On Tue, Jul 25, 2023 at 10:55 AM James Clark <james.clark@xxxxxxx> wrote: > > But I just checked now and it's just bear [1] that causes the issue. > Maybe it sets errno before forking and that persists in the child > processes? Not 100% sure how it works. I did debug scripts/kallsyms and > errno was already set on the first line of main(), so it's not some > other library call in kallsyms that is setting it but not being checked. I think this is https://github.com/rizsotto/Bear/issues/469: bear preloads a library which was setting it to non-zero. Now, even if bear was breaking a guarantee C programs have (`errno` for the initial thread at program startup is meant to be 0 according to the C standard), it is still a good idea to set `errno` to zero here in case something else happens to change `errno` within `kallsyms` in the future. With the repro and the `bear` link issue added: Reviewed-by: Miguel Ojeda <ojeda@xxxxxxxxxx> Cheers, Miguel
