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/9.2/sys/i386/i386/db_trace.c 244337 2012-12-17 05:13:15Z 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     void *);
  181 static void decode_syscall(int, struct thread *);
  182 
  183 static const char * watchtype_str(int type);
  184 int  i386_set_watch(int watchnum, unsigned int watchaddr, int size, int access,
  185                     struct dbreg *d);
  186 int  i386_clr_watch(int watchnum, struct dbreg *d);
  187 
  188 /*
  189  * Figure out how many arguments were passed into the frame at "fp".
  190  */
  191 static int
  192 db_numargs(fp)
  193         struct i386_frame *fp;
  194 {
  195         char   *argp;
  196         int     inst;
  197         int     args;
  198 
  199         argp = (char *)db_get_value((int)&fp->f_retaddr, 4, FALSE);
  200         /*
  201          * XXX etext is wrong for LKMs.  We should attempt to interpret
  202          * the instruction at the return address in all cases.  This
  203          * may require better fault handling.
  204          */
  205         if (argp < btext || argp >= etext) {
  206                 args = -1;
  207         } else {
  208 retry:
  209                 inst = db_get_value((int)argp, 4, FALSE);
  210                 if ((inst & 0xff) == 0x59)      /* popl %ecx */
  211                         args = 1;
  212                 else if ((inst & 0xffff) == 0xc483)     /* addl $Ibs, %esp */
  213                         args = ((inst >> 16) & 0xff) / 4;
  214                 else if ((inst & 0xf8ff) == 0xc089) {   /* movl %eax, %Reg */
  215                         argp += 2;
  216                         goto retry;
  217                 } else
  218                         args = -1;
  219         }
  220         return (args);
  221 }
  222 
  223 static void
  224 db_print_stack_entry(name, narg, argnp, argp, callpc, frame)
  225         const char *name;
  226         int narg;
  227         char **argnp;
  228         int *argp;
  229         db_addr_t callpc;
  230         void *frame;
  231 {
  232         int n = narg >= 0 ? narg : 5;
  233 
  234         db_printf("%s(", name);
  235         while (n) {
  236                 if (argnp)
  237                         db_printf("%s=", *argnp++);
  238                 db_printf("%r", db_get_value((int)argp, 4, FALSE));
  239                 argp++;
  240                 if (--n != 0)
  241                         db_printf(",");
  242         }
  243         if (narg < 0)
  244                 db_printf(",...");
  245         db_printf(") at ");
  246         db_printsym(callpc, DB_STGY_PROC);
  247         if (frame != NULL)
  248                 db_printf("/frame 0x%r", (register_t)frame);
  249         db_printf("\n");
  250 }
  251 
  252 static void
  253 decode_syscall(int number, struct thread *td)
  254 {
  255         struct proc *p;
  256         c_db_sym_t sym;
  257         db_expr_t diff;
  258         sy_call_t *f;
  259         const char *symname;
  260 
  261         db_printf(" (%d", number);
  262         p = (td != NULL) ? td->td_proc : NULL;
  263         if (p != NULL && 0 <= number && number < p->p_sysent->sv_size) {
  264                 f = p->p_sysent->sv_table[number].sy_call;
  265                 sym = db_search_symbol((db_addr_t)f, DB_STGY_ANY, &diff);
  266                 if (sym != DB_SYM_NULL && diff == 0) {
  267                         db_symbol_values(sym, &symname, NULL);
  268                         db_printf(", %s, %s", p->p_sysent->sv_name, symname);
  269                 }
  270         }
  271         db_printf(")");
  272 }
  273 
  274 /*
  275  * Figure out the next frame up in the call stack.
