Re: [musl] [PATCH] use __scc and unsigned long for socketcall

[Rich Felker <dalias@libc.org>]

On Fri, Jul 01, 2022 at 11:09:10AM -0400, Alex Xu (Hello71) wrote:
> otherwise, pointer arguments are sign-extended on x32, resulting in
> EFAULT.
> ---
>  src/internal/syscall.h | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/src/internal/syscall.h b/src/internal/syscall.h
> index 4f41e1dc..7c74775c 100644
> --- a/src/internal/syscall.h
> +++ b/src/internal/syscall.h
> @@ -58,22 +58,22 @@ hidden long __syscall_ret(unsigned long),
>  #define __syscall_cp(...) __SYSCALL_DISP(__syscall_cp,__VA_ARGS__)
>  #define syscall_cp(...) __syscall_ret(__syscall_cp(__VA_ARGS__))
>  
> -static inline long __alt_socketcall(int sys, int sock, int cp, long a, long b, long c, long d, long e, long f)
> +static inline long __alt_socketcall(int sys, int sock, int cp, syscall_arg_t a, syscall_arg_t b, syscall_arg_t c, syscall_arg_t d, syscall_arg_t e, syscall_arg_t f)
>  {

OK.

>  	long r;
>  	if (cp) r = __syscall_cp(sys, a, b, c, d, e, f);
>  	else r = __syscall(sys, a, b, c, d, e, f);
>  	if (r != -ENOSYS) return r;
>  #ifdef SYS_socketcall
> -	if (cp) r = __syscall_cp(SYS_socketcall, sock, ((long[6]){a, b, c, d, e, f}));
> -	else r = __syscall(SYS_socketcall, sock, ((long[6]){a, b, c, d, e, f}));
> +	if (cp) r = __syscall_cp(SYS_socketcall, sock, ((unsigned long[6]){a, b, c, d, e, f}));
> +	else r = __syscall(SYS_socketcall, sock, ((unsigned long[6]){a, b, c, d, e, f}));
>  #endif
>  	return r;

Does this part have any functional change or purpose? I'm not seeing it.

>  }
>  #define __socketcall(nm, a, b, c, d, e, f) __alt_socketcall(SYS_##nm, __SC_##nm, 0, \
> -	(long)(a), (long)(b), (long)(c), (long)(d), (long)(e), (long)(f))
> +	__scc(a), __scc(b), __scc(c), __scc(d), __scc(e), __scc(f))
>  #define __socketcall_cp(nm, a, b, c, d, e, f) __alt_socketcall(SYS_##nm, __SC_##nm, 1, \
> -	(long)(a), (long)(b), (long)(c), (long)(d), (long)(e), (long)(f))
> +	__scc(a), __scc(b), __scc(c), __scc(d), __scc(e), __scc(f))
>  
>  /* fixup legacy 16-bit junk */

Looks good.

Rich