1/*
2 * Copyright (c) 2009 Cisco Systems, Inc.  All Rights Reserved.
3 * Copyright (c) 2009 FUJITSU LIMITED.  All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of version 2 of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
12 *
13 * Further, this software is distributed without any warranty that it is
14 * free of the rightful claim of any third person regarding infringement
15 * or the like.  Any license provided herein, whether implied or
16 * otherwise, applies only to this software file.  Patent licenses, if
17 * any, provided herein do not apply to combinations of this program with
18 * other software, or any other product whatsoever.
19 *
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write the Free Software Foundation, Inc.,
22 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 *
24 * Author: Liu Bo <liubo2009@cn.fujitsu.com>
25 * Author: Ngie Cooper <yaneurabeya@gmail.com>
26 *
27 */
28
29#ifndef LTP_RT_SIGACTION_H
30#define LTP_RT_SIGACTION_H
31
32#include "ltp_signal.h"
33
34#define INVAL_SA_PTR ((void *)-1)
35
36#if defined(__mips__)
37struct kernel_sigaction {
38	unsigned int sa_flags;
39	__sighandler_t k_sa_handler;
40	sigset_t sa_mask;
41};
42#else
43struct kernel_sigaction {
44	__sighandler_t k_sa_handler;
45	unsigned long sa_flags;
46	void (*sa_restorer) (void);
47	sigset_t sa_mask;
48};
49#endif
50
51/* This macro marks if (struct sigaction) has .sa_restorer member */
52#if !defined(__ia64__) && !defined(__alpha__) && !defined(__hppa__) && !defined(__mips__)
53# define HAVE_SA_RESTORER
54#endif
55
56#ifdef __x86_64__
57
58/*
59 * From asm/signal.h -- this value isn't exported anywhere outside of glibc and
60 * asm/signal.h and is only required for the rt_sig* function family because
61 * sigaction(2), et all, appends this if necessary to
62 * (struct sigaction).sa_flags. HEH.
63 *
64 * I do #undef though, just in case...
65 *
66 * Also, from .../arch/x86/kernel/signal.c:448 for v2.6.30 (something or
67 * other):
68 *
69 * x86-64 should always use SA_RESTORER.
70 *
71 * -- thus SA_RESTORER must always be defined along with
72 * (struct sigaction).sa_restorer for this architecture.
73 */
74#undef SA_RESTORER
75#define SA_RESTORER     0x04000000
76
77void (*restore_rt)(void);
78
79static void handler_h(int signal)
80{
81	return;
82}
83
84/* Setup an initial signal handler for signal number = sig for x86_64. */
85static inline int sig_initial(int sig)
86{
87	int ret_code = -1;
88	struct sigaction act, oact;
89
90	act.sa_handler = handler_h;
91	act.sa_flags = 0;
92	/* Clear out the signal set. */
93	if (sigemptyset(&act.sa_mask) < 0) {
94		/* Add the signal to the mask set. */
95	} else if (sigaddset(&act.sa_mask, sig) < 0) {
96		/* Set act.sa_restorer via syscall(2) */
97	} else if (sigaction(sig, &act, &oact) < 0) {
98		/* Copy oact.sa_restorer via syscall(2) */
99	} else if (sigaction(sig, &act, &oact) < 0) {
100		/* And voila -- we just tricked the kernel into giving us our
101		 * restorer function! */
102	} else {
103		restore_rt = oact.sa_restorer;
104		ret_code = 0;
105	}
106
107	return ret_code;
108}
109
110#endif /* __x86_64__ */
111
112#ifdef __sparc__
113# if defined __arch64__ || defined __sparcv9
114
115/*
116 * Based on glibc/sysdeps/unix/sysv/linux/sparc/sparc64/sigaction.c
117 */
118
119extern char *__rt_sig_stub;
120
