The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

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

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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/10.3/sys/i386/i386/db_trace.c 290731 2015-11-12 23:49:47Z jhb $");
   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_esp;
   52 static db_varfcn_t db_frame;
   53 static db_varfcn_t db_frame_seg;
   54 static db_varfcn_t db_gs;
   55 static db_varfcn_t db_ss;
   56 
   57 /*
   58  * Machine register set.
   59  */
   60 #define DB_OFFSET(x)    (db_expr_t *)offsetof(struct trapframe, x)
   61 struct db_variable db_regs[] = {
   62         { "cs",         DB_OFFSET(tf_cs),       db_frame_seg },
   63         { "ds",         DB_OFFSET(tf_ds),       db_frame_seg },
   64         { "es",         DB_OFFSET(tf_es),       db_frame_seg },
   65         { "fs",         DB_OFFSET(tf_fs),       db_frame_seg },
   66         { "gs",         NULL,                   db_gs },
   67         { "ss",         NULL,                   db_ss },
   68         { "eax",        DB_OFFSET(tf_eax),      db_frame },
   69         { "ecx",        DB_OFFSET(tf_ecx),      db_frame },
   70         { "edx",        DB_OFFSET(tf_edx),      db_frame },
   71         { "ebx",        DB_OFFSET(tf_ebx),      db_frame },
   72         { "esp",        NULL,                   db_esp },
   73         { "ebp",        DB_OFFSET(tf_ebp),      db_frame },
   74         { "esi",        DB_OFFSET(tf_esi),      db_frame },
   75         { "edi",        DB_OFFSET(tf_edi),      db_frame },
   76         { "eip",        DB_OFFSET(tf_eip),      db_frame },
   77         { "efl",        DB_OFFSET(tf_eflags),   db_frame },
   78 };
   79 struct db_variable *db_eregs = db_regs + nitems(db_regs);
   80 
   81 static __inline int
   82 get_esp(struct trapframe *tf)
   83 {
   84         return ((ISPL(tf->tf_cs)) ? tf->tf_esp :
   85             (db_expr_t)tf + (uintptr_t)DB_OFFSET(tf_esp));
   86 }
   87 
   88 static int
   89 db_frame(struct db_variable *vp, db_expr_t *valuep, int op)
   90 {
   91         int *reg;
   92 
   93         if (kdb_frame == NULL)
   94                 return (0);
   95 
   96         reg = (int *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep);
   97         if (op == DB_VAR_GET)
   98                 *valuep = *reg;
   99         else
  100                 *reg = *valuep;
  101         return (1);
  102 }
  103 
  104 static int
  105 db_frame_seg(struct db_variable *vp, db_expr_t *valuep, int op)
  106 {
  107         uint16_t *reg;
  108 
  109         if (kdb_frame == NULL)
  110                 return (0);
  111 
  112         reg = (uint16_t *)((uintptr_t)kdb_frame + (db_expr_t)vp->valuep);
  113         if (op == DB_VAR_GET)
  114                 *valuep = *reg;
  115         else
  116                 *reg = *valuep;
  117         return (1);
  118 }
  119 
  120 static int
  121 db_esp(struct db_variable *vp, db_expr_t *valuep, int op)
  122 {
  123 
  124         if (kdb_frame == NULL)
  125                 return (0);
  126 
  127         if (op == DB_VAR_GET)
  128                 *valuep = get_esp(kdb_frame);
  129         else if (ISPL(kdb_frame->tf_cs))
  130                 kdb_frame->tf_esp = *valuep;
  131         return (1);
  132 }
  133 
  134 static int
  135 db_gs(struct db_variable *vp, db_expr_t *valuep, int op)
  136 {
  137 
  138         if (op == DB_VAR_GET)
  139                 *valuep = rgs();
  140         else
  141                 load_gs(*valuep);
  142         return (1);
  143 }
  144 
  145 static int
  146 db_ss(struct db_variable *vp, db_expr_t *valuep, int op)
  147 {
  148 
  149         if (kdb_frame == NULL)
  150                 return (0);
  151 
  152         if (op == DB_VAR_GET)
  153                 *valuep = (ISPL(kdb_frame->tf_cs)) ? kdb_frame->tf_ss : rss();
  154         else if (ISPL(kdb_frame->tf_cs))
  155                 kdb_frame->tf_ss = *valuep;
  156         return (1);
  157 }
  158 
  159 #define NORMAL          0
  160 #define TRAP            1
  161 #define INTERRUPT       2
  162 #define SYSCALL         3
  163 #define DOUBLE_FAULT    4
  164 #define TRAP_INTERRUPT  5
  165 #define TRAP_TIMERINT   6
  166 
  167 static void db_nextframe(struct i386_frame **, db_addr_t *, struct thread *);
  168 static int db_numargs(struct i386_frame *);
  169 static void db_print_stack_entry(const char *, int, char **, int *, db_addr_t,
  170     void *);
  171 static void decode_syscall(int, struct thread *);
  172 
  173 static const char * watchtype_str(int type);
  174 int  i386_set_watch(int watchnum, unsigned int watchaddr, int size, int access,
  175                     struct dbreg *d);
  176 int  i386_clr_watch(int watchnum, struct dbreg *d);
  177 
  178 /*
  179  * Figure out how many arguments were passed into the frame at "fp".
