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/9.0/sys/arm/arm/undefined.c 196484 2009-08-23 23:37:53Z cognet $");
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 #endif
86
87 #ifdef KDB
88 #include <machine/db_machdep.h>
89 #endif
90
91 static int gdb_trapper(u_int, u_int, struct trapframe *, int);
92 #ifdef FAST_FPE
93 extern int want_resched;
94 #endif
95
96 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS];
97
98
99 void *
100 install_coproc_handler(int coproc, undef_handler_t handler)
101 {
102 struct undefined_handler *uh;
103
104 KASSERT(coproc >= 0 && coproc < MAX_COPROCS, ("bad coproc"));
105 KASSERT(handler != NULL, ("handler is NULL")); /* Used to be legal. */
106
107 /* XXX: M_TEMP??? */
108 uh = malloc(sizeof(*uh), M_TEMP, M_WAITOK);
109 uh->uh_handler = handler;
110 install_coproc_handler_static(coproc, uh);
111 return uh;
112 }
113
114 void
115 install_coproc_handler_static(int coproc, struct undefined_handler *uh)
116 {
117
118 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link);
119 }
120
121 void
122 remove_coproc_handler(void *cookie)
123 {
124 struct undefined_handler *uh = cookie;
125
126 LIST_REMOVE(uh, uh_link);
127 free(uh, M_TEMP);
128 }
129
130
131 static int
132 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code)
133 {
134 struct thread *td;
135 ksiginfo_t ksi;
136
137 td = (curthread == NULL) ? &thread0 : curthread;
138
139 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) {
140 if (code == FAULT_USER) {
141 ksiginfo_init_trap(&ksi);
142 ksi.ksi_signo = SIGTRAP;
143 ksi.ksi_code = TRAP_BRKPT;
144 ksi.ksi_addr = (u_int32_t *)addr;
145 trapsignal(td, &ksi);
146 return 0;
147 }
148 #if 0
149 #ifdef KGDB
150 return !kgdb_trap(T_BREAKPOINT, frame);
151 #endif
152 #endif
153 }
154 return 1;
155 }
156
157 static struct undefined_handler gdb_uh;
158
159 void
160 undefined_init()
161 {
162 int loop;
163
164 /* Not actually necessary -- the initialiser is just NULL */
165 for (loop = 0; loop < MAX_COPROCS; ++loop)
166 LIST_INIT(&undefined_handlers[loop]);
167
168 /* Install handler for GDB breakpoints */
169 gdb_uh.uh_handler = gdb_trapper;
170 install_coproc_handler_static(0, &gdb_uh);
171 }
172
173
174 void
175 undefinedinstruction(trapframe_t *frame)
176 {
177 struct thread *td;
178 u_int fault_pc;
179 int fault_instruction;
180 int fault_code;
181 int coprocessor;
182 struct undefined_handler *uh;
183 #ifdef VERBOSE_ARM32
184 int s;
185 #endif
186 ksiginfo_t ksi;
187
188 /* Enable interrupts if they were enabled before the exception. */
189 if (!(frame->tf_spsr & I32_bit))
190 enable_interrupts(I32_bit|F32_bit);
191
192 frame->tf_pc -= INSN_SIZE;
193 PCPU_INC(cnt.v_trap);
194
195 fault_pc = frame->tf_pc;
196
197 /*
198 * Get the current thread/proc structure or thread0/proc0 if there is
199 * none.
200 */
201 td = curthread == NULL ? &thread0 : curthread;
202
203 /*
204 * Make sure the program counter is correctly aligned so we
205 * don't take an alignment fault trying to read the opcode.
206 */
207 if (__predict_false((fault_pc & 3) != 0)) {
208 ksiginfo_init_trap(&ksi);
209 ksi.ksi_signo = SIGILL;
210 ksi.ksi_code = ILL_ILLADR;
211 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
212 trapsignal(td, &ksi);
213 userret(td, frame);
214 return;
215 }
216
217 /*
218 * Should use fuword() here .. but in the interests of squeezing every
219 * bit of speed we will just use ReadWord(). We know the instruction
220 * can be read as was just executed so this will never fail unless the
221 * kernel is screwed up in which case it does not really matter does
222 * it ?
223 */
224
225 fault_instruction = *(u_int32_t *)fault_pc;
226
227 /* Update vmmeter statistics */
228 #if 0
229 uvmexp.traps++;
230 #endif
231 /* Check for coprocessor instruction */
232
233 /*
234 * According to the datasheets you only need to look at bit 27 of the
235 * instruction to tell the difference between and undefined
236 * instruction and a coprocessor instruction following an undefined
237 * instruction trap.
238 */
239
240 if ((fault_instruction & (1 << 27)) != 0)
241 coprocessor = (fault_instruction >> 8) & 0x0f;
242 else
243 coprocessor = 0;
244
245 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) {
246 /*
247 * Modify the fault_code to reflect the USR/SVC state at
248 * time of fault.
249 */
250 fault_code = FAULT_USER;
251 td->td_frame = frame;
252 } else
253 fault_code = 0;
254
255 /* OK this is were we do something about the instruction. */
256 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link)
257 if (uh->uh_handler(fault_pc, fault_instruction, frame,
258 fault_code) == 0)
259 break;
260
261 if (fault_code & FAULT_USER && fault_instruction == PTRACE_BREAKPOINT) {
262 PROC_LOCK(td->td_proc);
263 _PHOLD(td->td_proc);
264 ptrace_clear_single_step(td);
265 _PRELE(td->td_proc);
266 PROC_UNLOCK(td->td_proc);
267 return;
268 }
269
270 if (uh == NULL && (fault_code & FAULT_USER)) {
271 /* Fault has not been handled */
272 ksiginfo_init_trap(&ksi);
273 ksi.ksi_signo = SIGILL;
274 ksi.ksi_code = ILL_ILLOPC;
275 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
276 trapsignal(td, &ksi);
277 }
278
279 if ((fault_code & FAULT_USER) == 0) {
280 if (fault_instruction == KERNEL_BREAKPOINT) {
281 #ifdef KDB
282 kdb_trap(T_BREAKPOINT, 0, frame);
283 #else
284 printf("No debugger in kernel.\n");
285 #endif
286 return;
287 } else
288 panic("Undefined instruction in kernel.\n");
289 }
290
291 #ifdef FAST_FPE
292 /* Optimised exit code */
293 {
294
295 /*
296 * Check for reschedule request, at the moment there is only
297 * 1 ast so this code should always be run
298 */
299
300 if (want_resched) {
301 /*
302 * We are being preempted.
303 */
304 preempt(0);
305 }
306
307 /* Invoke MI userret code */
308 mi_userret(td);
309
310 #if 0
311 l->l_priority = l->l_usrpri;
312
313 curcpu()->ci_schedstate.spc_curpriority = l->l_priority;
314 #endif
315 }
316
317 #else
318 userret(td, frame);
319 #endif
320 }
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