  276  */
  277 static void
  278 db_nextframe(struct i386_frame **fp, db_addr_t *ip, struct thread *td)
  279 {
  280         struct trapframe *tf;
  281         int frame_type;
  282         int eip, esp, ebp;
  283         db_expr_t offset;
  284         c_db_sym_t sym;
  285         const char *name;
  286 
  287         eip = db_get_value((int) &(*fp)->f_retaddr, 4, FALSE);
  288         ebp = db_get_value((int) &(*fp)->f_frame, 4, FALSE);
  289 
  290         /*
  291          * Figure out frame type.  We look at the address just before
  292          * the saved instruction pointer as the saved EIP is after the
  293          * call function, and if the function being called is marked as
  294          * dead (such as panic() at the end of dblfault_handler()), then
  295          * the instruction at the saved EIP will be part of a different
  296          * function (syscall() in this example) rather than the one that
  297          * actually made the call.
  298          */
  299         frame_type = NORMAL;
  300         sym = db_search_symbol(eip - 1, DB_STGY_ANY, &offset);
  301         db_symbol_values(sym, &name, NULL);
  302         if (name != NULL) {
  303                 if (strcmp(name, "calltrap") == 0 ||
  304                     strcmp(name, "fork_trampoline") == 0)
  305                         frame_type = TRAP;
  306                 else if (strncmp(name, "Xatpic_intr", 11) == 0 ||
  307                     strncmp(name, "Xapic_isr", 9) == 0)
  308                         frame_type = INTERRUPT;
  309                 else if (strcmp(name, "Xlcall_syscall") == 0 ||
  310                     strcmp(name, "Xint0x80_syscall") == 0)
  311                         frame_type = SYSCALL;
  312                 else if (strcmp(name, "dblfault_handler") == 0)
  313                         frame_type = DOUBLE_FAULT;
  314                 /* XXX: These are interrupts with trap frames. */
  315                 else if (strcmp(name, "Xtimerint") == 0)
  316                         frame_type = TRAP_TIMERINT;
  317                 else if (strcmp(name, "Xcpustop") == 0 ||
  318                     strcmp(name, "Xrendezvous") == 0 ||
  319                     strcmp(name, "Xipi_intr_bitmap_handler") == 0 ||
  320                     strcmp(name, "Xlazypmap") == 0)
  321                         frame_type = TRAP_INTERRUPT;
  322         }
  323 
  324         /*
  325          * Normal frames need no special processing.
  326          */
  327         if (frame_type == NORMAL) {
  328                 *ip = (db_addr_t) eip;
  329                 *fp = (struct i386_frame *) ebp;
  330                 return;
  331         }
  332 
  333         db_print_stack_entry(name, 0, 0, 0, eip, &(*fp)->f_frame);
  334 
  335         /*
  336          * For a double fault, we have to snag the values from the
  337          * previous TSS since a double fault uses a task gate to
  338          * switch to a known good state.
  339          */
  340         if (frame_type == DOUBLE_FAULT) {
  341                 esp = PCPU_GET(common_tss.tss_esp);
  342                 eip = PCPU_GET(common_tss.tss_eip);
  343                 ebp = PCPU_GET(common_tss.tss_ebp);
  344                 db_printf(
  345                     "--- trap 0x17, eip = %#r, esp = %#r, ebp = %#r ---\n",
  346                     eip, esp, ebp);
  347                 *ip = (db_addr_t) eip;
  348                 *fp = (struct i386_frame *) ebp;
  349                 return;
  350         }
  351 
  352         /*
  353          * Point to base of trapframe which is just above the
  354          * current frame.
