1 /* $NetBSD: sig_machdep.c,v 1.27 2024/05/17 21:37:07 thorpej Exp $ */
2
3 /*
4 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * Changed for the VAX port (and for readability) /IC
8 *
9 * This code is derived from software contributed to Berkeley by the Systems
10 * Programming Group of the University of Utah Computer Science Department.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * from: Utah Hdr: machdep.c 1.63 91/04/24
37 *
38 * @(#)machdep.c 7.16 (Berkeley) 6/3/91
39 */
40
41 /*
42 * Copyright (c) 2002, Hugh Graham.
43 * Copyright (c) 1994, 1998 Ludd, University of Lule}, Sweden.
44 * Copyright (c) 1993 Adam Glass
45 * Copyright (c) 1988 University of Utah.
46 *
47 * Changed for the VAX port (and for readability) /IC
48 *
49 * This code is derived from software contributed to Berkeley by the Systems
50 * Programming Group of the University of Utah Computer Science Department.
51 *
52 * Redistribution and use in source and binary forms, with or without
53 * modification, are permitted provided that the following conditions
54 * are met:
55 * 1. Redistributions of source code must retain the above copyright
56 * notice, this list of conditions and the following disclaimer.
57 * 2. Redistributions in binary form must reproduce the above copyright
58 * notice, this list of conditions and the following disclaimer in the
59 * documentation and/or other materials provided with the distribution.
60 * 3. Neither the name of the University nor the names of its contributors
61 * may be used to endorse or promote products derived from this software
62 * without specific prior written permission.
63 *
64 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
65 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
66 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
67 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
68 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
69 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
70 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
71 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
72 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
73 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
74 * SUCH DAMAGE.
75 *
76 * from: Utah Hdr: machdep.c 1.63 91/04/24
77 *
78 * @(#)machdep.c 7.16 (Berkeley) 6/3/91
79 */
80
81 #include <sys/cdefs.h>
82 __KERNEL_RCSID(0, "$NetBSD: sig_machdep.c,v 1.27 2024/05/17 21:37:07 thorpej Exp $");
83
84 #include "opt_ddb.h"
85 #include "opt_compat_netbsd.h"
86 #include "opt_compat_ultrix.h"
87 #include "opt_multiprocessor.h"
88 #include "opt_lockdebug.h"
89
90 #include <sys/param.h>
91 #include <sys/systm.h>
92 #include <sys/cpu.h>
93 #include <sys/proc.h>
94 #include <sys/signal.h>
95
96 #include <machine/macros.h>
97 #include <machine/reg.h>
98
99 #ifdef DDB
100 #include <machine/db_machdep.h>
101 #include <ddb/db_sym.h>
102 #include <ddb/db_extern.h>
103 #endif
104
105 typedef vaddr_t (*sig_setupstack_t)(const struct ksiginfo *, const sigset_t *,
106 int, struct lwp *, struct trapframe *, vaddr_t, int, vaddr_t);
107
108 static vaddr_t setupstack_siginfo3(const struct ksiginfo *, const sigset_t *,
109 int, struct lwp *, struct trapframe *, vaddr_t, int, vaddr_t);
110
111 const static sig_setupstack_t sig_setupstacks[] = {
112 #if defined(COMPAT_13) || defined(COMPAT_ULTRIX)
113 setupstack_oldsigcontext, /* 0 */
114 setupstack_oldsigcontext, /* 1 */
115 #else
116 0, /* 0 */
117 0, /* 1 */
118 #endif
119 #if defined(COMPAT_16) || defined(COMPAT_ULTRIX)
120 setupstack_sigcontext2, /* 2 */
121 #else
122 0, /* 2 */
123 #endif
124 setupstack_siginfo3, /* 3 */
125 };
126
127 /*
128 * Brief description of how sendsig() works:
129 * A struct sigcontext is allocated on the user stack. The relevant
130 * registers are saved in it. Below it is a struct trampframe constructed, it
131 * is actually an argument list for callg. The user
132 * stack pointer is put below all structs.
133 *
134 * The registers will contain when the signal handler is called:
135 * pc, psl - Obvious
136 * sp - An address below all structs
137 * fp - The address of the signal handler
138 * ap - The address to the callg frame
139 *
140 * The trampoline code will save r0-r5 before doing anything else.
