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db_variables.c revision 1.41
      1 /*	$NetBSD: db_variables.c,v 1.41 2009/03/07 22:02:17 ad Exp $	*/
      2 
      3 /*
      4  * Mach Operating System
      5  * Copyright (c) 1991,1990 Carnegie Mellon University
      6  * All Rights Reserved.
      7  *
      8  * Permission to use, copy, modify and distribute this software and its
      9  * documentation is hereby granted, provided that both the copyright
     10  * notice and this permission notice appear in all copies of the
     11  * software, derivative works or modified versions, and any portions
     12  * thereof, and that both notices appear in supporting documentation.
     13  *
     14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
     16  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     17  *
     18  * Carnegie Mellon requests users of this software to return to
     19  *
     20  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     21  *  School of Computer Science
     22  *  Carnegie Mellon University
     23  *  Pittsburgh PA 15213-3890
     24  *
     25  * any improvements or extensions that they make and grant Carnegie the
     26  * rights to redistribute these changes.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: db_variables.c,v 1.41 2009/03/07 22:02:17 ad Exp $");
     31 
     32 #ifdef _KERNEL_OPT
     33 #include "opt_ddbparam.h"
     34 #endif
     35 
     36 #include <sys/param.h>
     37 #include <sys/proc.h>
     38 #include <uvm/uvm_extern.h>
     39 #include <sys/sysctl.h>
     40 
     41 #include <ddb/ddb.h>
     42 #include <ddb/ddbvar.h>
     43 
     44 /*
     45  * If this is non-zero, the DDB will be entered when the system
     46  * panics.  Initialize it so that it's patchable.
     47  */
     48 #ifndef DDB_ONPANIC
     49 #define DDB_ONPANIC	0
     50 #endif
     51 int		db_onpanic = DDB_ONPANIC;
     52 
     53 /*
     54  * Can  DDB can be entered from the console?
     55  */
     56 #ifndef	DDB_FROMCONSOLE
     57 #define	DDB_FROMCONSOLE 1
     58 #endif
     59 int		db_fromconsole = DDB_FROMCONSOLE;
     60 
     61 /*
     62  * Output DDB output to the message buffer?
     63  */
     64 #ifndef DDB_TEE_MSGBUF
     65 #define DDB_TEE_MSGBUF 0
     66 #endif
     67 int		db_tee_msgbuf = DDB_TEE_MSGBUF;
     68 
     69 
     70 static int	db_rw_internal_variable(const struct db_variable *, db_expr_t *,
     71 		    int);
     72 static int	db_find_variable(const struct db_variable **);
     73 
     74 /* XXX must all be ints for sysctl. */
     75 const struct db_variable db_vars[] = {
     76 	{ "radix",	(void *)&db_radix,	db_rw_internal_variable, NULL },
     77 	{ "maxoff",	(void *)&db_maxoff,	db_rw_internal_variable, NULL },
     78 	{ "maxwidth",	(void *)&db_max_width,	db_rw_internal_variable, NULL },
     79 	{ "tabstops",	(void *)&db_tab_stop_width, db_rw_internal_variable, NULL },
     80 	{ "lines",	(void *)&db_max_line,	db_rw_internal_variable, NULL },
     81 	{ "onpanic",	(void *)&db_onpanic,	db_rw_internal_variable, NULL },
     82 	{ "fromconsole", (void *)&db_fromconsole, db_rw_internal_variable, NULL },
     83 	{ "tee_msgbuf",	(void *)&db_tee_msgbuf,	db_rw_internal_variable, NULL },
     84 };
     85 const struct db_variable * const db_evars = db_vars + sizeof(db_vars)/sizeof(db_vars[0]);
     86 
     87 /*
     88  * ddb command line access to the DDB variables defined above.
