19bc776351
This might be useful for debugging applications that use a special LDT. However, printing of all segment registers is currently broken. Don't print "last exception: " before the FPU opcode and pc, etc. The opcode and pc, etc., are for the last FPU _instruction_. Pass the saved exception status word to print_387_status() so that the exception(s) that caused or will cause a trap can be seen. The kernel has supported this since 1.1 or before. The kernel still clobbers the tag word if a trap occurs. Remove unused null function clear_regs().
610 lines
15 KiB
C
610 lines
15 KiB
C
/* Native-dependent code for BSD Unix running on i386's, for GDB.
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Copyright 1988, 1989, 1991, 1992 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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$Id: freebsd-nat.c,v 1.2 1994/12/30 23:25:44 jkh Exp $
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*/
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#include <sys/types.h>
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#include <sys/param.h>
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#include <signal.h>
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#include <sys/user.h>
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#include <machine/reg.h>
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#include <machine/frame.h>
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#include <sys/ptrace.h>
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#include "defs.h"
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/* this table must line up with REGISTER_NAMES in tm-i386v.h */
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/* symbols like 'tEAX' come from <machine/reg.h> */
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static int tregmap[] =
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{
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tEAX, tECX, tEDX, tEBX,
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tESP, tEBP, tESI, tEDI,
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tEIP, tEFLAGS, tCS, tSS,
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tDS, tES, tSS, tSS, /* lies: no fs or gs */
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};
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/* blockend is the value of u.u_ar0, and points to the
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place where ES is stored. */
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int
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i386_register_u_addr (blockend, regnum)
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int blockend;
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int regnum;
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{
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return (blockend + 4 * tregmap[regnum]);
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}
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#define fpstate save87
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#define U_FPSTATE(u) u.u_pcb.pcb_savefpu
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static void
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i387_to_double (from, to)
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char *from;
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char *to;
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{
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long *lp;
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/* push extended mode on 387 stack, then pop in double mode
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*
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* first, set exception masks so no error is generated -
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* number will be rounded to inf or 0, if necessary
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*/
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asm ("pushl %eax"); /* grab a stack slot */
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asm ("fstcw (%esp)"); /* get 387 control word */
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asm ("movl (%esp),%eax"); /* save old value */
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asm ("orl $0x3f,%eax"); /* mask all exceptions */
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asm ("pushl %eax");
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asm ("fldcw (%esp)"); /* load new value into 387 */
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asm ("movl 8(%ebp),%eax");
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asm ("fldt (%eax)"); /* push extended number on 387 stack */
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asm ("fwait");
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asm ("movl 12(%ebp),%eax");
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asm ("fstpl (%eax)"); /* pop double */
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asm ("fwait");
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asm ("popl %eax"); /* flush modified control word */
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asm ("fnclex"); /* clear exceptions */
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asm ("fldcw (%esp)"); /* restore original control word */
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asm ("popl %eax"); /* flush saved copy */
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}
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#if 0
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static void
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double_to_i387 (from, to)
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char *from;
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char *to;
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{
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/* push double mode on 387 stack, then pop in extended mode
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* no errors are possible because every 64-bit pattern
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* can be converted to an extended
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*/
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asm ("movl 8(%ebp),%eax");
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asm ("fldl (%eax)");
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asm ("fwait");
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asm ("movl 12(%ebp),%eax");
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asm ("fstpt (%eax)");
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asm ("fwait");
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}
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#endif
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struct env387
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{
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unsigned short control;
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unsigned short r0;
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unsigned short status;
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unsigned short r1;
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unsigned short tag;
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unsigned short r2;
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unsigned long eip;
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unsigned short code_seg;
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unsigned short opcode;
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unsigned long operand;
