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      1 /*      $NetBSD: compat_sigaltstack.h,v 1.4 2021/11/01 05:07:16 thorpej Exp $        */
      2 
      3 /* Wrapper for calling sigaltstack1() from compat (or other) code */
      4 
      5 /* Maybe these definitions could be global. */
      6 #ifdef SCARG_P32
      7 /* compat32 */
      8 #define	SCARG_COMPAT_PTR(uap,p)	SCARG_P32(uap, p)
      9 #define	COMPAT_GET_PTR(p)	NETBSD32PTR64(p)
     10 #define	COMPAT_SET_PTR(p, v)	NETBSD32PTR32(p, v)
     11 #else
     12 /* not a size change */
     13 #define	SCARG_COMPAT_PTR(uap,p)	SCARG(uap, p)
     14 #define	COMPAT_GET_PTR(p)	(p)
     15 #define	COMPAT_SET_PTR(p, v)	((p) = (v))
     16 #endif
     17 
     18 #define compat_sigaltstack(uap, compat_ss, ss_onstack, ss_disable) do { \
     19 	struct compat_ss css; \
     20 	stack_t nss, oss; \
     21 	int error; \
     22 \
     23 	if (SCARG_COMPAT_PTR(uap, nss)) { \
     24 		error = copyin(SCARG_COMPAT_PTR(uap, nss), &css, sizeof css); \
     25 		if (error) \
     26 			return error; \
     27 		nss.ss_sp = COMPAT_GET_PTR(css.ss_sp); \
     28 		nss.ss_size = css.ss_size; \
     29 		if (ss_onstack == SS_ONSTACK && ss_disable == SS_DISABLE) \
     30 			nss.ss_flags = css.ss_flags; \
     31 		else \
     32 			nss.ss_flags = \
     33 			    (css.ss_flags & ss_onstack ? SS_ONSTACK : 0) \
     34 			    | (css.ss_flags & ss_disable ? SS_DISABLE : 0); \
     35 	} \
     36 \
     37 	error = sigaltstack1(curlwp, SCARG_COMPAT_PTR(uap, nss) ? &nss : 0, \
     38 				SCARG_COMPAT_PTR(uap, oss) ? &oss : 0); \
     39 	if (error) \
     40 		return (error); \
     41 \
     42 	if (SCARG_COMPAT_PTR(uap, oss)) { \
     43 		COMPAT_SET_PTR(css.ss_sp, oss.ss_sp); \
     44 		css.ss_size = oss.ss_size; \
     45 		if (ss_onstack == SS_ONSTACK && ss_disable == SS_DISABLE) \
     46 			css.ss_flags = oss.ss_flags; \
     47 		else \
     48 			css.ss_flags = \
     49 			    (oss.ss_flags & SS_ONSTACK ? ss_onstack : 0) \
     50 			    | (oss.ss_flags & SS_DISABLE ? ss_disable : 0); \
     51 		error = copyout(&css, SCARG_COMPAT_PTR(uap, oss), sizeof(css));\
     52 		if (error) \
     53 			return (error); \
     54 	} \
     55 	return (0); \
     56 } while (0)
     57