The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/db_trace.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 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/9.1/sys/i386/i386/db_trace.c 183413 2008-09-27 15:54:04Z kib $");
   29 
   30 #include <sys/param.h>
   31 #include <sys/systm.h>
   32 #include <sys/kdb.h>
   33 #include <sys/proc.h>
   34 #include <sys/sysent.h>
   35 
   36 #include <machine/cpu.h>
   37 #include <machine/md_var.h>
   38 #include <machine/pcb.h>
   39 #include <machine/reg.h>
   40 #include <machine/stack.h>
   41 
   42 #include <vm/vm.h>
   43 #include <vm/vm_param.h>
   44 #include <vm/pmap.h>
   45 
   46 #include <ddb/ddb.h>
   47 #include <ddb/db_access.h>
   48 #include <ddb/db_sym.h>
   49 #include <ddb/db_variables.h>
   50 
   51 static db_varfcn_t db_dr0;
   52 static db_varfcn_t db_dr1;
   53 static db_varfcn_t db_dr2;
   54 static db_varfcn_t db_dr3;
   55 static db_varfcn_t db_dr4;
   56 static db_varfcn_t db_dr5;
   57 static db_varfcn_t db_dr6;
   58 static db_varfcn_t db_dr7;
   59 static db_varfcn_t db_esp;
   60 static db_varfcn_t db_frame;
   61 static db_varfcn_t db_ss;
   62 
   63 /*
   64  * Machine register set.
   65  */
   66 #define DB_OFFSET(x)    (db_expr_t *)offsetof(struct trapframe, x)
   67 struct db_variable db_regs[] = {
   68         { "cs",         DB_OFFSET(tf_cs),       db_frame },
   69         { "ds",         DB_OFFSET(tf_ds),       db_frame },
   70         { "es",         DB_OFFSET(tf_es),       db_frame },
   71         { "fs",         DB_OFFSET(tf_fs),       db_frame },
   72         { "ss",         NULL,                   db_ss },
   73         { "eax",        DB_OFFSET(tf_eax),      db_frame },
   74         { "ecx",        DB_OFFSET(tf_ecx),      db_frame },
   75         { "edx",        DB_OFFSET(tf_edx),      db_frame },
   76         { "ebx",        DB_OFFSET(tf_ebx),      db_frame },
   77         { "esp",        NULL,                   db_esp },
   78         { "ebp",        DB_OFFSET(tf_ebp),      db_frame },
   79         { "esi",        DB_OFFSET(tf_esi),      db_frame },
   80         { "edi",        DB_OFFSET(tf_edi),      db_frame },
   81         { "eip",        DB_OFFSET(tf_eip),      db_frame },
   82         { "efl",        DB_OFFSET(tf_eflags),   db_frame },
   83 #define DB_N_SHOW_REGS  15      /* Don't show registers after here. */
   84         { "dr0",        NULL,                   db_dr0 },
   85         { "dr1",        NULL,                   db_dr1 },
   86         { "dr2",        NULL,                   db_dr2 },
   87         { "dr3",        NULL,                   db_dr3 },
   88         { "dr4",        NULL,                   db_dr4 },
   89         { "dr5",        NULL,                   db_dr5 },
   90         { "dr6",        NULL,                   db_dr6 },
   91         { "dr7",        NULL,                   db_dr7 },
   92 };
   93 struct db_variable *db_eregs = db_regs + DB_N_SHOW_REGS;
   94 
   95 #define DB_DRX_FUNC(reg)                \
   96 static int                              \
   97 db_ ## reg (vp, valuep, op)             \
   98         struct db_variable *vp;         \
   99         db_expr_t * valuep;             \
  100         int op;                         \
  101 {                                       \
  102         if (op == DB_VAR_GET)           \
  103                 *valuep = r ## reg ();  \
  104         else                            \
  105                 load_ ## reg (*valuep); \
  106         return (1);                     \
  107 }
  108 
  109 DB_DRX_FUNC(dr0)
  110 DB_DRX_FUNC(dr1)
  111 DB_DRX_FUNC(dr2)
  112 DB_DRX_FUNC(dr3)
  113 DB_DRX_FUNC(dr4)
  114 DB_DRX_FUNC(dr5)
  115 DB_DRX_FUNC(dr6)
  116 DB_DRX_FUNC(dr7)
  117 
  118 static __inline int
  119 get_esp(struct trapframe *tf)
  120 {
  121         return ((ISPL(tf->tf_cs)) ? tf->tf_esp :
  122             (db_expr_t)tf + (uintptr_t)DB_OFFSET(tf_esp));
  123 }
  124 
  125 static int
  126 db_frame(struct db_variable *vp, db_expr_t *valuep, int op)
  127 {
  128         int *reg;
  129 
  130         if (kdb_frame == NULL)
  131                 return (0);
  132 
  133         reg = (int *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep);
  134         if (op == DB_VAR_GET)
  135                 *valuep = *reg;
  136         else
  137                 *reg = *valuep;
  138         return (1);
  139 }
  140 
  141 static int
  142 db_esp(struct db_variable *vp, db_expr_t *valuep, int op)
  143 {
  144 
  145         if (kdb_frame == NULL)
