xref: /openbmc/linux/arch/arc/kernel/troubleshoot.c (revision 58d9ceb7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4  */
5 
6 #include <linux/ptrace.h>
7 #include <linux/module.h>
8 #include <linux/mm.h>
9 #include <linux/fs.h>
10 #include <linux/kdev_t.h>
11 #include <linux/proc_fs.h>
12 #include <linux/file.h>
13 #include <linux/sched/mm.h>
14 #include <linux/sched/debug.h>
15 
16 #include <asm/arcregs.h>
17 #include <asm/irqflags.h>
18 
19 #define ARC_PATH_MAX	256
20 
print_regs_scratch(struct pt_regs * regs)21 static noinline void print_regs_scratch(struct pt_regs *regs)
22 {
23 	pr_cont("BTA: 0x%08lx\n SP: 0x%08lx  FP: 0x%08lx BLK: %pS\n",
24 		regs->bta, regs->sp, regs->fp, (void *)regs->blink);
25 	pr_cont("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
26 		regs->lp_start, regs->lp_end, regs->lp_count);
27 
28 	pr_info("r00: 0x%08lx\tr01: 0x%08lx\tr02: 0x%08lx\n"	\
29 		"r03: 0x%08lx\tr04: 0x%08lx\tr05: 0x%08lx\n"	\
30 		"r06: 0x%08lx\tr07: 0x%08lx\tr08: 0x%08lx\n"	\
31 		"r09: 0x%08lx\tr10: 0x%08lx\tr11: 0x%08lx\n"	\
32 		"r12: 0x%08lx\t",
33 		regs->r0, regs->r1, regs->r2,
34 		regs->r3, regs->r4, regs->r5,
35 		regs->r6, regs->r7, regs->r8,
36 		regs->r9, regs->r10, regs->r11,
37 		regs->r12);
38 }
39 
print_regs_callee(struct callee_regs * regs)40 static void print_regs_callee(struct callee_regs *regs)
41 {
42 	pr_cont("r13: 0x%08lx\tr14: 0x%08lx\n"			\
43 		"r15: 0x%08lx\tr16: 0x%08lx\tr17: 0x%08lx\n"	\
44 		"r18: 0x%08lx\tr19: 0x%08lx\tr20: 0x%08lx\n"	\
45 		"r21: 0x%08lx\tr22: 0x%08lx\tr23: 0x%08lx\n"	\
46 		"r24: 0x%08lx\tr25: 0x%08lx\n",
47 		regs->r13, regs->r14,
48 		regs->r15, regs->r16, regs->r17,
49 		regs->r18, regs->r19, regs->r20,
50 		regs->r21, regs->r22, regs->r23,
51 		regs->r24, regs->r25);
52 }
53 
print_task_path_n_nm(struct task_struct * tsk)54 static void print_task_path_n_nm(struct task_struct *tsk)
55 {
56 	char *path_nm = NULL;
57 	struct mm_struct *mm;
58 	struct file *exe_file;
59 	char buf[ARC_PATH_MAX];
60 
61 	mm = get_task_mm(tsk);
62 	if (!mm)
63 		goto done;
64 
65 	exe_file = get_mm_exe_file(mm);
66 	mmput(mm);
67 
68 	if (exe_file) {
69 		path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1);
70 		fput(exe_file);
71 	}
72 
73 done:
74 	pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
75 }
76 
show_faulting_vma(unsigned long address)77 static void show_faulting_vma(unsigned long address)
78 {
79 	struct vm_area_struct *vma;
80 	struct mm_struct *active_mm = current->active_mm;
81 
82 	/* can't use print_vma_addr() yet as it doesn't check for
83 	 * non-inclusive vma
84 	 */
85 	mmap_read_lock(active_mm);
86 	vma = vma_lookup(active_mm, address);
87 
88 	/* Lookup the vma at the address and report if the container VMA is not
89 	 * found
90 	 */
91 	if (vma) {
92 		char buf[ARC_PATH_MAX];
93 		char *nm = "?";
94 
95 		if (vma->vm_file) {
96 			nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
97 			if (IS_ERR(nm))
98 				nm = "?";
99 		}
100 		pr_info("  @off 0x%lx in [%s]  VMA: 0x%08lx to 0x%08lx\n",
101 			vma->vm_start < TASK_UNMAPPED_BASE ?
