1 /*
2  * Copyright (c) 2019 Intel Corporation.
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  */
6 
7 #include <zephyr/kernel.h>
8 
9 #include <kernel_internal.h>
10 #include <zephyr/kernel_structs.h>
11 #include <zephyr/sys/__assert.h>
12 #include <zephyr/arch/cpu.h>
13 #include <zephyr/logging/log_ctrl.h>
14 #include <zephyr/logging/log.h>
15 #include <zephyr/fatal.h>
16 #include <zephyr/debug/coredump.h>
17 
18 LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
19 
20 /* LCOV_EXCL_START */
arch_system_halt(unsigned int reason)21 FUNC_NORETURN __weak void arch_system_halt(unsigned int reason)
22 {
23 	ARG_UNUSED(reason);
24 
25 	/* TODO: What's the best way to totally halt the system if SMP
26 	 * is enabled?
27 	 */
28 
29 	(void)arch_irq_lock();
30 	for (;;) {
31 		/* Spin endlessly */
32 	}
33 }
34 /* LCOV_EXCL_STOP */
35 
36 /* LCOV_EXCL_START */
k_sys_fatal_error_handler(unsigned int reason,const z_arch_esf_t * esf)37 __weak void k_sys_fatal_error_handler(unsigned int reason,
38 				      const z_arch_esf_t *esf)
39 {
40 	ARG_UNUSED(esf);
41 
42 	LOG_PANIC();
43 	LOG_ERR("Halting system");
44 	arch_system_halt(reason);
45 	CODE_UNREACHABLE;
46 }
47 /* LCOV_EXCL_STOP */
48 
thread_name_get(struct k_thread * thread)49 static const char *thread_name_get(struct k_thread *thread)
50 {
51 	const char *thread_name = (thread != NULL) ? k_thread_name_get(thread) : NULL;
52 
53 	if ((thread_name == NULL) || (thread_name[0] == '\0')) {
54 		thread_name = "unknown";
55 	}
56 
57 	return thread_name;
58 }
59 
reason_to_str(unsigned int reason)60 static const char *reason_to_str(unsigned int reason)
61 {
62 	switch (reason) {
63 	case K_ERR_CPU_EXCEPTION:
64 		return "CPU exception";
65 	case K_ERR_SPURIOUS_IRQ:
66 		return "Unhandled interrupt";
67 	case K_ERR_STACK_CHK_FAIL:
68 		return "Stack overflow";
69 	case K_ERR_KERNEL_OOPS:
70 		return "Kernel oops";
71 	case K_ERR_KERNEL_PANIC:
72 		return "Kernel panic";
73 	default:
74 		return "Unknown error";
75 	}
76 }
77 
78 /* LCOV_EXCL_START */
k_fatal_halt(unsigned int reason)79 FUNC_NORETURN void k_fatal_halt(unsigned int reason)
80 {
81 	arch_system_halt(reason);
82 }
83 /* LCOV_EXCL_STOP */
84 
z_fatal_error(unsigned int reason,const z_arch_esf_t * esf)85 void z_fatal_error(unsigned int reason, const z_arch_esf_t *esf)
86 {
87 	/* We can't allow this code to be preempted, but don't need to
88 	 * synchronize between CPUs, so an arch-layer lock is
89 	 * appropriate.
90 	 */
91 	unsigned int key = arch_irq_lock();
92 	struct k_thread *thread = IS_ENABLED(CONFIG_MULTITHREADING) ?
93 			_current : NULL;
94 
95 	/* twister looks for the "ZEPHYR FATAL ERROR" string, don't
96 	 * change it without also updating twister
97 	 */
98 	LOG_ERR(">>> ZEPHYR FATAL ERROR %d: %s on CPU %d", reason,
99 		reason_to_str(reason), _current_cpu->id);
100 
101 	/* FIXME: This doesn't seem to work as expected on all arches.
102 	 * Need a reliable way to determine whether the fault happened when
103 	 * an IRQ or exception was being handled, or thread context.
104 	 *
105 	 * See #17656
106 	 */
107 #if defined(CONFIG_ARCH_HAS_NESTED_EXCEPTION_DETECTION)
108 	if ((esf != NULL) && arch_is_in_nested_exception(esf)) {
109 		LOG_ERR("Fault during interrupt handling\n");
110 	}
111 #endif
112 
113 	LOG_ERR("Current thread: %p (%s)", thread,
114 		thread_name_get(thread));
115 
116 	coredump(reason, esf, thread);
117 
118 	k_sys_fatal_error_handler(reason, esf);
119 
120 	/* If the system fatal error handler returns, then kill the faulting
121 	 * thread; a policy decision was made not to hang the system.
122 	 *
123 	 * Policy for fatal errors in ISRs: unconditionally panic.
124 	 *
125 	 * There is one exception to this policy: a stack sentinel
126 	 * check may be performed (on behalf of the current thread)
127 	 * during ISR exit, but in this case the thread should be
128 	 * aborted.
129 	 *
130 	 * Note that k_thread_abort() returns on some architectures but
131 	 * not others; e.g. on ARC, x86_64, Xtensa with ASM2, ARM
132 	 */
133 	if (!IS_ENABLED(CONFIG_TEST)) {
134 		__ASSERT(reason != K_ERR_KERNEL_PANIC,
135 			 "Attempted to recover from a kernel panic condition");
136 		/* FIXME: #17656 */
137 #if defined(CONFIG_ARCH_HAS_NESTED_EXCEPTION_DETECTION)
138 		if ((esf != NULL) && arch_is_in_nested_exception(esf)) {
139 #if defined(CONFIG_STACK_SENTINEL)
140 			if (reason != K_ERR_STACK_CHK_FAIL) {
141 				__ASSERT(0,
142 				 "Attempted to recover from a fatal error in ISR");
143 			 }
144 #endif /* CONFIG_STACK_SENTINEL */
145 		}
146 #endif /* CONFIG_ARCH_HAS_NESTED_EXCEPTION_DETECTION */
147 	} else {
148 		/* Test mode */
149 #if defined(CONFIG_ARCH_HAS_NESTED_EXCEPTION_DETECTION)
150 		if ((esf != NULL) && arch_is_in_nested_exception(esf)) {
151 			/* Abort the thread only on STACK Sentinel check fail. */
152 #if defined(CONFIG_STACK_SENTINEL)
153 			if (reason != K_ERR_STACK_CHK_FAIL) {
154 				arch_irq_unlock(key);
155 				return;
156 			}
157 #else
158 			arch_irq_unlock(key);
159 			return;
160 #endif /* CONFIG_STACK_SENTINEL */
161 		} else {
162 			/* Abort the thread only if the fault is not due to
163 			 * a spurious ISR handler triggered.
164 			 */
165 			if (reason == K_ERR_SPURIOUS_IRQ) {
166 				arch_irq_unlock(key);
167 				return;
168 			}
169 		}
170 #endif /*CONFIG_ARCH_HAS_NESTED_EXCEPTION_DETECTION */
171 	}
172 
173 	arch_irq_unlock(key);
174 
175 	if (IS_ENABLED(CONFIG_MULTITHREADING)) {
176 		k_thread_abort(thread);
177 	}
178 }
179