  146                 return (0);
  147 
  148         if (op == DB_VAR_GET)
  149                 *valuep = get_esp(kdb_frame);
  150         else if (ISPL(kdb_frame->tf_cs))
  151                 kdb_frame->tf_esp = *valuep;
  152         return (1);
  153 }
  154 
  155 static int
  156 db_ss(struct db_variable *vp, db_expr_t *valuep, int op)
  157 {
  158 
  159         if (kdb_frame == NULL)
  160                 return (0);
  161 
  162         if (op == DB_VAR_GET)
  163                 *valuep = (ISPL(kdb_frame->tf_cs)) ? kdb_frame->tf_ss : rss();
  164         else if (ISPL(kdb_frame->tf_cs))
  165                 kdb_frame->tf_ss = *valuep;
  166         return (1);
  167 }
  168 
  169 #define NORMAL          0
  170 #define TRAP            1
  171 #define INTERRUPT       2
  172 #define SYSCALL         3
  173 #define DOUBLE_FAULT    4
  174 #define TRAP_INTERRUPT  5
  175 #define TRAP_TIMERINT   6
  176 
  177 static void db_nextframe(struct i386_frame **, db_addr_t *, struct thread *);
  178 static int db_numargs(struct i386_frame *);
  179 static void db_print_stack_entry(const char *, int, char **, int *, db_addr_t);
  180 static void decode_syscall(int, struct thread *);
  181 
  182 static const char * watchtype_str(int type);
  183 int  i386_set_watch(int watchnum, unsigned int watchaddr, int size, int access,
  184                     struct dbreg *d);
  185 int  i386_clr_watch(int watchnum, struct dbreg *d);
  186 
  187 /*
  188  * Figure out how many arguments were passed into the frame at "fp".
  189  */
  190 static int
  191 db_numargs(fp)
  192         struct i386_frame *fp;
  193 {
  194         char   *argp;
  195         int     inst;
  196         int     args;
  197 
  198         argp = (char *)db_get_value((int)&fp->f_retaddr, 4, FALSE);
  199         /*
  200          * XXX etext is wrong for LKMs.  We should attempt to interpret
  201          * the instruction at the return address in all cases.  This
  202          * may require better fault handling.
  203          */
  204         if (argp < btext || argp >= etext) {
  205                 args = -1;
  206         } else {
  207 retry:
  208                 inst = db_get_value((int)argp, 4, FALSE);
  209                 if ((inst & 0xff) == 0x59)      /* popl %ecx */
  210                         args = 1;
  211                 else if ((inst & 0xffff) == 0xc483)     /* addl $Ibs, %esp */
  212                         args = ((inst >> 16) & 0xff) / 4;
  213                 else if ((inst & 0xf8ff) == 0xc089) {   /* movl %eax, %Reg */
  214                         argp += 2;
  215                         goto retry;
  216                 } else
  217                         args = -1;
  218         }
  219         return (args);
  220 }
  221 
  222 static void
  223 db_print_stack_entry(name, narg, argnp, argp, callpc)
  224         const char *name;
  225         int narg;
  226         char **argnp;
  227         int *argp;
  228         db_addr_t callpc;
  229 {
  230         int n = narg >= 0 ? narg : 5;
  231 
  232         db_printf("%s(", name);
  233         while (n) {
  234                 if (argnp)
  235                         db_printf("%s=", *argnp++);
  236                 db_printf("%r", db_get_value((int)argp, 4, FALSE));
  237                 argp++;
  238                 if (--n != 0)
  239                         db_printf(",");
  240         }
  241         if (narg < 0)
  242                 db_printf(",...");
  243         db_printf(") at ");
  244         db_printsym(callpc, DB_STGY_PROC);
  245         db_printf("\n");
  246 }
  247 
  248 static void
  249 decode_syscall(int number, struct thread *td)
  250 {
  251         struct proc *p;
  252         c_db_sym_t sym;
  253         db_expr_t diff;
  254         sy_call_t *f;
  255         const char *symname;
  256 
  257         db_printf(" (%d", number);
  258         p = (td != NULL) ? td->td_proc : NULL;
  259         if (p != NULL && 0 <= number && number < p->p_sysent->sv_size) {
  260                 f = p->p_sysent->sv_table[number].sy_call;
  261                 sym = db_search_symbol((db_addr_t)f, DB_STGY_ANY, &diff);
  262                 if (sym != DB_SYM_NULL && diff == 0) {
  263                         db_symbol_values(sym, &symname, NULL);
  264                         db_printf(", %s, %s", p->p_sysent->sv_name, symname);
  265                 }
  266         }
  267         db_printf(")");
  268 }
  269 
  270 /*
  271  * Figure out the next frame up in the call stack.