  180  */
  181 static int
  182 db_numargs(fp)
  183         struct i386_frame *fp;
  184 {
  185         char   *argp;
  186         int     inst;
  187         int     args;
  188 
  189         argp = (char *)db_get_value((int)&fp->f_retaddr, 4, FALSE);
  190         /*
  191          * XXX etext is wrong for LKMs.  We should attempt to interpret
  192          * the instruction at the return address in all cases.  This
  193          * may require better fault handling.
  194          */
  195         if (argp < btext || argp >= etext) {
  196                 args = -1;
  197         } else {
  198 retry:
  199                 inst = db_get_value((int)argp, 4, FALSE);
  200                 if ((inst & 0xff) == 0x59)      /* popl %ecx */
  201                         args = 1;
  202                 else if ((inst & 0xffff) == 0xc483)     /* addl $Ibs, %esp */
  203                         args = ((inst >> 16) & 0xff) / 4;
  204                 else if ((inst & 0xf8ff) == 0xc089) {   /* movl %eax, %Reg */
  205                         argp += 2;
  206                         goto retry;
  207                 } else
  208                         args = -1;
  209         }
  210         return (args);
  211 }
  212 
  213 static void
  214 db_print_stack_entry(name, narg, argnp, argp, callpc, frame)
  215         const char *name;
  216         int narg;
  217         char **argnp;
  218         int *argp;
  219         db_addr_t callpc;
  220         void *frame;
  221 {
  222         int n = narg >= 0 ? narg : 5;
  223 
  224         db_printf("%s(", name);
  225         while (n) {
  226                 if (argnp)
  227                         db_printf("%s=", *argnp++);
  228                 db_printf("%r", db_get_value((int)argp, 4, FALSE));
  229                 argp++;
  230                 if (--n != 0)
  231                         db_printf(",");
  232         }
  233         if (narg < 0)
  234                 db_printf(",...");
  235         db_printf(") at ");
  236         db_printsym(callpc, DB_STGY_PROC);
  237         if (frame != NULL)
  238                 db_printf("/frame 0x%r", (register_t)frame);
  239         db_printf("\n");
  240 }
  241 
  242 static void
  243 decode_syscall(int number, struct thread *td)
  244 {
  245         struct proc *p;
  246         c_db_sym_t sym;
  247         db_expr_t diff;
  248         sy_call_t *f;
  249         const char *symname;
  250 
  251         db_printf(" (%d", number);
  252         p = (td != NULL) ? td->td_proc : NULL;
  253         if (p != NULL && 0 <= number && number < p->p_sysent->sv_size) {
  254                 f = p->p_sysent->sv_table[number].sy_call;
  255                 sym = db_search_symbol((db_addr_t)f, DB_STGY_ANY, &diff);
  256                 if (sym != DB_SYM_NULL && diff == 0) {
  257                         db_symbol_values(sym, &symname, NULL);
  258                         db_printf(", %s, %s", p->p_sysent->sv_name, symname);
  259                 }
  260         }
  261         db_printf(")");
  262 }
  263 
  264 /*
  265  * Figure out the next frame up in the call stack.
