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db_trace.c revision 1.18
      1 /*	$NetBSD: db_trace.c,v 1.18 2001/01/19 01:41:36 shin Exp $	*/
      2 
      3 /*
      4  * Mach Operating System
      5  * Copyright (c) 1993-1987 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 Mellon
     26  * the rights to redistribute these changes.
     27  */
     28 
     29 #include <sys/types.h>
     30 #include <sys/param.h>
     31 #include <sys/systm.h>
     32 #include <sys/proc.h>
     33 #include <sys/user.h>
     34 
     35 #include <mips/mips_opcode.h>
     36 
     37 #include <machine/param.h>
     38 #include <machine/db_machdep.h>
     39 #include <ddb/db_interface.h>
     40 #include <ddb/db_output.h>
     41 #include <ddb/db_variables.h>
     42 #include <ddb/db_sym.h>
     43 
     44 int __start __P((void));	/* lowest kernel code address */
     45 vaddr_t getreg_val __P((db_expr_t regno));
     46 
     47 #define REG_ARG(i)	(4+i)
     48 #define SAVES_RA(x)	isa_spill((x),31)
     49 
     50 #define KERN_SAVE_REG_IDX(vp)	( \
     51 	((vp)->valuep >= (int *)(&((struct mips_saved_state *)0)->s0) &&    \
     52 	 (vp)->valuep <= (int *)(&((struct mips_saved_state *)0)->s7))?	    \
     53 		vp->valuep - (int *)(&((struct mips_saved_state *)0)->s0):  \
     54 	((vp)->valuep >= (int *)(&((struct mips_saved_state *)0)->sp) &&    \
     55 	 (vp)->valuep <= (int *)(&((struct mips_saved_state *)0)->ra))?	    \
     56 		((vp)->valuep-(int *)(&((struct mips_saved_state *)0)->sp)) + \
     57 		 ((int *)(&((struct mips_kernel_state *)0)->sp) - (int *)0):  \
     58 	 -1)
     59 
     60 db_sym_t localsym __P((db_sym_t sym, boolean_t isreg, int *lex_level));
     61 
     62 /*
     63  * Machine register set.
     64  */
     65 struct mips_saved_state *db_cur_exc_frame = 0;
     66 
     67 /*
     68  *  forward declarations
     69  */
     70 int print_exception_frame __P((struct mips_saved_state *fp,
     71 			       unsigned epc));
     72 
     73 /*XXX*/
     74 void stacktrace_subr __P((int a0, int a1, int a2, int a3,
     75 			  u_int pc, u_int sp, u_int fp, u_int ra,
     76 			  void (*)(const char*, ...)));
     77 
     78 /*
     79  * Stack trace helper.
     80  */
     81 void db_mips_stack_trace __P((int count, vaddr_t stackp,
     82 			      vaddr_t the_pc, vaddr_t the_ra, int flags,
     83 			      vaddr_t kstackp));
     84 int db_mips_variable_func __P((const struct db_variable *vp, db_expr_t *valuep,
     85 			       int db_var_fun));
     86 
     87 #define DB_SETF_REGS db_mips_variable_func
     88 #define DBREGS_REG()
     89 
     90 const struct db_variable db_regs[] = {
     91 	{ "at",	(long *)&ddb_regs.f_regs[AST],  DB_SETF_REGS },
     92 	{ "v0",	(long *)&ddb_regs.f_regs[V0],  DB_SETF_REGS },
     93 	{ "v1",	(long *)&ddb_regs.f_regs[V1],  DB_SETF_REGS },
     94 	{ "a0",	(long *)&ddb_regs.f_regs[A0],  DB_SETF_REGS },
     95 	{ "a1",	(long *)&ddb_regs.f_regs[A1],  DB_SETF_REGS },
     96 	{ "a2",	(long *)&ddb_regs.f_regs[A2],  DB_SETF_REGS },
     97 	{ "a3",	(long *)&ddb_regs.f_regs[A3],  DB_SETF_REGS },
     98 	{ "t0",	(long *)&ddb_regs.f_regs[T0],  DB_SETF_REGS },
     99 	{ "t1",	(long *)&ddb_regs.f_regs[T1],  DB_SETF_REGS },
