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db_trace.c revision 1.40
      1 /*	$NetBSD: db_trace.c,v 1.40 2010/07/07 01:22:35 chs 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/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: db_trace.c,v 1.40 2010/07/07 01:22:35 chs Exp $");
     31 
     32 #include "opt_ddb.h"
     33 
     34 #include <sys/types.h>
     35 #include <sys/param.h>
     36 #include <sys/systm.h>
     37 #include <sys/proc.h>
     38 #include <sys/cpu.h>
     39 
     40 #include <mips/mips_opcode.h>
     41 
     42 #include <machine/db_machdep.h>
     43 
     44 #include <ddb/db_interface.h>
     45 #include <ddb/db_output.h>
     46 #include <ddb/db_variables.h>
     47 #include <ddb/db_sym.h>
     48 
     49 int __start(void);	/* lowest kernel code address */
     50 vaddr_t getreg_val(db_expr_t regno);
     51 
     52 #define REG_ARG(i)	(4+i)
     53 #define SAVES_RA(x)	isa_spill((x),31)
     54 
     55 #define KERN_SAVE_REG_IDX(vp)	( \
     56 	((vp)->valuep >= (int *)(&((struct mips_saved_state *)0)->s0) &&    \
     57 	 (vp)->valuep <= (int *)(&((struct mips_saved_state *)0)->s7))?	    \
     58 		vp->valuep - (int *)(&((struct mips_saved_state *)0)->s0):  \
     59 	((vp)->valuep >= (int *)(&((struct mips_saved_state *)0)->sp) &&    \
     60 	 (vp)->valuep <= (int *)(&((struct mips_saved_state *)0)->ra))?	    \
     61 		((vp)->valuep-(int *)(&((struct mips_saved_state *)0)->sp)) + \
     62 		 ((int *)(&((struct mips_kernel_state *)0)->sp) - (int *)0):  \
     63 	 -1)
     64 
     65 db_sym_t localsym(db_sym_t sym, bool isreg, int *lex_level);
     66 
     67 /*
     68  * Machine register set.
     69  */
     70 struct mips_saved_state *db_cur_exc_frame = 0;
     71 
     72 /*XXX*/
     73 void	stacktrace_subr(mips_reg_t, mips_reg_t, mips_reg_t, mips_reg_t,
     74 	    vaddr_t, vaddr_t, vaddr_t, vaddr_t,
     75 	    void (*)(const char*, ...));
     76 
     77 /*
     78  * Stack trace helper.
     79  */
     80 void db_mips_stack_trace(int, vaddr_t, vaddr_t, vaddr_t, int, vaddr_t);
     81 int db_mips_variable_func(const struct db_variable *, db_expr_t *, int);
     82 
     83 #define DB_SETF_REGS db_mips_variable_func
     84 #define DBREGS_REG()
     85 
     86 const struct db_variable db_regs[] = {
     87 	{ "at",	(long *)&ddb_regs.f_regs[_R_AST],  DB_SETF_REGS },
     88 	{ "v0",	(long *)&ddb_regs.f_regs[_R_V0],  DB_SETF_REGS },
     89 	{ "v1",	(long *)&ddb_regs.f_regs[_R_V1],  DB_SETF_REGS },
     90 	{ "a0",	(long *)&ddb_regs.f_regs[_R_A0],  DB_SETF_REGS },
     91 	{ "a1",	(long *)&ddb_regs.f_regs[_R_A1],  DB_SETF_REGS },
     92 	{ "a2",	(long *)&ddb_regs.f_regs[_R_A2],  DB_SETF_REGS },
     93 	{ "a3",	(long *)&ddb_regs.f_regs[_R_A3],  DB_SETF_REGS },
     94 #if defined(__mips_n32) || defined(__mips_n64)
     95 	{ "a4",	(long *)&ddb_regs.f_regs[_R_A4],  DB_SETF_REGS },