  355          */
  356         if (frame_type == INTERRUPT)
  357                 tf = (struct trapframe *)((int)*fp + 16);
  358         else if (frame_type == TRAP_INTERRUPT)
  359                 tf = (struct trapframe *)((int)*fp + 8);
  360         else
  361                 tf = (struct trapframe *)((int)*fp + 12);
  362 
  363         if (INKERNEL((int) tf)) {
  364                 esp = get_esp(tf);
  365                 eip = tf->tf_eip;
  366                 ebp = tf->tf_ebp;
  367                 switch (frame_type) {
  368                 case TRAP:
  369                         db_printf("--- trap %#r", tf->tf_trapno);
  370                         break;
  371                 case SYSCALL:
  372                         db_printf("--- syscall");
  373                         decode_syscall(tf->tf_eax, td);
  374                         break;
  375                 case TRAP_TIMERINT:
  376                 case TRAP_INTERRUPT:
  377                 case INTERRUPT:
  378                         db_printf("--- interrupt");
  379                         break;
  380                 default:
  381                         panic("The moon has moved again.");
  382                 }
  383                 db_printf(", eip = %#r, esp = %#r, ebp = %#r ---\n", eip,
  384                     esp, ebp);
  385         }
  386 
  387         *ip = (db_addr_t) eip;
  388         *fp = (struct i386_frame *) ebp;
  389 }
  390 
  391 static int
  392 db_backtrace(struct thread *td, struct trapframe *tf, struct i386_frame *frame,
  393     db_addr_t pc, int count)
  394 {
  395         struct i386_frame *actframe;
  396 #define MAXNARG 16
  397         char *argnames[MAXNARG], **argnp = NULL;
  398         const char *name;
  399         int *argp;
  400         db_expr_t offset;
  401         c_db_sym_t sym;
  402         int instr, narg;
  403         boolean_t first;
  404 
  405         /*
  406          * If an indirect call via an invalid pointer caused a trap,
  407          * %pc contains the invalid address while the return address
  408          * of the unlucky caller has been saved by CPU on the stack
  409          * just before the trap frame.  In this case, try to recover
  410          * the caller's address so that the first frame is assigned
  411          * to the right spot in the right function, for that is where
  412          * the failure actually happened.
  413          *
  414          * This trick depends on the fault address stashed in tf_err
  415          * by trap_fatal() before entering KDB.
  416          */
  417         if (kdb_frame && pc == kdb_frame->tf_err) {
  418                 /*
  419                  * Find where the trap frame actually ends.
  420                  * It won't contain tf_esp or tf_ss unless crossing rings.
  421                  */
  422                 if (ISPL(kdb_frame->tf_cs))
  423                         instr = (int)(kdb_frame + 1);
  424                 else
  425                         instr = (int)&kdb_frame->tf_esp;
  426                 pc = db_get_value(instr, 4, FALSE);
  427         }
  428 
  429         if (count == -1)
  430                 count = 1024;
  431 
  432         first = TRUE;
  433         while (count-- && !db_pager_quit) {
  434                 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
  435                 db_symbol_values(sym, &name, NULL);
  436 
  437                 /*
  438                  * Attempt to determine a (possibly fake) frame that gives
  439                  * the caller's pc.  It may differ from `frame' if the
  440                  * current function never sets up a standard frame or hasn't
  441                  * set one up yet or has just discarded one.  The last two
  442                  * cases can be guessed fairly reliably for code generated
  443                  * by gcc.  The first case is too much trouble to handle in
  444                  * general because the amount of junk on the stack depends
  445                  * on the pc (the special handling of "calltrap", etc. in
  446                  * db_nextframe() works because the `next' pc is special).
  447                  */
  448                 actframe = frame;
  449                 if (first) {
  450                         if (tf != NULL) {
  451                                 instr = db_get_value(pc, 4, FALSE);
  452                                 if ((instr & 0xffffff) == 0x00e58955) {
  453                                         /* pushl %ebp; movl %esp, %ebp */
  454                                         actframe = (void *)(get_esp(tf) - 4);
  455                                 } else if ((instr & 0xffff) == 0x0000e589) {
  456                                         /* movl %esp, %ebp */
  457                                         actframe = (void *)get_esp(tf);
  458                                         if (tf->tf_ebp == 0) {
  459                                                 /* Fake frame better. */
  460                                                 frame = actframe;
  461                                         }
  462                                 } else if ((instr & 0xff) == 0x000000c3) {
  463                                         /* ret */
  464                                         actframe = (void *)(get_esp(tf) - 4);
  465                                 } else if (offset == 0) {
  466                                         /* Probably an assembler symbol. */
  467                                         actframe = (void *)(get_esp(tf) - 4);
  468                                 }
  469                         } else if (strcmp(name, "fork_trampoline") == 0) {
  470                                 /*
  471                                  * Don't try to walk back on a stack for a
  472                                  * process that hasn't actually been run yet.
