Home | History | Annotate | Line # | Download | only in mips
db_trace.c revision 1.41
      1 /*	$NetBSD: db_trace.c,v 1.41 2011/02/20 07:45:47 matt 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 1.41 2011/02/20 07:45:47 matt 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.r_regs[_R_AST],  DB_SETF_REGS },
     88 	{ "v0",	(long *)&ddb_regs.r_regs[_R_V0],  DB_SETF_REGS },
     89 	{ "v1",	(long *)&ddb_regs.r_regs[_R_V1],  DB_SETF_REGS },
     90 	{ "a0",	(long *)&ddb_regs.r_regs[_R_A0],  DB_SETF_REGS },
     91 	{ "a1",	(long *)&ddb_regs.r_regs[_R_A1],  DB_SETF_REGS },
     92 	{ "a2",	(long *)&ddb_regs.r_regs[_R_A2],  DB_SETF_REGS },
     93 	{ "a3",	(long *)&ddb_regs.r_regs[_R_A3],  DB_SETF_REGS },
     94 #if defined(__mips_n32) || defined(__mips_n64)
     95 	{ "a4",	(long *)&ddb_regs.r_regs[_R_A4],  DB_SETF_REGS },
     96 	{ "a5",	(long *)&ddb_regs.r_regs[_R_A5],  DB_SETF_REGS },
     97 	{ "a6",	(long *)&ddb_regs.r_regs[_R_A6],  DB_SETF_REGS },
     98 	{ "a7",	(long *)&ddb_regs.r_regs[_R_A7],  DB_SETF_REGS },
     99 	{ "t0",	(long *)&ddb_regs.r_regs[_R_T0],  DB_SETF_REGS },
    100 	{ "t1",	(long *)&ddb_regs.r_regs[_R_T1],  DB_SETF_REGS },
    101 	{ "t2",	(long *)&ddb_regs.r_regs[_R_T2],  DB_SETF_REGS },
    102 	{ "t3",	(long *)&ddb_regs.r_regs[_R_T3],  DB_SETF_REGS },
    103 #else
    104 	{ "t0",	(long *)&ddb_regs.r_regs[_R_T0],  DB_SETF_REGS },
    105 	{ "t1",	(long *)&ddb_regs.r_regs[_R_T1],  DB_SETF_REGS },
    106 	{ "t2",	(long *)&ddb_regs.r_regs[_R_T2],  DB_SETF_REGS },
    107 	{ "t3",	(long *)&ddb_regs.r_regs[_R_T3],  DB_SETF_REGS },
    108 	{ "t4",	(long *)&ddb_regs.r_regs[_R_T4],  DB_SETF_REGS },
    109 	{ "t5",	(long *)&ddb_regs.r_regs[_R_T5],  DB_SETF_REGS },
    110 	{ "t6",	(long *)&ddb_regs.r_regs[_R_T6],  DB_SETF_REGS },
    111 	{ "t7",	(long *)&ddb_regs.r_regs[_R_T7],  DB_SETF_REGS },
    112 #endif /* __mips_n32 || __mips_n64 */
    113 	{ "s0",	(long *)&ddb_regs.r_regs[_R_S0],  DB_SETF_REGS },
    114 	{ "s1",	(long *)&ddb_regs.r_regs[_R_S1],  DB_SETF_REGS },
    115 	{ "s2",	(long *)&ddb_regs.r_regs[_R_S2],  DB_SETF_REGS },
    116 	{ "s3",	(long *)&ddb_regs.r_regs[_R_S3],  DB_SETF_REGS },
    117 	{ "s4",	(long *)&ddb_regs.r_regs[_R_S4],  DB_SETF_REGS },
    118 	{ "s5",	(long *)&ddb_regs.r_regs[_R_S5],  DB_SETF_REGS },
    119 	{ "s6",	(long *)&ddb_regs.r_regs[_R_S6],  DB_SETF_REGS },
    120 	{ "s7",	(long *)&ddb_regs.r_regs[_R_S7],  DB_SETF_REGS },
    121 	{ "t8",	(long *)&ddb_regs.r_regs[_R_T8],  DB_SETF_REGS },
    122 	{ "t9",	(long *)&ddb_regs.r_regs[_R_T9],  DB_SETF_REGS },
    123 	{ "k0",	(long *)&ddb_regs.r_regs[_R_K0],  DB_SETF_REGS },
    124 	{ "k1",	(long *)&ddb_regs.r_regs[_R_K1],  DB_SETF_REGS },
    125 	{ "gp",	(long *)&ddb_regs.r_regs[_R_GP],  DB_SETF_REGS },
    126 	{ "sp",	(long *)&ddb_regs.r_regs[_R_SP],  DB_SETF_REGS },
    127 	{ "fp",	(long *)&ddb_regs.r_regs[_R_S8],  DB_SETF_REGS },/* frame ptr */
    128 	{ "ra",	(long *)&ddb_regs.r_regs[_R_RA],  DB_SETF_REGS },
    129 	{ "sr",	(long *)&ddb_regs.r_regs[_R_SR],  DB_SETF_REGS },
    130 	{ "mdlo",(long *)&ddb_regs.r_regs[_R_MULLO],  DB_SETF_REGS },
    131 	{ "mdhi",(long *)&ddb_regs.r_regs[_R_MULHI],  DB_SETF_REGS },
    132 	{ "bad", (long *)&ddb_regs.r_regs[_R_BADVADDR], DB_SETF_REGS },
    133 	{ "cs",	(long *)&ddb_regs.r_regs[_R_CAUSE],  DB_SETF_REGS },
    134 	{ "pc",	(long *)&ddb_regs.r_regs[_R_PC],  DB_SETF_REGS },
    135 };
    136 const struct db_variable * const db_eregs = db_regs + __arraycount(db_regs);
    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 		struct reg * regs = &ddb_regs;
    152 		stacktrace_subr(regs->r_regs[_R_A0],
    153 				regs->r_regs[_R_A1],
    154 				regs->r_regs[_R_A2],
    155 				regs->r_regs[_R_A3],
    156 				regs->r_regs[_R_PC],
