1 /* $NetBSD: compat_16_machdep.c,v 1.21 2023/03/04 08:52:19 skrll Exp $ */
2
3 /*
4 * Copyright (c) 1994-1998 Mark Brinicombe.
5 * Copyright (c) 1994 Brini.
6 * All rights reserved.
7 *
8 * This code is derived from software written for Brini by Mark Brinicombe
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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by Mark Brinicombe
21 * for the NetBSD Project.
22 * 4. The name of the company nor the name of the author may be used to
23 * endorse or promote products derived from this software without specific
24 * prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
27 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
28 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29 * IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
30 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
31 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 *
38 * Machine dependent functions for kernel setup
39 *
40 * Created : 17/09/94
41 */
42
43
44 #include <sys/cdefs.h>
45 __KERNEL_RCSID(0, "$NetBSD: compat_16_machdep.c,v 1.21 2023/03/04 08:52:19 skrll Exp $");
46
47 #ifdef _KERNEL_OPT
48 #include "opt_compat_netbsd.h"
49 #include "opt_armfpe.h"
50 #endif
51
52 #include <sys/param.h>
53 #include <sys/mount.h> /* XXX only needed by syscallargs.h */
54 #include <sys/proc.h>
55 #include <sys/signal.h>
56 #include <sys/syscallargs.h>
57 #include <sys/systm.h>
58 #include <sys/ras.h>
59 #include <sys/ucontext.h>
60
61 #include <arm/armreg.h>
62 #include <arm/locore.h>
63
64 #include <machine/cpu.h>
65 #include <machine/frame.h>
66 #include <arm/cpufunc.h>
67
68 /*
69 * Send an interrupt to process.
70 *
71 * Stack is set up to allow sigcode stored
72 * in u. to call routine, followed by kcall
73 * to sigreturn routine below. After sigreturn
74 * resets the signal mask, the stack, and the
75 * frame pointer, it returns to the user specified pc.
76 */
77 #if defined(COMPAT_16) || defined(COMPAT_13)
78
79 #include <compat/sys/signal.h>
80 #include <compat/sys/signalvar.h>
81
82 void
sendsig_sigcontext(const ksiginfo_t * ksi,const sigset_t * mask)83 sendsig_sigcontext(const ksiginfo_t *ksi, const sigset_t *mask)
84 {
85 struct lwp * const l = curlwp;
86 struct proc * const p = l->l_proc;
87 struct sigacts * const ps = p->p_sigacts;
88 struct trapframe * const tf = lwp_trapframe(l);
89 struct sigframe_sigcontext *fp, frame;
90 int onstack, error;
91 int sig = ksi->ksi_signo;
92 u_long code = KSI_TRAPCODE(ksi);
93 sig_t catcher = SIGACTION(p, sig).sa_handler;
94
95 fp = getframe(l, sig, &onstack);
96
97 /* make room on the stack */
98 fp--;
99
100 /* make the stack aligned */
101 fp = (void *)STACK_ALIGN(fp, STACK_ALIGNBYTES);
102
103 /* Save register context. */
104 frame.sf_sc.sc_r0 = tf->tf_r0;
105 frame.sf_sc.sc_r1 = tf->tf_r1;
106 frame.sf_sc.sc_r2 = tf->tf_r2;
107 frame.sf_sc.sc_r3 = tf->tf_r3;
108 frame.sf_sc.sc_r4 = tf->tf_r4;
109 frame.sf_sc.sc_r5 = tf->tf_r5;
110 frame.sf_sc.sc_r6 = tf->tf_r6;
111 frame.sf_sc.sc_r7 = tf->tf_r7;
112 frame.sf_sc.sc_r8 = tf->tf_r8;
113 frame.sf_sc.sc_r9 = tf->tf_r9;
114 frame.sf_sc.sc_r10 = tf->tf_r10;
115 frame.sf_sc.sc_r11 = tf->tf_r11;
116 frame.sf_sc.sc_r12 = tf->tf_r12;
117 frame.sf_sc.sc_usr_sp = tf->tf_usr_sp;
118 frame.sf_sc.sc_usr_lr = tf->tf_usr_lr;
119 frame.sf_sc.sc_svc_lr = tf->tf_svc_lr;
120 frame.sf_sc.sc_pc = tf->tf_pc;
121 frame.sf_sc.sc_spsr = tf->tf_spsr;
122
123 /* Save signal stack. */
124 frame.sf_sc.sc_onstack = l->l_sigstk.ss_flags & SS_ONSTACK;
125
126 /* Save signal mask. */
127 frame.sf_sc.sc_mask = *mask;
128
129 #ifdef COMPAT_13
130 /*
131 * XXX We always have to save an old style signal mask because
132 * XXX we might be delivering a signal to a process which will
133 * XXX escape from the signal in a non-standard way and invoke
134 * XXX sigreturn() directly.
135 */
136 native_sigset_to_sigset13(mask, &frame.sf_sc.__sc_mask13);
137 #endif
138
139 sendsig_reset(l, sig);
140 mutex_exit(p->p_lock);
141 error = copyout(&frame, fp, sizeof(frame));
142 mutex_enter(p->p_lock);
143
144 if (error != 0) {
145 /*
146 * Process has trashed its stack; give it an illegal
147 * instruction to halt it in its tracks.