     96 	{ "a5",	(long *)&ddb_regs.f_regs[_R_A5],  DB_SETF_REGS },
     97 	{ "a6",	(long *)&ddb_regs.f_regs[_R_A6],  DB_SETF_REGS },
     98 	{ "a7",	(long *)&ddb_regs.f_regs[_R_A7],  DB_SETF_REGS },
     99 	{ "t0",	(long *)&ddb_regs.f_regs[_R_T0],  DB_SETF_REGS },
    100 	{ "t1",	(long *)&ddb_regs.f_regs[_R_T1],  DB_SETF_REGS },
    101 	{ "t2",	(long *)&ddb_regs.f_regs[_R_T2],  DB_SETF_REGS },
    102 	{ "t3",	(long *)&ddb_regs.f_regs[_R_T3],  DB_SETF_REGS },
    103 #else
    104 	{ "t0",	(long *)&ddb_regs.f_regs[_R_T0],  DB_SETF_REGS },
    105 	{ "t1",	(long *)&ddb_regs.f_regs[_R_T1],  DB_SETF_REGS },
    106 	{ "t2",	(long *)&ddb_regs.f_regs[_R_T2],  DB_SETF_REGS },
    107 	{ "t3",	(long *)&ddb_regs.f_regs[_R_T3],  DB_SETF_REGS },
    108 	{ "t4",	(long *)&ddb_regs.f_regs[_R_T4],  DB_SETF_REGS },
    109 	{ "t5",	(long *)&ddb_regs.f_regs[_R_T5],  DB_SETF_REGS },
    110 	{ "t6",	(long *)&ddb_regs.f_regs[_R_T6],  DB_SETF_REGS },
    111 	{ "t7",	(long *)&ddb_regs.f_regs[_R_T7],  DB_SETF_REGS },
    112 #endif /* __mips_n32 || __mips_n64 */
    113 	{ "s0",	(long *)&ddb_regs.f_regs[_R_S0],  DB_SETF_REGS },
    114 	{ "s1",	(long *)&ddb_regs.f_regs[_R_S1],  DB_SETF_REGS },
    115 	{ "s2",	(long *)&ddb_regs.f_regs[_R_S2],  DB_SETF_REGS },
    116 	{ "s3",	(long *)&ddb_regs.f_regs[_R_S3],  DB_SETF_REGS },
    117 	{ "s4",	(long *)&ddb_regs.f_regs[_R_S4],  DB_SETF_REGS },
    118 	{ "s5",	(long *)&ddb_regs.f_regs[_R_S5],  DB_SETF_REGS },
    119 	{ "s6",	(long *)&ddb_regs.f_regs[_R_S6],  DB_SETF_REGS },
    120 	{ "s7",	(long *)&ddb_regs.f_regs[_R_S7],  DB_SETF_REGS },
    121 	{ "t8",	(long *)&ddb_regs.f_regs[_R_T8],  DB_SETF_REGS },
    122 	{ "t9",	(long *)&ddb_regs.f_regs[_R_T9],  DB_SETF_REGS },
    123 	{ "k0",	(long *)&ddb_regs.f_regs[_R_K0],  DB_SETF_REGS },
    124 	{ "k1",	(long *)&ddb_regs.f_regs[_R_K1],  DB_SETF_REGS },
    125 	{ "gp",	(long *)&ddb_regs.f_regs[_R_GP],  DB_SETF_REGS },
    126 	{ "sp",	(long *)&ddb_regs.f_regs[_R_SP],  DB_SETF_REGS },
    127 	{ "fp",	(long *)&ddb_regs.f_regs[_R_S8],  DB_SETF_REGS },/* frame ptr */
    128 	{ "ra",	(long *)&ddb_regs.f_regs[_R_RA],  DB_SETF_REGS },
    129 	{ "sr",	(long *)&ddb_regs.f_regs[_R_SR],  DB_SETF_REGS },
    130 	{ "mdlo",(long *)&ddb_regs.f_regs[_R_MULLO],  DB_SETF_REGS },
    131 	{ "mdhi",(long *)&ddb_regs.f_regs[_R_MULHI],  DB_SETF_REGS },
    132 	{ "bad", (long *)&ddb_regs.f_regs[_R_BADVADDR], DB_SETF_REGS },
    133 	{ "cs",	(long *)&ddb_regs.f_regs[_R_CAUSE],  DB_SETF_REGS },
    134 	{ "pc",	(long *)&ddb_regs.f_regs[_R_PC],  DB_SETF_REGS },
    135 };
    136 const struct db_variable * const db_eregs = db_regs + sizeof(db_regs)/sizeof(db_regs[0]);
    137 
    138 void
    139 db_stack_trace_print(db_expr_t addr, bool have_addr, db_expr_t count,
    140     const char *modif, void (*pr)(const char *, ...))
