sys/arm/arm/db_trace.c

   1 /*      $NetBSD: db_trace.c,v 1.8 2003/01/17 22:28:48 thorpej Exp $     */
   2
   3 /*-
   4  * Copyright (c) 2000, 2001 Ben Harris
   5  * Copyright (c) 1996 Scott K. Stevens
   6  *
   7  * Mach Operating System
   8  * Copyright (c) 1991,1990 Carnegie Mellon University
   9  * All Rights Reserved.
  10  *
  11  * Permission to use, copy, modify and distribute this software and its
  12  * documentation is hereby granted, provided that both the copyright
  13  * notice and this permission notice appear in all copies of the
  14  * software, derivative works or modified versions, and any portions
  15  * thereof, and that both notices appear in supporting documentation.
  16  *
  17  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  18  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  19  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  20  *
  21  * Carnegie Mellon requests users of this software to return to
  22  *
  23  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  24  *  School of Computer Science
  25  *  Carnegie Mellon University
  26  *  Pittsburgh PA 15213-3890
  27  *
  28  * any improvements or extensions that they make and grant Carnegie the
  29  * rights to redistribute these changes.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 __FBSDID("$FreeBSD$");
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36
  37
  38 #include <sys/proc.h>
  39 #include <sys/kdb.h>
  40 #include <sys/stack.h>
  41 #include <machine/armreg.h>
  42 #include <machine/asm.h>
  43 #include <machine/cpufunc.h>
  44 #include <machine/db_machdep.h>
  45 #include <machine/pcb.h>
  46 #include <machine/stack.h>
  47 #include <machine/vmparam.h>
  48 #include <ddb/ddb.h>
  49 #include <ddb/db_access.h>
  50 #include <ddb/db_sym.h>
  51 #include <ddb/db_output.h>
  52
  53 /*
  54  * APCS stack frames are awkward beasts, so I don't think even trying to use
  55  * a structure to represent them is a good idea.
  56  *
  57  * Here's the diagram from the APCS.  Increasing address is _up_ the page.
  58  *
  59  *          save code pointer       [fp]        <- fp points to here
  60  *          return link value       [fp, #-4]
  61  *          return sp value         [fp, #-8]
  62  *          return fp value         [fp, #-12]
  63  *          [saved v7 value]
  64  *          [saved v6 value]
  65  *          [saved v5 value]
  66  *          [saved v4 value]
  67  *          [saved v3 value]
  68  *          [saved v2 value]
  69  *          [saved v1 value]
  70  *          [saved a4 value]
  71  *          [saved a3 value]
  72  *          [saved a2 value]
  73  *          [saved a1 value]
  74  *
  75  * The save code pointer points twelve bytes beyond the start of the
  76  * code sequence (usually a single STM) that created the stack frame.
  77  * We have to disassemble it if we want to know which of the optional
  78  * fields are actually present.
  79  */
  80
  81 static void
  82 db_stack_trace_cmd(db_expr_t addr, db_expr_t count)
  83 {
  84         u_int32_t       *frame, *lastframe;
  85         c_db_sym_t sym;
  86         const char *name;
  87         db_expr_t value;
  88         db_expr_t offset;
  89         boolean_t       kernel_only = TRUE;
  90         int     scp_offset;
  91
  92         frame = (u_int32_t *)addr;
  93         lastframe = NULL;
  94         scp_offset = -(get_pc_str_offset() >> 2);
  95
  96         while (count-- && frame != NULL && !db_pager_quit) {
  97                 db_addr_t       scp;
  98                 u_int32_t       savecode;
  99                 int             r;
 100                 u_int32_t       *rp;
 101                 const char      *sep;
 102
 103                 /*
 104                  * In theory, the SCP isn't guaranteed to be in the function
 105                  * that generated the stack frame.  We hope for the best.
 106                  */
 107                 scp = frame[FR_SCP];
 108
 109                 sym = db_search_symbol(scp, DB_STGY_ANY, &offset);
 110                 if (sym == C_DB_SYM_NULL) {
 111                         value = 0;
 112                         name = "(null)";
 113                 } else
 114                         db_symbol_values(sym, &name, &value);
 115                 db_printf("%s() at ", name);
 116                 db_printsym(scp, DB_STGY_PROC);
 117                 db_printf("\n");
 118 #ifdef __PROG26
 119                 db_printf("scp=0x%08x rlv=0x%08x (", scp, frame[FR_RLV] & R15_PC);
 120                 db_printsym(frame[FR_RLV] & R15_PC, DB_STGY_PROC);
 121                 db_printf(")\n");
 122 #else
 123                 db_printf("scp=0x%08x rlv=0x%08x (", scp, frame[FR_RLV]);
 124                 db_printsym(frame[FR_RLV], DB_STGY_PROC);
 125                 db_printf(")\n");
 126 #endif
 127                 db_printf("\trsp=0x%08x rfp=0x%08x", frame[FR_RSP], frame[FR_RFP]);
 128
 129                 savecode = ((u_int32_t *)scp)[scp_offset];
 130                 if ((savecode & 0x0e100000) == 0x08000000) {
 131                         /* Looks like an STM */
 132                         rp = frame - 4;
 133                         sep = "\n\t";
 134                         for (r = 10; r >= 0; r--) {
 135                                 if (savecode & (1 << r)) {
 136                                         db_printf("%sr%d=0x%08x",
 137                                             sep, r, *rp--);
 138                                         sep = (frame - rp) % 4 == 2 ?
 139                                             "\n\t" : " ";
 140                                 }
 141                         }
 142                 }
 143
 144                 db_printf("\n");
 145
 146                 /*
 147                  * Switch to next frame up
 148                  */
 149                 if (frame[FR_RFP] == 0)
 150                         break; /* Top of stack */
 151
 152                 lastframe = frame;
 153                 frame = (u_int32_t *)(frame[FR_RFP]);
 154
 155                 if (INKERNEL((int)frame)) {
 156                         /* staying in kernel */
 157                         if (frame <= lastframe) {
 158                                 db_printf("Bad frame pointer: %p\n", frame);
 159                                 break;
 160                         }
 161                 } else if (INKERNEL((int)lastframe)) {
 162                         /* switch from user to kernel */
 163                         if (kernel_only)
 164                                 break;  /* kernel stack only */
 165                 } else {
 166                         /* in user */
 167                         if (frame <= lastframe) {
 168                                 db_printf("Bad user frame pointer: %p\n",
 169                                           frame);
 170                                 break;
 171                         }
 172                 }
 173         }
 174 }
 175
 176 /* XXX stubs */
 177 void
 178 db_md_list_watchpoints()
 179 {
 180 }
 181
 182 int
 183 db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
 184 {
 185         return (0);
 186 }
 187
 188 int
 189 db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
 190 {
 191         return (0);
 192 }
 193
 194 int
 195 db_trace_thread(struct thread *thr, int count)
 196 {
 197         struct pcb *ctx;
 198
 199         ctx = kdb_thr_ctx(thr);
 200         db_stack_trace_cmd(ctx->un_32.pcb32_r11, -1);
 201         return (0);
 202 }
 203
 204 void
 205 db_trace_self(void)
 206 {
 207         db_addr_t addr;
 208
 209         addr = (db_addr_t)__builtin_frame_address(0);
 210         db_stack_trace_cmd(addr, -1);
 211 }