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>
70 #include <vm/vm_extern.h>
72 #include <machine/armreg.h>
73 #include <machine/asm.h>
74 #include <machine/cpu.h>
75 #include <machine/frame.h>
76 #include <machine/undefined.h>
77 #include <machine/trap.h>
79 #include <machine/disassem.h>
82 #include <ddb/db_output.h>
86 #include <machine/db_machdep.h>
89 #define ARM_COPROC_INSN(insn) (((insn) & (1 << 27)) != 0)
90 #define ARM_VFP_INSN(insn) ((((insn) & 0xfe000000) == 0xf2000000) || \
91 (((insn) & 0xff100000) == 0xf4000000))
92 #define ARM_COPROC(insn) (((insn) >> 8) & 0xf)
94 #define THUMB_32BIT_INSN(insn) ((insn) >= 0xe800)
95 #define THUMB_COPROC_INSN(insn) (((insn) & (3 << 26)) == (3 << 26))
96 #define THUMB_COPROC_UNDEFINED(insn) (((insn) & 0x3e << 20) == 0)
97 #define THUMB_VFP_INSN(insn) (((insn) & (3 << 24)) == (3 << 24))
98 #define THUMB_COPROC(insn) (((insn) >> 8) & 0xf)
100 #define COPROC_VFP 10
102 static int gdb_trapper(u_int, u_int, struct trapframe *, int);
104 LIST_HEAD(, undefined_handler) undefined_handlers[MAX_COPROCS];
108 install_coproc_handler(int coproc, undef_handler_t handler)
110 struct undefined_handler *uh;
112 KASSERT(coproc >= 0 && coproc < MAX_COPROCS, ("bad coproc"));
113 KASSERT(handler != NULL, ("handler is NULL")); /* Used to be legal. */
116 uh = malloc(sizeof(*uh), M_TEMP, M_WAITOK);
117 uh->uh_handler = handler;
118 install_coproc_handler_static(coproc, uh);
123 install_coproc_handler_static(int coproc, struct undefined_handler *uh)
126 LIST_INSERT_HEAD(&undefined_handlers[coproc], uh, uh_link);
130 remove_coproc_handler(void *cookie)
132 struct undefined_handler *uh = cookie;
134 LIST_REMOVE(uh, uh_link);
140 gdb_trapper(u_int addr, u_int insn, struct trapframe *frame, int code)
145 td = (curthread == NULL) ? &thread0 : curthread;
147 if (insn == GDB_BREAKPOINT || insn == GDB5_BREAKPOINT) {
148 if (code == FAULT_USER) {
149 ksiginfo_init_trap(&ksi);
150 ksi.ksi_signo = SIGTRAP;
151 ksi.ksi_code = TRAP_BRKPT;
152 ksi.ksi_addr = (u_int32_t *)addr;
153 trapsignal(td, &ksi);
158 return !kgdb_trap(T_BREAKPOINT, frame);
165 static struct undefined_handler gdb_uh;
172 /* Not actually necessary -- the initialiser is just NULL */
173 for (loop = 0; loop < MAX_COPROCS; ++loop)
174 LIST_INIT(&undefined_handlers[loop]);
176 /* Install handler for GDB breakpoints */
177 gdb_uh.uh_handler = gdb_trapper;
178 install_coproc_handler_static(0, &gdb_uh);
183 undefinedinstruction(struct trapframe *frame)
187 int fault_instruction;
190 struct undefined_handler *uh;
197 /* Enable interrupts if they were enabled before the exception. */
198 if (__predict_true(frame->tf_spsr & PSR_I) == 0)
199 enable_interrupts(PSR_I);
200 if (__predict_true(frame->tf_spsr & PSR_F) == 0)
201 enable_interrupts(PSR_F);
203 PCPU_INC(cnt.v_trap);
205 fault_pc = frame->tf_pc;
208 * Get the current thread/proc structure or thread0/proc0 if there is
211 td = curthread == NULL ? &thread0 : curthread;
214 if ((frame->tf_spsr & PSR_T) == 0) {
216 * Make sure the program counter is correctly aligned so we
217 * don't take an alignment fault trying to read the opcode.