  272  */
  273 static void
  274 db_nextframe(struct i386_frame **fp, db_addr_t *ip, struct thread *td)
  275 {
  276         struct trapframe *tf;
  277         int frame_type;
  278         int eip, esp, ebp;
  279         db_expr_t offset;
  280         c_db_sym_t sym;
  281         const char *name;
  282 
  283         eip = db_get_value((int) &(*fp)->f_retaddr, 4, FALSE);
  284         ebp = db_get_value((int) &(*fp)->f_frame, 4, FALSE);
  285 
  286         /*
  287          * Figure out frame type.  We look at the address just before
  288          * the saved instruction pointer as the saved EIP is after the
  289          * call function, and if the function being called is marked as
  290          * dead (such as panic() at the end of dblfault_handler()), then
  291          * the instruction at the saved EIP will be part of a different
  292          * function (syscall() in this example) rather than the one that
  293          * actually made the call.
  294          */
  295         frame_type = NORMAL;
  296         sym = db_search_symbol(eip - 1, DB_STGY_ANY, &offset);
  297         db_symbol_values(sym, &name, NULL);
  298         if (name != NULL) {
  299                 if (strcmp(name, "calltrap") == 0 ||
  300                     strcmp(name, "fork_trampoline") == 0)
  301                         frame_type = TRAP;
  302                 else if (strncmp(name, "Xatpic_intr", 11) == 0 ||
  303                     strncmp(name, "Xapic_isr", 9) == 0)
  304                         frame_type = INTERRUPT;
  305                 else if (strcmp(name, "Xlcall_syscall") == 0 ||
  306                     strcmp(name, "Xint0x80_syscall") == 0)
  307                         frame_type = SYSCALL;
  308                 else if (strcmp(name, "dblfault_handler") == 0)
  309                         frame_type = DOUBLE_FAULT;
  310                 /* XXX: These are interrupts with trap frames. */
  311                 else if (strcmp(name, "Xtimerint") == 0)
  312                         frame_type = TRAP_TIMERINT;
  313                 else if (strcmp(name, "Xcpustop") == 0 ||
  314                     strcmp(name, "Xrendezvous") == 0 ||
  315                     strcmp(name, "Xipi_intr_bitmap_handler") == 0 ||
  316                     strcmp(name, "Xlazypmap") == 0)
  317                         frame_type = TRAP_INTERRUPT;
  318         }
  319 
  320         /*
  321          * Normal frames need no special processing.
  322          */
  323         if (frame_type == NORMAL) {
  324                 *ip = (db_addr_t) eip;
  325                 *fp = (struct i386_frame *) ebp;
  326                 return;
  327         }
  328 
  329         db_print_stack_entry(name, 0, 0, 0, eip);
  330 
  331         /*
  332          * For a double fault, we have to snag the values from the
  333          * previous TSS since a double fault uses a task gate to
  334          * switch to a known good state.
  335          */
  336         if (frame_type == DOUBLE_FAULT) {
  337                 esp = PCPU_GET(common_tss.tss_esp);
  338                 eip = PCPU_GET(common_tss.tss_eip);
  339                 ebp = PCPU_GET(common_tss.tss_ebp);
  340                 db_printf(
  341                     "--- trap 0x17, eip = %#r, esp = %#r, ebp = %#r ---\n",
  342                     eip, esp, ebp);
  343                 *ip = (db_addr_t) eip;
  344                 *fp = (struct i386_frame *) ebp;
  345                 return;
  346         }
  347 
  348         /*
  349          * Point to base of trapframe which is just above the
  350          * current frame.