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unsigned short operand_seg;
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unsigned short r3;
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unsigned char regs[8][10];
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};
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/* static */ void
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print_387_control_word (control)
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unsigned int control;
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{
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printf ("control 0x%04x: ", control);
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printf ("compute to ");
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switch ((control >> 8) & 3)
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{
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case 0: printf ("24 bits; "); break;
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case 1: printf ("(bad); "); break;
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case 2: printf ("53 bits; "); break;
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case 3: printf ("64 bits; "); break;
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}
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printf ("round ");
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switch ((control >> 10) & 3)
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{
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case 0: printf ("NEAREST; "); break;
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case 1: printf ("DOWN; "); break;
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case 2: printf ("UP; "); break;
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case 3: printf ("CHOP; "); break;
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}
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if (control & 0x3f)
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{
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printf ("mask:");
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if (control & 0x0001) printf (" INVALID");
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if (control & 0x0002) printf (" DENORM");
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if (control & 0x0004) printf (" DIVZ");
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if (control & 0x0008) printf (" OVERF");
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if (control & 0x0010) printf (" UNDERF");
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if (control & 0x0020) printf (" LOS");
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printf (";");
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}
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printf ("\n");
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if (control & 0xe080) printf ("warning: reserved bits on 0x%x\n",
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control & 0xe080);
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}
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/* static */ void
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print_387_status_word (status)
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unsigned int status;
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{
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printf ("status 0x%04x: ", status);
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if (status & 0xff)
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{
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printf ("exceptions:");
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if (status & 0x0001) printf (" INVALID");
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if (status & 0x0002) printf (" DENORM");
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if (status & 0x0004) printf (" DIVZ");
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if (status & 0x0008) printf (" OVERF");
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if (status & 0x0010) printf (" UNDERF");
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if (status & 0x0020) printf (" LOS");
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if (status & 0x0040) printf (" FPSTACK");
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printf ("; ");
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}
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printf ("flags: %d%d%d%d; ",
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(status & 0x4000) != 0,
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(status & 0x0400) != 0,
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(status & 0x0200) != 0,
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(status & 0x0100) != 0);
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printf ("top %d\n", (status >> 11) & 7);
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}
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static void
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print_387_status (status, ep)
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unsigned short status;
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struct env387 *ep;
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{
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int i;
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int bothstatus;
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int top;
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int fpreg;
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unsigned char *p;
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bothstatus = ((status != 0) && (ep->status != 0));
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if (status != 0)
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{
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if (bothstatus)
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printf ("u: ");
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print_387_status_word ((unsigned int)status);
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}
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if (ep->status != 0)
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{
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if (bothstatus)
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printf ("e: ");
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print_387_status_word ((unsigned int)ep->status);
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}
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print_387_control_word ((unsigned int)ep->control);
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printf ("opcode 0x%x; ", ep->opcode);
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printf ("pc 0x%x:0x%x; ", ep->code_seg, ep->eip);
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printf ("operand 0x%x:0x%x\n", ep->operand_seg, ep->operand);
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top = (ep->status >> 11) & 7;
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printf (" regno tag msb lsb value\n");
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for (fpreg = 7; fpreg >= 0; fpreg--)
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{
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int st_regno;
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double val;
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/* The physical regno `fpreg' is only relevant as an index into the
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* tag word. Logical `%st' numbers are required for indexing ep->regs.