148 */
149 sigexit(l, SIGILL);
150 /* NOTREACHED */
151 }
152
153 /*
154 * Build context to run handler in. We invoke the handler
155 * directly, only returning via the trampoline. Note the
156 * trampoline version numbers are coordinated with machine-
157 * dependent code in libc.
158 */
159
160 /*
161 * this was all in the switch below, seemed daft to duplicate it, if
162 * we do a new trampoline version it might change then
163 */
164 tf->tf_r0 = sig;
165 tf->tf_r1 = code;
166 tf->tf_r2 = (int)&fp->sf_sc;
167 tf->tf_pc = (int)catcher;
168 #ifdef THUMB_CODE
169 if (((int) catcher) & 1)
170 tf->tf_spsr |= PSR_T_bit;
171 else
172 tf->tf_spsr &= ~PSR_T_bit;
173 #endif
174 tf->tf_usr_sp = (int)fp;
175
176 switch (ps->sa_sigdesc[sig].sd_vers) {
177 case __SIGTRAMP_SIGCODE_VERSION: /* legacy on-stack sigtramp */
178 tf->tf_usr_lr = (int)p->p_sigctx.ps_sigcode;
179 /* XXX This should not be needed. */
180 cpu_icache_sync_all();
181 break;
182 case __SIGTRAMP_SIGCONTEXT_VERSION:
183 tf->tf_usr_lr = (int)ps->sa_sigdesc[sig].sd_tramp;
184 break;
185
186 default:
187 /* Don't know what trampoline version; kill it. */
188 sigexit(l, SIGILL);
189 }
190
191 /* Remember that we're now on the signal stack. */
192 if (onstack)
193 l->l_sigstk.ss_flags |= SS_ONSTACK;
194 }
195
196 /*
197 * System call to cleanup state after a signal
198 * has been taken. Reset signal mask and
199 * stack state from context left by sendsig (above).
200 * Return to previous pc and psl as specified by
201 * context left by sendsig. Check carefully to
202 * make sure that the user has not modified the
203 * psr to gain improper privileges or to cause
204 * a machine fault.
205 */
206
207 int
compat_16_sys___sigreturn14(struct lwp * l,const struct compat_16_sys___sigreturn14_args * uap,register_t * retval)208 compat_16_sys___sigreturn14(struct lwp *l, const struct compat_16_sys___sigreturn14_args *uap, register_t *retval)
209 {
210 /* {
211 syscallarg(struct sigcontext *) sigcntxp;
212 } */
213 struct trapframe * const tf = lwp_trapframe(l);
214 struct proc * const p = l->l_proc;
215 struct sigcontext *scp, context;
216
217 /*
218 * we do a rather scary test in userland
219 */
220 if (uap == NULL)
221 return (EFAULT);
222
223 /*
224 * The trampoline code hands us the context.
225 * It is unsafe to keep track of it ourselves, in the event that a
226 * program jumps out of a signal handler.
227 */
228 scp = SCARG(uap, sigcntxp);
229 if (copyin((void *)scp, &context, sizeof(*scp)) != 0)
230 return (EFAULT);
231
232 /*
233 * Make sure the processor mode has not been tampered with and
234 * interrupts have not been disabled.
235 */
236 if (!VALID_PSR(context.sc_spsr))
237 return EINVAL;
238
239 /* Restore register context. */
240 tf->tf_r0 = context.sc_r0;
241 tf->tf_r1 = context.sc_r1;
242 tf->tf_r2 = context.sc_r2;
243 tf->tf_r3 = context.sc_r3;
244 tf->tf_r4 = context.sc_r4;
245 tf->tf_r5 = context.sc_r5;
246 tf->tf_r6 = context.sc_r6;
247 tf->tf_r7 = context.sc_r7;
248 tf->tf_r8 = context.sc_r8;
249 tf->tf_r9 = context.sc_r9;
250 tf->tf_r10 = context.sc_r10;
251 tf->tf_r11 = context.sc_r11;
252 tf->tf_r12 = context.sc_r12;
253 tf->tf_usr_sp = context.sc_usr_sp;
254 tf->tf_usr_lr = context.sc_usr_lr;
255 tf->tf_svc_lr = context.sc_svc_lr;
256 tf->tf_pc = context.sc_pc;
257 tf->tf_spsr = context.sc_spsr;
258
259 mutex_enter(p->p_lock);
260
261 /* Restore signal stack. */
262 if (context.sc_onstack & SS_ONSTACK)
263 l->l_sigstk.ss_flags |= SS_ONSTACK;
264 else
265 l->l_sigstk.ss_flags &= ~SS_ONSTACK;
266
267 /* Restore signal mask. */
268 (void) sigprocmask1(l, SIG_SETMASK, &context.sc_mask, 0);
269
270 mutex_exit(p->p_lock);
271
272 return (EJUSTRETURN);
273 }
274 #endif
275