kernel: Make SMP support default (and non-optional).
[dragonfly.git] / sys / platform / vkernel / i386 / db_interface.c
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1/*
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
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.
11 *
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.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 *
26 * $FreeBSD: src/sys/i386/i386/db_interface.c,v 1.48.2.1 2000/07/07 00:38:46 obrien Exp $
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27 */
28
29/*
30 * Interface to new debugger.
31 */
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/reboot.h>
35#include <sys/cons.h>
36#include <sys/vkernel.h>
33bb509e 37#include <sys/thread.h>
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38
39#include <machine/cpu.h>
40#include <machine/smp.h>
41#include <machine/globaldata.h>
42#include <machine/md_var.h>
43
44#include <vm/vm.h>
45#include <vm/pmap.h>
46
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47#include <sys/thread2.h>
48
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49#include <ddb/ddb.h>
50
51#include <setjmp.h>
52
4090d6ff 53static jmp_buf *db_nofault = NULL;
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54extern jmp_buf db_jmpbuf;
55
56extern void gdb_handle_exception (db_regs_t *, int, int);
57
58int db_active;
59db_regs_t ddb_regs;
60
61static jmp_buf db_global_jmpbuf;
62static int db_global_jmpbuf_valid;
63
64#ifdef __GNUC__
65#define rss() ({u_short ss; __asm __volatile("mov %%ss,%0" : "=r" (ss)); ss;})
66#endif
67
68/*
69 * kdb_trap - field a TRACE or BPT trap
70 */
71int
72kdb_trap(int type, int code, struct i386_saved_state *regs)
73{
74 volatile int ddb_mode = !(boothowto & RB_GDB);
75
76 /*
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
83 * %eip.
84 */
85 if (cons_unavail && ddb_mode) {
86 if (type == T_TRCTRAP) {
87 regs->tf_eflags &= ~PSL_T;
88 return (1);
89 }
90 return (0);
91 }
92
93 switch (type) {
94 case T_BPTFLT: /* breakpoint */
95 case T_TRCTRAP: /* debug exception */
96 break;
97
98 default:
99 /*
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() - kprintf() might be reentered and trap.
104 * The debugger should be given control first.
105 */
106 if (ddb_mode)
107 db_printf("kernel: type %d trap, code=%x\n", type, code);
108
109 if (db_nofault) {
110 jmp_buf *no_fault = db_nofault;
4090d6ff 111 db_nofault = NULL;
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112 longjmp(*no_fault, 1);
113 }
114 }
115
116 /*
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.
120 */
121 if (db_global_jmpbuf_valid)
122 longjmp(db_global_jmpbuf, 1);
123
124 /*
125 * XXX We really should switch to a local stack here.
126 */
127 ddb_regs = *regs;
128
129 /*
130 * If in kernel mode, esp and ss are not saved, so dummy them up.
131 */
132 if (ISPL(regs->tf_cs) == 0) {
133 ddb_regs.tf_esp = (int)&regs->tf_esp;
134 ddb_regs.tf_ss = rss();
135 }
136
33bb509e 137 crit_enter();
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138 db_printf("\nCPU%d stopping CPUs: 0x%08x\n",
139 mycpu->gd_cpuid, mycpu->gd_other_cpus);
140
141 /* We stop all CPUs except ourselves (obviously) */
142 stop_cpus(mycpu->gd_other_cpus);
143
144 db_printf(" stopped\n");
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145
146 setjmp(db_global_jmpbuf);
147 db_global_jmpbuf_valid = TRUE;
148 db_active++;
cb118784 149 vcons_set_mode(1);
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150 if (ddb_mode) {
151 cndbctl(TRUE);
152 db_trap(type, code);
153 cndbctl(FALSE);
154 } else
155 gdb_handle_exception(&ddb_regs, type, code);
156 db_active--;
cb118784 157 vcons_set_mode(0);
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158 db_global_jmpbuf_valid = FALSE;
159
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160 db_printf("\nCPU%d restarting CPUs: 0x%016jx\n",
161 mycpu->gd_cpuid, (uintmax_t)stopped_cpus);
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162
163 /* Restart all the CPUs we previously stopped */
164 if (stopped_cpus != mycpu->gd_other_cpus) {
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165 db_printf("whoa, other_cpus: 0x%08x, stopped_cpus: 0x%016jx\n",
166 mycpu->gd_other_cpus, (uintmax_t)stopped_cpus);
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167 panic("stop_cpus() failed");
168 }
169 restart_cpus(stopped_cpus);
170
171 db_printf(" restarted\n");
33bb509e 172 crit_exit();
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173
174 regs->tf_eip = ddb_regs.tf_eip;
175 regs->tf_eflags = ddb_regs.tf_eflags;
176 regs->tf_eax = ddb_regs.tf_eax;
177 regs->tf_ecx = ddb_regs.tf_ecx;
178 regs->tf_edx = ddb_regs.tf_edx;
179 regs->tf_ebx = ddb_regs.tf_ebx;
180
181 /*
182 * If in user mode, the saved ESP and SS were valid, restore them.