     89  */
     90 static int
     91 db_rw_internal_variable(const struct db_variable *vp, db_expr_t *valp, int rw)
     92 {
     93 
     94 	if (rw == DB_VAR_GET)
     95 		*valp = *(int *)vp->valuep;
     96 	else
     97 		*(int *)vp->valuep = *valp;
     98 	return (0);
     99 }
    100 
    101 /*
    102  * sysctl(3) access to the DDB variables defined above.
    103  */
    104 #ifdef _KERNEL
    105 SYSCTL_SETUP(sysctl_ddb_setup, "sysctl ddb subtree setup")
    106 {
    107 
    108 	sysctl_createv(clog, 0, NULL, NULL,
    109 		       CTLFLAG_PERMANENT,
    110 		       CTLTYPE_NODE, "ddb", NULL,
    111 		       NULL, 0, NULL, 0,
    112 		       CTL_DDB, CTL_EOL);
    113 
    114 	sysctl_createv(clog, 0, NULL, NULL,
    115 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    116 		       CTLTYPE_INT, "radix",
    117 		       SYSCTL_DESCR("Input and output radix"),
    118 		       NULL, 0, &db_radix, 0,
    119 		       CTL_DDB, DDBCTL_RADIX, CTL_EOL);
    120 	sysctl_createv(clog, 0, NULL, NULL,
    121 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    122 		       CTLTYPE_INT, "maxoff",
    123 		       SYSCTL_DESCR("Maximum symbol offset"),
    124 		       NULL, 0, &db_maxoff, 0,
    125 		       CTL_DDB, DDBCTL_MAXOFF, CTL_EOL);
    126 	sysctl_createv(clog, 0, NULL, NULL,
    127 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    128 		       CTLTYPE_INT, "maxwidth",
    129 		       SYSCTL_DESCR("Maximum output line width"),
    130 		       NULL, 0, &db_max_width, 0,
    131 		       CTL_DDB, DDBCTL_MAXWIDTH, CTL_EOL);
    132 	sysctl_createv(clog, 0, NULL, NULL,
    133 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    134 		       CTLTYPE_INT, "lines",
    135 		       SYSCTL_DESCR("Number of display lines"),
    136 		       NULL, 0, &db_max_line, 0,
    137 		       CTL_DDB, DDBCTL_LINES, CTL_EOL);
    138 	sysctl_createv(clog, 0, NULL, NULL,
    139 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    140 		       CTLTYPE_INT, "tabstops",
    141 		       SYSCTL_DESCR("Output tab width"),
    142 		       NULL, 0, &db_tab_stop_width, 0,
    143 		       CTL_DDB, DDBCTL_TABSTOPS, CTL_EOL);
    144 	sysctl_createv(clog, 0, NULL, NULL,
    145 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    146 		       CTLTYPE_INT, "onpanic",
    147 		       SYSCTL_DESCR("Whether to enter ddb on a kernel panic"),
    148 		       NULL, 0, &db_onpanic, 0,
    149 		       CTL_DDB, DDBCTL_ONPANIC, CTL_EOL);
    150 	sysctl_createv(clog, 0, NULL, NULL,
    151 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    152 		       CTLTYPE_INT, "fromconsole",
    153 		       SYSCTL_DESCR("Whether ddb can be entered from the "
    154 				    "console"),
    155 		       NULL, 0, &db_fromconsole, 0,
    156 		       CTL_DDB, DDBCTL_FROMCONSOLE, CTL_EOL);
    157 	sysctl_createv(clog, 0, NULL, NULL,
    158 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    159 		       CTLTYPE_INT, "tee_msgbuf",
    160 		       SYSCTL_DESCR("Whether to tee ddb output to the msgbuf"),
    161 		       NULL, 0, &db_tee_msgbuf, 0,
    162 		       CTL_DDB, CTL_CREATE, CTL_EOL);
    163 
    164 	sysctl_createv(clog, 0, NULL, NULL,
    165 		       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