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*/
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st_regno = (fpreg + 8 - top) & 7;
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printf ("%%st(%d) %s ", st_regno, fpreg == top ? "=>" : " ");
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switch ((ep->tag >> (fpreg * 2)) & 3)
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{
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case 0: printf ("valid "); break;
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case 1: printf ("zero "); break;
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case 2: printf ("trap "); break;
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case 3: printf ("empty "); break;
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}
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for (i = 9; i >= 0; i--)
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printf ("%02x", ep->regs[st_regno][i]);
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i387_to_double (ep->regs[st_regno], (char *)&val);
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printf (" %g\n", val);
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}
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}
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void
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i386_float_info ()
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{
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struct user u; /* just for address computations */
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int i;
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/* fpstate defined in <sys/user.h> */
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struct fpstate *fpstatep;
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char buf[sizeof (struct fpstate) + 2 * sizeof (int)];
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unsigned int uaddr;
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char fpvalid;
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unsigned int rounded_addr;
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unsigned int rounded_size;
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/*extern int corechan;*/
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int skip;
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extern int inferior_pid;
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uaddr = (char *)&U_FPSTATE(u) - (char *)&u;
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if (inferior_pid)
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{
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int *ip;
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rounded_addr = uaddr & -sizeof (int);
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rounded_size = (((uaddr + sizeof (struct fpstate)) - uaddr) +
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sizeof (int) - 1) / sizeof (int);
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skip = uaddr - rounded_addr;
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ip = (int *)buf;
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for (i = 0; i < rounded_size; i++)
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{
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*ip++ = ptrace (PT_READ_U, inferior_pid, (caddr_t)rounded_addr, 0);
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rounded_addr += sizeof (int);
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}
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}
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else
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{
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#if 1
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printf("float info: can't do a core file (yet)\n");
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return;
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#else
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if (lseek (corechan, uaddr, 0) < 0)
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perror_with_name ("seek on core file");
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if (myread (corechan, buf, sizeof (struct fpstate)) < 0)
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perror_with_name ("read from core file");
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skip = 0;
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#endif
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}
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fpstatep = (struct fpstate *)(buf + skip);
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print_387_status (fpstatep->sv_ex_sw, (struct env387 *)fpstatep);
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}
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#ifdef KERNEL_DEBUG
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#include <sys/proc.h>
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#include <sys/stat.h>
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#include <sys/fcntl.h>
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#include <unistd.h>
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#include <vm/vm.h>
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#include <vm/vm_param.h>
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#include <machine/vmparam.h>
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#include <machine/pcb.h>
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#define KERNOFF ((unsigned)KERNBASE)
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#define INKERNEL(x) ((x) >= KERNOFF)
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static CORE_ADDR sbr;
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static CORE_ADDR curpcb;
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static CORE_ADDR kstack;
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static int found_pcb;
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static int devmem;
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static int kfd;
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static struct pcb pcb;
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int read_pcb (int, CORE_ADDR);
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static CORE_ADDR kvtophys (int, CORE_ADDR);
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static physrd(int, u_int, char*, int);
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extern CORE_ADDR ksym_lookup(const char *);
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/* substitutes for the stuff in libkvm which doesn't work */
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/* most of this was taken from the old kgdb */
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/* we don't need all this stuff, but the call should look the same */
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kvm_open (efile, cfile, sfile, perm, errout)
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char *efile;
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char *cfile;
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void *sfile;
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int perm;
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int errout;
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{
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struct stat stb;
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CORE_ADDR addr;
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int cfd;
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if ((cfd = open(cfile, perm, 0)) < 0)
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return (cfd);
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fstat(cfd, &stb);
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if ((stb.st_mode & S_IFMT) == S_IFCHR && stb.st_rdev == makedev(2, 0)) {
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devmem = 1;
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kfd = open ("/dev/kmem", perm, 0);
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}
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physrd(cfd, ksym_lookup("IdlePTD") - KERNOFF, (char*)&sbr, sizeof sbr);
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printf("IdlePTD %x\n", sbr);
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curpcb = ksym_lookup("curpcb") - KERNOFF;
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physrd(cfd, curpcb, (char*)&curpcb, sizeof curpcb);
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kstack = ksym_lookup("kstack");
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found_pcb = 1; /* for vtophys */
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if (!devmem)
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read_pcb(cfd, ksym_lookup("dumppcb") - KERNOFF);
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else
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read_pcb(cfd, kvtophys(cfd, kstack));
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return (cfd);
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}
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kvm_close (fd)
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{
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return (close (fd));
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}
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kvm_write(core_kd, memaddr, myaddr, len)
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CORE_ADDR memaddr;
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char *myaddr;
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{
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int cc;
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if (devmem) {
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if (kfd > 0) {
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/*
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* Just like kvm_read, only we write.
