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