  473                                  */
  474                                 db_print_stack_entry(name, 0, 0, 0, pc,
  475                                     actframe);
  476                                 break;
  477                         }
  478                         first = FALSE;
  479                 }
  480 
  481                 argp = &actframe->f_arg0;
  482                 narg = MAXNARG;
  483                 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
  484                         argnp = argnames;
  485                 } else {
  486                         narg = db_numargs(frame);
  487                 }
  488 
  489                 db_print_stack_entry(name, narg, argnp, argp, pc, actframe);
  490 
  491                 if (actframe != frame) {
  492                         /* `frame' belongs to caller. */
  493                         pc = (db_addr_t)
  494                             db_get_value((int)&actframe->f_retaddr, 4, FALSE);
  495                         continue;
  496                 }
  497 
  498                 db_nextframe(&frame, &pc, td);
  499 
  500                 if (INKERNEL((int)pc) && !INKERNEL((int) frame)) {
  501                         sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
  502                         db_symbol_values(sym, &name, NULL);
  503                         db_print_stack_entry(name, 0, 0, 0, pc, frame);
  504                         break;
  505                 }
  506                 if (!INKERNEL((int) frame)) {
  507                         break;
  508                 }
  509         }
  510 
  511         return (0);
  512 }
  513 
  514 void
  515 db_trace_self(void)
  516 {
  517         struct i386_frame *frame;
  518         db_addr_t callpc;
  519         register_t ebp;
  520 
  521         __asm __volatile("movl %%ebp,%0" : "=r" (ebp));
  522         frame = (struct i386_frame *)ebp;
  523         callpc = (db_addr_t)db_get_value((int)&frame->f_retaddr, 4, FALSE);
  524         frame = frame->f_frame;
  525         db_backtrace(curthread, NULL, frame, callpc, -1);
  526 }
  527 
  528 int
  529 db_trace_thread(struct thread *thr, int count)
  530 {
  531         struct pcb *ctx;
  532 
  533         ctx = kdb_thr_ctx(thr);
  534         return (db_backtrace(thr, NULL, (struct i386_frame *)ctx->pcb_ebp,
  535                     ctx->pcb_eip, count));
  536 }
  537 
  538 int
  539 i386_set_watch(watchnum, watchaddr, size, access, d)
  540         int watchnum;
  541         unsigned int watchaddr;
  542         int size;
  543         int access;
  544         struct dbreg *d;
  545 {
  546         int i, len;
  547 
  548         if (watchnum == -1) {
  549                 for (i = 0; i < 4; i++)
  550                         if (!DBREG_DR7_ENABLED(d->dr[7], i))
  551                                 break;
  552                 if (i < 4)
  553                         watchnum = i;
  554                 else
  555                         return (-1);
  556         }
  557 
  558         switch (access) {
  559         case DBREG_DR7_EXEC:
  560                 size = 1; /* size must be 1 for an execution breakpoint */
  561                 /* fall through */
  562         case DBREG_DR7_WRONLY:
  563         case DBREG_DR7_RDWR:
  564                 break;
  565         default:
  566                 return (-1);
  567         }
  568 
  569         /*
  570          * we can watch a 1, 2, or 4 byte sized location
  571          */
  572         switch (size) {
  573         case 1:
  574                 len = DBREG_DR7_LEN_1;
  575                 break;
  576         case 2:
  577                 len = DBREG_DR7_LEN_2;
  578                 break;
  579         case 4:
  580                 len = DBREG_DR7_LEN_4;
  581                 break;
  582         default:
  583                 return (-1);
  584         }
  585 
  586         /* clear the bits we are about to affect */
  587         d->dr[7] &= ~DBREG_DR7_MASK(watchnum);
  588 
  589         /* set drN register to the address, N=watchnum */
  590         DBREG_DRX(d, watchnum) = watchaddr;
  591 
