xref: /optee_os/core/arch/arm/kernel/unwind_arm64.c (revision 95bec10a7d4de4bf8d7cb6c535b80ec76f2b3c94)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*-
3  * Copyright (c) 2015 Linaro Limited
4  * Copyright (c) 2015 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * This software was developed by Semihalf under
8  * the sponsorship of the FreeBSD Foundation.
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 AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <arm.h>
33 #include <kernel/thread.h>
34 #include <kernel/unwind.h>
35 #include <kernel/tee_misc.h>
36 #include <kernel/tee_ta_manager.h>
37 #include <string.h>
38 #include <tee/tee_svc.h>
39 #include <trace.h>
40 #include <user_ta_header.h>
41 #include <util.h>
42 
43 #include "unwind_private.h"
44 
45 static void copy_in_reg(uint64_t *reg, vaddr_t addr)
46 {
47 	memcpy(reg, (void *)addr, sizeof(*reg));
48 }
49 
50 #ifdef CFG_SYSCALL_FTRACE
51 static void ftrace_core_map_lr(uint64_t *lr)
52 {
53 	struct ftrace_buf *fbuf = NULL;
54 	struct tee_ta_session *s = NULL;
55 
56 	if (tee_ta_get_current_session(&s) != TEE_SUCCESS)
57 		return;
58 
59 	if (!s->fbuf)
60 		return;
61 
62 	fbuf = s->fbuf;
63 
64 	/*
65 	 * Function tracer inserts return hook (addr: &__ftrace_return)
66 	 * via modifying lr values in the stack frames. And during aborts,
67 	 * stack trace picks these modified lr values which needs to be
68 	 * replaced with original lr value. So here we use the ftrace return
69 	 * stack to retrieve original lr value but we need to first check if
70 	 * it has actually been modified or not in case TA is profiled
71 	 * partially.
72 	 */
73 	if ((*lr == (uint64_t)&__ftrace_return) &&
74 	    fbuf->lr_idx < fbuf->ret_idx) {
75 		fbuf->lr_idx++;
76 		*lr = fbuf->ret_stack[fbuf->ret_idx - fbuf->lr_idx];
77 	}
78 }
79 #else
80 static void ftrace_core_map_lr(uint64_t *lr __unused)
81 {
82 }
83 #endif
84 
85 bool unwind_stack_arm64(struct unwind_state_arm64 *frame,
86 			vaddr_t stack, size_t stack_size)
87 {
88 	vaddr_t fp = frame->fp;
89 
90 	if (!core_is_buffer_inside(fp, sizeof(uint64_t) * 3,
91 				   stack, stack_size))
92 		return false;
93 
94 	frame->sp = fp + 0x10;
95 	/* FP to previous frame (X29) */
96 	copy_in_reg(&frame->fp, fp);
97 	/* LR (X30) */
98 	copy_in_reg(&frame->pc, fp + 8);
99 
100 	ftrace_core_map_lr(&frame->pc);
101 
102 	frame->pc -= 4;
103 
104 	return true;
105 }
106 
107 #if (TRACE_LEVEL > 0)
108 
109 void print_stack_arm64(int level, struct unwind_state_arm64 *state,
110 		       vaddr_t stack, size_t stack_size)
111 {
112 	trace_printf_helper_raw(level, true, "Call stack:");
113 
114 	do {
115 		trace_printf_helper_raw(level, true, " 0x%016" PRIx64,
116 					state->pc);
117 	} while (unwind_stack_arm64(state, stack, stack_size));
118 }
119 
120 void print_kernel_stack(int level)
121 {
122 	struct unwind_state_arm64 state;
123 	uaddr_t stack = thread_stack_start();
124 	size_t stack_size = thread_stack_size();
125 
126 	memset(&state, 0, sizeof(state));
127 	state.pc = read_pc();
128 	state.fp = read_fp();
129 
130 	print_stack_arm64(level, &state, stack, stack_size);
131 }
132 
133 #endif
134 
135 vaddr_t *unw_get_kernel_stack(void)
136 {
137 	size_t n = 0;
138 	size_t size = 0;
139 	vaddr_t *tmp = NULL;
140 	vaddr_t *addr = NULL;
141 	struct unwind_state_arm64 state = { 0 };
142 	uaddr_t stack = thread_stack_start();
143 	size_t stack_size = thread_stack_size();
144 
145 	state.pc = read_pc();
146 	state.fp = read_fp();
147 
148 	while (unwind_stack_arm64(&state, stack, stack_size)) {
149 		tmp = unw_grow(addr, &size, (n + 1) * sizeof(vaddr_t));
150 		if (!tmp)
151 			goto err;
152 		addr = tmp;
153 		addr[n] = state.pc;
154 		n++;
155 	}
156 
157 	if (addr) {
158 		tmp = unw_grow(addr, &size, (n + 1) * sizeof(vaddr_t));
159 		if (!tmp)
160 			goto err;
161 		addr = tmp;
162 		addr[n] = 0;
163 	}
164 
165 	return addr;
166 err:
167 	EMSG("Out of memory");
168 	free(addr);
169 	return NULL;
170 }
171