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/6.2/sys/arm/arm/undefined.c 156401 2006-03-07 18:08:09Z jhb $");
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/types.h>
62 #include <sys/lock.h>
63 #include <sys/mutex.h>
64 #include <sys/signalvar.h>
65 #include <sys/ptrace.h>
66 #ifdef KDB
67 #include <sys/kdb.h>
68 #endif
69 #ifdef FAST_FPE
70 #include <sys/acct.h>
71 #endif
72
73 #include <vm/vm.h>
74 #include <vm/vm_extern.h>
75
76 #include <machine/asm.h>
77 #include <machine/cpu.h>
78 #include <machine/frame.h>
79 #include <machine/undefined.h>
80 #include <machine/trap.h>
81
82 #include <machine/disassem.h>
83
84 #ifdef DDB
85 #include <ddb/db_output.h>
86 #include <machine/db_machdep.h>
87 #endif
88
89 #ifdef acorn26
90 #include <machine/machdep.h>
91 #endif
92
93 static int gdb_trapper(u_int, u_int, struct trapframe *, int);
94 #ifdef FAST_FPE
95 extern int want_resched;
96 #endif
97
98 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS];
99
100
101 void *
102 install_coproc_handler(int coproc, undef_handler_t handler)
103 {
104 struct undefined_handler *uh;
105
106 KASSERT(coproc >= 0 && coproc < MAX_COPROCS, ("bad coproc"));
107 KASSERT(handler != NULL, ("handler is NULL")); /* Used to be legal. */
108
109 /* XXX: M_TEMP??? */
110 MALLOC(uh, struct undefined_handler *, sizeof(*uh), M_TEMP, M_WAITOK);
111 uh->uh_handler = handler;
112 install_coproc_handler_static(coproc, uh);
113 return uh;
114 }
115
116 void
117 install_coproc_handler_static(int coproc, struct undefined_handler *uh)
118 {
119
120 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link);
121 }
122
123 void
124 remove_coproc_handler(void *cookie)
125 {
126 struct undefined_handler *uh = cookie;
127
128 LIST_REMOVE(uh, uh_link);
129 FREE(uh, M_TEMP);
130 }
131
132
133 static int
134 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code)
135 {
136 struct thread *td;
137 td = (curthread == NULL) ? &thread0 : curthread;
138
139 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) {
140 if (code == FAULT_USER) {
141 trapsignal(td, SIGTRAP, 0);
142 return 0;
143 }
144 #if 0
145 #ifdef KGDB
146 return !kgdb_trap(T_BREAKPOINT, frame);
147 #endif
148 #endif
149 }
150 return 1;
151 }
152
153 static struct undefined_handler gdb_uh;
154
155 void
156 undefined_init()
157 {
158 int loop;
159
160 /* Not actually necessary -- the initialiser is just NULL */
161 for (loop = 0; loop < MAX_COPROCS; ++loop)
162 LIST_INIT(&undefined_handlers[loop]);
163
164 /* Install handler for GDB breakpoints */
165 gdb_uh.uh_handler = gdb_trapper;
166 install_coproc_handler_static(0, &gdb_uh);
167 }
168
169
170 void
171 undefinedinstruction(trapframe_t *frame)
172 {
173 struct thread *td;
174 u_int fault_pc;
175 int fault_instruction;
176 int fault_code;
177 int coprocessor;
178 struct undefined_handler *uh;
179 #ifdef VERBOSE_ARM32
180 int s;
181 #endif
182
183 /* Enable interrupts if they were enabled before the exception. */
184 if (!(frame->tf_spsr & I32_bit))
185 enable_interrupts(I32_bit);
186
187 frame->tf_pc -= INSN_SIZE;
188 PCPU_LAZY_INC(cnt.v_trap);
189
190 fault_pc = frame->tf_pc;
191
192 /*
193 * Get the current thread/proc structure or thread0/proc0 if there is
194 * none.
195 */
196 td = curthread == NULL ? &thread0 : curthread;
197
198 /*
199 * Make sure the program counter is correctly aligned so we
200 * don't take an alignment fault trying to read the opcode.
201 */
202 if (__predict_false((fault_pc & 3) != 0)) {
203 trapsignal(td, SIGILL, 0);
204 userret(td, frame, 0);
205 return;
206 }
207
208 /*
209 * Should use fuword() here .. but in the interests of squeezing every
210 * bit of speed we will just use ReadWord(). We know the instruction
211 * can be read as was just executed so this will never fail unless the
212 * kernel is screwed up in which case it does not really matter does
213 * it ?
214 */
215
216 fault_instruction = *(u_int32_t *)fault_pc;
217
218 /* Update vmmeter statistics */
219 #if 0
220 uvmexp.traps++;
221 #endif
222 /* Check for coprocessor instruction */
223
224 /*
225 * According to the datasheets you only need to look at bit 27 of the
226 * instruction to tell the difference between and undefined
227 * instruction and a coprocessor instruction following an undefined
228 * instruction trap.
229 */
230
231 if ((fault_instruction & (1 << 27)) != 0)
232 coprocessor = (fault_instruction >> 8) & 0x0f;
233 else
234 coprocessor = 0;
235
236 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) {
237 /*
238 * Modify the fault_code to reflect the USR/SVC state at
239 * time of fault.
240 */
241 fault_code = FAULT_USER;
242 td->td_frame = frame;
243 } else
244 fault_code = 0;
245
246 /* OK this is were we do something about the instruction. */
247 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link)
248 if (uh->uh_handler(fault_pc, fault_instruction, frame,
249 fault_code) == 0)
250 break;
251
252 if (fault_code & FAULT_USER && fault_instruction == PTRACE_BREAKPOINT) {
253 PROC_LOCK(td->td_proc);
254 _PHOLD(td->td_proc);
255 ptrace_clear_single_step(td);
256 _PRELE(td->td_proc);
257 PROC_UNLOCK(td->td_proc);
258 return;
259 }
260
261 if (uh == NULL && (fault_code & FAULT_USER)) {
262 /* Fault has not been handled */
263 trapsignal(td, SIGILL, 0);
264 }
265
266 if ((fault_code & FAULT_USER) == 0) {
267 if (fault_instruction == KERNEL_BREAKPOINT) {
268 #ifdef KDB
269 kdb_trap(T_BREAKPOINT, 0, frame);
270 #else
271 printf("No debugger in kernel.\n");
272 #endif
273 return;
274 } else
275 panic("Undefined instruction in kernel.\n");
276 }
277
278 #ifdef FAST_FPE
279 /* Optimised exit code */
280 {
281
282 /*
283 * Check for reschedule request, at the moment there is only
284 * 1 ast so this code should always be run
285 */
286
287 if (want_resched) {
288 /*
289 * We are being preempted.
290 */
291 preempt(0);
292 }
293
294 /* Invoke MI userret code */
295 mi_userret(td);
296
297 #if 0
298 l->l_priority = l->l_usrpri;
299
300 curcpu()->ci_schedstate.spc_curpriority = l->l_priority;
301 #endif
302 }
303
304 #else
305 userret(td, frame, 0);
306 #endif
307 }
Cache object: 957b11ef24c1267241bd8cadb42216fb
|