141 */
142 struct trampoline3 {
143 unsigned int narg; /* Argument count (== 3) */
144 int sig; /* Signal number */
145 vaddr_t sip; /* Pointer to siginfo_t */
146 vaddr_t ucp; /* Pointer to ucontext_t */
147 };
148
149 static vaddr_t
setupstack_siginfo3(const struct ksiginfo * ksi,const sigset_t * mask,int vers,struct lwp * l,struct trapframe * tf,vaddr_t sp,int onstack,vaddr_t handler)150 setupstack_siginfo3(const struct ksiginfo *ksi, const sigset_t *mask, int vers,
151 struct lwp *l, struct trapframe *tf, vaddr_t sp, int onstack,
152 vaddr_t handler)
153 {
154 struct trampoline3 tramp;
155 struct proc * const p = l->l_proc;
156 ucontext_t uc;
157 bool error;
158
159 /*
160 * Arguments given to the signal handler.
161 */
162 memset(&tramp, 0, sizeof(tramp));
163 tramp.narg = 3;
164 tramp.sig = ksi->ksi_signo;
165 sp -= sizeof(uc); tramp.ucp = sp;
166 sp -= sizeof(siginfo_t); tramp.sip = sp;
167 sp -= sizeof(tramp);
168
169 /* Save register context. */
170 memset(&uc, 0, sizeof(uc));
171 uc.uc_flags = _UC_SIGMASK;
172 uc.uc_sigmask = *mask;
173 uc.uc_link = l->l_ctxlink;
174 uc.uc_flags |= (l->l_sigstk.ss_flags & SS_ONSTACK)
175 ? _UC_SETSTACK : _UC_CLRSTACK;
176 sendsig_reset(l, ksi->ksi_signo);
177 mutex_exit(p->p_lock);
178 cpu_getmcontext(l, &uc.uc_mcontext, &uc.uc_flags);
179
180 tf->tf_fp = handler;
181
182 /* Copy the context to the stack. */
183 error = (copyout(&uc, (char *)tramp.ucp, sizeof(uc)) != 0 ||
184 copyout(&ksi->ksi_info, (char *)tramp.sip, sizeof(ksi->ksi_info)) != 0 ||
185 copyout(&tramp, (char *)sp, sizeof(tramp)) != 0);
186
187 mutex_enter(p->p_lock);
188 if (error)
189 sigexit(l, SIGILL);
190
191 return sp;
192 };
193
194 void
sendsig_sighelper(const ksiginfo_t * ksi,const sigset_t * mask)195 sendsig_sighelper(const ksiginfo_t *ksi, const sigset_t *mask)
196 {
197 struct lwp * const l = curlwp;
198 struct proc * const p = l->l_proc;
199 struct trapframe * const tf = l->l_md.md_utf;
200 stack_t * const ss = &l->l_sigstk;
201 const struct sigact_sigdesc * const sd =
202 &p->p_sigacts->sa_sigdesc[ksi->ksi_signo];
203 vaddr_t sp;
204 int onstack;
205 sig_setupstack_t setup;
206
207 /* Figure what stack we are running on. */
208 onstack = (ss->ss_flags & (SS_DISABLE | SS_ONSTACK)) == 0 &&
209 (sd->sd_sigact.sa_flags & SA_ONSTACK) != 0;
210 sp = onstack ? ((vaddr_t)ss->ss_sp + ss->ss_size) : tf->tf_sp;
211
212 if (sd->sd_vers > __SIGTRAMP_SIGINFO_VERSION ||
213 (setup = sig_setupstacks[sd->sd_vers]) == NULL)
214 goto nosupport;
215
216 sp = (*setup)(ksi, mask, sd->sd_vers, l, tf, sp, onstack,
217 (vaddr_t)sd->sd_sigact.sa_handler);
218 if (sp == 0)
219 goto nosupport;
220
221 if (sd->sd_vers == 0)
222 tf->tf_pc = (register_t)p->p_sigctx.ps_sigcode;
223 else
224 tf->tf_pc = (register_t)sd->sd_tramp;
225
226 tf->tf_psl = PSL_U | PSL_PREVU;
227 tf->tf_sp = sp;
228 tf->tf_ap = sp;
229
230 if (onstack)
231 ss->ss_flags |= SS_ONSTACK;
232 return;
233
234 nosupport:
235 /* Don't know what trampoline version; kill it. */
236 printf("sendsig(sig %d): bad version %d\n",
237 ksi->ksi_signo, sd->sd_vers);
238 sigexit(l, SIGILL);
239 }
240