1 /*
2  * Copyright (c) 2014 Wind River Systems, Inc.
3  *
4  * SPDX-License-Identifier: Apache-2.0
5  */
6 
7 /**
8  * @file
9  * @brief Kernel fatal error handler for ARM Cortex-M and Cortex-R
10  *
11  * This module provides the z_arm_fatal_error() routine for ARM Cortex-M
12  * and Cortex-R CPUs.
13  */
14 
15 #include <zephyr/kernel.h>
16 #include <kernel_arch_data.h>
17 #include <zephyr/logging/log.h>
18 LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
19 
esf_dump(const z_arch_esf_t * esf)20 static void esf_dump(const z_arch_esf_t *esf)
21 {
22 	LOG_ERR("r0/a1:  0x%08x  r1/a2:  0x%08x  r2/a3:  0x%08x",
23 		esf->basic.a1, esf->basic.a2, esf->basic.a3);
24 	LOG_ERR("r3/a4:  0x%08x r12/ip:  0x%08x r14/lr:  0x%08x",
25 		esf->basic.a4, esf->basic.ip, esf->basic.lr);
26 	LOG_ERR(" xpsr:  0x%08x", esf->basic.xpsr);
27 #if defined(CONFIG_FPU) && defined(CONFIG_FPU_SHARING)
28 	for (int i = 0; i < ARRAY_SIZE(esf->fpu.s); i += 4) {
29 		LOG_ERR("s[%2d]:  0x%08x  s[%2d]:  0x%08x"
30 			"  s[%2d]:  0x%08x  s[%2d]:  0x%08x",
31 			i, (uint32_t)esf->fpu.s[i],
32 			i + 1, (uint32_t)esf->fpu.s[i + 1],
33 			i + 2, (uint32_t)esf->fpu.s[i + 2],
34 			i + 3, (uint32_t)esf->fpu.s[i + 3]);
35 	}
36 #ifdef CONFIG_VFP_FEATURE_REGS_S64_D32
37 	for (int i = 0; i < ARRAY_SIZE(esf->fpu.d); i += 4) {
38 		LOG_ERR("d[%2d]:  0x%16llx  d[%2d]:  0x%16llx"
39 			"  d[%2d]:  0x%16llx  d[%2d]:  0x%16llx",
40 			i, (uint64_t)esf->fpu.d[i],
41 			i + 1, (uint64_t)esf->fpu.d[i + 1],
42 			i + 2, (uint64_t)esf->fpu.d[i + 2],
43 			i + 3, (uint64_t)esf->fpu.d[i + 3]);
44 	}
45 #endif
46 	LOG_ERR("fpscr:  0x%08x", esf->fpu.fpscr);
47 #endif
48 #if defined(CONFIG_EXTRA_EXCEPTION_INFO)
49 	const struct _callee_saved *callee = esf->extra_info.callee;
50 
51 	if (callee != NULL) {
52 		LOG_ERR("r4/v1:  0x%08x  r5/v2:  0x%08x  r6/v3:  0x%08x",
53 			callee->v1, callee->v2, callee->v3);
54 		LOG_ERR("r7/v4:  0x%08x  r8/v5:  0x%08x  r9/v6:  0x%08x",
55 			callee->v4, callee->v5, callee->v6);
56 		LOG_ERR("r10/v7: 0x%08x  r11/v8: 0x%08x    psp:  0x%08x",
57 			callee->v7, callee->v8, callee->psp);
58 	}
59 
60 	LOG_ERR("EXC_RETURN: 0x%0x", esf->extra_info.exc_return);
61 
62 #endif /* CONFIG_EXTRA_EXCEPTION_INFO */
63 	LOG_ERR("Faulting instruction address (r15/pc): 0x%08x",
64 		esf->basic.pc);
65 }
66 
z_arm_fatal_error(unsigned int reason,const z_arch_esf_t * esf)67 void z_arm_fatal_error(unsigned int reason, const z_arch_esf_t *esf)
68 {
69 
70 	if (esf != NULL) {
71 		esf_dump(esf);
72 	}
73 	z_fatal_error(reason, esf);
74 }
75 
76 /**
77  * @brief Handle a software-generated fatal exception
78  * (e.g. kernel oops, panic, etc.).
79  *
80  * Notes:
81  * - the function is invoked in SVC Handler
82  * - if triggered from nPRIV mode, only oops and stack fail error reasons
83  *   may be propagated to the fault handling process.
84  * - We expect the supplied exception stack frame to always be a valid
85  *   frame. That is because, if the ESF cannot be stacked during an SVC,
86  *   a processor fault (e.g. stacking error) will be generated, and the
87  *   fault handler will executed instead of the SVC.
88  *
89  * @param esf exception frame
90  * @param callee_regs Callee-saved registers (R4-R11)
91  */
z_do_kernel_oops(const z_arch_esf_t * esf,_callee_saved_t * callee_regs)92 void z_do_kernel_oops(const z_arch_esf_t *esf, _callee_saved_t *callee_regs)
93 {
94 #if !(defined(CONFIG_EXTRA_EXCEPTION_INFO) && defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE))
95 	ARG_UNUSED(callee_regs);
96 #endif
97 	/* Stacked R0 holds the exception reason. */
98 	unsigned int reason = esf->basic.r0;
99 
100 #if defined(CONFIG_USERSPACE)
101 	if (z_arm_preempted_thread_in_user_mode(esf)) {
102 		/*
103 		 * Exception triggered from user mode.
104 		 *
105 		 * User mode is only allowed to induce oopses and stack check
106 		 * failures via software-triggered system fatal exceptions.
107 		 */
108 		if (!((esf->basic.r0 == K_ERR_KERNEL_OOPS) ||
109 			(esf->basic.r0 == K_ERR_STACK_CHK_FAIL))) {
110 
111 			reason = K_ERR_KERNEL_OOPS;
112 		}
113 	}
114 
115 #endif /* CONFIG_USERSPACE */
116 
117 #if !defined(CONFIG_EXTRA_EXCEPTION_INFO)
118 	z_arm_fatal_error(reason, esf);
119 #else
120 	z_arch_esf_t esf_copy;
121 
122 	memcpy(&esf_copy, esf, offsetof(z_arch_esf_t, extra_info));
123 #if defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
124 	/* extra exception info is collected in callee_reg param
125 	 * on CONFIG_ARMV7_M_ARMV8_M_MAINLINE
126 	 */
127 
128 	esf_copy.extra_info = (struct __extra_esf_info) {
129 		.callee = callee_regs,
130 	};
131 #else
132 	/* extra exception info is not collected for kernel oops
133 	 * path today so we make a copy of the ESF and zero out
134 	 * that information
135 	 */
136 	esf_copy.extra_info = (struct __extra_esf_info) { 0 };
137 #endif /* CONFIG_ARMV7_M_ARMV8_M_MAINLINE */
138 
139 	z_arm_fatal_error(reason, &esf_copy);
140 #endif /* CONFIG_EXTRA_EXCEPTION_INFO */
141 }
142 
arch_syscall_oops(void * ssf_ptr)143 FUNC_NORETURN void arch_syscall_oops(void *ssf_ptr)
144 {
145 	uint32_t *ssf_contents = ssf_ptr;
146 	z_arch_esf_t oops_esf = { 0 };
147 
148 	/* TODO: Copy the rest of the register set out of ssf_ptr */
149 	oops_esf.basic.pc = ssf_contents[3];
150 
151 	z_arm_fatal_error(K_ERR_KERNEL_OOPS, &oops_esf);
152 	CODE_UNREACHABLE;
153 }
154