    100 	{ "t2",	(long *)&ddb_regs.f_regs[T2],  DB_SETF_REGS },
    101 	{ "t3",	(long *)&ddb_regs.f_regs[T3],  DB_SETF_REGS },
    102 	{ "t4",	(long *)&ddb_regs.f_regs[T4],  DB_SETF_REGS },
    103 	{ "t5",	(long *)&ddb_regs.f_regs[T5],  DB_SETF_REGS },
    104 	{ "t6",	(long *)&ddb_regs.f_regs[T6],  DB_SETF_REGS },
    105 	{ "t7",	(long *)&ddb_regs.f_regs[T7],  DB_SETF_REGS },
    106 	{ "s0",	(long *)&ddb_regs.f_regs[S0],  DB_SETF_REGS },
    107 	{ "s1",	(long *)&ddb_regs.f_regs[S1],  DB_SETF_REGS },
    108 	{ "s2",	(long *)&ddb_regs.f_regs[S2],  DB_SETF_REGS },
    109 	{ "s3",	(long *)&ddb_regs.f_regs[S3],  DB_SETF_REGS },
    110 	{ "s4",	(long *)&ddb_regs.f_regs[S4],  DB_SETF_REGS },
    111 	{ "s5",	(long *)&ddb_regs.f_regs[S5],  DB_SETF_REGS },
    112 	{ "s6",	(long *)&ddb_regs.f_regs[S6],  DB_SETF_REGS },
    113 	{ "s7",	(long *)&ddb_regs.f_regs[S7],  DB_SETF_REGS },
    114 	{ "t8",	(long *)&ddb_regs.f_regs[T8],  DB_SETF_REGS },
    115 	{ "t9",	(long *)&ddb_regs.f_regs[T9],  DB_SETF_REGS },
    116 	{ "k0",	(long *)&ddb_regs.f_regs[K0],  DB_SETF_REGS },
    117 	{ "k1",	(long *)&ddb_regs.f_regs[K1],  DB_SETF_REGS },
    118 	{ "gp",	(long *)&ddb_regs.f_regs[GP],  DB_SETF_REGS },
    119 	{ "sp",	(long *)&ddb_regs.f_regs[SP],  DB_SETF_REGS },
    120 	{ "fp",	(long *)&ddb_regs.f_regs[S8],  DB_SETF_REGS },	/* frame ptr */
    121 	{ "ra",	(long *)&ddb_regs.f_regs[RA],  DB_SETF_REGS },
    122 	{ "sr",	(long *)&ddb_regs.f_regs[SR],  DB_SETF_REGS },
    123 	{ "mdlo",(long *)&ddb_regs.f_regs[MULLO],  DB_SETF_REGS },
    124 	{ "mdhi",(long *)&ddb_regs.f_regs[MULHI],  DB_SETF_REGS },
    125 	{ "bad", (long *)&ddb_regs.f_regs[BADVADDR], DB_SETF_REGS },
    126 	{ "cs",	(long *)&ddb_regs.f_regs[CAUSE],  DB_SETF_REGS },
    127 	{ "pc",	(long *)&ddb_regs.f_regs[PC],  DB_SETF_REGS },
    128 };
    129 const struct db_variable * const db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
    130 
    131 void
    132 db_stack_trace_print(addr, have_addr, count, modif, pr)
    133 	db_expr_t	addr;
    134 	boolean_t	have_addr;
    135 	db_expr_t	count;
    136 	char		*modif;
    137 	void		(*pr) __P((const char *, ...));
    138 {
    139 #ifndef DDB_TRACE
    140 	struct pcb *pcb;
    141 	struct proc *p;
    142 
    143 	if (!have_addr) {
    144 		stacktrace_subr(ddb_regs.f_regs[A0], ddb_regs.f_regs[A1],
    145 				ddb_regs.f_regs[A2], ddb_regs.f_regs[A3],
    146 				ddb_regs.f_regs[PC],
    147 				ddb_regs.f_regs[SP],
    148 				/* non-virtual frame pointer */
    149 				ddb_regs.f_regs[S8],
    150 				ddb_regs.f_regs[RA],
    151 				pr);
    152 		return;
    153 	}
    154 
    155 	/* "trace/t" */
    156 	(*pr)("pid %d ", (int)addr);
    157 	p = pfind(addr);
    158 	if (p == NULL) {
    159 		(*pr)("not found\n");
    160 		return;
    161 	}
    162 	if (!(p->p_flag&P_INMEM)) {
    163 		(*pr)("swapped out\n");
    164 		return;
    165 	}
    166 
    167 	pcb = &(p->p_addr->u_pcb);
    168 	(*pr)("at %p\n", pcb);
    169 
    170 	stacktrace_subr(0,0,0,0,	/* no args known */
    171 			(int)cpu_switch,
    172 			pcb->pcb_context[8],
    173 			pcb->pcb_context[9],
    174 			pcb->pcb_context[10],
    175 			pr);
    176 #else
    177 /*
    178  * Incomplete but practically useful stack backtrace.
