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
21 /*
22 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
23 * -Prints 3 regs per line and a CR.
24 * -To continue, callee regs right after scratch, special handling of CR
25 */
print_reg_file(long * reg_rev,int start_num)26 static noinline void print_reg_file(long *reg_rev, int start_num)
27 {
28 unsigned int i;
29 char buf[512];
30 int n = 0, len = sizeof(buf);
31
32 for (i = start_num; i < start_num + 13; i++) {
33 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
34 i, (unsigned long)*reg_rev);
35
36 if (((i + 1) % 3) == 0)
37 n += scnprintf(buf + n, len - n, "\n");
38
39 /* because pt_regs has regs reversed: r12..r0, r25..r13 */
40 if (is_isa_arcv2() && start_num == 0)
41 reg_rev++;
42 else
43 reg_rev--;
44 }
45
46 if (start_num != 0)
47 n += scnprintf(buf + n, len - n, "\n\n");
48
49 /* To continue printing callee regs on same line as scratch regs */
50 if (start_num == 0)
51 pr_info("%s", buf);
52 else
53 pr_cont("%s\n", buf);
54 }
55
show_callee_regs(struct callee_regs * cregs)56 static void show_callee_regs(struct callee_regs *cregs)
57 {
58 print_reg_file(&(cregs->r13), 13);
59 }
60
print_task_path_n_nm(struct task_struct * tsk)61 static void print_task_path_n_nm(struct task_struct *tsk)
62 {
63 char *path_nm = NULL;
64 struct mm_struct *mm;
65 struct file *exe_file;
66 char buf[ARC_PATH_MAX];
67
68 mm = get_task_mm(tsk);
69 if (!mm)
70 goto done;
71
72 exe_file = get_mm_exe_file(mm);
73 mmput(mm);
74
75 if (exe_file) {
76 path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1);
77 fput(exe_file);
78 }
79
80 done:
81 pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
82 }
83
show_faulting_vma(unsigned long address)84 static void show_faulting_vma(unsigned long address)
85 {
86 struct vm_area_struct *vma;
87 struct mm_struct *active_mm = current->active_mm;
88
89 /* can't use print_vma_addr() yet as it doesn't check for
90 * non-inclusive vma
91 */
92 down_read(&active_mm->mmap_sem);
93 vma = find_vma(active_mm, address);
94
95 /* check against the find_vma( ) behaviour which returns the next VMA
96 * if the container VMA is not found
97 */
98 if (vma && (vma->vm_start <= address)) {
99 char buf[ARC_PATH_MAX];
100 char *nm = "?";
101
102 if (vma->vm_file) {
103 nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
104 if (IS_ERR(nm))
105 nm = "?";
106 }
107 pr_info(" @off 0x%lx in [%s]\n"
108 " VMA: 0x%08lx to 0x%08lx\n",
109 vma->vm_start < TASK_UNMAPPED_BASE ?