    141 {
    142 #ifndef DDB_TRACE
    143 	struct pcb *pcb;
    144 	struct proc *p;
    145 	struct lwp *l;
    146 	const char *cp = modif;
    147 	char c;
    148 	bool lwpaddr = false;
    149 
    150 	if (!have_addr) {
    151 		stacktrace_subr(ddb_regs.f_regs[_R_A0],
    152 				ddb_regs.f_regs[_R_A1],
    153 				ddb_regs.f_regs[_R_A2],
    154 				ddb_regs.f_regs[_R_A3],
    155 				ddb_regs.f_regs[_R_PC],
    156 				ddb_regs.f_regs[_R_SP],
    157 				/* non-virtual frame pointer */
    158 				ddb_regs.f_regs[_R_S8],
    159 				ddb_regs.f_regs[_R_RA],
    160 				pr);
    161 		return;
    162 	}
    163 
    164 	while ((c = *cp++) != 0) {
    165 		if (c == 'a') {
    166 			lwpaddr = true;
    167 		}
    168 	}
    169 
    170 	if (lwpaddr) {
    171 		l = (struct lwp *)addr;
    172 		(*pr)("pid %d.%d ", l->l_proc->p_pid, l->l_lid);
    173 	} else {
    174 		/* "trace/t" */
    175 
    176 		(*pr)("pid %d ", (int)addr);
    177 		p = proc_find_raw(addr);
    178 		if (p == NULL) {
    179 			(*pr)("not found\n");
    180 			return;
    181 		}
    182 		l = LIST_FIRST(&p->p_lwps); /* XXX NJWLWP */
    183 	}
    184 	pcb = lwp_getpcb(l);
    185 	(*pr)("at %p\n", pcb);
    186 
    187 	stacktrace_subr(0,0,0,0,	/* no args known */
    188 			(vaddr_t)cpu_switchto,
    189 			pcb->pcb_context.val[_L_SP],
    190 			pcb->pcb_context.val[_L_S8],
    191 			pcb->pcb_context.val[_L_RA],
    192 			pr);
    193 #else
    194 /*
    195  * Incomplete but practically useful stack backtrace.
    196  */
    197 #define	MIPS_JR_RA	0x03e00008	/* instruction code for jr ra */
    198 #define	MIPS_JR_K0	0x03400008	/* instruction code for jr k0 */
    199 #define	MIPS_ERET	0x42000018	/* instruction code for eret */
    200 	register_t va, pc, ra, sp, func;
    201 	int insn;
    202 	InstFmt i;
    203 	int stacksize;
    204 	db_addr_t offset;
    205 	const char *name;
    206 	extern char verylocore[];
    207 
    208 	pc = ddb_regs.f_regs[_R_PC];
    209 	sp = ddb_regs.f_regs[_R_SP];
    210 	ra = ddb_regs.f_regs[_R_RA];
    211 	do {
    212 		va = pc;
    213 		do {
    214 			va -= sizeof(int);
    215 			insn = *(int *)(intptr_t)va;
    216 			if (insn == MIPS_ERET)
    217 				goto mips3_eret;
    218 		} while (insn != MIPS_JR_RA && insn != MIPS_JR_K0);
    219 		va += sizeof(int);
    220 	mips3_eret:
    221 		va += sizeof(int);
    222 		while (*(int *)(intptr_t)va == 0x00000000)
    223 			va += sizeof(int);
    224 		func = va;
    225 		stacksize = 0;
    226 		do {
    227 			i.word = *(int *)(intptr_t)va;
    228 			if (((i.IType.op == OP_SW) || (i.IType.op == OP_SD))
    229 			    && i.IType.rs == _R_SP
    230 			    && i.IType.rt == _R_RA)
    231 				ra = *(int *)(intptr_t)(sp + (short)i.IType.imm);
    232 			if (((i.IType.op == OP_ADDIU) || (i.IType.op == OP_DADDIU))
    233 			    && i.IType.rs == _R_SP
    234 			    && i.IType.rt == _R_SP)
    235 				stacksize = -(short)i.IType.imm;
    236 			va += sizeof(int);
    237 		} while (va < pc);
    238 
    239 		db_find_sym_and_offset(func, &name, &offset);
    240 		if (name == 0)
    241 			name = "?";
    242 		(*pr)("%s()+0x%x, called by %p, stack size %d\n",
    243 			name, pc - func, (void *)(intptr_t)ra, stacksize);
    244 
    245 		if (ra == pc) {
    246 			(*pr)("-- loop? --\n");
    247 			return;
    248 		}
    249 		sp += stacksize;
    250 		pc = ra;
    251 	} while (pc > (intptr_t)verylocore);
    252 	if (pc < 0x80000000)
    253 		(*pr)("-- user process --\n");
    254 	else
    255 		(*pr)("-- kernel entry --\n");
    256 #endif
    257 }
    258 
    259 void
    260 db_mips_stack_trace(int count, vaddr_t stackp, vaddr_t the_pc, vaddr_t the_ra,
    261     int flags, vaddr_t kstackp)
    262 {
    263 
    264 	/* nothing... */
    265 }
    266 
    267 
    268 int
    269 db_mips_variable_func (const struct db_variable *vp, db_expr_t *valuep,
    270     int db_var_fcn)
    271 {
    272 
    273 	switch (db_var_fcn) {
    274 	case DB_VAR_GET:
    275 		*valuep = *(mips_reg_t *) vp->valuep;
    276 		break;
    277 	case DB_VAR_SET:
    278 		*(mips_reg_t *) vp->valuep = *valuep;
    279 		break;
    280 	}
    281 	return 0;
    282 }
    283