183 */
184 if (ISPL(regs->tf_cs)) {
185 regs->tf_esp = ddb_regs.tf_esp;
186 regs->tf_ss = ddb_regs.tf_ss & 0xffff;
187 }
188
189 regs->tf_ebp = ddb_regs.tf_ebp;
190 regs->tf_esi = ddb_regs.tf_esi;
191 regs->tf_edi = ddb_regs.tf_edi;
192 regs->tf_es = ddb_regs.tf_es & 0xffff;
193 regs->tf_fs = ddb_regs.tf_fs & 0xffff;
4e7c41c5 194 regs->tf_gs = ddb_regs.tf_gs & 0xffff;
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195 regs->tf_cs = ddb_regs.tf_cs & 0xffff;
196 regs->tf_ds = ddb_regs.tf_ds & 0xffff;
197 return (1);
198}
199
200/*
201 * Read bytes from kernel address space for debugger.
202 */
203void
204db_read_bytes(vm_offset_t addr, size_t size, char *data)
205{
206 char *src;
207
208 db_nofault = &db_jmpbuf;
209
210 src = (char *)addr;
211 while (size-- > 0)
212 *data++ = *src++;
213
4090d6ff 214 db_nofault = NULL;
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215}
216
217/*
218 * Write bytes to kernel address space for debugger.
219 */
220void
221db_write_bytes(vm_offset_t addr, size_t size, char *data)
222{
223 char *dst;
224#if 0
225 vpte_t *ptep0 = NULL;
226 vpte_t oldmap0 = 0;
227 vm_offset_t addr1;
228 vpte_t *ptep1 = NULL;
229 vpte_t oldmap1 = 0;
230#endif
231
232 db_nofault = &db_jmpbuf;
233#if 0
234 if (addr > trunc_page((vm_offset_t)btext) - size &&
235 addr < round_page((vm_offset_t)etext)) {
236
237 ptep0 = pmap_kpte(addr);
238 oldmap0 = *ptep0;
239 *ptep0 |= VPTE_W;
240
241 /* Map another page if the data crosses a page boundary. */
242 if ((*ptep0 & PG_PS) == 0) {
243 addr1 = trunc_page(addr + size - 1);
244 if (trunc_page(addr) != addr1) {
245 ptep1 = pmap_kpte(addr1);
246 oldmap1 = *ptep1;
247 *ptep1 |= VPTE_W;
248 }
249 } else {
250 addr1 = trunc_4mpage(addr + size - 1);
251 if (trunc_4mpage(addr) != addr1) {
252 ptep1 = pmap_kpte(addr1);
253 oldmap1 = *ptep1;
254 *ptep1 |= VPTE_W;
255 }
256 }
257
258 cpu_invltlb();
259 }
260#endif
261
262 dst = (char *)addr;
263
264 while (size-- > 0)
265 *dst++ = *data++;
266
4090d6ff 267 db_nofault = NULL;
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268
269#if 0
270 if (ptep0) {
271 *ptep0 = oldmap0;
272
273 if (ptep1)
274 *ptep1 = oldmap1;
275
276 cpu_invltlb();
277 }
278#endif
279}
280
281/*
282 * The debugger sometimes needs to know the actual KVM address represented
283 * by the instruction pointer, stack pointer, or base pointer. Normally
284 * the actual KVM address is simply the contents of the register. However,
285 * if the debugger is entered from the BIOS or VM86 we need to figure out
286 * the offset from the segment register.
287 */
288db_addr_t
289PC_REGS(db_regs_t *regs)
290{
291 return(regs->tf_eip);
292}
293
294db_addr_t
295SP_REGS(db_regs_t *regs)
296{
297 return(regs->tf_esp);
298}
299
300db_addr_t
301BP_REGS(db_regs_t *regs)
302{
303 return(regs->tf_ebp);
304}
305
306/*
307 * XXX
308 * Move this to machdep.c and allow it to be called if any debugger is
309 * installed.
310 */
311void
312Debugger(const char *msg)
313{
314 static volatile u_char in_Debugger;
315
316 /*
317 * XXX
318 * Do nothing if the console is in graphics mode. This is
319 * OK if the call is for the debugger hotkey but not if the call
320 * is a weak form of panicing.
321 */
322 if (cons_unavail && !(boothowto & RB_GDB))
323 return;
324
325 if (!in_Debugger) {
326 in_Debugger = 1;
327 db_printf("Debugger(\"%s\")\n", msg);
328 breakpoint();
329 in_Debugger = 0;
330 }
331}