1 /* $NetBSD: undefined.c,v 1.22 2003/11/29 22:21:29 bjh21 Exp $ */
4 * Copyright (c) 2001 Ben Harris.
5 * Copyright (c) 1995 Mark Brinicombe.
6 * Copyright (c) 1995 Brini.
9 * This code is derived from software written for Brini by Mark Brinicombe
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
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.
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
38 * RiscBSD kernel project
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
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>
59 #include <sys/syslog.h>
60 #include <sys/vmmeter.h>
62 #include <sys/mutex.h>
63 #include <sys/signalvar.h>
64 #include <sys/ptrace.h>
65 #include <sys/vmmeter.h>
71 #include <vm/vm_extern.h>
73 #include <machine/armreg.h>
74 #include <machine/asm.h>
75 #include <machine/cpu.h>
76 #include <machine/frame.h>
77 #include <machine/undefined.h>
78 #include <machine/trap.h>
80 #include <machine/disassem.h>
83 #include <ddb/db_output.h>
87 #include <machine/db_machdep.h>
90 #define ARM_COPROC_INSN(insn) (((insn) & (1 << 27)) != 0)
91 #define ARM_VFP_INSN(insn) ((((insn) & 0xfe000000) == 0xf2000000) || \
92 (((insn) & 0xff100000) == 0xf4000000))
93 #define ARM_COPROC(insn) (((insn) >> 8) & 0xf)
95 #define THUMB_32BIT_INSN(insn) ((insn) >= 0xe800)
96 #define THUMB_COPROC_INSN(insn) (((insn) & (3 << 26)) == (3 << 26))
97 #define THUMB_COPROC_UNDEFINED(insn) (((insn) & 0x3e << 20) == 0)
98 #define THUMB_VFP_INSN(insn) (((insn) & (3 << 24)) == (3 << 24))
99 #define THUMB_COPROC(insn) (((insn) >> 8) & 0xf)
101 #define COPROC_VFP 10
103 static int gdb_trapper(u_int, u_int, struct trapframe *, int);
105 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS];
109 install_coproc_handler(int coproc, undef_handler_t handler)
111 struct undefined_handler *uh;
113 KASSERT(coproc >= 0 && coproc < MAX_COPROCS, ("bad coproc"));
114 KASSERT(handler != NULL, ("handler is NULL")); /* Used to be legal. */
117 uh = malloc(sizeof(*uh), M_TEMP, M_WAITOK);
118 uh->uh_handler = handler;
119 install_coproc_handler_static(coproc, uh);
124 install_coproc_handler_static(int coproc, struct undefined_handler *uh)
127 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link);
131 remove_coproc_handler(void *cookie)
133 struct undefined_handler *uh = cookie;
135 LIST_REMOVE(uh, uh_link);
141 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code)
146 td = (curthread == NULL) ? &thread0 : curthread;
148 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) {
149 if (code == FAULT_USER) {
150 ksiginfo_init_trap(&ksi);
151 ksi.ksi_signo = SIGTRAP;
152 ksi.ksi_code = TRAP_BRKPT;
153 ksi.ksi_addr = (u_int32_t *)addr;
154 trapsignal(td, &ksi);
159 return !kgdb_trap(T_BREAKPOINT, frame);
166 static struct undefined_handler gdb_uh;
173 /* Not actually necessary -- the initialiser is just NULL */
174 for (loop = 0; loop < MAX_COPROCS; ++loop)
175 LIST_INIT(&undefined_handlers[loop]);
177 /* Install handler for GDB breakpoints */
178 gdb_uh.uh_handler = gdb_trapper;
179 install_coproc_handler_static(0, &gdb_uh);
184 undefinedinstruction(struct trapframe *frame)
188 int fault_instruction;
191 struct undefined_handler *uh;
198 /* Enable interrupts if they were enabled before the exception. */
199 if (__predict_true(frame->tf_spsr & PSR_I) == 0)
200 enable_interrupts(PSR_I);
201 if (__predict_true(frame->tf_spsr & PSR_F) == 0)
202 enable_interrupts(PSR_F);
204 PCPU_INC(cnt.v_trap);
206 fault_pc = frame->tf_pc;
209 * Get the current thread/proc structure or thread0/proc0 if there is
212 td = curthread == NULL ? &thread0 : curthread;
215 if ((frame->tf_spsr & PSR_T) == 0) {
217 * Make sure the program counter is correctly aligned so we
218 * don't take an alignment fault trying to read the opcode.
