xref: /freebsd/sys/riscv/riscv/db_trace.c (revision 6419bb52)
1 /*-
2  * Copyright (c) 2015 The FreeBSD Foundation
3  * Copyright (c) 2016 Ruslan Bukin <br@bsdpad.com>
4  * All rights reserved.
5  * Copyright (c) 2020 John Baldwin <jhb@FreeBSD.org>
6  *
7  * Portions of this software were developed by Semihalf under
8  * the sponsorship of the FreeBSD Foundation.
9  *
10  * Portions of this software were developed by SRI International and the
11  * University of Cambridge Computer Laboratory under DARPA/AFRL contract
12  * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
13  *
14  * Portions of this software were developed by the University of Cambridge
15  * Computer Laboratory as part of the CTSRD Project, with support from the
16  * UK Higher Education Innovation Fund (HEIF).
17  *
18  * Redistribution and use in source and binary forms, with or without
19  * modification, are permitted provided that the following conditions
20  * are met:
21  * 1. Redistributions of source code must retain the above copyright
22  *    notice, this list of conditions and the following disclaimer.
23  * 2. Redistributions in binary form must reproduce the above copyright
24  *    notice, this list of conditions and the following disclaimer in the
25  *    documentation and/or other materials provided with the distribution.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
42 
43 #include <sys/param.h>
44 #include <sys/kdb.h>
45 #include <sys/proc.h>
46 
47 #include <ddb/ddb.h>
48 #include <ddb/db_sym.h>
49 
50 #include <machine/pcb.h>
51 #include <machine/riscvreg.h>
52 #include <machine/stack.h>
53 #include <machine/vmparam.h>
54 
55 void
56 db_md_list_watchpoints()
57 {
58 
59 }
60 
61 int
62 db_md_clr_watchpoint(db_expr_t addr, db_expr_t size)
63 {
64 
65 	return (0);
66 }
67 
68 int
69 db_md_set_watchpoint(db_expr_t addr, db_expr_t size)
70 {
71 
72 	return (0);
73 }
74 
75 static void
76 db_stack_trace_cmd(struct unwind_state *frame)
77 {
78 	const char *name;
79 	db_expr_t offset;
80 	db_expr_t value;
81 	c_db_sym_t sym;
82 	uint64_t pc;
83 
84 	while (1) {
85 		pc = frame->pc;
86 
87 		sym = db_search_symbol(pc, DB_STGY_ANY, &offset);
88 		if (sym == C_DB_SYM_NULL) {
89 			value = 0;
90 			name = "(null)";
91 		} else
92 			db_symbol_values(sym, &name, &value);
93 
94 		db_printf("%s() at ", name);
95 		db_printsym(frame->pc, DB_STGY_PROC);
96 		db_printf("\n");
97 
98 		if (strcmp(name, "cpu_exception_handler_supervisor") == 0 ||
99 		    strcmp(name, "cpu_exception_handler_user") == 0) {
100 			struct trapframe *tf;
101 
102 			tf = (struct trapframe *)(uintptr_t)frame->sp;
103 
104 			if (tf->tf_scause & EXCP_INTR)
105 				db_printf("--- interrupt %ld\n",
106 				    tf->tf_scause & EXCP_MASK);
107 			else
108 				db_printf("--- exception %ld, tval = %#lx\n",
109 				    tf->tf_scause & EXCP_MASK,
110 				    tf->tf_stval);
111 			frame->sp = (uint64_t)tf->tf_sp;
112 			frame->fp = (uint64_t)tf->tf_s[0];
113 			frame->pc = (uint64_t)tf->tf_sepc;
114 			if (!INKERNEL(frame->fp))
115 				break;
116 			continue;
117 		}
118 
119 		if (strcmp(name, "fork_trampoline") == 0)
120 			break;
121 
122 		if (unwind_frame(frame) < 0)
123 			break;
124 	}
125 }
126 
127 int
128 db_trace_thread(struct thread *thr, int count)
129 {
130 	struct unwind_state frame;
131 	struct pcb *ctx;
132 
133 	ctx = kdb_thr_ctx(thr);
134 
135 	frame.sp = (uint64_t)ctx->pcb_sp;
136 	frame.fp = (uint64_t)ctx->pcb_s[0];
137 	frame.pc = (uint64_t)ctx->pcb_ra;
138 	db_stack_trace_cmd(&frame);
139 	return (0);
140 }
141 
142 void
143 db_trace_self(void)
144 {
145 	struct unwind_state frame;
146 	uint64_t sp;
147 
148 	__asm __volatile("mv %0, sp" : "=&r" (sp));
149 
150 	frame.sp = sp;
151 	frame.fp = (uint64_t)__builtin_frame_address(0);
152 	frame.pc = (uint64_t)db_trace_self;
153 	db_stack_trace_cmd(&frame);
154 }
155