sig_machdep.c revision 1.39
1/*	$NetBSD: sig_machdep.c,v 1.39 2011/02/07 09:39:48 matt Exp $	*/
2
3/*
4 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
5 * Copyright (C) 1995, 1996 TooLs GmbH.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by TooLs GmbH.
19 * 4. The name of TooLs GmbH may not be used to endorse or promote products
20 *    derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
28 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35__KERNEL_RCSID(0, "$NetBSD: sig_machdep.c,v 1.39 2011/02/07 09:39:48 matt Exp $");
36
37#include "opt_ppcarch.h"
38#include "opt_altivec.h"
39
40#include <sys/param.h>
41#include <sys/mount.h>
42#include <sys/proc.h>
43#include <sys/syscallargs.h>
44#include <sys/systm.h>
45#include <sys/ucontext.h>
46
47#include <uvm/uvm_extern.h>
48
49#include <powerpc/fpu.h>
50#include <powerpc/altivec.h>
51#include <powerpc/pcb.h>
52
53/*
54 * Send a signal to process.
55 */
56void
57sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask)
58{
59	struct lwp * const l = curlwp;
60	struct proc * const p = l->l_proc;
61	struct trapframe * const tf = l->l_md.md_utf;
62	struct sigaltstack * const ss = &l->l_sigstk;
63	const struct sigact_sigdesc * const sd =
64	    &p->p_sigacts->sa_sigdesc[ksi->ksi_signo];
65	/* save handler before sendsig_reset trashes it! */
66	const void * const handler = sd->sd_sigact.sa_handler;
67	ucontext_t uc;
68	vaddr_t sp, sip, ucp;
69	int onstack, error;
70
71	/* Do we need to jump onto the signal stack? */
72	onstack = (ss->ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
73	    (sd->sd_sigact.sa_flags & SA_ONSTACK) != 0;
74
75	/* Find top of stack.  */
76	sp = (onstack ? (vaddr_t)ss->ss_sp + ss->ss_size : tf->tf_fixreg[1]);
77	sp &= ~(CALLFRAMELEN-1);
78
79	/* Allocate space for the ucontext.  */
80	sp -= sizeof(ucontext_t);
81	ucp = sp;
82
83	/* Allocate space for the siginfo.  */
84	sp -= sizeof(siginfo_t);
85	sip = sp;
86
87	sp &= ~(CALLFRAMELEN-1);
88
89	/* Save register context. */
90	uc.uc_flags = _UC_SIGMASK;
91	uc.uc_sigmask = *mask;
92	uc.uc_link = l->l_ctxlink;
93	memset(&uc.uc_stack, 0, sizeof(uc.uc_stack));
94	sendsig_reset(l, ksi->ksi_signo);
95	mutex_exit(p->p_lock);
96	cpu_getmcontext(l, &uc.uc_mcontext, &uc.uc_flags);
97
98	/*
99	 * Copy the siginfo and ucontext onto the user's stack.
100	 */
101	error = (copyout(&ksi->ksi_info, (void *)sip, sizeof(ksi->ksi_info)) != 0 ||
102	    copyout(&uc, (void *)ucp, sizeof(uc)) != 0);
103	mutex_enter(p->p_lock);
104
105	if (error) {
106		/*
107		 * Process has trashed its stack; give it an illegal
108		 * instruction to halt it in its tracks.
109		 */
110		sigexit(l, SIGILL);
111		/* NOTREACHED */
112	}
113
114	/*
115	 * Build context to run handler in.  Note the trampoline version
116	 * numbers are coordinated with machine-dependent code in libc.