    179  */
    180 #define	MIPS_JR_RA	0x03e00008	/* instruction code for jr ra */
    181 #define	MIPS_JR_K0	0x03400008	/* instruction code for jr k0 */
    182 #define	MIPS_ERET	0x42000018	/* instruction code for eret */
    183 	unsigned va, pc, ra, sp, func;
    184 	int insn;
    185 	InstFmt i;
    186 	int stacksize;
    187 	db_addr_t offset;
    188 	char *name;
    189 	extern char verylocore[];
    190 
    191 	pc = ddb_regs.f_regs[PC];
    192 	sp = ddb_regs.f_regs[SP];
    193 	ra = ddb_regs.f_regs[RA];
    194 	do {
    195 		va = pc;
    196 		do {
    197 			va -= sizeof(int);
    198 			insn = *(int *)va;
    199 			if (insn == MIPS_ERET)
    200 				goto mips3_eret;
    201 		} while (insn != MIPS_JR_RA && insn != MIPS_JR_K0);
    202 		va += sizeof(int);
    203 	mips3_eret:
    204 		va += sizeof(int);
    205 		while (*(int *)va == 0x00000000)
    206 			va += sizeof(int);
    207 		func = va;
    208 		stacksize = 0;
    209 		do {
    210 			i.word = *(int *)va;
    211 			if (i.IType.op == OP_SW
    212 			    && i.IType.rs == SP
    213 			    && i.IType.rt == RA)
    214 				ra = *(int *)(sp + (short)i.IType.imm);
    215 			if (i.IType.op == OP_ADDIU
    216 			    && i.IType.rs == SP
    217 			    && i.IType.rt == SP)
    218 				stacksize = -(short)i.IType.imm;
    219 			va += sizeof(int);
    220 		} while (va < pc);
    221 
    222 		db_find_sym_and_offset(func, &name, &offset);
    223 		if (name == 0)
    224 			name = "?";
    225 		(*pr)("%s()+0x%x, called by %p, stack size %d\n",
    226 			name, pc - func, (void *)ra, stacksize);
    227 
    228 		if (ra == pc) {
    229 			(*pr)("-- loop? --\n");
    230 			return;
    231 		}
    232 		sp += stacksize;
    233 		pc = ra;
    234 	} while (pc > (unsigned)verylocore);
    235 	if (pc < 0x80000000)
    236 		(*pr)("-- user process --\n");
    237 	else
    238 		(*pr)("-- kernel entry --\n");
    239 #endif
    240 }
    241 
    242 void
    243 db_mips_stack_trace(count, stackp, the_pc, the_ra, flags, kstackp)
    244 	int count;
    245 	vaddr_t stackp, the_pc, the_ra;
    246 	int flags;
    247 	vaddr_t kstackp;
    248 {
    249 	return;
    250 }
    251 
    252 
    253 int
    254 db_mips_variable_func (const struct db_variable *vp,
    255 	db_expr_t *valuep,
    256 	int db_var_fcn)
    257 {
    258 	switch (db_var_fcn) {
    259 	case DB_VAR_GET:
    260 		*valuep = *(mips_reg_t *) vp->valuep;
    261 		break;
    262 	case DB_VAR_SET:
    263 		*(mips_reg_t *) vp->valuep = *valuep;
    264 		break;
    265 	}
    266 	return 0;
    267 }
    268