  266  */
  267 static void
  268 db_nextframe(struct i386_frame **fp, db_addr_t *ip, struct thread *td)
  269 {
  270         struct trapframe *tf;
  271         int frame_type;
  272         int eip, esp, ebp;
  273         db_expr_t offset;
  274         c_db_sym_t sym;
  275         const char *name;
  276 
  277         eip = db_get_value((int) &(*fp)->f_retaddr, 4, FALSE);
  278         ebp = db_get_value((int) &(*fp)->f_frame, 4, FALSE);
  279 
  280         /*
  281          * Figure out frame type.  We look at the address just before
  282          * the saved instruction pointer as the saved EIP is after the
  283          * call function, and if the function being called is marked as
  284          * dead (such as panic() at the end of dblfault_handler()), then
  285          * the instruction at the saved EIP will be part of a different
  286          * function (syscall() in this example) rather than the one that
  287          * actually made the call.
  288          */
  289         frame_type = NORMAL;
  290         sym = db_search_symbol(eip - 1, DB_STGY_ANY, &offset);
  291         db_symbol_values(sym, &name, NULL);
  292         if (name != NULL) {
  293                 if (strcmp(name, "calltrap") == 0 ||
  294                     strcmp(name, "fork_trampoline") == 0)
  295                         frame_type = TRAP;
  296                 else if (strncmp(name, "Xatpic_intr", 11) == 0 ||
  297                     strncmp(name, "Xapic_isr", 9) == 0)
  298                         frame_type = INTERRUPT;
  299                 else if (strcmp(name, "Xlcall_syscall") == 0 ||
  300                     strcmp(name, "Xint0x80_syscall") == 0)
  301                         frame_type = SYSCALL;
  302                 else if (strcmp(name, "dblfault_handler") == 0)
  303                         frame_type = DOUBLE_FAULT;
  304                 /* XXX: These are interrupts with trap frames. */
  305                 else if (strcmp(name, "Xtimerint") == 0)
  306                         frame_type = TRAP_TIMERINT;
  307                 else if (strcmp(name, "Xcpustop") == 0 ||
  308                     strcmp(name, "Xrendezvous") == 0 ||
  309                     strcmp(name, "Xipi_intr_bitmap_handler") == 0 ||
  310                     strcmp(name, "Xlazypmap") == 0)
  311                         frame_type = TRAP_INTERRUPT;
  312         }
  313 
  314         /*
  315          * Normal frames need no special processing.
  316          */
  317         if (frame_type == NORMAL) {
  318                 *ip = (db_addr_t) eip;
  319                 *fp = (struct i386_frame *) ebp;
  320                 return;
  321         }
  322 
  323         db_print_stack_entry(name, 0, 0, 0, eip, &(*fp)->f_frame);
  324 
  325         /*
  326          * For a double fault, we have to snag the values from the
  327          * previous TSS since a double fault uses a task gate to
  328          * switch to a known good state.
  329          */
  330         if (frame_type == DOUBLE_FAULT) {
  331                 esp = PCPU_GET(common_tss.tss_esp);
  332                 eip = PCPU_GET(common_tss.tss_eip);
  333                 ebp = PCPU_GET(common_tss.tss_ebp);
  334                 db_printf(
  335                     "--- trap 0x17, eip = %#r, esp = %#r, ebp = %#r ---\n",
  336                     eip, esp, ebp);
  337                 *ip = (db_addr_t) eip;
  338                 *fp = (struct i386_frame *) ebp;
  339                 return;
  340         }
  341 
  342         /*
  343          * Point to base of trapframe which is just above the
  344          * current frame.
