Re: [UNIKRAFT PATCH] lib/syscall_shim: Enable UK_LIBC_SYSCALLS when library is unselected

[Gaulthier Gain <Gaulthier.Gain@xxxxxxxxx>]

Reviewed-by: Gaulthier Gain <gaulthier.gain@xxxxxxxxx>

> On 20 May 2020, at 18:41, Simon Kuenzer <simon.kuenzer@xxxxxxxxx> wrote:
> 
> Always enables UK_LIBC_SYSCALLS as soon as syscall_shim is
> disabled. This enables all libc-style wrapper implementations of
> system calls (e.g., open(), write()) when system calls are not
> enabled. Those wrappers can only be disabled when syscall_shim is
> selected and the hidden option LIBSYSCALL_SHIM_NOWRAPPER is set. This
> is a very special case that may only be caused by some libcs that are
> based on system calls and provide own libc-style wrappers (e.g., musl).
> 
> Signed-off-by: Simon Kuenzer <simon.kuenzer@xxxxxxxxx>
> ---
> lib/syscall_shim/include/uk/syscall.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/syscall_shim/include/uk/syscall.h 
> b/lib/syscall_shim/include/uk/syscall.h
> index 1be4ab91..ffa9f1ee 100644
> --- a/lib/syscall_shim/include/uk/syscall.h
> +++ b/lib/syscall_shim/include/uk/syscall.h
> @@ -51,11 +51,11 @@
>  * UK_LIBC_SYSCALLS can be set to 0 through compilation flags.
>  */
> #ifndef UK_LIBC_SYSCALLS
> -#if CONFIG_LIBSYSCALL_SHIM_NOWRAPPER
> +#if CONFIG_LIBSYSCALL_SHIM && CONFIG_LIBSYSCALL_SHIM_NOWRAPPER
> #define UK_LIBC_SYSCALLS (0)
> #else
> #define UK_LIBC_SYSCALLS (1)
> -#endif /* CONFIG_LIBSYSCALL_SHIM_NOWRAPPER */
> +#endif /* CONFIG_LIBSYSCALL_SHIM && CONFIG_LIBSYSCALL_SHIM_NOWRAPPER */
> #endif /* UK_LIBC_SYSCALLS */
> 
> #define __uk_scc(X) ((long) (X))
> -- 
> 2.20.1
> 
>