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; 97 98 frame = (u_int32_t *)addr; 99 lastframe = NULL; 100 scp_offset = -(get_pc_str_offset() >> 2); 101 102 while (count-- && frame != NULL && !db_pager_quit) { 103 db_addr_t scp; 104 u_int32_t savecode; 105 int r; 106 u_int32_t *rp; 107 const char *sep; 108 109 /* 110 * In theory, the SCP isn't guaranteed to be in the function 111 * that generated the stack frame. We hope for the best. 112 */ 113 scp = frame[FR_SCP]; 114 115 sym = db_search_symbol(scp, DB_STGY_ANY, &offset); 116 if (sym == C_DB_SYM_NULL) { 117 value = 0; 118 name = "(null)"; 119 } else 120 db_symbol_values(sym, &name, &value); 121 db_printf("%s() at ", name); 122 db_printsym(scp, DB_STGY_PROC); 123 db_printf("\n"); 124 #ifdef __PROG26 125 db_printf("scp=0x%08x rlv=0x%08x (", scp, frame[FR_RLV] & R15_PC); 126 db_printsym(frame[FR_RLV] & R15_PC, DB_STGY_PROC); 127 db_printf(")\n"); 128 #else 129 db_printf("scp=0x%08x rlv=0x%08x (", scp, frame[FR_RLV]); 130 db_printsym(frame[FR_RLV], DB_STGY_PROC); 131 db_printf(")\n"); 132 #endif 133 db_printf("\trsp=0x%08x rfp=0x%08x", frame[FR_RSP], frame[FR_RFP]); 134 135 savecode = ((u_int32_t *)scp)[scp_offset]; 136 if ((savecode & 0x0e100000) == 0x08000000) { 137 /* Looks like an STM */ 138 rp = frame - 4; 139 sep = "\n\t"; 140 for (r = 10; r >= 0; r--) { 141 if (savecode & (1 << r)) { 142 db_printf("%sr%d=0x%08x", 143 sep, r, *rp--); 144 sep = (frame - rp) % 4 == 2 ? 145 "\n\t" : " "; 146 } 147 } 148 } 149 150 db_printf("\n"); 151 152 /* 153 * Switch to next frame up 154 */ 155 if (frame[FR_RFP] == 0) 156 break; /* Top of stack */ 157 158 lastframe = frame; 159 frame = (u_int32_t *)(frame[FR_RFP]); 160 161 if (INKERNEL((int)frame)) { 162 /* staying in kernel */ 163 if (frame <= lastframe) { 164 db_printf("Bad frame pointer: %p\n", frame); 165 break; 166 } 167 } else if (INKERNEL((int)lastframe)) { 168 /* switch from user to kernel */ 169 if (kernel_only) 170 break; /* kernel stack only */ 171 } else { 172 /* in user */ 173 if (frame <= lastframe) { 174 db_printf("Bad user frame pointer: %p\n", 175 frame); 176 break; 177 } 178 } 179 } 180 } 181 182 /* XXX stubs */ 183 void 184 db_md_list_watchpoints() 185 { 186 } 187 188 int 189 db_md_clr_watchpoint(db_expr_t addr, db_expr_t size) 190 { 191 return (0); 192 } 193 194 int 195 db_md_set_watchpoint(db_expr_t addr, db_expr_t size) 196 { 197 return (0); 198 } 199 200 int 201 db_trace_thread(struct thread *thr, int count) 202 { 203 uint32_t addr; 204 205 if (thr == curthread) 206 addr = (uint32_t)__builtin_frame_address(0); 207 else 208 addr = thr->td_pcb->un_32.pcb32_r11; 209 db_stack_trace_cmd(addr, -1); 210 return (0); 211 } 212 213 void 214 db_trace_self(void) 215 { 216 db_trace_thread(curthread, -1); 217 } 218 219 void 220 stack_save(struct stack *st) 221 { 222 vm_offset_t callpc; 223 u_int32_t *frame; 224 225 stack_zero(st); 226 frame = (u_int32_t *)__builtin_frame_address(0); 227 while (1) { 228 if (!INKERNEL(frame)) 229 break; 230 callpc = frame[FR_SCP]; 231 if (stack_put(st, callpc) == -1) 232 break; 233 frame = (u_int32_t *)(frame[FR_RFP]); 234 } 235 } 236