  345          */
  346         if (frame_type == INTERRUPT)
  347                 tf = (struct trapframe *)((int)*fp + 16);
  348         else if (frame_type == TRAP_INTERRUPT)
  349                 tf = (struct trapframe *)((int)*fp + 8);
  350         else
  351                 tf = (struct trapframe *)((int)*fp + 12);
  352 
  353         if (INKERNEL((int) tf)) {
  354                 esp = get_esp(tf);
  355                 eip = tf->tf_eip;
  356                 ebp = tf->tf_ebp;
  357                 switch (frame_type) {
  358                 case TRAP:
  359                         db_printf("--- trap %#r", tf->tf_trapno);
  360                         break;
  361                 case SYSCALL:
  362                         db_printf("--- syscall");
  363                         decode_syscall(tf->tf_eax, td);
  364                         break;
  365                 case TRAP_TIMERINT:
  366                 case TRAP_INTERRUPT:
  367                 case INTERRUPT:
  368                         db_printf("--- interrupt");
  369                         break;
  370                 default:
  371                         panic("The moon has moved again.");
  372                 }
  373                 db_printf(", eip = %#r, esp = %#r, ebp = %#r ---\n", eip,
  374                     esp, ebp);
  375         }
  376 
  377         *ip = (db_addr_t) eip;
  378         *fp = (struct i386_frame *) ebp;
  379 }
  380 
  381 static int
  382 db_backtrace(struct thread *td, struct trapframe *tf, struct i386_frame *frame,
  383     db_addr_t pc, register_t sp, int count)
  384 {
  385         struct i386_frame *actframe;
  386 #define MAXNARG 16
  387         char *argnames[MAXNARG], **argnp = NULL;
  388         const char *name;
  389         int *argp;
  390         db_expr_t offset;
  391         c_db_sym_t sym;
  392         int instr, narg;
  393         boolean_t first;
  394 
  395         /*
  396          * If an indirect call via an invalid pointer caused a trap,
  397          * %pc contains the invalid address while the return address
  398          * of the unlucky caller has been saved by CPU on the stack
  399          * just before the trap frame.  In this case, try to recover
  400          * the caller's address so that the first frame is assigned
  401          * to the right spot in the right function, for that is where
  402          * the failure actually happened.
  403          *
  404          * This trick depends on the fault address stashed in tf_err
  405          * by trap_fatal() before entering KDB.
  406          */
  407         if (kdb_frame && pc == kdb_frame->tf_err) {
  408                 /*
  409                  * Find where the trap frame actually ends.
  410                  * It won't contain tf_esp or tf_ss unless crossing rings.
  411                  */
  412                 if (ISPL(kdb_frame->tf_cs))
  413                         instr = (int)(kdb_frame + 1);
  414                 else
  415                         instr = (int)&kdb_frame->tf_esp;
  416                 pc = db_get_value(instr, 4, FALSE);
  417         }
  418 
  419         if (count == -1)
  420                 count = 1024;
  421 
  422         first = TRUE;
  423         while (count-- && !db_pager_quit) {
  424                 sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
  425                 db_symbol_values(sym, &name, NULL);
  426 
  427                 /*
  428                  * Attempt to determine a (possibly fake) frame that gives
  429                  * the caller's pc.  It may differ from `frame' if the
  430                  * current function never sets up a standard frame or hasn't
  431                  * set one up yet or has just discarded one.  The last two
  432                  * cases can be guessed fairly reliably for code generated
  433                  * by gcc.  The first case is too much trouble to handle in
  434                  * general because the amount of junk on the stack depends
  435                  * on the pc (the special handling of "calltrap", etc. in
  436                  * db_nextframe() works because the `next' pc is special).
  437                  */
  438                 actframe = frame;
  439                 if (first) {
  440                         first = FALSE;
  441                         if (sym == C_DB_SYM_NULL && sp != 0) {
  442                                 /*
  443                                  * If a symbol couldn't be found, we've probably
  444                                  * jumped to a bogus location, so try and use
  445                                  * the return address to find our caller.
  446                                  */
  447                                 db_print_stack_entry(name, 0, 0, 0, pc,
  448                                     NULL);
  449                                 pc = db_get_value(sp, 4, FALSE);
  450                                 if (db_search_symbol(pc, DB_STGY_PROC,
  451                                     &offset) == C_DB_SYM_NULL)
  452                                         break;
  453                                 continue;
  454                         } else if (tf != NULL) {
  455                                 instr = db_get_value(pc, 4, FALSE);
  456                                 if ((instr & 0xffffff) == 0x00e58955) {
  457                                         /* pushl %ebp; movl %esp, %ebp */
  458                                         actframe = (void *)(get_esp(tf) - 4);
  459                                 } else if ((instr & 0xffff) == 0x0000e589) {
  460                                         /* movl %esp, %ebp */
  461                                         actframe = (void *)get_esp(tf);
  462                                         if (tf->tf_ebp == 0) {
  463                                                 /* Fake frame better. */
  464                                                 frame = actframe;
  465                                         }
  466                                 } else if ((instr & 0xff) == 0x000000c3) {
  467                                         /* ret */
  468                                         actframe = (void *)(get_esp(tf) - 4);
  469                                 } else if (offset == 0) {
  470                                         /* Probably an assembler symbol. */
  471                                         actframe = (void *)(get_esp(tf) - 4);
  472                                 }
  473                         } else if (strcmp(name, "fork_trampoline") == 0) {
  474                                 /*
  475                                  * Don't try to walk back on a stack for a
  476                                  * process that hasn't actually been run yet.
