2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
16 * Carnegie Mellon requests users of this software to return to
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
26 * $FreeBSD: src/sys/i386/i386/db_interface.c,v 1.48.2.1 2000/07/07 00:38:46 obrien Exp $
27 * $DragonFly: src/sys/platform/pc32/i386/db_interface.c,v 1.2 2003/06/17 04:28:35 dillon Exp $
31 * Interface to new debugger.
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/reboot.h>
38 #include <machine/cpu.h>
40 #include <machine/smp.h>
41 #include <machine/smptests.h> /** CPUSTOP_ON_DDBBREAK */
51 static jmp_buf *db_nofault = 0;
52 extern jmp_buf db_jmpbuf;
54 extern void gdb_handle_exception __P((db_regs_t *, int, int));
59 static jmp_buf db_global_jmpbuf;
60 static int db_global_jmpbuf_valid;
63 #define rss() ({u_short ss; __asm __volatile("mov %%ss,%0" : "=r" (ss)); ss;})
67 * kdb_trap - field a TRACE or BPT trap
70 kdb_trap(type, code, regs)
72 register struct i386_saved_state *regs;
74 volatile int ddb_mode = !(boothowto & RB_GDB);
77 * XXX try to do nothing if the console is in graphics mode.
78 * Handle trace traps (and hardware breakpoints...) by ignoring
79 * them except for forgetting about them. Return 0 for other
80 * traps to say that we haven't done anything. The trap handler
81 * will usually panic. We should handle breakpoint traps for
82 * our breakpoints by disarming our breakpoints and fixing up
85 if (cons_unavail && ddb_mode) {
86 if (type == T_TRCTRAP) {
87 regs->tf_eflags &= ~PSL_T;
94 case T_BPTFLT: /* breakpoint */
95 case T_TRCTRAP: /* debug exception */
100 * XXX this is almost useless now. In most cases,
101 * trap_fatal() has already printed a much more verbose
102 * message. However, it is dangerous to print things in
103 * trap_fatal() - printf() might be reentered and trap.
104 * The debugger should be given control first.
107 db_printf("kernel: type %d trap, code=%x\n", type, code);
110 jmp_buf *no_fault = db_nofault;
112 longjmp(*no_fault, 1);
117 * This handles unexpected traps in ddb commands, including calls to
118 * non-ddb functions. db_nofault only applies to memory accesses by
119 * internal ddb commands.
121 if (db_global_jmpbuf_valid)
122 longjmp(db_global_jmpbuf, 1);
125 * XXX We really should switch to a local stack here.
130 * If in kernel mode, esp and ss are not saved, so dummy them up.
132 if (ISPL(regs->tf_cs) == 0) {
133 ddb_regs.tf_esp = (int)®s->tf_esp;
134 ddb_regs.tf_ss = rss();
138 #ifdef CPUSTOP_ON_DDBBREAK
140 #if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
141 db_printf("\nCPU%d stopping CPUs: 0x%08x\n", cpuid, other_cpus);
142 #endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
144 /* We stop all CPUs except ourselves (obviously) */
145 stop_cpus(other_cpus);
147 #if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
148 db_printf(" stopped\n");
149 #endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
151 #endif /* CPUSTOP_ON_DDBBREAK */
154 (void) setjmp(db_global_jmpbuf);
155 db_global_jmpbuf_valid = TRUE;
162 gdb_handle_exception(&ddb_regs, type, code);
164 db_global_jmpbuf_valid = FALSE;
167 #ifdef CPUSTOP_ON_DDBBREAK
169 #if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
170 db_printf("\nCPU%d restarting CPUs: 0x%08x\n", cpuid, stopped_cpus);
171 #endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
173 /* Restart all the CPUs we previously stopped */
174 if (stopped_cpus != other_cpus && smp_started != 0) {
175 db_printf("whoa, other_cpus: 0x%08x, stopped_cpus: 0x%08x\n",
176 other_cpus, stopped_cpus);
177 panic("stop_cpus() failed");
179 restart_cpus(stopped_cpus);
181 #if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
182 db_printf(" restarted\n");
183 #endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
185 #endif /* CPUSTOP_ON_DDBBREAK */
188 regs->tf_eip = ddb_regs.tf_eip;
189 regs->tf_eflags = ddb_regs.tf_eflags;
190 regs->tf_eax = ddb_regs.tf_eax;
191 regs->tf_ecx = ddb_regs.tf_ecx;
192 regs->tf_edx = ddb_regs.tf_edx;
193 regs->tf_ebx = ddb_regs.tf_ebx;
196 * If in user mode, the saved ESP and SS were valid, restore them.
198 if (ISPL(regs->tf_cs)) {
199 regs->tf_esp = ddb_regs.tf_esp;
200 regs->tf_ss = ddb_regs.tf_ss & 0xffff;
203 regs->tf_ebp = ddb_regs.tf_ebp;
204 regs->tf_esi = ddb_regs.tf_esi;
205 regs->tf_edi = ddb_regs.tf_edi;
206 regs->tf_es = ddb_regs.tf_es & 0xffff;
207 regs->tf_fs = ddb_regs.tf_fs & 0xffff;
208 regs->tf_cs = ddb_regs.tf_cs & 0xffff;
209 regs->tf_ds = ddb_regs.tf_ds & 0xffff;
214 * Read bytes from kernel address space for debugger.
217 db_read_bytes(addr, size, data)
219 register size_t size;
224 db_nofault = &db_jmpbuf;
234 * Write bytes to kernel address space for debugger.
237 db_write_bytes(addr, size, data)
239 register size_t size;
244 unsigned *ptep0 = NULL;
245 unsigned oldmap0 = 0;
247 unsigned *ptep1 = NULL;
248 unsigned oldmap1 = 0;
250 db_nofault = &db_jmpbuf;
252 if (addr > trunc_page((vm_offset_t)btext) - size &&
253 addr < round_page((vm_offset_t)etext)) {
255 ptep0 = pmap_pte(kernel_pmap, addr);
259 /* Map another page if the data crosses a page boundary. */
260 if ((*ptep0 & PG_PS) == 0) {
261 addr1 = trunc_page(addr + size - 1);
262 if (trunc_page(addr) != addr1) {
263 ptep1 = pmap_pte(kernel_pmap, addr1);
268 addr1 = trunc_4mpage(addr + size - 1);
269 if (trunc_4mpage(addr) != addr1) {
270 ptep1 = pmap_pte(kernel_pmap, addr1);
298 * Move this to machdep.c and allow it to be called if any debugger is
305 static volatile u_char in_Debugger;
309 * Do nothing if the console is in graphics mode. This is
310 * OK if the call is for the debugger hotkey but not if the call
311 * is a weak form of panicing.
313 if (cons_unavail && !(boothowto & RB_GDB))
318 db_printf("Debugger(\"%s\")\n", msg);