[Devel] [PATCH vz10] selftests/rseq: skip syscall_errors_test when libc owns the registration

[Konstantin Khorenko]

nack.

After that we just get all tests SKIPPED,
while we should better unregister rseq and execute the test.

Mainstream has also fixed that but in different way - it prevents glibc registering rseq from the very beginning:
cb48828f06af ("selftests/rseq: Don't run tests with runner scripts outside of the scripts")

--
Best regards,

Konstantin Khorenko,
Virtuozzo Linux Kernel Team

On 8/21/26 17:24, Eva Kurchatova wrote:
> The test requires the calling thread to be unregistered and expects
> EFAULT when registering an invalid address. glibc >= 2.35 registers
> rseq for every thread at startup, so the kernel rejects the second
> registration with EINVAL before it ever touches the address.
> 
> https://virtuozzo.atlassian.net/browse/VSTOR-139675
> Feature: fix selftests
> Signed-off-by: Eva Kurchatova <eva.kurchatova at virtuozzo.com>
> ---
>  tools/testing/selftests/rseq/syscall_errors_test.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/tools/testing/selftests/rseq/syscall_errors_test.c b/tools/testing/selftests/rseq/syscall_errors_test.c
> index a5d9e1f8a2dc..9e6bf6b1df96 100644
> --- a/tools/testing/selftests/rseq/syscall_errors_test.c
> +++ b/tools/testing/selftests/rseq/syscall_errors_test.c
> @@ -34,6 +34,15 @@ int main(void)
>  		goto error;
>  	}
>  
> +	/*
> +	 * The expectations below only hold for a thread which is not
> +	 * registered, while glibc >= 2.35 registers every thread at startup.
> +	 */
> +	if (rseq_current_cpu_raw() >= 0) {
> +		fprintf(stderr, "rseq is already registered, skipping\n");
> +		return 4;
> +	}
> +
>  	/* The current thread is NOT registered. */
>  
>  	/* EINVAL */