  477                                  */
  478                                 db_print_stack_entry(name, 0, 0, 0, pc,
  479                                     actframe);
  480                                 break;
  481                         }
  482                 }
  483 
  484                 argp = &actframe->f_arg0;
  485                 narg = MAXNARG;
  486                 if (sym != NULL && db_sym_numargs(sym, &narg, argnames)) {
  487                         argnp = argnames;
  488                 } else {
  489                         narg = db_numargs(frame);
  490                 }
  491 
  492                 db_print_stack_entry(name, narg, argnp, argp, pc, actframe);
  493 
  494                 if (actframe != frame) {
  495                         /* `frame' belongs to caller. */
  496                         pc = (db_addr_t)
  497                             db_get_value((int)&actframe->f_retaddr, 4, FALSE);
  498                         continue;
  499                 }
  500 
  501                 db_nextframe(&frame, &pc, td);
  502 
  503                 if (INKERNEL((int)pc) && !INKERNEL((int) frame)) {
  504                         sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
  505                         db_symbol_values(sym, &name, NULL);
  506                         db_print_stack_entry(name, 0, 0, 0, pc, frame);
  507                         break;
  508                 }
  509                 if (!INKERNEL((int) frame)) {
  510                         break;
  511                 }
  512         }
  513 
  514         return (0);
  515 }
  516 
  517 void
  518 db_trace_self(void)
  519 {
  520         struct i386_frame *frame;
  521         db_addr_t callpc;
  522         register_t ebp;
  523 
  524         __asm __volatile("movl %%ebp,%0" : "=r" (ebp));
  525         frame = (struct i386_frame *)ebp;
  526         callpc = (db_addr_t)db_get_value((int)&frame->f_retaddr, 4, FALSE);
  527         frame = frame->f_frame;
  528         db_backtrace(curthread, NULL, frame, callpc, 0, -1);
  529 }
  530 
  531 int
  532 db_trace_thread(struct thread *thr, int count)
  533 {
  534         struct pcb *ctx;
  535         struct trapframe *tf;
  536 
  537         ctx = kdb_thr_ctx(thr);
  538         tf = thr == kdb_thread ? kdb_frame : NULL;
  539         return (db_backtrace(thr, tf, (struct i386_frame *)ctx->pcb_ebp,
  540             ctx->pcb_eip, ctx->pcb_esp, count));
  541 }
  542 
  543 int
  544 i386_set_watch(watchnum, watchaddr, size, access, d)
  545         int watchnum;
  546         unsigned int watchaddr;
  547         int size;
  548         int access;
  549         struct dbreg *d;
  550 {
  551         int i, len;
  552 
  553         if (watchnum == -1) {
  554                 for (i = 0; i < 4; i++)
  555                         if (!DBREG_DR7_ENABLED(d->dr[7], i))
  556                                 break;
  557                 if (i < 4)
  558                         watchnum = i;
  559                 else
  560                         return (-1);
  561         }
  562 
  563         switch (access) {
  564         case DBREG_DR7_EXEC:
  565                 size = 1; /* size must be 1 for an execution breakpoint */
  566                 /* fall through */
  567         case DBREG_DR7_WRONLY:
  568         case DBREG_DR7_RDWR:
  569                 break;
  570         default:
  571                 return (-1);
  572         }
  573 
  574         /*
  575          * we can watch a 1, 2, or 4 byte sized location
  576          */
  577         switch (size) {
  578         case 1:
  579                 len = DBREG_DR7_LEN_1;
  580                 break;
  581         case 2:
  582                 len = DBREG_DR7_LEN_2;
  583                 break;
  584         case 4:
  585                 len = DBREG_DR7_LEN_4;
  586                 break;
  587         default:
  588                 return (-1);
  589         }
  590 
  591         /* clear the bits we are about to affect */
  592         d->dr[7] &= ~DBREG_DR7_MASK(watchnum);
  593 
  594         /* set drN register to the address, N=watchnum */
  595         DBREG_DRX(d, watchnum) = watchaddr;
