FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/gdb_machdep.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2004 Marcel Moolenaar
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     *
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kdb.h>
    #include <sys/kernel.h>
    #include <sys/proc.h>
    #include <sys/reg.h>
    #include <sys/signal.h>
    
    #include <machine/endian.h>
    #include <machine/frame.h>
    #include <machine/gdb_machdep.h>
    #include <machine/pcb.h>
    #include <machine/trap.h>
    
    #include <gdb/gdb.h>
    #include <gdb/gdb_int.h>
    
    void *
    gdb_cpu_getreg(int regnum, size_t *regsz)
    {
            static uint32_t _kcodesel = GSEL(GCODE_SEL, SEL_KPL);
            static uint32_t _kdatasel = GSEL(GDATA_SEL, SEL_KPL);
            static uint32_t _kprivsel = GSEL(GPRIV_SEL, SEL_KPL);
    
            *regsz = gdb_cpu_regsz(regnum);
    
            if (kdb_thread == curthread) {
                    switch (regnum) {
                    case 0: return (&kdb_frame->tf_eax);
                    case 1: return (&kdb_frame->tf_ecx);
                    case 2: return (&kdb_frame->tf_edx);
                    case 9: return (&kdb_frame->tf_eflags);
                    case 10: return (&kdb_frame->tf_cs);
                    case 12: return (&kdb_frame->tf_ds);
                    case 13: return (&kdb_frame->tf_es);
                    case 14: return (&kdb_frame->tf_fs);
                    }
            }
            switch (regnum) {
            case 3:  return (&kdb_thrctx->pcb_ebx);
            case 4:  return (&kdb_thrctx->pcb_esp);
            case 5:  return (&kdb_thrctx->pcb_ebp);
            case 6:  return (&kdb_thrctx->pcb_esi);
            case 7:  return (&kdb_thrctx->pcb_edi);
            case 8:  return (&kdb_thrctx->pcb_eip);
            case 10: return (&_kcodesel);
            case 11: return (&_kdatasel);
            case 12: return (&_kdatasel);
            case 13: return (&_kdatasel);
            case 14: return (&_kprivsel);
            case 15: return (&kdb_thrctx->pcb_gs);
            }
            return (NULL);
    }
    
    void
    gdb_cpu_setreg(int regnum, void *val)
    {
    
            switch (regnum) {
            case GDB_REG_PC:
                    kdb_thrctx->pcb_eip = *(register_t *)val;
                    if (kdb_thread  == curthread)
                            kdb_frame->tf_eip = *(register_t *)val;
            }
    }
    
    int
   gdb_cpu_signal(int type, int code)
   {
   
           switch (type) {
           case T_BPTFLT: return (SIGTRAP);
           case T_ARITHTRAP: return (SIGFPE);
           case T_PROTFLT: return (SIGSEGV);
           case T_TRCTRAP: return (SIGTRAP);
           case T_PAGEFLT: return (SIGSEGV);
           case T_DIVIDE: return (SIGFPE);
           case T_NMI: return (SIGTRAP);
           case T_FPOPFLT: return (SIGILL);
           case T_TSSFLT: return (SIGSEGV);
           case T_SEGNPFLT: return (SIGSEGV);
           case T_STKFLT: return (SIGSEGV);
           case T_XMMFLT: return (SIGFPE);
           }
           return (SIGEMT);
   }
   
   void
   gdb_cpu_stop_reason(int type, int code)
   {
           uintmax_t val;
   
           val = 0;
           if (type == T_TRCTRAP) {
                   /* NB: 'code' contains the value of dr6 at the trap. */
                   if ((code & DBREG_DR6_B(0)) != 0) {
                           val = rdr0();
                   }
                   if ((code & DBREG_DR6_B(1)) != 0) {
                           val = rdr1();
                   }
                   if ((code & DBREG_DR6_B(2)) != 0) {
                           val = rdr2();
                   }
                   if ((code & DBREG_DR6_B(3)) != 0) {
                           val = rdr3();
                   }
   
                   /*
                    * TODO: validate the bits in DR7 to differentiate between a
                    * watchpoint trap and a hardware breakpoint trap (currently
                    * unsupported).
                    */
                   if (val != 0) {
                           gdb_tx_str("watch:");
                           gdb_tx_varhex(val);
                           gdb_tx_char(';');
                   }
           }
   }

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