GNU Linux-libre 4.19.314-gnu1
[releases.git] / arch / arc / kernel / troubleshoot.c
1 /*
2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  */
7
8 #include <linux/ptrace.h>
9 #include <linux/module.h>
10 #include <linux/mm.h>
11 #include <linux/fs.h>
12 #include <linux/kdev_t.h>
13 #include <linux/proc_fs.h>
14 #include <linux/file.h>
15 #include <linux/sched/mm.h>
16 #include <linux/sched/debug.h>
17
18 #include <asm/arcregs.h>
19 #include <asm/irqflags.h>
20
21 #define ARC_PATH_MAX    256
22
23 /*
24  * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
25  *   -Prints 3 regs per line and a CR.
26  *   -To continue, callee regs right after scratch, special handling of CR
27  */
28 static noinline void print_reg_file(long *reg_rev, int start_num)
29 {
30         unsigned int i;
31         char buf[512];
32         int n = 0, len = sizeof(buf);
33
34         for (i = start_num; i < start_num + 13; i++) {
35                 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
36                                i, (unsigned long)*reg_rev);
37
38                 if (((i + 1) % 3) == 0)
39                         n += scnprintf(buf + n, len - n, "\n");
40
41                 /* because pt_regs has regs reversed: r12..r0, r25..r13 */
42                 if (is_isa_arcv2() && start_num == 0)
43                         reg_rev++;
44                 else
45                         reg_rev--;
46         }
47
48         if (start_num != 0)
49                 n += scnprintf(buf + n, len - n, "\n\n");
50
51         /* To continue printing callee regs on same line as scratch regs */
52         if (start_num == 0)
53                 pr_info("%s", buf);
54         else
55                 pr_cont("%s\n", buf);
56 }
57
58 static void show_callee_regs(struct callee_regs *cregs)
59 {
60         print_reg_file(&(cregs->r13), 13);
61 }
62
63 static void print_task_path_n_nm(struct task_struct *tsk)
64 {
65         char *path_nm = NULL;
66         struct mm_struct *mm;
67         struct file *exe_file;
68         char buf[ARC_PATH_MAX];
69
70         mm = get_task_mm(tsk);
71         if (!mm)
72                 goto done;
73
74         exe_file = get_mm_exe_file(mm);
75         mmput(mm);
76
77         if (exe_file) {
78                 path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1);
79                 fput(exe_file);
80         }
81
82 done:
83         pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
84 }
85
86 static void show_faulting_vma(unsigned long address)
87 {
88         struct vm_area_struct *vma;
89         struct mm_struct *active_mm = current->active_mm;
90
91         /* can't use print_vma_addr() yet as it doesn't check for
92          * non-inclusive vma
93          */
94         down_read(&active_mm->mmap_sem);
95         vma = find_vma(active_mm, address);
96
97         /* check against the find_vma( ) behaviour which returns the next VMA
98          * if the container VMA is not found
99          */
100         if (vma && (vma->vm_start <= address)) {
101                 char buf[ARC_PATH_MAX];
102                 char *nm = "?";
103
104                 if (vma->vm_file) {
105                         nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
106                         if (IS_ERR(nm))
107                                 nm = "?";
108                 }
109                 pr_info("    @off 0x%lx in [%s]\n"
110                         "    VMA: 0x%08lx to 0x%08lx\n",
111                         vma->vm_start < TASK_UNMAPPED_BASE ?