219 if (__predict_false((fault_pc & 3) != 0)) {
220 ksiginfo_init_trap(&ksi);
221 ksi.ksi_signo = SIGILL;
222 ksi.ksi_code = ILL_ILLADR;
223 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
224 trapsignal(td, &ksi);
230 * Should use fuword() here .. but in the interests of
231 * squeezing every bit of speed we will just use ReadWord().
232 * We know the instruction can be read as was just executed
233 * so this will never fail unless the kernel is screwed up
234 * in which case it does not really matter does it ?
237 fault_instruction = *(u_int32_t *)fault_pc;
239 /* Check for coprocessor instruction */
242 * According to the datasheets you only need to look at bit
243 * 27 of the instruction to tell the difference between and
244 * undefined instruction and a coprocessor instruction
245 * following an undefined instruction trap.
248 if (ARM_COPROC_INSN(fault_instruction))
249 coprocessor = ARM_COPROC(fault_instruction);
250 else { /* check for special instructions */
251 if (ARM_VFP_INSN(fault_instruction))
252 coprocessor = COPROC_VFP; /* vfp / simd */
256 fault_instruction = *(uint16_t *)fault_pc;
257 if (THUMB_32BIT_INSN(fault_instruction)) {
258 fault_instruction <<= 16;
259 fault_instruction |= *(uint16_t *)(fault_pc + 2);
262 * Is it a Coprocessor, Advanced SIMD, or
263 * Floating-point instruction.
265 if (THUMB_COPROC_INSN(fault_instruction)) {
266 if (THUMB_COPROC_UNDEFINED(fault_instruction)) {
268 } else if (THUMB_VFP_INSN(fault_instruction))
269 coprocessor = COPROC_VFP;
272 THUMB_COPROC(fault_instruction);
277 * No support for Thumb-2 on this cpu
279 ksiginfo_init_trap(&ksi);
280 ksi.ksi_signo = SIGILL;
281 ksi.ksi_code = ILL_ILLADR;
282 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
283 trapsignal(td, &ksi);
289 if ((frame->tf_spsr & PSR_MODE) == PSR_USR32_MODE) {
291 * Modify the fault_code to reflect the USR/SVC state at
294 fault_code = FAULT_USER;
295 td->td_frame = frame;
299 /* OK this is were we do something about the instruction. */
300 LIST_FOREACH(uh, &undefined_handlers[coprocessor], uh_link)
301 if (uh->uh_handler(fault_pc, fault_instruction, frame,
305 if (fault_code & FAULT_USER) {
306 /* TODO: No support for ptrace from Thumb-2 */
307 if ((frame->tf_spsr & PSR_T) == 0 &&
308 fault_instruction == PTRACE_BREAKPOINT) {
309 PROC_LOCK(td->td_proc);
311 error = ptrace_clear_single_step(td);
313 PROC_UNLOCK(td->td_proc);
315 ksiginfo_init_trap(&ksi);
316 ksi.ksi_signo = SIGILL;
317 ksi.ksi_code = ILL_ILLOPC;
318 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
319 trapsignal(td, &ksi);
325 if (uh == NULL && (fault_code & FAULT_USER)) {
326 /* Fault has not been handled */
327 ksiginfo_init_trap(&ksi);
328 ksi.ksi_signo = SIGILL;
329 ksi.ksi_code = ILL_ILLOPC;
330 ksi.ksi_addr = (u_int32_t *)(intptr_t) fault_pc;
331 trapsignal(td, &ksi);
334 if ((fault_code & FAULT_USER) == 0) {
335 if (fault_instruction == KERNEL_BREAKPOINT) {
337 kdb_trap(T_BREAKPOINT, 0, frame);
339 printf("No debugger in kernel.\n");
344 panic("Undefined instruction in kernel.\n");