  351          */
  352         if (frame_type == INTERRUPT)
  353                 tf = (struct trapframe *)((int)*fp + 16);
  354         else if (frame_type == TRAP_INTERRUPT)
  355                 tf = (struct trapframe *)((int)*fp + 8);
  356         else
  357                 tf = (struct trapframe *)((int)*fp + 12);
  358 
  359         if (INKERNEL((int) tf)) {
  360                 esp = get_esp(tf);
  361                 eip = tf->tf_eip;
  362                 ebp = tf->tf_ebp;
  363                 switch (frame_type) {
  364                 case TRAP:
  365                         db_printf("--- trap %#r", tf->tf_trapno);
  366                         break;
  367                 case SYSCALL:
  368                         db_printf("--- syscall");
  369                         decode_syscall(tf->tf_eax, td);
  370                         break;
  371                 case TRAP_TIMERINT:
  372                 case TRAP_INTERRUPT:
  373                 case INTERRUPT:
  374                         db_printf("--- interrupt");
  375                         break;
  376                 default:
  377                         panic("The moon has moved again.");
  378                 }
  379                 db_printf(", eip = %#r, esp = %#r, ebp = %#r ---\n", eip,
  380                     esp, ebp);
  381         }
  382 
  383         *ip = (db_addr_t) eip;
  384         *fp = (struct i386_frame *) ebp;
  385 }
  386 
  387 static int
  388 db_backtrace(struct thread *td, struct trapframe *tf, struct i386_frame *frame,
  389     db_addr_t pc, int count)
  390 {
  391         struct i386_frame *actframe;
  392 #define MAXNARG 16
  393         char *argnames[MAXNARG], **argnp = NULL;
  394         const char *name;
  395         int *argp;
  396         db_expr_t offset;
  397         c_db_sym_t sym;
  398         int instr, narg;
  399         boolean_t first;
  400 
  401         /*
  402          * If an indirect call via an invalid pointer caused a trap,
  403          * %pc contains the invalid address while the return address
  404          * of the unlucky caller has been saved by CPU on the stack
  405          * just before the trap frame.  In this case, try to recover
  406          * the caller's address so that the first frame is assigned
  407          * to the right spot in the right function, for that is where
  408          * the failure actually happened.
  409          *
  410          * This trick depends on the fault address stashed in tf_err
  411          * by trap_fatal() before entering KDB.
  412          */
  413         if (kdb_frame && pc == kdb_frame->tf_err) {
  414                 /*
  415                  * Find where the trap frame actually ends.
  416                  * It won't contain tf_esp or tf_ss unless crossing rings.
  417                  */
  418                 if (ISPL(kdb_frame->tf_cs))
  419                         instr = (int)(kdb_frame + 1);
  420                 else
  421                         instr = (int)&kdb_frame->tf_esp;
  422                 pc = db_get_value(instr, 4, FALSE);
  423         }
  424 
  425         if (count == -1)
  426                 count = 1024;
  427 
  428         first = TRUE;
  429         while (count-- && !db_pager_quit) {
  430                 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
  431                 db_symbol_values(sym, &name, NULL);
  432 
  433                 /*
  434                  * Attempt to determine a (possibly fake) frame that gives
  435                  * the caller's pc.  It may differ from `frame' if the
  436                  * current function never sets up a standard frame or hasn't
  437                  * set one up yet or has just discarded one.  The last two
  438                  * cases can be guessed fairly reliably for code generated
  439                  * by gcc.  The first case is too much trouble to handle in
  440                  * general because the amount of junk on the stack depends
  441                  * on the pc (the special handling of "calltrap", etc. in
  442                  * db_nextframe() works because the `next' pc is special).
