xref: /netbsd/sys/arch/powerpc/powerpc/sig_machdep.c (revision 6550d01e)
1 /*	$NetBSD: sig_machdep.c,v 1.38 2011/01/18 01:02:55 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 1.38 2011/01/18 01:02:55 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  */
56 void
57 sendsig_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 = trapframe(l);
62 	struct sigaltstack *ss = &l->l_sigstk;
63 	const struct sigact_sigdesc *sd =
64 	    &p->p_sigacts->sa_sigdesc[ksi->ksi_signo];
65 	ucontext_t uc;
66 	vaddr_t sp, sip, ucp;
67 	int onstack, error;
68 
69 	/* Do we need to jump onto the signal stack? */
70 	onstack = (ss->ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
71 	    (sd->sd_sigact.sa_flags & SA_ONSTACK) != 0;
72 
73 	/* Find top of stack.  */
74 	sp = (onstack ? (vaddr_t)ss->ss_sp + ss->ss_size : tf->tf_fixreg[1]);
75 	sp &= ~(CALLFRAMELEN-1);
76 
77 	/* Allocate space for the ucontext.  */
78 	sp -= sizeof(ucontext_t);
79 	ucp = sp;
80 
81 	/* Allocate space for the siginfo.  */
82 	sp -= sizeof(siginfo_t);
83 	sip = sp;
84 
85 	sp &= ~(CALLFRAMELEN-1);
86 
87 	/* Save register context. */
88 	uc.uc_flags = _UC_SIGMASK;
89 	uc.uc_sigmask = *mask;
90 	uc.uc_link = l->l_ctxlink;
91 	memset(&uc.uc_stack, 0, sizeof(uc.uc_stack));
92 	sendsig_reset(l, ksi->ksi_signo);
93 	mutex_exit(p->p_lock);
94 	cpu_getmcontext(l, &uc.uc_mcontext, &uc.uc_flags);
95 
96 	/*
97 	 * Copy the siginfo and ucontext onto the user's stack.
98 	 */
99 	error = (copyout(&ksi->ksi_info, (void *)sip, sizeof(ksi->ksi_info)) != 0 ||
100 	    copyout(&uc, (void *)ucp, sizeof(uc)) != 0);
101 	mutex_enter(p->p_lock);
102 
103 	if (error) {
104 		/*
105 		 * Process has trashed its stack; give it an illegal
106 		 * instruction to halt it in its tracks.
107 		 */
108 		sigexit(l, SIGILL);
109 		/* NOTREACHED */
110 	}
111 
112 	/*
113 	 * Build context to run handler in.  Note the trampoline version
114 	 * numbers are coordinated with machine-dependent code in libc.
115 	 */
116 	switch (sd->sd_vers) {
117 	case 2:		/* siginfo sigtramp */
118 		tf->tf_fixreg[1]  = (register_t)sp - CALLFRAMELEN;
119 		tf->tf_fixreg[3]  = (register_t)ksi->ksi_signo;
120 		tf->tf_fixreg[4]  = (register_t)sip;
121 		tf->tf_fixreg[5]  = (register_t)ucp;
122 		/* Preserve ucp across call to signal function */
123 		tf->tf_fixreg[30] = (register_t)ucp;
124 		tf->tf_lr         = (register_t)sd->sd_tramp;
125 		tf->tf_srr0       = (register_t)sd->sd_sigact.sa_handler;
126 		break;
127 
128 	default:
129 		goto nosupport;
130 	}
131 
132 	/* Remember that we're now on the signal stack. */
133 	if (onstack)
134 		ss->ss_flags |= SS_ONSTACK;
135 	return;
136 
137  nosupport:
138 	/* Don't know what trampoline version; kill it. */
139 	printf("sendsig_siginfo(sig %d): bad version %d\n",