    166 		       CTLTYPE_STRING, "commandonenter",
    167 		       SYSCTL_DESCR("Command to be executed on each ddb enter"),
    168 		       NULL, 0, &db_cmd_on_enter, DB_LINE_MAXLEN,
    169 		       CTL_DDB, CTL_CREATE, CTL_EOL);
    170 }
    171 #endif	/* _KERNEL */
    172 
    173 int
    174 db_find_variable(const struct db_variable **varp)
    175 {
    176 	int	t;
    177 	const struct db_variable *vp;
    178 
    179 	t = db_read_token();
    180 	if (t == tIDENT) {
    181 		for (vp = db_vars; vp < db_evars; vp++) {
    182 			if (!strcmp(db_tok_string, vp->name)) {
    183 				*varp = vp;
    184 				return (1);
    185 			}
    186 		}
    187 		for (vp = db_regs; vp < db_eregs; vp++) {
    188 			if (!strcmp(db_tok_string, vp->name)) {
    189 				*varp = vp;
    190 				return (1);
    191 			}
    192 		}
    193 	}
    194 	db_error("Unknown variable\n");
    195 	/*NOTREACHED*/
    196 	return 0;
    197 }
    198 
    199 int
    200 db_get_variable(db_expr_t *valuep)
    201 {
    202 	const struct db_variable *vp;
    203 
    204 	if (!db_find_variable(&vp))
    205 		return (0);
    206 
    207 	db_read_variable(vp, valuep);
    208 
    209 	return (1);
    210 }
    211 
    212 int
    213 db_set_variable(db_expr_t value)
    214 {
    215 	const struct db_variable *vp;
    216 
    217 	if (!db_find_variable(&vp))
    218 		return (0);
    219 
    220 	db_write_variable(vp, &value);
    221 
    222 	return (1);
    223 }
    224 
    225 
    226 void
    227 db_read_variable(const struct db_variable *vp, db_expr_t *valuep)
    228 {
    229 	int (*func)(const struct db_variable *, db_expr_t *, int) = vp->fcn;
    230 
    231 	if (func == FCN_NULL)
    232 		*valuep = *(vp->valuep);
    233 	else
    234 		(*func)(vp, valuep, DB_VAR_GET);
    235 }
    236 
    237 void
    238 db_write_variable(const struct db_variable *vp, db_expr_t *valuep)
    239 {
    240 	int (*func)(const struct db_variable *, db_expr_t *, int) = vp->fcn;
    241 
    242 	if (func == FCN_NULL)
    243 		*(vp->valuep) = *valuep;
    244 	else
    245 		(*func)(vp, valuep, DB_VAR_SET);
    246 }
    247 
    248 /*ARGSUSED*/
    249 void
    250 db_set_cmd(db_expr_t addr, bool have_addr,
    251     db_expr_t count, const char *modif)
    252 {
    253 	db_expr_t	value;
    254 	db_expr_t	old_value;
    255 	const struct db_variable *vp = NULL;	/* XXX: GCC */
    256 	int	t;
    257 
    258 	t = db_read_token();
    259 	if (t != tDOLLAR) {
    260 		db_error("Unknown variable\n");
    261 		/*NOTREACHED*/
    262 	}
    263 	if (!db_find_variable(&vp)) {
    264 		db_error("Unknown variable\n");
    265 		/*NOTREACHED*/
    266 	}
    267 
    268 	t = db_read_token();
    269 	if (t != tEQ)
    270 		db_unread_token(t);
    271 
    272 	if (!db_expression(&value)) {
    273 		db_error("No value\n");
    274 		/*NOTREACHED*/
    275 	}
    276 	if (db_read_token() != tEOL) {
    277 		db_error("?\n");
    278 		/*NOTREACHED*/
    279 	}
    280 
    281 	db_read_variable(vp, &old_value);
    282 	db_printf("$%s\t\t%s = ", vp->name, db_num_to_str(old_value));
    283 	db_printf("%s\n", db_num_to_str(value));
    284 	db_write_variable(vp, &value);
    285 }
    286