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      1 /*	$NetBSD: db_trace.c,v 1.7 2024/11/25 22:04:14 skrll Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Matt Thomas of 3am Software Foundry.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 
     34 __RCSID("$NetBSD: db_trace.c,v 1.7 2024/11/25 22:04:14 skrll Exp $");
     35 
     36 #include <sys/param.h>
     37 
     38 #include <sys/proc.h>
     39 #include <sys/systm.h>
     40 #include <sys/types.h>
     41 
     42 #include <riscv/db_machdep.h>
     43 
     44 #include <uvm/uvm_extern.h>
     45 
     46 #include <ddb/db_user.h>
     47 #include <ddb/db_access.h>
     48 #include <ddb/db_command.h>
     49 #include <ddb/db_output.h>
     50 #include <ddb/db_variables.h>
     51 #include <ddb/db_sym.h>
     52 #include <ddb/db_proc.h>
     53 #include <ddb/db_lwp.h>
     54 #include <ddb/db_extern.h>
     55 #include <ddb/db_interface.h>
     56 
     57 #ifndef _KERNEL
     58 #include <stddef.h>
     59 #endif
     60 
     61 #define MAXBACKTRACE	128	/* against infinite loop */
     62 #define TRACEFLAG_LOOKUPLWP	0x00000001
     63 
     64 #define IN_USER_VM_ADDRESS(addr)	\
     65 	(VM_MIN_ADDRESS <= (addr) && (addr) < VM_MAX_ADDRESS)
     66 #define IN_KERNEL_VM_ADDRESS(addr)	\
     67 	(VM_MIN_KERNEL_ADDRESS <= (addr) && (addr) < VM_MAX_KERNEL_ADDRESS)
     68 
     69 static bool __unused
     70 is_lwp(void *p)
     71 {
     72 	lwp_t *lwp;
     73 
     74 	for (lwp = db_lwp_first(); lwp != NULL; lwp = db_lwp_next(lwp)) {
     75 		if (lwp == p)
     76 			return true;
     77 	}
     78 	return false;
     79 }
     80 
     81 static const char *
     82 getlwpnamebysp(uint64_t sp)
     83 {
     84 #if defined(_KERNEL)
     85 	lwp_t *lwp;
     86 
     87 	for (lwp = db_lwp_first(); lwp != NULL; lwp = db_lwp_next(lwp)) {
     88 		uint64_t uarea = uvm_lwp_getuarea(lwp);
     89 		if ((uarea <= sp) && (sp < (uarea + USPACE))) {
     90 			return lwp->l_name;
     91 		}
     92 	}
     93 #endif
     94 	return "unknown";
     95 }
     96 
     97 static void
     98 pr_traceaddr(const char *prefix, uint64_t frame, uint64_t pc, int flags,
     99     void (*pr)(const char *, ...) __printflike(1, 2))
    100 {
    101 	db_expr_t offset;
    102 	db_sym_t sym;
    103 	const char *name;
    104 
    105 	sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
    106 	if (sym != DB_SYM_NULL) {
    107 		db_symbol_values(sym, &name, NULL);
    108 
    109 		if (flags & TRACEFLAG_LOOKUPLWP) {
    110 			(*pr)("%s %016" PRIx64 " %s %s() at %016" PRIx64,
    111 			    prefix, frame, getlwpnamebysp(frame), name, pc);
    112 		} else {
    113 			(*pr)("%s %016" PRIx64 " %s() at %016" PRIx64 " ",
    114 			    prefix, frame, name, pc);
    115 		}
    116 		db_printsym(pc, DB_STGY_PROC, pr);
    117 		(*pr)("\n");
    118 	} else {
    119 		if (flags & TRACEFLAG_LOOKUPLWP) {
    120 			(*pr)("%s %016" PRIx64 " %s ?() at %016" PRIx64 "\n",
    121 			    prefix, frame, getlwpnamebysp(frame), pc);
    122 		} else {
    123 			(*pr)("%s %016" PRIx64 " ?() at %016" PRIx64 "\n", prefix, frame, pc);
    124 		}
    125 	}
    126 }
    127 
    128 void
    129 db_stack_trace_print(db_expr_t addr, bool have_addr, db_expr_t count,
    130     const char *modif, void (*pr)(const char *, ...) __printflike(1, 2))
    131 {
    132 	vaddr_t ra, fp, lastra, lastfp;
    133 	struct trapframe *tf = NULL;
    134 	int flags = 0;
    135 	bool trace_user = false;
    136 	bool trace_thread = false;
    137 	bool trace_lwp = false;
    138 
    139 	pr("have_addr: %s\n", have_addr ? "true" : "false");
    140 	if (have_addr)
    141 		pr("addr: %lx\n", addr);
    142 	pr("count: %ld\n", count);
    143 	pr("modif: %s\n", modif);
    144 
    145 	for (; *modif != '\0'; modif++) {
    146 		switch (*modif) {
    147 		case 'a':
    148 			trace_lwp = true;
    149 			trace_thread = false;
    150 			break;
    151 		case 'l':
    152 			break;
    153 		case 't':
    154 			trace_thread = true;
    155 			trace_lwp = false;
    156 			break;
    157 		case 'u':
    158 			trace_user = true;
    159 			break;
    160 		case 'x':
    161 			flags |= TRACEFLAG_LOOKUPLWP;
    162 			break;
    163 		default:
    164 			pr("usage: bt[/ulx] [frame-address][,count]\n");
    165 			pr("       bt/t[ulx] [pid][,count]\n");
    166 			pr("       bt/a[ulx] [lwpaddr][,count]\n");
    167 			pr("\n");
    168 			pr("       /x      reverse lookup lwp name from sp\n");
    169 			return;
    170 		}
    171 	}
    172 
    173 #if defined(_KERNEL)
    174 	if (!have_addr) {
    175 		if (trace_lwp) {
    176 			addr = (db_expr_t)curlwp;
    177 		} else if (trace_thread) {
    178 			addr = curlwp->l_proc->p_pid;
    179 		} else {
    180 			tf = DDB_REGS;
    181 		}
    182 	}
    183 #endif
    184 
    185 	if (trace_thread) {
    186 		proc_t *pp;
    187 
    188 		if ((pp = db_proc_find((pid_t)addr)) == 0) {
    189 			(*pr)("trace: pid %d: not found\n", (int)addr);
    190 			return;
    191 		}
    192 		db_read_bytes((db_addr_t)pp + offsetof(proc_t, p_lwps.lh_first),
    193 		    sizeof(addr), (char *)&addr);
    194 		trace_thread = false;
    195 		trace_lwp = true;
    196 	}
    197 
    198 #if 0
    199 	/* "/a" is abbreviated? */
    200 	if (!trace_lwp && is_lwp(addr))
    201 		trace_lwp = true;
    202 #endif
    203 
    204 	if (trace_lwp) {
    205 		proc_t p;
    206 		struct lwp l;
    207 
    208 		db_read_bytes(addr, sizeof(l), (char *)&l);
    209 		db_read_bytes((db_addr_t)l.l_proc, sizeof(p), (char *)&p);
    210 
    211 #if defined(_KERNEL)
    212 		if (addr == (db_expr_t)curlwp) {
    213 			fp = (register_t)&DDB_REGS->tf_s0; /* s0 = fp */
    214 			tf = DDB_REGS;
    215 			(*pr)("trace: pid %d lid %d (curlwp) at tf %p\n",
    216 			    p.p_pid, l.l_lid, tf);
    217 		} else
    218 #endif
    219 		{
    220 			tf = l.l_md.md_ktf;
    221 			db_read_bytes((db_addr_t)&tf->tf_s0, sizeof(fp), (char *)&fp);
    222 			(*pr)("trace: pid %d lid %d at tf %p\n",
    223 			    p.p_pid, l.l_lid, tf);
    224 		}
    225 	} else if (tf == NULL) {
    226 		fp = addr;
    227 		pr("trace fp %016" PRIxVADDR "\n", fp);
    228 	} else {
    229 		pr("trace tf %p\n", tf);
    230 	}
    231 
    232 	if (count > MAXBACKTRACE)
    233 		count = MAXBACKTRACE;
    234 
    235 	if (tf != NULL) {
    236 #if defined(_KERNEL)
    237 		(*pr)("---- trapframe %p (%zu bytes) ----\n",
    238 		    tf, sizeof(*tf));
    239 		dump_trapframe(tf, pr);
    240 		(*pr)("------------------------"
    241 		      "------------------------\n");
    242 
    243 #endif
    244 		lastfp = lastra = ra = fp = 0;
    245 		db_read_bytes((db_addr_t)&tf->tf_ra, sizeof(ra), (char *)&ra);
    246 		db_read_bytes((db_addr_t)&tf->tf_s0, sizeof(fp), (char *)&fp);
    247 
    248 		pr_traceaddr("fp", fp, ra - 4, flags, pr);
    249 	}
    250 	for (; (count > 0) && (fp != 0); count--) {
    251 
    252 		lastfp = fp;
    253 		fp = ra = 0;
    254 		/*
    255 		 * normal stack frame
    256 		 *  fp[-1]  saved fp(s0) value
    257 		 *  fp[-2]  saved ra value
    258 		 */
    259 		db_read_bytes(lastfp - 1 * sizeof(register_t), sizeof(ra), (char *)&ra);
    260 		db_read_bytes(lastfp - 2 * sizeof(register_t), sizeof(fp), (char *)&fp);
    261 
    262 		if (!trace_user && (IN_USER_VM_ADDRESS(ra) || IN_USER_VM_ADDRESS(fp)))
    263 			break;
    264 #if defined(_KERNEL)
    265 		extern char exception_kernexit[];
    266 
    267 		if (((char *)ra == (char *)exception_kernexit)) {
    268 
    269 			tf = (struct trapframe *)lastfp;
    270 
    271 			lastra = ra;
    272 			ra = fp = 0;
    273 			db_read_bytes((db_addr_t)&tf->tf_pc, sizeof(ra), (char *)&ra);
    274 			db_read_bytes((db_addr_t)&tf->tf_s0, sizeof(fp), (char *)&fp);
    275 
    276 			pr_traceaddr("tf", (db_addr_t)tf, lastra, flags, pr);
    277 
    278 			(*pr)("---- trapframe %p (%zu bytes) ----\n",
    279 			    tf, sizeof(*tf));
    280 			dump_trapframe(tf, pr);
    281 			(*pr)("------------------------"
    282 			      "------------------------\n");
    283 			if (ra == 0)
    284 				break;
    285 			tf = NULL;
    286 
    287 			if (!trace_user && IN_USER_VM_ADDRESS(ra))
    288 				break;
    289 
    290 			pr_traceaddr("fp", fp, ra, flags, pr);
    291 
    292 		} else
    293 #endif
    294 		{
    295 			pr_traceaddr("fp", fp, ra - 4, flags, pr);
    296 		}
    297 	}
    298 }
    299