  592         /* enable the watchpoint */
  593         d->dr[7] |= DBREG_DR7_SET(watchnum, len, access,
  594             DBREG_DR7_GLOBAL_ENABLE);
  595 
  596         return (watchnum);
  597 }
  598 
  599 
  600 int
  601 i386_clr_watch(watchnum, d)
  602         int watchnum;
  603         struct dbreg *d;
  604 {
  605 
  606         if (watchnum < 0 || watchnum >= 4)
  607                 return (-1);
  608 
  609         d->dr[7] &= ~DBREG_DR7_MASK(watchnum);
  610         DBREG_DRX(d, watchnum) = 0;
  611 
  612         return (0);
  613 }
  614 
  615 
  616 int
  617 db_md_set_watchpoint(addr, size)
  618         db_expr_t addr;
  619         db_expr_t size;
  620 {
  621         struct dbreg d;
  622         int avail, i, wsize;
  623 
  624         fill_dbregs(NULL, &d);
  625 
  626         avail = 0;
  627         for(i = 0; i < 4; i++) {
  628                 if (!DBREG_DR7_ENABLED(d.dr[7], i))
  629                         avail++;
  630         }
  631 
  632         if (avail * 4 < size)
  633                 return (-1);
  634 
  635         for (i = 0; i < 4 && (size > 0); i++) {
  636                 if (!DBREG_DR7_ENABLED(d.dr[7], i)) {
  637                         if (size > 2)
  638                                 wsize = 4;
  639                         else
  640                                 wsize = size;
  641                         i386_set_watch(i, addr, wsize,
  642                                        DBREG_DR7_WRONLY, &d);
  643                         addr += wsize;
  644                         size -= wsize;
  645                 }
  646         }
  647 
  648         set_dbregs(NULL, &d);
  649 
  650         return(0);
  651 }
  652 
  653 
  654 int
  655 db_md_clr_watchpoint(addr, size)
  656         db_expr_t addr;
  657         db_expr_t size;
  658 {
  659         struct dbreg d;
  660         int i;
  661 
  662         fill_dbregs(NULL, &d);
  663 
  664         for(i = 0; i < 4; i++) {
  665                 if (DBREG_DR7_ENABLED(d.dr[7], i)) {
  666                         if ((DBREG_DRX((&d), i) >= addr) &&
  667                             (DBREG_DRX((&d), i) < addr+size))
  668                                 i386_clr_watch(i, &d);
  669 
  670                 }
  671         }
  672 
  673         set_dbregs(NULL, &d);
  674 
  675         return(0);
  676 }
  677 
  678 
  679 static const char *
  680 watchtype_str(type)
  681         int type;
  682 {
  683         switch (type) {
  684                 case DBREG_DR7_EXEC   : return "execute";    break;
  685                 case DBREG_DR7_RDWR   : return "read/write"; break;
  686                 case DBREG_DR7_WRONLY : return "write";      break;
  687                 default               : return "invalid";    break;
  688         }
  689 }
  690 
  691 
  692 void
  693 db_md_list_watchpoints()
  694 {
  695         struct dbreg d;
  696         int i, len, type;
  697 
  698         fill_dbregs(NULL, &d);
  699 
  700         db_printf("\nhardware watchpoints:\n");
  701         db_printf("  watch    status        type  len     address\n");
  702         db_printf("  -----  --------  ----------  ---  ----------\n");
  703         for (i = 0; i < 4; i++) {
  704                 if (DBREG_DR7_ENABLED(d.dr[7], i)) {
  705                         type = DBREG_DR7_ACCESS(d.dr[7], i);
  706                         len = DBREG_DR7_LEN(d.dr[7], i);
  707                         db_printf("  %-5d  %-8s  %10s  %3d  ",
  708                             i, "enabled", watchtype_str(type), len + 1);
  709                         db_printsym((db_addr_t)DBREG_DRX((&d), i), DB_STGY_ANY);
  710                         db_printf("\n");
  711                 } else {
  712                         db_printf("  %-5d  disabled\n", i);
  713                 }
  714         }
  715 
  716         db_printf("\ndebug register values:\n");
  717         for (i = 0; i < 8; i++) {
  718                 db_printf("  dr%d 0x%08x\n", i, DBREG_DRX((&d), i));
  719         }
  720         db_printf("\n");
  721 }
  722 
  723 

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