1 /* $NetBSD: compat_16_machdep.c,v 1.2 2021/10/27 04:15:00 thorpej Exp $ */
2
3 /*-
4 * Copyright (c) 1996, 1997, 1998, 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Charles M. Hannum and by Jason R. Thorpe of the Numerical Aerospace
9 * Simulation Facility, NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 /*-
34 * Copyright (c) 1982, 1987, 1990 The Regents of the University of California.
35 * All rights reserved.
36 *
37 * This code is derived from software contributed to Berkeley by
38 * William Jolitz.
39 *
40 * Redistribution and use in source and binary forms, with or without
41 * modification, are permitted provided that the following conditions
42 * are met:
43 * 1. Redistributions of source code must retain the above copyright
44 * notice, this list of conditions and the following disclaimer.
45 * 2. Redistributions in binary form must reproduce the above copyright
46 * notice, this list of conditions and the following disclaimer in the
47 * documentation and/or other materials provided with the distribution.
48 * 3. Neither the name of the University nor the names of its contributors
49 * may be used to endorse or promote products derived from this software
50 * without specific prior written permission.
51 *
52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62 * SUCH DAMAGE.
63 *
64 * @(#)machdep.c 7.4 (Berkeley) 6/3/91
65 */
66
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: compat_16_machdep.c,v 1.2 2021/10/27 04:15:00 thorpej Exp $");
69
70 #ifdef _KERNEL_OPT
71 #include "opt_compat_netbsd.h"
72 #endif
73
74 #include <sys/param.h>
75 #include <sys/systm.h>
76 #include <sys/proc.h>
77 #include <sys/signal.h>
78 #include <sys/signalvar.h>
79 #include <sys/syscallargs.h>
80 #include <compat/sys/signal.h>
81 #include <compat/sys/signalvar.h>
82
83
84 #ifdef COMPAT_16
85 /*
86 * Stack is set up to allow sigcode stored
87 * in u. to call routine, followed by kcall
88 * to sigreturn routine below. After sigreturn
89 * resets the signal mask, the stack, and the
90 * frame pointer, it returns to the user
91 * specified pc, psl.
92 */
93 void
sendsig_sigcontext(const ksiginfo_t * ksi,const sigset_t * mask)94 sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *mask)
95 {
96 struct lwp *l = curlwp;
97 struct proc *p = l->l_proc;
98 struct sigacts *ps = p->p_sigacts;
99 struct trapframe *tf = l->l_md.md_regs;
100 int sig = ksi->ksi_info._signo;
101 sig_t catcher = SIGACTION(p, sig).sa_handler;
102 struct sigframe_sigcontext *fp, frame;
103 int onstack, error;
104
105 fp = getframe(l, sig, &onstack);
106 --fp;
107
108 /* Save register context. */
109 frame.sf_sc.sc_ssr = tf->tf_ssr;
110 frame.sf_sc.sc_spc = tf->tf_spc;
111 frame.sf_sc.sc_pr = tf->tf_pr;
112 frame.sf_sc.sc_r15 = tf->tf_r15;
113 frame.sf_sc.sc_r14 = tf->tf_r14;
114 frame.sf_sc.sc_r13 = tf->tf_r13;
115 frame.sf_sc.sc_r12 = tf->tf_r12;
116 frame.sf_sc.sc_r11 = tf->tf_r11;
117 frame.sf_sc.sc_r10 = tf->tf_r10;
118 frame.sf_sc.sc_r9 = tf->tf_r9;
119 frame.sf_sc.sc_r8 = tf->tf_r8;
120 frame.sf_sc.sc_r7 = tf->tf_r7;
121 frame.sf_sc.sc_r6 = tf->tf_r6;
122 frame.sf_sc.sc_r5 = tf->tf_r5;
123 frame.sf_sc.sc_r4 = tf->tf_r4;
124 frame.sf_sc.sc_r3 = tf->tf_r3;
125 frame.sf_sc.sc_r2 = tf->tf_r2;
126 frame.sf_sc.sc_r1 = tf->tf_r1;
127 frame.sf_sc.sc_r0 = tf->tf_r0;
128 frame.sf_sc.sc_expevt = tf->tf_expevt;
129
130 /* Save signal stack. */
131 frame.sf_sc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK;
132
133 /* Save signal mask. */
134 frame.sf_sc.sc_mask = *mask;
135
136 sendsig_reset(l, sig);
137
138 mutex_exit(p->p_lock);
139 error = copyout(&frame, fp, sizeof(frame));
140 mutex_enter(p->p_lock);
141
142 if (error != 0) {
143 /*
144 * Process has trashed its stack; give it an illegal
145 * instruction to halt it in its tracks.
