1 /* $NetBSD: undefined.c,v 1.22 2003/11/29 22:21:29 bjh21 Exp $ */
2
3 /*-
4 * Copyright (c) 2001 Ben Harris.
5 * Copyright (c) 1995 Mark Brinicombe.
6 * Copyright (c) 1995 Brini.
7 * All rights reserved.
8 *
9 * This code is derived from software written for Brini by Mark Brinicombe
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 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by Brini.
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 BRINI ``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 BRINI 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 * RiscBSD kernel project
39 *
40 * undefined.c
41 *
42 * Fault handler
43 *
44 * Created : 06/01/95
45 */
46
47
48 #include "opt_ddb.h"
49
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD: releng/8.1/sys/arm/arm/undefined.c 184205 2008-10-23 15:53:51Z des $");
52
53 #include <sys/param.h>
54 #include <sys/malloc.h>
55 #include <sys/queue.h>
56 #include <sys/signal.h>
57 #include <sys/systm.h>
58 #include <sys/proc.h>
59 #include <sys/syslog.h>
60 #include <sys/vmmeter.h>
61 #include <sys/lock.h>
62 #include <sys/mutex.h>
63 #include <sys/signalvar.h>
64 #include <sys/ptrace.h>
65 #ifdef KDB
66 #include <sys/kdb.h>
67 #endif
68 #ifdef FAST_FPE
69 #include <sys/acct.h>
70 #endif
71
72 #include <vm/vm.h>
73 #include <vm/vm_extern.h>
74
75 #include <machine/asm.h>
76 #include <machine/cpu.h>
77 #include <machine/frame.h>
78 #include <machine/undefined.h>
79 #include <machine/trap.h>
80
81 #include <machine/disassem.h>
82
83 #ifdef DDB
84 #include <ddb/db_output.h>
85 #include <machine/db_machdep.h>
86 #endif
87
88 #ifdef acorn26
89 #include <machine/machdep.h>
90 #endif
91
92 static int gdb_trapper(u_int, u_int, struct trapframe *, int);
93 #ifdef FAST_FPE
94 extern int want_resched;
95 #endif
96
97 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS];
98
99
100 void *
101 install_coproc_handler(int coproc, undef_handler_t handler)
102 {
103 struct undefined_handler *uh;
104
105 KASSERT(coproc >= 0 && coproc < MAX_COPROCS, ("bad coproc"));
106 KASSERT(handler != NULL, ("handler is NULL")); /* Used to be legal. */
107
108 /* XXX: M_TEMP??? */
109 uh = malloc(sizeof(*uh), M_TEMP, M_WAITOK);
110 uh->uh_handler = handler;
111 install_coproc_handler_static(coproc, uh);
112 return uh;
113 }
114
115 void
116 install_coproc_handler_static(int coproc, struct undefined_handler *uh)
117 {
118
119 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link);
120 }
121
122 void
123 remove_coproc_handler(void *cookie)
124 {
125 struct undefined_handler *uh = cookie;
126
127 LIST_REMOVE(uh, uh_link);
128 free(uh, M_TEMP);
129 }
130
131
132 static int
133 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code)
134 {
135 struct thread *td;
136 ksiginfo_t ksi;
137
138 td = (curthread == NULL) ? &thread0 : curthread;
139
140 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) {
141 if (code == FAULT_USER) {
142 ksiginfo_init_trap(&ksi);
143 ksi.ksi_signo = SIGTRAP;
144 ksi.ksi_code = TRAP_BRKPT;
145 ksi.ksi_addr = (u_int32_t *)addr;
146 trapsignal(td, &ksi);
147 return 0;
148 }
149 #if 0
150 #ifdef KGDB
151 return !kgdb_trap(T_BREAKPOINT, frame);
152 #endif
153 #endif
154 }
155 return 1;
156 }
157
158 static struct undefined_handler gdb_uh;
159
160 void
161 undefined_init()
162 {
163 int loop;
164
165 /* Not actually necessary -- the initialiser is just NULL */
166 for (loop = 0; loop < MAX_COPROCS; ++loop)
167 LIST_INIT(&undefined_handlers[loop]);
168
169 /* Install handler for GDB breakpoints */
170 gdb_uh.uh_handler = gdb_trapper;
171 install_coproc_handler_static(0, &gdb_uh);
172 }
173
174
175 void
176 undefinedinstruction(trapframe_t *frame)
177 {
178 struct thread *td;
179 u_int fault_pc;
180 int fault_instruction;
181 int fault_code;
182 int coprocessor;
183 struct undefined_handler *uh;
184 #ifdef VERBOSE_ARM32
185 int s;
186 #endif
187 ksiginfo_t ksi;
188
189 /* Enable interrupts if they were enabled before the exception. */
190 if (!(frame->tf_spsr & I32_bit))
191 enable_interrupts(I32_bit|F32_bit);
192
193 frame->tf_pc -= INSN_SIZE;
194 PCPU_INC(cnt.v_trap);
195
196 fault_pc = frame->tf_pc;
197
198 /*
199 * Get the current thread/proc structure or thread0/proc0 if there is
200 * none.