220 if (__predict_false((fault_pc & 3) != 0)) {
221 ksiginfo_init_trap(&ksi);
222 ksi.ksi_signo = SIGILL;
223 ksi.ksi_code = ILL_ILLADR;
224 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
225 trapsignal(td, &ksi);
231 * Should use fuword() here .. but in the interests of
232 * squeezing every bit of speed we will just use ReadWord().
233 * We know the instruction can be read as was just executed
234 * so this will never fail unless the kernel is screwed up
235 * in which case it does not really matter does it ?
238 fault_instruction = *(u_int32_t *)fault_pc;
240 /* Check for coprocessor instruction */
243 * According to the datasheets you only need to look at bit
244 * 27 of the instruction to tell the difference between and
245 * undefined instruction and a coprocessor instruction
246 * following an undefined instruction trap.
249 if (ARM_COPROC_INSN(fault_instruction))
250 coprocessor = ARM_COPROC(fault_instruction);
251 else { /* check for special instructions */
252 if (ARM_VFP_INSN(fault_instruction))
253 coprocessor = COPROC_VFP; /* vfp / simd */
257 fault_instruction = *(uint16_t *)fault_pc;
258 if (THUMB_32BIT_INSN(fault_instruction)) {
259 fault_instruction <<= 16;
260 fault_instruction |= *(uint16_t *)(fault_pc + 2);
263 * Is it a Coprocessor, Advanced SIMD, or
264 * Floating-point instruction.
266 if (THUMB_COPROC_INSN(fault_instruction)) {
267 if (THUMB_COPROC_UNDEFINED(fault_instruction)) {
269 } else if (THUMB_VFP_INSN(fault_instruction))
270 coprocessor = COPROC_VFP;
273 THUMB_COPROC(fault_instruction);
278 * No support for Thumb-2 on this cpu
280 ksiginfo_init_trap(&ksi);
281 ksi.ksi_signo = SIGILL;
282 ksi.ksi_code = ILL_ILLADR;
283 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
284 trapsignal(td, &ksi);
290 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) {
292 * Modify the fault_code to reflect the USR/SVC state at
295 fault_code = FAULT_USER;
296 td->td_frame = frame;
300 /* OK this is were we do something about the instruction. */
301 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link)
302 if (uh->uh_handler(fault_pc, fault_instruction, frame,
306 if (fault_code & FAULT_USER) {
307 /* TODO: No support for ptrace from Thumb-2 */
308 if ((frame->tf_spsr & PSR_T) == 0 &&
309 fault_instruction == PTRACE_BREAKPOINT) {
310 PROC_LOCK(td->td_proc);
312 error = ptrace_clear_single_step(td);
314 PROC_UNLOCK(td->td_proc);
316 ksiginfo_init_trap(&ksi);
317 ksi.ksi_signo = SIGILL;
318 ksi.ksi_code = ILL_ILLOPC;
319 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
320 trapsignal(td, &ksi);
326 if (uh == NULL && (fault_code & FAULT_USER)) {
327 /* Fault has not been handled */
328 ksiginfo_init_trap(&ksi);
329 ksi.ksi_signo = SIGILL;
330 ksi.ksi_code = ILL_ILLOPC;
331 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
332 trapsignal(td, &ksi);
335 if ((fault_code & FAULT_USER) == 0) {
336 if (fault_instruction == KERNEL_BREAKPOINT) {
338 kdb_trap(T_BREAKPOINT, 0, frame);
340 printf("No debugger in kernel.\n");
345 panic("Undefined instruction in kernel.\n");