  443                  */
  444                 actframe = frame;
  445                 if (first) {
  446                         if (tf != NULL) {
  447                                 instr = db_get_value(pc, 4, FALSE);
  448                                 if ((instr & 0xffffff) == 0x00e58955) {
  449                                         /* pushl %ebp; movl %esp, %ebp */
  450                                         actframe = (void *)(get_esp(tf) - 4);
  451                                 } else if ((instr & 0xffff) == 0x0000e589) {
  452                                         /* movl %esp, %ebp */
  453                                         actframe = (void *)get_esp(tf);
  454                                         if (tf->tf_ebp == 0) {
  455                                                 /* Fake frame better. */
  456                                                 frame = actframe;
  457                                         }
  458                                 } else if ((instr & 0xff) == 0x000000c3) {
  459                                         /* ret */
  460                                         actframe = (void *)(get_esp(tf) - 4);
  461                                 } else if (offset == 0) {
  462                                         /* Probably an assembler symbol. */
  463                                         actframe = (void *)(get_esp(tf) - 4);
  464                                 }
  465                         } else if (strcmp(name, "fork_trampoline") == 0) {
  466                                 /*
  467                                  * Don't try to walk back on a stack for a
  468                                  * process that hasn't actually been run yet.
  469                                  */
  470                                 db_print_stack_entry(name, 0, 0, 0, pc);
  471                                 break;
  472                         }
  473                         first = FALSE;
  474                 }
  475 
  476                 argp = &actframe->f_arg0;
  477                 narg = MAXNARG;
  478                 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
  479                         argnp = argnames;
  480                 } else {
  481                         narg = db_numargs(frame);
  482                 }
  483 
  484                 db_print_stack_entry(name, narg, argnp, argp, pc);
  485 
  486                 if (actframe != frame) {
  487                         /* `frame' belongs to caller. */
  488                         pc = (db_addr_t)
  489                             db_get_value((int)&actframe->f_retaddr, 4, FALSE);
  490                         continue;
  491                 }
  492 
  493                 db_nextframe(&frame, &pc, td);
  494 
  495                 if (INKERNEL((int)pc) && !INKERNEL((int) frame)) {
  496                         sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
  497                         db_symbol_values(sym, &name, NULL);
  498                         db_print_stack_entry(name, 0, 0, 0, pc);
  499                         break;
  500                 }
  501                 if (!INKERNEL((int) frame)) {
  502                         break;
  503                 }
  504         }
  505 
  506         return (0);
  507 }
  508 
  509 void
  510 db_trace_self(void)
  511 {
  512         struct i386_frame *frame;
  513         db_addr_t callpc;
  514         register_t ebp;
  515 
  516         __asm __volatile("movl %%ebp,%0" : "=r" (ebp));
  517         frame = (struct i386_frame *)ebp;
  518         callpc = (db_addr_t)db_get_value((int)&frame->f_retaddr, 4, FALSE);
  519         frame = frame->f_frame;
  520         db_backtrace(curthread, NULL, frame, callpc, -1);
  521 }
  522 
  523 int
  524 db_trace_thread(struct thread *thr, int count)
  525 {
  526         struct pcb *ctx;
  527 
  528         ctx = kdb_thr_ctx(thr);
  529         return (db_backtrace(thr, NULL, (struct i386_frame *)ctx->pcb_ebp,
  530                     ctx->pcb_eip, count));
  531 }
  532 
  533 int
  534 i386_set_watch(watchnum, watchaddr, size, access, d)
  535         int watchnum;
  536         unsigned int watchaddr;
  537         int size;
  538         int access;
  539         struct dbreg *d;
  540 {
  541         int i, len;
  542 
  543         if (watchnum == -1) {
  544                 for (i = 0; i < 4; i++)
  545                         if (!DBREG_DR7_ENABLED(d->dr[7], i))
  546                                 break;
  547                 if (i < 4)
  548                         watchnum = i;
  549                 else
  550                         return (-1);
  551         }
  552 
  553         switch (access) {
  554         case DBREG_DR7_EXEC:
  555                 size = 1; /* size must be 1 for an execution breakpoint */
  556                 /* fall through */
  557         case DBREG_DR7_WRONLY:
  558         case DBREG_DR7_RDWR:
  559                 break;
  560         default:
  561                 return (-1);
  562         }
  563 
  564         /*
  565          * we can watch a 1, 2, or 4 byte sized location
  566          */
  567         switch (size) {
  568         case 1:
  569                 len = DBREG_DR7_LEN_1;
  570                 break;
  571         case 2:
  572                 len = DBREG_DR7_LEN_2;
  573                 break;
  574         case 4:
  575                 len = DBREG_DR7_LEN_4;
  576                 break;
  577         default:
  578                 return (-1);
  579         }
  580 
  581         /* clear the bits we are about to affect */
  582         d->dr[7] &= ~DBREG_DR7_MASK(watchnum);
  583 
  584         /* set drN register to the address, N=watchnum */
  585         DBREG_DRX(d, watchnum) = watchaddr;
  586 
  587         /* enable the watchpoint */
  588         d->dr[7] |= DBREG_DR7_SET(watchnum, len, access,
  589             DBREG_DR7_GLOBAL_ENABLE);
  590 
  591         return (watchnum);
  592 }
  593 
  594 
  595 int
  596 i386_clr_watch(watchnum, d)
  597         int watchnum;
  598         struct dbreg *d;
  599 {
  600 
  601         if (watchnum < 0 || watchnum >= 4)
  602                 return (-1);
  603 
  604         d->dr[7] &= ~DBREG_DR7_MASK(watchnum);
  605         DBREG_DRX(d, watchnum) = 0;
  606 
  607         return (0);
  608 }
  609 
  610 
  611 int
  612 db_md_set_watchpoint(addr, size)
  613         db_expr_t addr;
  614         db_expr_t size;
  615 {
  616         struct dbreg d;
  617         int avail, i, wsize;
  618 
  619         fill_dbregs(NULL, &d);
  620 
  621         avail = 0;
  622         for(i = 0; i < 4; i++) {
  623                 if (!DBREG_DR7_ENABLED(d.dr[7], i))
  624                         avail++;
  625         }
  626 
  627         if (avail * 4 < size)
  628                 return (-1);
  629 
  630         for (i = 0; i < 4 && (size > 0); i++) {
  631                 if (!DBREG_DR7_ENABLED(d.dr[7], i)) {
  632                         if (size > 2)
  633                                 wsize = 4;
  634                         else
  635                                 wsize = size;
  636                         i386_set_watch(i, addr, wsize,
  637                                        DBREG_DR7_WRONLY, &d);
  638                         addr += wsize;
  639                         size -= wsize;
  640                 }
  641         }
  642 
  643         set_dbregs(NULL, &d);
  644 
  645         return(0);
  646 }
  647 
  648 
  649 int
  650 db_md_clr_watchpoint(addr, size)
  651         db_expr_t addr;
  652         db_expr_t size;
  653 {
  654         struct dbreg d;
  655         int i;
  656 
  657         fill_dbregs(NULL, &d);
  658 
  659         for(i = 0; i < 4; i++) {
  660                 if (DBREG_DR7_ENABLED(d.dr[7], i)) {
  661                         if ((DBREG_DRX((&d), i) >= addr) &&
  662                             (DBREG_DRX((&d), i) < addr+size))
  663                                 i386_clr_watch(i, &d);
  664 
  665                 }
  666         }
  667 
  668         set_dbregs(NULL, &d);
  669 
  670         return(0);
  671 }
  672 
  673 
  674 static const char *
  675 watchtype_str(type)
  676         int type;
  677 {
  678         switch (type) {
  679                 case DBREG_DR7_EXEC   : return "execute";    break;
  680                 case DBREG_DR7_RDWR   : return "read/write"; break;
  681                 case DBREG_DR7_WRONLY : return "write";      break;
  682                 default               : return "invalid";    break;
  683         }
  684 }
  685 
  686 
  687 void
  688 db_md_list_watchpoints()
  689 {
  690         struct dbreg d;
  691         int i, len, type;
  692 
  693         fill_dbregs(NULL, &d);
  694 
  695         db_printf("\nhardware watchpoints:\n");
  696         db_printf("  watch    status        type  len     address\n");
  697         db_printf("  -----  --------  ----------  ---  ----------\n");
  698         for (i = 0; i < 4; i++) {
  699                 if (DBREG_DR7_ENABLED(d.dr[7], i)) {
  700                         type = DBREG_DR7_ACCESS(d.dr[7], i);
  701                         len = DBREG_DR7_LEN(d.dr[7], i);
  702                         db_printf("  %-5d  %-8s  %10s  %3d  ",
  703                             i, "enabled", watchtype_str(type), len + 1);
  704                         db_printsym((db_addr_t)DBREG_DRX((&d), i), DB_STGY_ANY);
  705                         db_printf("\n");
  706                 } else {
  707                         db_printf("  %-5d  disabled\n", i);
  708                 }
  709         }
  710 
  711         db_printf("\ndebug register values:\n");
  712         for (i = 0; i < 8; i++) {
  713                 db_printf("  dr%d 0x%08x\n", i, DBREG_DRX((&d), i));
  714         }
  715         db_printf("\n");
  716 }
  717 
  718 

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