140 	    ksi->ksi_signo, sd->sd_vers);
141 	sigexit(l, SIGILL);
142 	/* NOTREACHED */
143 }
144 
145 void
146 cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flagp)
147 {
148 	const struct trapframe * const tf = trapframe(l);
149 	__greg_t * const gr = mcp->__gregs;
150 #if defined(PPC_HAVE_FPU)
151 	struct pcb * const pcb = lwp_getpcb(l);
152 #endif
153 
154 	/* Save GPR context. */
155 	(void)memcpy(gr, &tf->tf_fixreg, 32 * sizeof (gr[0])); /* GR0-31 */
156 	gr[_REG_CR]  = tf->tf_cr;
157 	gr[_REG_LR]  = tf->tf_lr;
158 	gr[_REG_PC]  = tf->tf_srr0;
159 	gr[_REG_MSR] = tf->tf_srr1 & PSL_USERSRR1;
160 #ifdef PPC_HAVE_FPU
161 	gr[_REG_MSR] |= pcb->pcb_flags & (PCB_FE0|PCB_FE1);
162 #endif
163 	gr[_REG_CTR] = tf->tf_ctr;
164 	gr[_REG_XER] = tf->tf_xer;
165 #ifdef PPC_OEA
166 	gr[_REG_MQ]  = tf->tf_mq;
167 #else
168 	gr[_REG_MQ]  = 0;
169 #endif
170 
171 	*flagp |= _UC_CPU;
172 
173 #ifdef PPC_HAVE_FPU
174 	/* Save FPU context, if any. */
175 	if (!fpu_save_to_mcontext(l, mcp, flagp))
176 #endif
177 		memset(&mcp->__fpregs, 0, sizeof(mcp->__fpregs));
178 
179 #if defined(ALTIVEC) || defined(PPC_HAVE_SPE)
180 	/* Save vector context, if any. */
181 	if (!vec_save_to_mcontext(l, mcp, flagp))
182 #endif
183 		memset(&mcp->__vrf, 0, sizeof (mcp->__vrf));
184 }
185 
186 int
187 cpu_setmcontext(struct lwp *l, const mcontext_t *mcp, unsigned int flags)
188 {
189 	struct trapframe * const tf = trapframe(l);
190 	const __greg_t * const gr = mcp->__gregs;
191 
192 	/* Restore GPR context, if any. */
193 	if (flags & _UC_CPU) {
194 #ifdef PPC_HAVE_FPU
195 		/*
196 		 * Always save the FP exception mode in the PCB.
197 		 */
198 		struct pcb * const pcb = lwp_getpcb(l);
199 		pcb->pcb_flags &= ~(PCB_FE0|PCB_FE1);
200 		pcb->pcb_flags |= gr[_REG_MSR] & (PCB_FE0|PCB_FE1);
201 #endif
202 
203 		(void)memcpy(&tf->tf_fixreg, gr, 32 * sizeof (gr[0]));
204 		tf->tf_cr   = gr[_REG_CR];
205 		tf->tf_lr   = gr[_REG_LR];
206 		tf->tf_srr0 = gr[_REG_PC];
207 		/*
208 		 * Accept all user-settable bits without complaint;
209 		 * userland should not need to know the machine-specific
210 		 * MSR value.
211 		 */
212 		tf->tf_srr1 = (gr[_REG_MSR] & PSL_USERMOD) | PSL_USERSET;
213 		tf->tf_ctr  = gr[_REG_CTR];
214 		tf->tf_xer  = gr[_REG_XER];
215 #ifdef PPC_OEA
216 		tf->tf_mq = gr[_REG_MQ];
217 #endif
218 	}
219 
220 #ifdef PPC_HAVE_FPU
221 	/* Restore FPU context, if any. */
222 	if (flags & _UC_FPU)
223 		fpu_restore_from_mcontext(l, mcp);
224 #endif
225 
226 #ifdef ALTIVEC
227 	/* Restore AltiVec context, if any. */
228 	if (flags & _UC_POWERPC_VEC)
229 		vec_restore_from_mcontext(l, mcp);
230 #endif
231 
232 #ifdef PPC_HAVE_SPE
233 	/* Restore SPE context, if any. */
234 	if (flags & _UC_POWERPC_SPE)
235 		vec_restore_from_mcontext(l, mcp);
236 #endif
237 
238 	return (0);
239 }
240