  596 
  597         /* enable the watchpoint */
  598         d->dr[7] |= DBREG_DR7_SET(watchnum, len, access,
  599             DBREG_DR7_GLOBAL_ENABLE);
  600 
  601         return (watchnum);
  602 }
  603 
  604 
  605 int
  606 i386_clr_watch(watchnum, d)
  607         int watchnum;
  608         struct dbreg *d;
  609 {
  610 
  611         if (watchnum < 0 || watchnum >= 4)
  612                 return (-1);
  613 
  614         d->dr[7] &= ~DBREG_DR7_MASK(watchnum);
  615         DBREG_DRX(d, watchnum) = 0;
  616 
  617         return (0);
  618 }
  619 
  620 
  621 int
  622 db_md_set_watchpoint(addr, size)
  623         db_expr_t addr;
  624         db_expr_t size;
  625 {
  626         struct dbreg d;
  627         int avail, i, wsize;
  628 
  629         fill_dbregs(NULL, &d);
  630 
  631         avail = 0;
  632         for(i = 0; i < 4; i++) {
  633                 if (!DBREG_DR7_ENABLED(d.dr[7], i))
  634                         avail++;
  635         }
  636 
  637         if (avail * 4 < size)
  638                 return (-1);
  639 
  640         for (i = 0; i < 4 && (size > 0); i++) {
  641                 if (!DBREG_DR7_ENABLED(d.dr[7], i)) {
  642                         if (size > 2)
  643                                 wsize = 4;
  644                         else
  645                                 wsize = size;
  646                         i386_set_watch(i, addr, wsize,
  647                                        DBREG_DR7_WRONLY, &d);
  648                         addr += wsize;
  649                         size -= wsize;
  650                 }
  651         }
  652 
  653         set_dbregs(NULL, &d);
  654 
  655         return(0);
  656 }
  657 
  658 
  659 int
  660 db_md_clr_watchpoint(addr, size)
  661         db_expr_t addr;
  662         db_expr_t size;
  663 {
  664         struct dbreg d;
  665         int i;
  666 
  667         fill_dbregs(NULL, &d);
  668 
  669         for(i = 0; i < 4; i++) {
  670                 if (DBREG_DR7_ENABLED(d.dr[7], i)) {
  671                         if ((DBREG_DRX((&d), i) >= addr) &&
  672                             (DBREG_DRX((&d), i) < addr+size))
  673                                 i386_clr_watch(i, &d);
  674 
  675                 }
  676         }
  677 
  678         set_dbregs(NULL, &d);
  679 
  680         return(0);
  681 }
  682 
  683 
  684 static const char *
  685 watchtype_str(type)
  686         int type;
  687 {
  688         switch (type) {
  689                 case DBREG_DR7_EXEC   : return "execute";    break;
  690                 case DBREG_DR7_RDWR   : return "read/write"; break;
  691                 case DBREG_DR7_WRONLY : return "write";      break;
  692                 default               : return "invalid";    break;
  693         }
  694 }
  695 
  696 
  697 void
  698 db_md_list_watchpoints()
  699 {
  700         struct dbreg d;
  701         int i, len, type;
  702 
  703         fill_dbregs(NULL, &d);
  704 
  705         db_printf("\nhardware watchpoints:\n");
  706         db_printf("  watch    status        type  len     address\n");
  707         db_printf("  -----  --------  ----------  ---  ----------\n");
  708         for (i = 0; i < 4; i++) {
  709                 if (DBREG_DR7_ENABLED(d.dr[7], i)) {
  710                         type = DBREG_DR7_ACCESS(d.dr[7], i);
  711                         len = DBREG_DR7_LEN(d.dr[7], i);
  712                         db_printf("  %-5d  %-8s  %10s  %3d  ",
  713                             i, "enabled", watchtype_str(type), len + 1);
  714                         db_printsym((db_addr_t)DBREG_DRX((&d), i), DB_STGY_ANY);
  715                         db_printf("\n");
  716                 } else {
  717                         db_printf("  %-5d  disabled\n", i);
  718                 }
  719         }
  720 
  721         db_printf("\ndebug register values:\n");
  722         for (i = 0; i < 8; i++) {
  723                 db_printf("  dr%d 0x%08x\n", i, DBREG_DRX((&d), i));
  724         }
  725         db_printf("\n");
  726 }
  727 
  728 

Cache object: d0c2087901ac858271d7c13e081796c3


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.