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*/
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errno = 0;
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if (lseek(kfd, (off_t)memaddr, 0) < 0 && errno != 0) {
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error("kvm_write:invalid address (%x)", memaddr);
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return (0);
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}
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cc = write(kfd, myaddr, len);
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if (cc < 0) {
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error("kvm_write:write failed");
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return (0);
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} else if (cc < len)
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error("kvm_write:short write");
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return (cc);
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} else
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return (0);
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} else {
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printf("kvm_write not implemented for dead kernels\n");
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return (0);
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}
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/* NOTREACHED */
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}
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kvm_read(core_kd, memaddr, myaddr, len)
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CORE_ADDR memaddr;
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char *myaddr;
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{
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return (kernel_core_file_hook (core_kd, memaddr, myaddr, len));
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}
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kvm_uread(core_kd, p, memaddr, myaddr, len)
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register struct proc *p;
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CORE_ADDR memaddr;
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char *myaddr;
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{
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register char *cp;
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char procfile[MAXPATHLEN];
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ssize_t amount;
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int fd;
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if (devmem) {
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cp = myaddr;
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sprintf(procfile, "/proc/%d/mem", p->p_pid);
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fd = open(procfile, O_RDONLY, 0);
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if (fd < 0) {
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error("cannot open %s", procfile);
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close(fd);
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return (0);
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}
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while (len > 0) {
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if (lseek(fd, memaddr, 0) == -1 && errno != 0) {
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error("invalid address (%x) in %s",
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memaddr, procfile);
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break;
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}
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amount = read(fd, cp, len);
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if (amount < 0) {
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error("error reading %s", procfile);
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break;
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}
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cp += amount;
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memaddr += amount;
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len -= amount;
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}
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close(fd);
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return (ssize_t)(cp - myaddr);
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} else {
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return (kernel_core_file_hook (core_kd, memaddr, myaddr, len));
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}
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}
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static
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physrd(cfd, addr, dat, len)
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u_int addr;
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char *dat;
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{
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if (lseek(cfd, (off_t)addr, L_SET) == -1)
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return (-1);
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return (read(cfd, dat, len));
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}
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static CORE_ADDR
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kvtophys (fd, addr)
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CORE_ADDR addr;
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{
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CORE_ADDR v;
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struct pte pte;
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static CORE_ADDR PTD = -1;
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CORE_ADDR current_ptd;
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/*if (devmem && kfd > 0)
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return (addr);
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/*
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* If we're looking at the kernel stack,
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* munge the address to refer to the user space mapping instead;
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* that way we get the requested process's kstack, not the running one.
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*/
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if (addr >= kstack && addr < kstack + ctob(UPAGES))
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addr = (addr - kstack) + curpcb;
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/*
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* We may no longer have a linear system page table...
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*
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* Here's the scoop. IdlePTD contains the physical address
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* of a page table directory that always maps the kernel.
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* IdlePTD is in memory that is mapped 1-to-1, so we can
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* find it easily given its 'virtual' address from ksym_lookup().
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* For hysterical reasons, the value of IdlePTD is stored in sbr.
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*
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* To look up a kernel address, we first convert it to a 1st-level
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* address and look it up in IdlePTD. This gives us the physical
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* address of a page table page; we extract the 2nd-level part of
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* VA and read the 2nd-level pte. Finally, we add the offset part
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* of the VA into the physical address from the pte and return it.
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*
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* User addresses are a little more complicated. If we don't have
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* a current PCB from read_pcb(), we use PTD, which is the (fixed)
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* virtual address of the current ptd. Since it's NOT in 1-to-1
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* kernel space, we must look it up using IdlePTD. If we do have
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* a pcb, we get the ptd from pcb_ptd.
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*/
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if (INKERNEL(addr))
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current_ptd = sbr;
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else if (found_pcb == 0) {
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if (PTD == -1)
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PTD = kvtophys(fd, ksym_lookup("PTD"));
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current_ptd = PTD;
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} else
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current_ptd = pcb.pcb_ptd;
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/*
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* Read the first-level page table (ptd).
