Re: [PATCH 12/22] bsd-user/freebsd/os-syscall.c: Add get_errno and host_to_target_errno

[Kyle Evans]

On Tue, Feb 1, 2022 at 5:15 AM Warner Losh <imp@bsdimp.com> wrote:
>
> Add the helper functions get_errno and host_to_target_errno. get_errno
> returns either the system call results, or the -errno when system call
> indicates failure by returning -1. Host_to_target_errno returns errno
> (since on FreeBSD they are the same on all architectures) along with a
> comment about why it's the identity.
>
> Signed-off-by: Warner Losh <imp@bsdimp.com>
> ---
>  bsd-user/freebsd/os-syscall.c | 23 +++++++++++++++++++++++
>  bsd-user/qemu.h               |  3 ++-
>  2 files changed, 25 insertions(+), 1 deletion(-)
>

Reviewed-by: Kyle Evans <kevans@FreeBSD.org>

> diff --git a/bsd-user/freebsd/os-syscall.c b/bsd-user/freebsd/os-syscall.c
> index 7e2bedb918d..2e84cf350b1 100644
> --- a/bsd-user/freebsd/os-syscall.c
> +++ b/bsd-user/freebsd/os-syscall.c
> @@ -44,6 +44,29 @@ void target_set_brk(abi_ulong new_brk)
>  {
>  }
>
> +/*
> + * errno conversion.
> + */
> +abi_long get_errno(abi_long ret)
> +{
> +
> +    if (ret == -1) {
> +        return -host_to_target_errno(errno);
> +    } else {
> +        return ret;
> +    }
> +}
> +
> +int host_to_target_errno(int err)
> +{
> +    /*
> +     * All the BSDs have the property that the error numbers are uniform 
> across
> +     * all architectures for a given BSD, though they may vary between 
> different
> +     * BSDs.
> +     */
> +    return err;
> +}
> +
>  bool is_error(abi_long ret)
>  {
>
> diff --git a/bsd-user/qemu.h b/bsd-user/qemu.h
> index e5742bd6c03..56042ddbc5d 100644
> --- a/bsd-user/qemu.h
> +++ b/bsd-user/qemu.h
> @@ -246,9 +246,10 @@ extern unsigned long target_dflssiz;
>  extern unsigned long target_maxssiz;
>  extern unsigned long target_sgrowsiz;
>
> -/* syscall.c */
> +/* os-syscall.c */
>  abi_long get_errno(abi_long ret);
>  bool is_error(abi_long ret);
> +int host_to_target_errno(int err);
>
>  /* os-sys.c */
>  abi_long do_freebsd_sysarch(void *cpu_env, abi_long arg1, abi_long arg2);
> --
> 2.33.1
>