121static void __attribute__((used)) __rt_sigreturn_stub(void)
122{
123	__asm__ ("__rt_sig_stub: mov %0, %%g1\n\t"
124		"ta  0x6d\n\t"
125		: /* no outputs */
126		: "i" (__NR_rt_sigreturn));
127}
128
129# else /* sparc32 */
130
131/*
132 * Based on glibc/sysdeps/unix/sysv/linux/sparc/sparc32/sigaction.c
133 */
134
135extern char *__rt_sig_stub, *__sig_stub;
136
137static void __attribute__((used)) __rt_sigreturn_stub(void)
138{
139	__asm__ ("__rt_sig_stub: mov %0, %%g1\n\t"
140		"ta  0x10\n\t"
141		: /* no outputs */
142		: "i" (__NR_rt_sigreturn));
143}
144
145static void __attribute__((used)) __sigreturn_stub(void)
146{
147	__asm__ ("__sig_stub: mov %0, %%g1\n\t"
148		"ta  0x10\n\t"
149		: /* no outputs */
150		: "i" (__NR_sigreturn));
151}
152
153# endif
154#endif /* __sparc__ */
155
156#ifdef __arc__
157
158#undef SA_RESTORER
159#define SA_RESTORER     0x04000000
160
161/*
162 * based on uClibc/libc/sysdeps/linux/arc/sigaction.c
163 */
164static void
165__attribute__ ((optimize("Os"))) __attribute__((used)) restore_rt(void)
166{
167	__asm__ (
168		"mov r8, %0	\n\t"
169#ifdef __ARCHS__
170		"trap_s	0	\n\t"
171#else
172		"trap0	\n\t"
173#endif
174		: /* no outputs */
175		: "i" (__NR_rt_sigreturn)
176		: "r8");
177}
178#endif
179
180/* This is a wrapper for __NR_rt_sigaction syscall.
181 * act/oact values of INVAL_SA_PTR is used to pass
182 * an invalid pointer to syscall(__NR_rt_sigaction)
183 *
184 * Based on glibc/sysdeps/unix/sysv/linux/{...}/sigaction.c
185 */
186
187static int ltp_rt_sigaction(int signum, const struct sigaction *act,
188			struct sigaction *oact, size_t sigsetsize)
189{
190	int ret;
191	struct kernel_sigaction kact, koact;
192	struct kernel_sigaction *kact_p = NULL;
193	struct kernel_sigaction *koact_p = NULL;
194
195	if (act == INVAL_SA_PTR) {
196		kact_p = INVAL_SA_PTR;
197	} else if (act) {
198		kact.k_sa_handler = act->sa_handler;
199		memcpy(&kact.sa_mask, &act->sa_mask, sizeof(sigset_t));
200		kact.sa_flags = act->sa_flags;
201#ifndef __mips__
202		kact.sa_restorer = NULL;
203#endif
204		kact_p = &kact;
205	}
206
207	if (oact == INVAL_SA_PTR)
208		koact_p = INVAL_SA_PTR;
209	else if (oact)
210		koact_p = &koact;
211
212#ifdef __x86_64__
213	sig_initial(signum);
214#endif
215
216#if defined __x86_64__ || defined __arc__
217	kact.sa_flags |= SA_RESTORER;
218	kact.sa_restorer = restore_rt;
219#endif
220
221#ifdef __sparc__
222	unsigned long stub = 0;
223# if defined __arch64__ || defined __sparcv9
224	stub = ((unsigned long) &__rt_sig_stub) - 8;
225# else /* sparc32 */
226	if ((kact.sa_flags & SA_SIGINFO) != 0)
227		stub = ((unsigned long) &__rt_sig_stub) - 8;
228	else
229		stub = ((unsigned long) &__sig_stub) - 8;
230# endif
231#endif
232
233
234#ifdef __sparc__
235	ret = ltp_syscall(__NR_rt_sigaction, signum,
236			kact_p, koact_p,
237			stub, sigsetsize);
238#else
239	ret = ltp_syscall(__NR_rt_sigaction, signum,
240			kact_p, koact_p,
241			sigsetsize);
242#endif
243
244	if (ret >= 0) {
245		if (oact && (oact != INVAL_SA_PTR)) {
246			oact->sa_handler = koact.k_sa_handler;
247			memcpy(&oact->sa_mask, &koact.sa_mask,
248				sizeof(sigset_t));
249			oact->sa_flags = koact.sa_flags;
250#ifdef HAVE_SA_RESTORER
251			oact->sa_restorer = koact.sa_restorer;
252#endif
253		}
254	}
255
256	return ret;
257}
258
259#endif /* LTP_RT_SIGACTION_H */
260