110 address : address - vma->vm_start,
111 nm, vma->vm_start, vma->vm_end);
112 } else
113 pr_info(" @No matching VMA found\n");
114
115 up_read(&active_mm->mmap_sem);
116 }
117
show_ecr_verbose(struct pt_regs * regs)118 static void show_ecr_verbose(struct pt_regs *regs)
119 {
120 unsigned int vec, cause_code;
121 unsigned long address;
122
123 pr_info("\n[ECR ]: 0x%08lx => ", regs->event);
124
125 /* For Data fault, this is data address not instruction addr */
126 address = current->thread.fault_address;
127
128 vec = regs->ecr_vec;
129 cause_code = regs->ecr_cause;
130
131 /* For DTLB Miss or ProtV, display the memory involved too */
132 if (vec == ECR_V_DTLB_MISS) {
133 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n",
134 (cause_code == 0x01) ? "Read" :
135 ((cause_code == 0x02) ? "Write" : "EX"),
136 address, regs->ret);
137 } else if (vec == ECR_V_ITLB_MISS) {
138 pr_cont("Insn could not be fetched\n");
139 } else if (vec == ECR_V_MACH_CHK) {
140 pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
141 "Double Fault" : "Other Fatal Err");
142
143 } else if (vec == ECR_V_PROTV) {
144 if (cause_code == ECR_C_PROTV_INST_FETCH)
145 pr_cont("Execute from Non-exec Page\n");
146 else if (cause_code == ECR_C_PROTV_MISALIG_DATA &&
147 IS_ENABLED(CONFIG_ISA_ARCOMPACT))
148 pr_cont("Misaligned r/w from 0x%08lx\n", address);
149 else
150 pr_cont("%s access not allowed on page\n",
151 (cause_code == 0x01) ? "Read" :
152 ((cause_code == 0x02) ? "Write" : "EX"));
153 } else if (vec == ECR_V_INSN_ERR) {
154 pr_cont("Illegal Insn\n");
155 #ifdef CONFIG_ISA_ARCV2
156 } else if (vec == ECR_V_MEM_ERR) {
157 if (cause_code == 0x00)
158 pr_cont("Bus Error from Insn Mem\n");
159 else if (cause_code == 0x10)
160 pr_cont("Bus Error from Data Mem\n");
161 else
162 pr_cont("Bus Error, check PRM\n");
163 } else if (vec == ECR_V_MISALIGN) {
164 pr_cont("Misaligned r/w from 0x%08lx\n", address);
165 #endif
166 } else if (vec == ECR_V_TRAP) {
167 if (regs->ecr_param == 5)
168 pr_cont("gcc generated __builtin_trap\n");
169 } else {
170 pr_cont("Check Programmer's Manual\n");
171 }
172 }
173
174 /************************************************************************
175 * API called by rest of kernel
176 ***********************************************************************/
177
show_regs(struct pt_regs * regs)178 void show_regs(struct pt_regs *regs)
179 {
180 struct task_struct *tsk = current;
181 struct callee_regs *cregs;
182
183 /*
184 * generic code calls us with preemption disabled, but some calls
185 * here could sleep, so re-enable to avoid lockdep splat
186 */
187 preempt_enable();
188
189 print_task_path_n_nm(tsk);
190 show_regs_print_info(KERN_INFO);
191
192 show_ecr_verbose(regs);
193
194 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n",
195 current->thread.fault_address,
196 (void *)regs->blink, (void *)regs->ret);
197
198 if (user_mode(regs))
199 show_faulting_vma(regs->ret); /* faulting code, not data */
200
201 pr_info("[STAT32]: 0x%08lx", regs->status32);
202
203 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
204
205 #ifdef CONFIG_ISA_ARCOMPACT
206 pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
207 (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
208 STS_BIT(regs, DE), STS_BIT(regs, AE),
209 STS_BIT(regs, A2), STS_BIT(regs, A1),
210 STS_BIT(regs, E2), STS_BIT(regs, E1));
211 #else
212 pr_cont(" : %2s%2s%2s%2s\n",
213 STS_BIT(regs, IE),
214 (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
215 STS_BIT(regs, DE), STS_BIT(regs, AE));
216 #endif
217 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
218 regs->bta, regs->sp, regs->fp);
219 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
220 regs->lp_start, regs->lp_end, regs->lp_count);
221
222 /* print regs->r0 thru regs->r12
223 * Sequential printing was generating horrible code
224 */
225 print_reg_file(&(regs->r0), 0);
226
227 /* If Callee regs were saved, display them too */
228 cregs = (struct callee_regs *)current->thread.callee_reg;
229 if (cregs)
230 show_callee_regs(cregs);
231
232 preempt_disable();
233 }
234
show_kernel_fault_diag(const char * str,struct pt_regs * regs,unsigned long address)235 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
236 unsigned long address)
237 {
238 current->thread.fault_address = address;
239
240 /* Show fault description */
241 pr_info("\n%s\n", str);
242
243 /* Caller and Callee regs */
244 show_regs(regs);
245
246 /* Show stack trace if this Fatality happened in kernel mode */
247 if (!user_mode(regs))
248 show_stacktrace(current, regs);
249 }
250