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*/
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v = current_ptd + ((unsigned)addr >> PD_SHIFT) * sizeof pte;
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if (physrd(fd, v, (char *)&pte, sizeof pte) < 0 || pte.pg_v == 0)
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return (~0);
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|
|
/*
|
|
* Read the second-level page table.
|
|
*/
|
|
v = i386_ptob(pte.pg_pfnum) + ((addr&PT_MASK) >> PG_SHIFT) * sizeof pte;
|
|
if (physrd(fd, v, (char *) &pte, sizeof(pte)) < 0 || pte.pg_v == 0)
|
|
return (~0);
|
|
|
|
addr = i386_ptob(pte.pg_pfnum) + (addr & PGOFSET);
|
|
#if 0
|
|
printf("vtophys(%x) -> %x\n", oldaddr, addr);
|
|
#endif
|
|
return (addr);
|
|
}
|
|
|
|
read_pcb (fd, uaddr)
|
|
CORE_ADDR uaddr;
|
|
{
|
|
int i;
|
|
int *pcb_regs = (int *)&pcb;
|
|
int eip;
|
|
|
|
if (physrd(fd, uaddr, (char *)&pcb, sizeof pcb) < 0) {
|
|
error("cannot read pcb at %x\n", uaddr);
|
|
return (-1);
|
|
}
|
|
printf("current pcb at %x\n", uaddr);
|
|
|
|
/*
|
|
* get the register values out of the sys pcb and
|
|
* store them where `read_register' will find them.
|
|
*/
|
|
for (i = 0; i < 8; ++i)
|
|
supply_register(i, &pcb_regs[i+10]);
|
|
supply_register(8, &pcb_regs[8]); /* eip */
|
|
supply_register(9, &pcb_regs[9]); /* eflags */
|
|
for (i = 10; i < 13; ++i) /* cs, ss, ds */
|
|
supply_register(i, &pcb_regs[i+9]);
|
|
supply_register(13, &pcb_regs[18]); /* es */
|
|
for (i = 14; i < 16; ++i) /* fs, gs */
|
|
supply_register(i, &pcb_regs[i+8]);
|
|
|
|
#if 0 /* doesn't work ??? */
|
|
/* Hmm... */
|
|
if (target_read_memory(pcb_regs[5+10]+4, &eip, sizeof eip, 0))
|
|
error("Cannot read PC.");
|
|
supply_register(8, &eip); /* eip */
|
|
#endif
|
|
|
|
/* XXX 80387 registers? */
|
|
}
|
|
|
|
/*
|
|
* read len bytes from kernel virtual address 'addr' into local
|
|
* buffer 'buf'. Return numbert of bytes if read ok, 0 otherwise. On read
|
|
* errors, portion of buffer not read is zeroed.
|
|
*/
|
|
kernel_core_file_hook(fd, addr, buf, len)
|
|
CORE_ADDR addr;
|
|
char *buf;
|
|
int len;
|
|
{
|
|
int i;
|
|
CORE_ADDR paddr;
|
|
register char *cp;
|
|
int cc;
|
|
|
|
cp = buf;
|
|
|
|
while (len > 0) {
|
|
paddr = kvtophys(fd, addr);
|
|
if (paddr == ~0) {
|
|
bzero(buf, len);
|
|
break;
|
|
}
|
|
/* we can't read across a page boundary */
|
|
i = min(len, NBPG - (addr & PGOFSET));
|
|
if ((cc = physrd(fd, paddr, cp, i)) <= 0) {
|
|
bzero(cp, len);
|
|
return (cp - buf);
|
|
}
|
|
cp += cc;
|
|
addr += cc;
|
|
len -= cc;
|
|
}
|
|
return (cp - buf);
|
|
}
|
|
#endif /* KERNEL_DEBUG */
|