201 */
202 td = curthread == NULL ? &thread0 : curthread;
203
204 /*
205 * Make sure the program counter is correctly aligned so we
206 * don't take an alignment fault trying to read the opcode.
207 */
208 if (__predict_false((fault_pc & 3) != 0)) {
209 ksiginfo_init_trap(&ksi);
210 ksi.ksi_signo = SIGILL;
211 ksi.ksi_code = ILL_ILLADR;
212 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
213 trapsignal(td, &ksi);
214 userret(td, frame);
215 return;
216 }
217
218 /*
219 * Should use fuword() here .. but in the interests of squeezing every
220 * bit of speed we will just use ReadWord(). We know the instruction
221 * can be read as was just executed so this will never fail unless the
222 * kernel is screwed up in which case it does not really matter does
223 * it ?
224 */
225
226 fault_instruction = *(u_int32_t *)fault_pc;
227
228 /* Update vmmeter statistics */
229 #if 0
230 uvmexp.traps++;
231 #endif
232 /* Check for coprocessor instruction */
233
234 /*
235 * According to the datasheets you only need to look at bit 27 of the
236 * instruction to tell the difference between and undefined
237 * instruction and a coprocessor instruction following an undefined
238 * instruction trap.
239 */
240
241 if ((fault_instruction & (1 << 27)) != 0)
242 coprocessor = (fault_instruction >> 8) & 0x0f;
243 else
244 coprocessor = 0;
245
246 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) {
247 /*
248 * Modify the fault_code to reflect the USR/SVC state at
249 * time of fault.
250 */
251 fault_code = FAULT_USER;
252 td->td_frame = frame;
253 } else
254 fault_code = 0;
255
256 /* OK this is were we do something about the instruction. */
257 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link)
258 if (uh->uh_handler(fault_pc, fault_instruction, frame,
259 fault_code) == 0)
260 break;
261
262 if (fault_code & FAULT_USER && fault_instruction == PTRACE_BREAKPOINT) {
263 PROC_LOCK(td->td_proc);
264 _PHOLD(td->td_proc);
265 ptrace_clear_single_step(td);
266 _PRELE(td->td_proc);
267 PROC_UNLOCK(td->td_proc);
268 return;
269 }
270
271 if (uh == NULL && (fault_code & FAULT_USER)) {
272 /* Fault has not been handled */
273 ksiginfo_init_trap(&ksi);
274 ksi.ksi_signo = SIGILL;
275 ksi.ksi_code = ILL_ILLOPC;
276 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
277 trapsignal(td, &ksi);
278 }
279
280 if ((fault_code & FAULT_USER) == 0) {
281 if (fault_instruction == KERNEL_BREAKPOINT) {
282 #ifdef KDB
283 kdb_trap(T_BREAKPOINT, 0, frame);
284 #else
285 printf("No debugger in kernel.\n");
286 #endif
287 return;
288 } else
289 panic("Undefined instruction in kernel.\n");
290 }
291
292 #ifdef FAST_FPE
293 /* Optimised exit code */
294 {
295
296 /*
297 * Check for reschedule request, at the moment there is only
298 * 1 ast so this code should always be run
299 */
300
301 if (want_resched) {
302 /*
303 * We are being preempted.
304 */
305 preempt(0);
306 }
307
308 /* Invoke MI userret code */
309 mi_userret(td);
310
311 #if 0
312 l->l_priority = l->l_usrpri;
313
314 curcpu()->ci_schedstate.spc_curpriority = l->l_priority;
315 #endif
316 }
317
318 #else
319 userret(td, frame);
320 #endif
321 }
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