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
21static 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
40static 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
54static 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(task: 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
73done:
74 pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
75}
76
77static 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(mm: active_mm);
86 vma = vma_lookup(mm: active_mm, addr: 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 = "anon";
94
95 if (vma->vm_file) {
96 /* XXX: can we use %pD below and get rid of buf? */
97 nm = d_path(file_user_path(f: vma->vm_file), buf,
98 ARC_PATH_MAX-1);
99 if (IS_ERR(ptr: nm))
100 nm = "?";
101 }
102 pr_info(" @off 0x%lx in [%s] VMA: 0x%08lx to 0x%08lx\n",
103 vma->vm_start < TASK_UNMAPPED_BASE ?
104 address : address - vma->vm_start,
105 nm, vma->vm_start, vma->vm_end);
106 } else
107 pr_info(" @No matching VMA found\n");
108
109 mmap_read_unlock(mm: active_mm);
110}
111
112static void show_ecr_verbose(struct pt_regs *regs)
113{
114 unsigned int vec, cause_code;
115 unsigned long address;
116
117 /* For Data fault, this is data address not instruction addr */
118 address = current->thread.fault_address;
119
120 vec = regs->ecr.vec;
121 cause_code = regs->ecr.cause;
122
123 /* For DTLB Miss or ProtV, display the memory involved too */
124 if (vec == ECR_V_DTLB_MISS) {
125 pr_cont("Invalid %s @ 0x%08lx by insn @ %pS\n",
126 (cause_code == 0x01) ? "Read" :
127 ((cause_code == 0x02) ? "Write" : "EX"),
128 address, (void *)regs->ret);
129 } else if (vec == ECR_V_ITLB_MISS) {
130 pr_cont("Insn could not be fetched\n");
131 } else if (vec == ECR_V_MACH_CHK) {
132 pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
133 "Double Fault" : "Other Fatal Err");
134
135 } else if (vec == ECR_V_PROTV) {
136 if (cause_code == ECR_C_PROTV_INST_FETCH)
137 pr_cont("Execute from Non-exec Page\n");
138 else if (cause_code == ECR_C_PROTV_MISALIG_DATA &&
139 IS_ENABLED(CONFIG_ISA_ARCOMPACT))
140 pr_cont("Misaligned r/w from 0x%08lx\n", address);
141 else
142 pr_cont("%s access not allowed on page\n",
143 (cause_code == 0x01) ? "Read" :
144 ((cause_code == 0x02) ? "Write" : "EX"));
145 } else if (vec == ECR_V_INSN_ERR) {
146 pr_cont("Illegal Insn\n");
147#ifdef CONFIG_ISA_ARCV2
148 } else if (vec == ECR_V_MEM_ERR) {
149 if (cause_code == 0x00)
150 pr_cont("Bus Error from Insn Mem\n");
151 else if (cause_code == 0x10)
152 pr_cont("Bus Error from Data Mem\n");
153 else
154 pr_cont("Bus Error, check PRM\n");
155 } else if (vec == ECR_V_MISALIGN) {
156 pr_cont("Misaligned r/w from 0x%08lx\n", address);
157#endif
158 } else if (vec == ECR_V_TRAP) {
159 if (regs->ecr.param == 5)
160 pr_cont("gcc generated __builtin_trap\n");
161 } else {
162 pr_cont("Check Programmer's Manual\n");
163 }
164}
165
166/************************************************************************
167 * API called by rest of kernel
168 ***********************************************************************/
169
170void show_regs(struct pt_regs *regs)
171{
172 struct task_struct *tsk = current;
173 struct callee_regs *cregs = (struct callee_regs *)tsk->thread.callee_reg;
174
175 /*
176 * generic code calls us with preemption disabled, but some calls
177 * here could sleep, so re-enable to avoid lockdep splat
178 */
179 preempt_enable();
180
181 print_task_path_n_nm(tsk);
182 show_regs_print_info(KERN_INFO);
183
184 show_ecr_verbose(regs);
185
186 if (user_mode(regs))
187 show_faulting_vma(address: regs->ret); /* faulting code, not data */
188
189 pr_info("ECR: 0x%08lx EFA: 0x%08lx ERET: 0x%08lx\n",
190 regs->ecr.full, current->thread.fault_address, regs->ret);
191
192 pr_info("STAT32: 0x%08lx", regs->status32);
193
194#define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
195
196#ifdef CONFIG_ISA_ARCOMPACT
197 pr_cont(" [%2s%2s%2s%2s%2s%2s%2s]",
198 (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
199 STS_BIT(regs, DE), STS_BIT(regs, AE),
200 STS_BIT(regs, A2), STS_BIT(regs, A1),
201 STS_BIT(regs, E2), STS_BIT(regs, E1));
202#else
203 pr_cont(" [%2s%2s%2s%2s] ",
204 STS_BIT(regs, IE),
205 (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
206 STS_BIT(regs, DE), STS_BIT(regs, AE));
207#endif
208
209 print_regs_scratch(regs);
210 if (cregs)
211 print_regs_callee(regs: cregs);
212
213 preempt_disable();
214}
215
216void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
217 unsigned long address)
218{
219 current->thread.fault_address = address;
220
221 /* Show fault description */
222 pr_info("\n%s\n", str);
223
224 /* Caller and Callee regs */
225 show_regs(regs);
226
227 /* Show stack trace if this Fatality happened in kernel mode */
228 if (!user_mode(regs))
229 show_stacktrace(current, regs, KERN_DEFAULT);
230}
231

source code of linux/arch/arc/kernel/troubleshoot.c