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/i386/i386/Attic/db_interface.c,v 1.4 2003/07/06 21:23:48 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 */
43 #include <machine/globaldata.h>
52 static jmp_buf *db_nofault = 0;
53 extern jmp_buf db_jmpbuf;
55 extern void gdb_handle_exception __P((db_regs_t *, int, int));
60 static jmp_buf db_global_jmpbuf;
61 static int db_global_jmpbuf_valid;
64 #define rss() ({u_short ss; __asm __volatile("mov %%ss,%0" : "=r" (ss)); ss;})
67 #define VERBOSE_CPUSTOP_ON_DDBBREAK
70 * kdb_trap - field a TRACE or BPT trap
73 kdb_trap(type, code, regs)
75 register struct i386_saved_state *regs;
77 volatile int ddb_mode = !(boothowto & RB_GDB);
80 * XXX try to do nothing if the console is in graphics mode.
81 * Handle trace traps (and hardware breakpoints...) by ignoring
82 * them except for forgetting about them. Return 0 for other
83 * traps to say that we haven't done anything. The trap handler
84 * will usually panic. We should handle breakpoint traps for
85 * our breakpoints by disarming our breakpoints and fixing up
88 if (cons_unavail && ddb_mode) {
89 if (type == T_TRCTRAP) {
90 regs->tf_eflags &= ~PSL_T;
97 case T_BPTFLT: /* breakpoint */
98 case T_TRCTRAP: /* debug exception */
103 * XXX this is almost useless now. In most cases,
104 * trap_fatal() has already printed a much more verbose
105 * message. However, it is dangerous to print things in
106 * trap_fatal() - printf() might be reentered and trap.
107 * The debugger should be given control first.
110 db_printf("kernel: type %d trap, code=%x\n", type, code);
113 jmp_buf *no_fault = db_nofault;
115 longjmp(*no_fault, 1);
120 * This handles unexpected traps in ddb commands, including calls to
121 * non-ddb functions. db_nofault only applies to memory accesses by
122 * internal ddb commands.
124 if (db_global_jmpbuf_valid)
125 longjmp(db_global_jmpbuf, 1);
128 * XXX We really should switch to a local stack here.
133 * If in kernel mode, esp and ss are not saved, so dummy them up.
135 if (ISPL(regs->tf_cs) == 0) {
136 ddb_regs.tf_esp = (int)®s->tf_esp;
137 ddb_regs.tf_ss = rss();
141 #ifdef CPUSTOP_ON_DDBBREAK
143 #if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
144 db_printf("\nCPU%d stopping CPUs: 0x%08x\n",
145 mycpu->gd_cpuid, mycpu->gd_other_cpus);
146 #endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
148 /* We stop all CPUs except ourselves (obviously) */
149 stop_cpus(mycpu->gd_other_cpus);
151 #if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
152 db_printf(" stopped\n");
153 #endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
155 #endif /* CPUSTOP_ON_DDBBREAK */
158 (void) setjmp(db_global_jmpbuf);
159 db_global_jmpbuf_valid = TRUE;
166 gdb_handle_exception(&ddb_regs, type, code);
168 db_global_jmpbuf_valid = FALSE;
171 #ifdef CPUSTOP_ON_DDBBREAK
173 #if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
174 db_printf("\nCPU%d restarting CPUs: 0x%08x\n",
175 mycpu->gd_cpuid, stopped_cpus);
176 #endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
178 /* Restart all the CPUs we previously stopped */
179 if (stopped_cpus != mycpu->gd_other_cpus && smp_started != 0) {
180 db_printf("whoa, other_cpus: 0x%08x, stopped_cpus: 0x%08x\n",
181 mycpu->gd_other_cpus, stopped_cpus);
182 panic("stop_cpus() failed");
184 restart_cpus(stopped_cpus);
186 #if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
187 db_printf(" restarted\n");
188 #endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
190 #endif /* CPUSTOP_ON_DDBBREAK */
193 regs->tf_eip = ddb_regs.tf_eip;
194 regs->tf_eflags = ddb_regs.tf_eflags;
195 regs->tf_eax = ddb_regs.tf_eax;
196 regs->tf_ecx = ddb_regs.tf_ecx;
197 regs->tf_edx = ddb_regs.tf_edx;
198 regs->tf_ebx = ddb_regs.tf_ebx;
201 * If in user mode, the saved ESP and SS were valid, restore them.
203 if (ISPL(regs->tf_cs)) {
204 regs->tf_esp = ddb_regs.tf_esp;
205 regs->tf_ss = ddb_regs.tf_ss & 0xffff;
208 regs->tf_ebp = ddb_regs.tf_ebp;
209 regs->tf_esi = ddb_regs.tf_esi;
210 regs->tf_edi = ddb_regs.tf_edi;
211 regs->tf_es = ddb_regs.tf_es & 0xffff;
212 regs->tf_fs = ddb_regs.tf_fs & 0xffff;
213 regs->tf_cs = ddb_regs.tf_cs & 0xffff;
214 regs->tf_ds = ddb_regs.tf_ds & 0xffff;
219 * Read bytes from kernel address space for debugger.
222 db_read_bytes(addr, size, data)
224 register size_t size;
229 db_nofault = &db_jmpbuf;
239 * Write bytes to kernel address space for debugger.
242 db_write_bytes(addr, size, data)
244 register size_t size;
249 unsigned *ptep0 = NULL;
250 unsigned oldmap0 = 0;
252 unsigned *ptep1 = NULL;
253 unsigned oldmap1 = 0;
255 db_nofault = &db_jmpbuf;
257 if (addr > trunc_page((vm_offset_t)btext) - size &&
258 addr < round_page((vm_offset_t)etext)) {
260 ptep0 = pmap_pte(kernel_pmap, addr);
264 /* Map another page if the data crosses a page boundary. */
265 if ((*ptep0 & PG_PS) == 0) {
266 addr1 = trunc_page(addr + size - 1);
267 if (trunc_page(addr) != addr1) {
268 ptep1 = pmap_pte(kernel_pmap, addr1);
273 addr1 = trunc_4mpage(addr + size - 1);
274 if (trunc_4mpage(addr) != addr1) {
275 ptep1 = pmap_pte(kernel_pmap, addr1);
303 * Move this to machdep.c and allow it to be called if any debugger is
310 static volatile u_char in_Debugger;
314 * Do nothing if the console is in graphics mode. This is
315 * OK if the call is for the debugger hotkey but not if the call
316 * is a weak form of panicing.
318 if (cons_unavail && !(boothowto & RB_GDB))
323 db_printf("Debugger(\"%s\")\n", msg);