1 /* $NetBSD: sig_machdep.c,v 1.23 2011/07/10 23:21:59 matt Exp $ */
2
3 /*-
4 * Copyright (c) 2003 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
33
34 __KERNEL_RCSID(0, "$NetBSD: sig_machdep.c,v 1.23 2011/07/10 23:21:59 matt Exp $");
35
36 #include "opt_cputype.h"
37
38 #include <sys/param.h>
39 #include <sys/cpu.h>
40 #include <sys/kernel.h>
41 #include <sys/proc.h>
42 #include <sys/signal.h>
43 #include <sys/signalvar.h>
44 #include <sys/mount.h>
45 #include <sys/syscallargs.h>
46
47 #include <mips/frame.h>
48 #include <mips/regnum.h>
49 #include <mips/locore.h>
50
51 void *
getframe(struct lwp * l,int sig,int * onstack)52 getframe(struct lwp *l, int sig, int *onstack)
53 {
54 struct proc * const p = l->l_proc;
55 struct trapframe * const tf = l->l_md.md_utf;
56
57 /* Do we need to jump onto the signal stack? */
58 *onstack = (l->l_sigstk.ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0
59 && (SIGACTION(p, sig).sa_flags & SA_ONSTACK) != 0;
60 if (*onstack)
61 return (char *)l->l_sigstk.ss_sp + l->l_sigstk.ss_size;
62 return (void *)(intptr_t)tf->tf_regs[_R_SP];
63 }
64
65 struct sigframe_siginfo {
66 siginfo_t sf_si;
67 ucontext_t sf_uc;
68 };
69
70 /*
71 * Send a signal to process.
72 */
73 void
sendsig_siginfo(const ksiginfo_t * ksi,const sigset_t * mask)74 sendsig_siginfo(const ksiginfo_t *ksi, const sigset_t *mask)
75 {
76 struct lwp * const l = curlwp;
77 struct proc * const p = l->l_proc;
78 struct sigacts * const sa = p->p_sigacts;
79 struct trapframe * const tf = l->l_md.md_utf;
80 int onstack, error;
81 const int signo = ksi->ksi_signo;
82 struct sigframe_siginfo *sf = getframe(l, signo, &onstack);
83 struct sigframe_siginfo ksf;
84 const sig_t catcher = SIGACTION(p, signo).sa_handler;
85
86 sf--;
87
88 ksf.sf_si._info = ksi->ksi_info;
89 ksf.sf_uc.uc_flags = _UC_SIGMASK
90 | (l->l_sigstk.ss_flags & SS_ONSTACK ? _UC_SETSTACK : _UC_CLRSTACK);
91 ksf.sf_uc.uc_sigmask = *mask;
92 ksf.sf_uc.uc_link = l->l_ctxlink;
93 memset(&ksf.sf_uc.uc_stack, 0, sizeof(ksf.sf_uc.uc_stack));
94 sendsig_reset(l, signo);
95
96 mutex_exit(p->p_lock);
97 cpu_getmcontext(l, &ksf.sf_uc.uc_mcontext, &ksf.sf_uc.uc_flags);
98 error = copyout(&ksf, sf, sizeof(ksf));
99 mutex_enter(p->p_lock);
100
101 if (error != 0) {
102 /*
103 * Process has trashed its stack; give it an illegal
104 * instruction to halt it in its tracks.
105 */
106 sigexit(l, SIGILL);
107 /* NOTREACHED */
108 }
109
110 /*
111 * Set up the registers to directly invoke the signal
112 * handler. The return address will be set up to point
113 * to the signal trampoline to bounce us back.
114 */
115 tf->tf_regs[_R_A0] = signo;
116 tf->tf_regs[_R_A1] = (intptr_t)&sf->sf_si;
117 tf->tf_regs[_R_A2] = (intptr_t)&sf->sf_uc;
118
119 tf->tf_regs[_R_PC] = (intptr_t)catcher;
120 tf->tf_regs[_R_T9] = (intptr_t)catcher;
121 tf->tf_regs[_R_SP] = (intptr_t)sf;
122 tf->tf_regs[_R_RA] = (intptr_t)sa->sa_sigdesc[signo].sd_tramp;
123
124 /* Remember that we're now on the signal stack. */
125 if (onstack)
126 l->l_sigstk.ss_flags |= SS_ONSTACK;
127 }
128