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/vmparam.h>
  47 #include <ddb/ddb.h>
  48 #include <ddb/db_access.h>
  49 #include <ddb/db_sym.h>
  50 #include <ddb/db_output.h>
  51
  52 #define INKERNEL(va)    (((vm_offset_t)(va)) >= VM_MIN_KERNEL_ADDRESS)
  53
  54 /*
  55  * APCS stack frames are awkward beasts, so I don't think even trying to use
  56  * a structure to represent them is a good idea.
  57  *
  58  * Here's the diagram from the APCS.  Increasing address is _up_ the page.
  59  *
  60  *          save code pointer       [fp]        <- fp points to here
  61  *          return link value       [fp, #-4]
  62  *          return sp value         [fp, #-8]
  63  *          return fp value         [fp, #-12]
  64  *          [saved v7 value]
  65  *          [saved v6 value]
  66  *          [saved v5 value]
  67  *          [saved v4 value]
  68  *          [saved v3 value]
  69  *          [saved v2 value]
  70  *          [saved v1 value]
  71  *          [saved a4 value]
  72  *          [saved a3 value]
  73  *          [saved a2 value]
  74  *          [saved a1 value]
  75  *
  76  * The save code pointer points twelve bytes beyond the start of the
  77  * code sequence (usually a single STM) that created the stack frame.
  78  * We have to disassemble it if we want to know which of the optional
  79  * fields are actually present.
  80  */
  81
  82 #define FR_SCP  (0)
  83 #define FR_RLV  (-1)
  84 #define FR_RSP  (-2)
  85 #define FR_RFP  (-3)
  86
  87 static void
  88 db_stack_trace_cmd(db_expr_t addr, db_expr_t count)
  89 {
  90         u_int32_t       *frame, *lastframe;
  91         c_db_sym_t sym;
  92         const char *name;
  93         db_expr_t value;
  94         db_expr_t offset;
  95         boolean_t       kernel_only = TRUE;
  96         int     scp_offset, quit;
  97
  98         frame = (u_int32_t *)addr;
  99         lastframe = NULL;
 100         scp_offset = -(get_pc_str_offset() >> 2);
 101
 102         quit = 0;
 103         db_setup_paging(db_simple_pager, &quit, db_lines_per_page);
 104         while (count-- && frame != NULL && !quit) {
 105                 db_addr_t       scp;
 106                 u_int32_t       savecode;
 107                 int             r;
 108                 u_int32_t       *rp;
 109                 const char      *sep;
 110
 111                 /*
 112                  * In theory, the SCP isn't guaranteed to be in the function
 113                  * that generated the stack frame.  We hope for the best.
 114                  */
 115                 scp = frame[FR_SCP];
 116
 117                 sym = db_search_symbol(scp, DB_STGY_ANY, &offset);
 118                 if (sym == C_DB_SYM_NULL) {
 119                         value = 0;
 120                         name = "(null)";
 121                 } else
 122                         db_symbol_values(sym, &name, &value);
 123                 db_printf("%s() at ", name);
 124                 db_printsym(scp, DB_STGY_PROC);
 125                 db_printf("\n");
 126 #ifdef __PROG26
 127                 db_printf("scp=0x%08x rlv=0x%08x (", scp, frame[FR_RLV] & R15_PC);
 128                 db_printsym(frame[FR_RLV] & R15_PC, DB_STGY_PROC);
 129                 db_printf(")\n");
 130 #else
 131                 db_printf("scp=0x%08x rlv=0x%08x (", scp, frame[FR_RLV]);
 132                 db_printsym(frame[FR_RLV], DB_STGY_PROC);
 133                 db_printf(")\n");
 134 #endif
 135                 db_printf("\trsp=0x%08x rfp=0x%08x", frame[FR_RSP], frame[FR_RFP]);
 136
 137                 savecode = ((u_int32_t *)scp)[scp_offset];
 138                 if ((savecode & 0x0e100000) == 0x08000000) {
 139                         /* Looks like an STM */
 140                         rp = frame - 4;
 141                         sep = "\n\t";
 142                         for (r = 10; r >= 0; r--) {
 143                                 if (savecode & (1 << r)) {
 144                                         db_printf("%sr%d=0x%08x",
 145                                             sep, r, *rp--);
 146                                         sep = (frame - rp) % 4 == 2 ?
 147                                             "\n\t" : " ";
 148                                 }
 149                         }
 150                 }
 151
 152                 db_printf("\n");
 153
 154                 /*
 155                  * Switch to next frame up
 156                  */
 157                 if (frame[FR_RFP] == 0)
 158                         break; /* Top of stack */
 159
 160                 lastframe = frame;
 161                 frame = (u_int32_t *)(frame[FR_RFP]);
 162
 163                 if (INKERNEL((int)frame)) {
 164                         /* staying in kernel */
 165                         if (frame <= lastframe) {
 166                                 db_printf("Bad frame pointer: %p\n", frame);
 167                                 break;
 168                         }
 169                 } else if (INKERNEL((int)lastframe)) {
 170                         /* switch from user to kernel */
 171                         if (kernel_only)
 172                                 break;  /* kernel stack only */
 173                 } else {
 174                         /* in user */
 175                         if (frame <= lastframe) {
 176                                 db_printf("Bad user frame pointer: %p\n",
 177                                           frame);
 178                                 break;
 179                         }
 180                 }
 181         }
 182 }
 183
 184 /* XXX stubs */
 185 void
 186 db_md_list_watchpoints()
 187 {
 188 }
 189
 190 int
 191 db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
 192 {
 193         return (0);
 194 }
 195
 196 int
 197 db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
 198 {
 199         return (0);
 200 }
 201
 202 int
 203 db_trace_thread(struct thread *thr, int count)
 204 {
 205         uint32_t addr;
 206
 207         if (thr == curthread)
 208                 addr = (uint32_t)__builtin_frame_address(0);
 209         else
 210                 addr = thr->td_pcb->un_32.pcb32_r11;
 211         db_stack_trace_cmd(addr, -1);
 212         return (0);
 213 }
 214
 215 void
 216 db_trace_self(void)
 217 {
 218         db_trace_thread(curthread, -1);
 219 }
 220
 221 void
 222 stack_save(struct stack *st)
 223 {
 224         vm_offset_t callpc;
 225         u_int32_t *frame;
 226
 227         stack_zero(st);
 228         frame = (u_int32_t *)__builtin_frame_address(0);
 229         while (1) {
 230                 if (!INKERNEL(frame))
 231                         break;
 232                 callpc = frame[FR_SCP];
 233                 if (stack_put(st, callpc) == -1)
 234                         break;
 235                 frame = (u_int32_t *)(frame[FR_RFP]);
 236         }
 237 }