freebsd-dev/sys/amd64/amd64/db_interface.c

316 lines
7.2 KiB
C

/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*
* $Id: db_interface.c,v 1.10 1997/07/18 19:45:41 smp Exp smp $
*/
/*
* Interface to new debugger.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <machine/cons.h>
#include <machine/md_var.h>
#include <machine/segments.h>
#ifdef SMP
#include <machine/smp.h>
#include <machine/smptests.h> /** CPUSTOP_ON_DDBBREAK */
#endif
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <ddb/ddb.h>
#include <setjmp.h>
static jmp_buf *db_nofault = 0;
extern jmp_buf db_jmpbuf;
extern void gdb_handle_exception __P((db_regs_t *, int, int));
db_regs_t ddb_regs;
static jmp_buf db_global_jmpbuf;
static int db_global_jmpbuf_valid;
#ifdef __GNUC__
#define rss() ({u_short ss; __asm __volatile("movl %%ss,%0" : "=r" (ss)); ss;})
#endif
/*
* kdb_trap - field a TRACE or BPT trap
*/
int
kdb_trap(type, code, regs)
int type, code;
register struct i386_saved_state *regs;
{
int ddb_mode = !(boothowto & RB_GDB);
/*
* XXX try to do nothing if the console is in graphics mode.
* Handle trace traps (and hardware breakpoints...) by ignoring
* them except for forgetting about them. Return 0 for other
* traps to say that we haven't done anything. The trap handler
* will usually panic. We should handle breakpoint traps for
* our breakpoints by disarming our breakpoints and fixing up
* %eip.
*/
if (cons_unavail && ddb_mode) {
if (type == T_TRCTRAP) {
regs->tf_eflags &= ~PSL_T;
return (1);
}
return (0);
}
switch (type) {
case T_BPTFLT: /* breakpoint */
case T_TRCTRAP: /* debug exception */
break;
default:
/*
* XXX this is almost useless now. In most cases,
* trap_fatal() has already printed a much more verbose
* message. However, it is dangerous to print things in
* trap_fatal() - printf() might be reentered and trap.
* The debugger should be given control first.
*/
if (ddb_mode)
db_printf("kernel: type %d trap, code=%x\n", type, code);
if (db_nofault) {
jmp_buf *no_fault = db_nofault;
db_nofault = 0;
longjmp(*no_fault, 1);
}
}
/*
* This handles unexpected traps in ddb commands, including calls to
* non-ddb functions. db_nofault only applies to memory accesses by
* internal ddb commands.
*/
if (db_global_jmpbuf_valid)
longjmp(db_global_jmpbuf, 1);
/*
* XXX We really should switch to a local stack here.
*/
ddb_regs = *regs;
/*
* If in kernel mode, esp and ss are not saved, so dummy them up.
*/
if (ISPL(regs->tf_cs) == 0) {
ddb_regs.tf_esp = (int)&regs->tf_esp;
ddb_regs.tf_ss = rss();
}
cnpollc(TRUE);
#ifdef SMP
#ifdef CPUSTOP_ON_DDBBREAK
#if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
db_printf("\nCPU%d stopping CPUs: 0x%08x\n", cpuid, other_cpus);
#endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
/* We stop all CPUs except ourselves (obviously) */
stop_cpus(other_cpus);
#if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
db_printf(" stopped\n");
#endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
#endif /* CPUSTOP_ON_DDBBREAK */
#endif /* SMP */
(void) setjmp(db_global_jmpbuf);
db_global_jmpbuf_valid = TRUE;
if (ddb_mode)
db_trap(type, code);
else
gdb_handle_exception(&ddb_regs, type, code);
db_global_jmpbuf_valid = FALSE;
#ifdef SMP
#ifdef CPUSTOP_ON_DDBBREAK
#if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
db_printf("\nCPU%d restarting CPUs: 0x%08x\n", cpuid, stopped_cpus);
#endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
/* Restart all the CPUs we previously stopped */
if (stopped_cpus != other_cpus) {
db_printf("whoa, other_cpus: 0x%08x, stopped_cpus: 0x%08x\n",
other_cpus, stopped_cpus);
panic("stop_cpus() failed");
}
restart_cpus(stopped_cpus);
#if defined(VERBOSE_CPUSTOP_ON_DDBBREAK)
db_printf(" restarted\n");
#endif /* VERBOSE_CPUSTOP_ON_DDBBREAK */
#endif /* CPUSTOP_ON_DDBBREAK */
#endif /* SMP */
cnpollc(FALSE);
regs->tf_eip = ddb_regs.tf_eip;
regs->tf_eflags = ddb_regs.tf_eflags;
regs->tf_eax = ddb_regs.tf_eax;
regs->tf_ecx = ddb_regs.tf_ecx;
regs->tf_edx = ddb_regs.tf_edx;
regs->tf_ebx = ddb_regs.tf_ebx;
/*
* If in user mode, the saved ESP and SS were valid, restore them.
*/
if (ISPL(regs->tf_cs)) {
regs->tf_esp = ddb_regs.tf_esp;
regs->tf_ss = ddb_regs.tf_ss & 0xffff;
}
regs->tf_ebp = ddb_regs.tf_ebp;
regs->tf_esi = ddb_regs.tf_esi;
regs->tf_edi = ddb_regs.tf_edi;
regs->tf_es = ddb_regs.tf_es & 0xffff;
regs->tf_cs = ddb_regs.tf_cs & 0xffff;
regs->tf_ds = ddb_regs.tf_ds & 0xffff;
return (1);
}
/*
* Read bytes from kernel address space for debugger.
*/
void
db_read_bytes(addr, size, data)
vm_offset_t addr;
register int size;
register char *data;
{
register char *src;
db_nofault = &db_jmpbuf;
src = (char *)addr;
while (--size >= 0)
*data++ = *src++;
db_nofault = 0;
}
/*
* Write bytes to kernel address space for debugger.
*/
void
db_write_bytes(addr, size, data)
vm_offset_t addr;
register int size;
register char *data;
{
register char *dst;
unsigned *ptep0 = NULL;
unsigned oldmap0 = 0;
vm_offset_t addr1;
unsigned *ptep1 = NULL;
unsigned oldmap1 = 0;
db_nofault = &db_jmpbuf;
if (addr >= VM_MIN_KERNEL_ADDRESS &&
addr <= round_page((vm_offset_t)&etext)) {
ptep0 = pmap_pte(kernel_pmap, addr);
oldmap0 = *ptep0;
*ptep0 |= PG_RW;
addr1 = trunc_page(addr + size - 1);
/* Map another page if the data crosses a page boundary. */
if (trunc_page(addr) != addr1) {
ptep1 = pmap_pte(kernel_pmap, addr1);
oldmap1 = *ptep1;
*ptep1 |= PG_RW;
}
invltlb();
}
dst = (char *)addr;
while (--size >= 0)
*dst++ = *data++;
db_nofault = 0;
if (ptep0) {
*ptep0 = oldmap0;
if (ptep1)
*ptep1 = oldmap1;
invltlb();
}
}
/*
* XXX
* Move this to machdep.c and allow it to be called if any debugger is
* installed.
*/
void
Debugger(msg)
const char *msg;
{
static volatile u_char in_Debugger;
/*
* XXX
* Do nothing if the console is in graphics mode. This is
* OK if the call is for the debugger hotkey but not if the call
* is a weak form of panicing.
*/
if (cons_unavail && !(boothowto & RB_GDB))
return;
if (!in_Debugger) {
in_Debugger = 1;
db_printf("Debugger(\"%s\")\n", msg);
breakpoint();
in_Debugger = 0;
}
}