returns errors. See individual patches for details.
> 
> Patch #1 adds a no-op libbpf_set_strict_mode() functionality to enable
> updating selftests.
> 
> Patch #2 gets rid of all the bad code patterns that will break in libbpf 1.0
> (exact -1 comparison for low-level APIs, direct IS_ERR() macro usage to check
> pointer-returning APIs for error, etc). These changes make selftest work in
> both legacy and 1.0 libbpf modes. Selftests also opt-in into 100% libbpf 1.0
> mode to automatically gain all the subsequent changes, which will come in
> follow up patches.
> 
> Patch #3 streamlines error reporting for low-level APIs wrapping bpf() syscall.
> 
> Patch #4 streamlines errors for all the rest APIs.
> 
> Patch #5 ensures that BPF skeletons propagate errors properly as well, as
> currently on error some APIs will return NULL with no way of checking exact
> error code.
> 
>   [0] https://docs.google.com/document/d/1UyjTZuPFWiPFyKk1tV5an11_iaRuec6U-ZESZ54nNTY
> 
> Andrii Nakryiko (5):
>   libbpf: add libbpf_set_strict_mode() API to turn on libbpf 1.0
>     behaviors
>   selftests/bpf: turn on libbpf 1.0 mode and fix all IS_ERR checks
>   libbpf: streamline error reporting for low-level APIs
>   libbpf: streamline error reporting for high-level APIs
>   bpftool: set errno on skeleton failures and propagate errors
> 

LGTM for the series,

Acked-by: John Fastabend <john.fastabend@gmail.com>