117	 */
118	switch (sd->sd_vers) {
119	case 2:		/* siginfo sigtramp */
120		tf->tf_fixreg[1]  = (register_t)sp - CALLFRAMELEN;
121		tf->tf_fixreg[3]  = (register_t)ksi->ksi_signo;
122		tf->tf_fixreg[4]  = (register_t)sip;
123		tf->tf_fixreg[5]  = (register_t)ucp;
124		/* Preserve ucp across call to signal function */
125		tf->tf_fixreg[30] = (register_t)ucp;
126		tf->tf_lr         = (register_t)sd->sd_tramp;
127		tf->tf_srr0       = (register_t)handler;
128		break;
129
130	default:
131		goto nosupport;
132	}
133
134	/* Remember that we're now on the signal stack. */
135	if (onstack)
136		ss->ss_flags |= SS_ONSTACK;
137	return;
138
139 nosupport:
140	/* Don't know what trampoline version; kill it. */
141	printf("sendsig_siginfo(sig %d): bad version %d\n",
142	    ksi->ksi_signo, sd->sd_vers);
143	sigexit(l, SIGILL);
144	/* NOTREACHED */
145}
146
147void
148cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flagp)
149{
150	const struct trapframe * const tf = trapframe(l);
151	__greg_t * const gr = mcp->__gregs;
152#if defined(PPC_HAVE_FPU)
153	struct pcb * const pcb = lwp_getpcb(l);
154#endif
155
156	/* Save GPR context. */
157	(void)memcpy(gr, &tf->tf_fixreg, 32 * sizeof (gr[0])); /* GR0-31 */
158	gr[_REG_CR]  = tf->tf_cr;
159	gr[_REG_LR]  = tf->tf_lr;
160	gr[_REG_PC]  = tf->tf_srr0;
161	gr[_REG_MSR] = tf->tf_srr1 & PSL_USERSRR1;
162#ifdef PPC_HAVE_FPU
163	gr[_REG_MSR] |= pcb->pcb_flags & (PCB_FE0|PCB_FE1);
164#endif
165	gr[_REG_CTR] = tf->tf_ctr;
166	gr[_REG_XER] = tf->tf_xer;
167#ifdef PPC_OEA
168	gr[_REG_MQ]  = tf->tf_mq;
169#else
170	gr[_REG_MQ]  = 0;
171#endif
172
173	*flagp |= _UC_CPU;
174
175#ifdef PPC_HAVE_FPU
176	/* Save FPU context, if any. */
177	if (!fpu_save_to_mcontext(l, mcp, flagp))
178#endif
179		memset(&mcp->__fpregs, 0, sizeof(mcp->__fpregs));
180
181#if defined(ALTIVEC) || defined(PPC_HAVE_SPE)
182	/* Save vector context, if any. */
183	if (!vec_save_to_mcontext(l, mcp, flagp))
184#endif
185		memset(&mcp->__vrf, 0, sizeof (mcp->__vrf));
186}
187
188int
189cpu_setmcontext(struct lwp *l, const mcontext_t *mcp, unsigned int flags)
190{
191	struct trapframe * const tf = trapframe(l);
192	const __greg_t * const gr = mcp->__gregs;
193
194	/* Restore GPR context, if any. */
195	if (flags & _UC_CPU) {
196#ifdef PPC_HAVE_FPU
197		/*
198		 * Always save the FP exception mode in the PCB.
199		 */
200		struct pcb * const pcb = lwp_getpcb(l);
201		pcb->pcb_flags &= ~(PCB_FE0|PCB_FE1);
202		pcb->pcb_flags |= gr[_REG_MSR] & (PCB_FE0|PCB_FE1);
203#endif
204
205		(void)memcpy(&tf->tf_fixreg, gr, 32 * sizeof (gr[0]));
206		tf->tf_cr   = gr[_REG_CR];
207		tf->tf_lr   = gr[_REG_LR];
208		tf->tf_srr0 = gr[_REG_PC];
209		/*
210		 * Accept all user-settable bits without complaint;
211		 * userland should not need to know the machine-specific
212		 * MSR value.
213		 */
214		tf->tf_srr1 = (gr[_REG_MSR] & PSL_USERMOD) | PSL_USERSET;
215		tf->tf_ctr  = gr[_REG_CTR];
216		tf->tf_xer  = gr[_REG_XER];
217#ifdef PPC_OEA
218		tf->tf_mq = gr[_REG_MQ];
219#endif
220	}
221
222#ifdef PPC_HAVE_FPU
223	/* Restore FPU context, if any. */
224	if (flags & _UC_FPU)
225		fpu_restore_from_mcontext(l, mcp);
226#endif
227
228#ifdef ALTIVEC
229	/* Restore AltiVec context, if any. */
230	if (flags & _UC_POWERPC_VEC)
231		vec_restore_from_mcontext(l, mcp);
232#endif
233
234#ifdef PPC_HAVE_SPE
235	/* Restore SPE context, if any. */
236	if (flags & _UC_POWERPC_SPE)
237		vec_restore_from_mcontext(l, mcp);
238#endif
239
240	return (0);
241}
242