    157 				regs->r_regs[_R_SP],
    158 				/* non-virtual frame pointer */
    159 				regs->r_regs[_R_S8],
    160 				regs->r_regs[_R_RA],
    161 				pr);
    162 		return;
    163 	}
    164 
    165 	while ((c = *cp++) != 0) {
    166 		if (c == 'a') {
    167 			lwpaddr = true;
    168 		}
    169 	}
    170 
    171 	if (lwpaddr) {
    172 		l = (struct lwp *)addr;
    173 		(*pr)("pid %d.%d ", l->l_proc->p_pid, l->l_lid);
    174 	} else {
    175 		/* "trace/t" */
    176 
    177 		(*pr)("pid %d ", (int)addr);
    178 		p = proc_find_raw(addr);
    179 		if (p == NULL) {
    180 			(*pr)("not found\n");
    181 			return;
    182 		}
    183 		l = LIST_FIRST(&p->p_lwps); /* XXX NJWLWP */
    184 	}
    185 	pcb = lwp_getpcb(l);
    186 	(*pr)("at %p\n", pcb);
    187 
    188 	stacktrace_subr(0,0,0,0,	/* no args known */
    189 			(vaddr_t)cpu_switchto,
    190 			pcb->pcb_context.val[_L_SP],
    191 			pcb->pcb_context.val[_L_S8],
    192 			pcb->pcb_context.val[_L_RA],
    193 			pr);
    194 #else
    195 /*
    196  * Incomplete but practically useful stack backtrace.
    197  */
    198 #define	MIPS_JR_RA	0x03e00008	/* instruction code for jr ra */
    199 #define	MIPS_JR_K0	0x03400008	/* instruction code for jr k0 */
    200 #define	MIPS_ERET	0x42000018	/* instruction code for eret */
    201 	register_t va, pc, ra, sp, func;
    202 	int insn;
    203 	InstFmt i;
    204 	int stacksize;
    205 	db_addr_t offset;
    206 	const char *name;
    207 	extern char verylocore[];
    208 
    209 	pc = ddb_regs.r_regs[_R_PC];
    210 	sp = ddb_regs.r_regs[_R_SP];
    211 	ra = ddb_regs.r_regs[_R_RA];
    212 	do {
    213 		va = pc;
    214 		do {
    215 			va -= sizeof(int);
    216 			insn = *(int *)(intptr_t)va;
    217 			if (insn == MIPS_ERET)
    218 				goto mips3_eret;
    219 		} while (insn != MIPS_JR_RA && insn != MIPS_JR_K0);
    220 		va += sizeof(int);
    221 	mips3_eret:
    222 		va += sizeof(int);
    223 		while (*(int *)(intptr_t)va == 0x00000000)
    224 			va += sizeof(int);
    225 		func = va;
    226 		stacksize = 0;
    227 		do {
    228 			i.word = *(int *)(intptr_t)va;
    229 			if (((i.IType.op == OP_SW) || (i.IType.op == OP_SD))
    230 			    && i.IType.rs == _R_SP
    231 			    && i.IType.rt == _R_RA)
    232 				ra = *(int *)(intptr_t)(sp + (short)i.IType.imm);
    233 			if (((i.IType.op == OP_ADDIU) || (i.IType.op == OP_DADDIU))
    234 			    && i.IType.rs == _R_SP
    235 			    && i.IType.rt == _R_SP)
    236 				stacksize = -(short)i.IType.imm;
    237 			va += sizeof(int);
    238 		} while (va < pc);
    239 
    240 		db_find_sym_and_offset(func, &name, &offset);
    241 		if (name == 0)
    242 			name = "?";
    243 		(*pr)("%s()+0x%x, called by %p, stack size %d\n",
    244 			name, pc - func, (void *)(intptr_t)ra, stacksize);
    245 
    246 		if (ra == pc) {
    247 			(*pr)("-- loop? --\n");
    248 			return;
    249 		}
    250 		sp += stacksize;
    251 		pc = ra;
    252 	} while (pc > (intptr_t)verylocore);
    253 	if (pc < 0x80000000)
    254 		(*pr)("-- user process --\n");
    255 	else
    256 		(*pr)("-- kernel entry --\n");
    257 #endif
    258 }
    259 
    260 void
    261 db_mips_stack_trace(int count, vaddr_t stackp, vaddr_t the_pc, vaddr_t the_ra,
    262     int flags, vaddr_t kstackp)
    263 {
    264 
    265 	/* nothing... */
    266 }
    267 
    268 
    269 int
    270 db_mips_variable_func (const struct db_variable *vp, db_expr_t *valuep,
    271     int db_var_fcn)
    272 {
    273 
    274 	switch (db_var_fcn) {
    275 	case DB_VAR_GET:
    276 		*valuep = *(mips_reg_t *) vp->valuep;
    277 		break;
    278 	case DB_VAR_SET:
    279 		*(mips_reg_t *) vp->valuep = *valuep;
    280 		break;
    281 	}
    282 	return 0;
    283 }
    284