102 				address : address - vma->vm_start,
103 			nm, vma->vm_start, vma->vm_end);
104 	} else
105 		pr_info("    @No matching VMA found\n");
106 
107 	mmap_read_unlock(active_mm);
108 }
109 
show_ecr_verbose(struct pt_regs * regs)110 static void show_ecr_verbose(struct pt_regs *regs)
111 {
112 	unsigned int vec, cause_code;
113 	unsigned long address;
114 
115 	/* For Data fault, this is data address not instruction addr */
116 	address = current->thread.fault_address;
117 
118 	vec = regs->ecr.vec;
119 	cause_code = regs->ecr.cause;
120 
121 	/* For DTLB Miss or ProtV, display the memory involved too */
122 	if (vec == ECR_V_DTLB_MISS) {
123 		pr_cont("Invalid %s @ 0x%08lx by insn @ %pS\n",
124 		       (cause_code == 0x01) ? "Read" :
125 		       ((cause_code == 0x02) ? "Write" : "EX"),
126 		       address, (void *)regs->ret);
127 	} else if (vec == ECR_V_ITLB_MISS) {
128 		pr_cont("Insn could not be fetched\n");
129 	} else if (vec == ECR_V_MACH_CHK) {
130 		pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
131 					"Double Fault" : "Other Fatal Err");
132 
133 	} else if (vec == ECR_V_PROTV) {
134 		if (cause_code == ECR_C_PROTV_INST_FETCH)
135 			pr_cont("Execute from Non-exec Page\n");
136 		else if (cause_code == ECR_C_PROTV_MISALIG_DATA &&
137 		         IS_ENABLED(CONFIG_ISA_ARCOMPACT))
138 			pr_cont("Misaligned r/w from 0x%08lx\n", address);
139 		else
140 			pr_cont("%s access not allowed on page\n",
141 				(cause_code == 0x01) ? "Read" :
142 				((cause_code == 0x02) ? "Write" : "EX"));
143 	} else if (vec == ECR_V_INSN_ERR) {
144 		pr_cont("Illegal Insn\n");
145 #ifdef CONFIG_ISA_ARCV2
146 	} else if (vec == ECR_V_MEM_ERR) {
147 		if (cause_code == 0x00)
148 			pr_cont("Bus Error from Insn Mem\n");
149 		else if (cause_code == 0x10)
150 			pr_cont("Bus Error from Data Mem\n");
151 		else
152 			pr_cont("Bus Error, check PRM\n");
153 	} else if (vec == ECR_V_MISALIGN) {
154 		pr_cont("Misaligned r/w from 0x%08lx\n", address);
155 #endif
156 	} else if (vec == ECR_V_TRAP) {
157 		if (regs->ecr.param == 5)
158 			pr_cont("gcc generated __builtin_trap\n");
159 	} else {
160 		pr_cont("Check Programmer's Manual\n");
161 	}
162 }
163 
164 /************************************************************************
165  *  API called by rest of kernel
166  ***********************************************************************/
167 
show_regs(struct pt_regs * regs)168 void show_regs(struct pt_regs *regs)
169 {
170 	struct task_struct *tsk = current;
171 	struct callee_regs *cregs = (struct callee_regs *)tsk->thread.callee_reg;
172 
173 	/*
174 	 * generic code calls us with preemption disabled, but some calls
175 	 * here could sleep, so re-enable to avoid lockdep splat
176 	 */
177 	preempt_enable();
178 
179 	print_task_path_n_nm(tsk);
180 	show_regs_print_info(KERN_INFO);
181 
182 	show_ecr_verbose(regs);
183 
184 	if (user_mode(regs))
185 		show_faulting_vma(regs->ret); /* faulting code, not data */
186 
187 	pr_info("ECR: 0x%08lx EFA: 0x%08lx ERET: 0x%08lx\n",
188 		regs->ecr.full, current->thread.fault_address, regs->ret);
189 
190 	pr_info("STAT32: 0x%08lx", regs->status32);
191 
192 #define STS_BIT(r, bit)	r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
193 
194 #ifdef CONFIG_ISA_ARCOMPACT
195 	pr_cont(" [%2s%2s%2s%2s%2s%2s%2s]",
196 			(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
197 			STS_BIT(regs, DE), STS_BIT(regs, AE),
198 			STS_BIT(regs, A2), STS_BIT(regs, A1),
199 			STS_BIT(regs, E2), STS_BIT(regs, E1));
200 #else
201 	pr_cont(" [%2s%2s%2s%2s]   ",
202 			STS_BIT(regs, IE),
203 			(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
204 			STS_BIT(regs, DE), STS_BIT(regs, AE));
205 #endif
206 
207 	print_regs_scratch(regs);
208 	if (cregs)
209 		print_regs_callee(cregs);
210 
211 	preempt_disable();
212 }
213 
show_kernel_fault_diag(const char * str,struct pt_regs * regs,unsigned long address)214 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
215 			    unsigned long address)
216 {
217 	current->thread.fault_address = address;
218 
219 	/* Show fault description */
220 	pr_info("\n%s\n", str);
221 
222 	/* Caller and Callee regs */
223 	show_regs(regs);
224 
225 	/* Show stack trace if this Fatality happened in kernel mode */
226 	if (!user_mode(regs))
227 		show_stacktrace(current, regs, KERN_DEFAULT);
228 }
229