146 */
147 sigexit(l, SIGILL);
148 /* NOTREACHED */
149 }
150
151 /*
152 * Build context to run handler in. We invoke the handler
153 * directly, only returning via the trampoline.
154 */
155 switch (ps->sa_sigdesc[sig].sd_vers) {
156 case __SIGTRAMP_SIGCODE_VERSION: /* legacy on-stack sigtramp */
157 tf->tf_pr = (int)p->p_sigctx.ps_sigcode;
158 break;
159
160 case __SIGTRAMP_SIGCONTEXT_VERSION:
161 tf->tf_pr = (int)ps->sa_sigdesc[sig].sd_tramp;
162 break;
163
164 default:
165 /* Don't know what trampoline version; kill it. */
166 printf("sendsig_sigcontext: bad version %d\n",
167 ps->sa_sigdesc[sig].sd_vers);
168 sigexit(l, SIGILL);
169 }
170
171 tf->tf_r4 = sig;
172 tf->tf_r5 = ksi->ksi_code;
173 tf->tf_r6 = (int)&fp->sf_sc;
174 tf->tf_spc = (int)catcher;
175 tf->tf_r15 = (int)fp;
176
177 /* Remember if we're now on the signal stack. */
178 if (onstack)
179 l->l_sigstk.ss_flags |= SS_ONSTACK;
180 }
181
182 /*
183 * System call to cleanup state after a signal
184 * has been taken. Reset signal mask and
185 * stack state from context left by sendsig (above).
186 * Return to previous pc and psl as specified by
187 * context left by sendsig. Check carefully to
188 * make sure that the user has not modified the
189 * psl to gain improper privileges or to cause
190 * a machine fault.
191 */
192 int
compat_16_sys___sigreturn14(struct lwp * l,const struct compat_16_sys___sigreturn14_args * uap,register_t * retval)193 compat_16_sys___sigreturn14(struct lwp *l, const struct compat_16_sys___sigreturn14_args *uap, register_t *retval)
194 {
195 /* {
196 syscallarg(struct sigcontext *) sigcntxp;
197 } */
198 struct sigcontext *scp, context;
199 struct trapframe *tf;
200 struct proc *p = l->l_proc;
201
202 /*
203 * The trampoline code hands us the context.
204 * It is unsafe to keep track of it ourselves, in the event that a
205 * program jumps out of a signal handler.
206 */
207 scp = SCARG(uap, sigcntxp);
208 if (copyin((void *)scp, &context, sizeof(*scp)) != 0)
209 return (EFAULT);
210
211 /* Restore signal context. */
212 tf = l->l_md.md_regs;
213
214 /* Check for security violations. */
215 if (((context.sc_ssr ^ tf->tf_ssr) & PSL_USERSTATIC) != 0)
216 return (EINVAL);
217
218 tf->tf_ssr = context.sc_ssr;
219
220 tf->tf_r0 = context.sc_r0;
221 tf->tf_r1 = context.sc_r1;
222 tf->tf_r2 = context.sc_r2;
223 tf->tf_r3 = context.sc_r3;
224 tf->tf_r4 = context.sc_r4;
225 tf->tf_r5 = context.sc_r5;
226 tf->tf_r6 = context.sc_r6;
227 tf->tf_r7 = context.sc_r7;
228 tf->tf_r8 = context.sc_r8;
229 tf->tf_r9 = context.sc_r9;
230 tf->tf_r10 = context.sc_r10;
231 tf->tf_r11 = context.sc_r11;
232 tf->tf_r12 = context.sc_r12;
233 tf->tf_r13 = context.sc_r13;
234 tf->tf_r14 = context.sc_r14;
235 tf->tf_spc = context.sc_spc;
236 tf->tf_r15 = context.sc_r15;
237 tf->tf_pr = context.sc_pr;
238
239 mutex_enter(p->p_lock);
240 /* Restore signal stack. */
241 if (context.sc_onstack & SS_ONSTACK)
242 l->l_sigstk.ss_flags |= SS_ONSTACK;
243 else
244 l->l_sigstk.ss_flags &= ~SS_ONSTACK;
245 /* Restore signal mask. */
246 (void) sigprocmask1(l, SIG_SETMASK, &context.sc_mask, 0);
247 mutex_exit(p->p_lock);
248
249 return (EJUSTRETURN);
250 }
251 #endif /* COMPAT_16 */
252