112                                 address : address - vma->vm_start,
113                         nm, vma->vm_start, vma->vm_end);
114         } else
115                 pr_info("    @No matching VMA found\n");
116
117         up_read(&active_mm->mmap_sem);
118 }
119
120 static void show_ecr_verbose(struct pt_regs *regs)
121 {
122         unsigned int vec, cause_code;
123         unsigned long address;
124
125         pr_info("\n[ECR   ]: 0x%08lx => ", regs->event);
126
127         /* For Data fault, this is data address not instruction addr */
128         address = current->thread.fault_address;
129
130         vec = regs->ecr_vec;
131         cause_code = regs->ecr_cause;
132
133         /* For DTLB Miss or ProtV, display the memory involved too */
134         if (vec == ECR_V_DTLB_MISS) {
135                 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n",
136                        (cause_code == 0x01) ? "Read" :
137                        ((cause_code == 0x02) ? "Write" : "EX"),
138                        address, regs->ret);
139         } else if (vec == ECR_V_ITLB_MISS) {
140                 pr_cont("Insn could not be fetched\n");
141         } else if (vec == ECR_V_MACH_CHK) {
142                 pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
143                                         "Double Fault" : "Other Fatal Err");
144
145         } else if (vec == ECR_V_PROTV) {
146                 if (cause_code == ECR_C_PROTV_INST_FETCH)
147                         pr_cont("Execute from Non-exec Page\n");
148                 else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
149                         pr_cont("Misaligned r/w from 0x%08lx\n", address);
150                 else
151                         pr_cont("%s access not allowed on page\n",
152                                 (cause_code == 0x01) ? "Read" :
153                                 ((cause_code == 0x02) ? "Write" : "EX"));
154         } else if (vec == ECR_V_INSN_ERR) {
155                 pr_cont("Illegal Insn\n");
156 #ifdef CONFIG_ISA_ARCV2
157         } else if (vec == ECR_V_MEM_ERR) {
158                 if (cause_code == 0x00)
159                         pr_cont("Bus Error from Insn Mem\n");
160                 else if (cause_code == 0x10)
161                         pr_cont("Bus Error from Data Mem\n");
162                 else
163                         pr_cont("Bus Error, check PRM\n");
164 #endif
165         } else if (vec == ECR_V_TRAP) {
166                 if (regs->ecr_param == 5)
167                         pr_cont("gcc generated __builtin_trap\n");
168         } else {
169                 pr_cont("Check Programmer's Manual\n");
170         }
171 }
172
173 /************************************************************************
174  *  API called by rest of kernel
175  ***********************************************************************/
176
177 void show_regs(struct pt_regs *regs)
178 {
179         struct task_struct *tsk = current;
180         struct callee_regs *cregs;
181
182         /*
183          * generic code calls us with preemption disabled, but some calls
184          * here could sleep, so re-enable to avoid lockdep splat
185          */
186         preempt_enable();
187
188         print_task_path_n_nm(tsk);
189         show_regs_print_info(KERN_INFO);
190
191         show_ecr_verbose(regs);
192
193         pr_info("[EFA   ]: 0x%08lx\n[BLINK ]: %pS\n[ERET  ]: %pS\n",
194                 current->thread.fault_address,
195                 (void *)regs->blink, (void *)regs->ret);
196
197         if (user_mode(regs))
198                 show_faulting_vma(regs->ret); /* faulting code, not data */
199
200         pr_info("[STAT32]: 0x%08lx", regs->status32);
201
202 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
203
204 #ifdef CONFIG_ISA_ARCOMPACT
205         pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
206                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
207                         STS_BIT(regs, DE), STS_BIT(regs, AE),
208                         STS_BIT(regs, A2), STS_BIT(regs, A1),
209                         STS_BIT(regs, E2), STS_BIT(regs, E1));
210 #else
211         pr_cont(" : %2s%2s%2s%2s\n",
212                         STS_BIT(regs, IE),
213                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
214                         STS_BIT(regs, DE), STS_BIT(regs, AE));
215 #endif
216         pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
217                 regs->bta, regs->sp, regs->fp);
218         pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
219                regs->lp_start, regs->lp_end, regs->lp_count);
220
221         /* print regs->r0 thru regs->r12
222          * Sequential printing was generating horrible code
223          */
224         print_reg_file(&(regs->r0), 0);
225
226         /* If Callee regs were saved, display them too */
227         cregs = (struct callee_regs *)current->thread.callee_reg;
228         if (cregs)
229                 show_callee_regs(cregs);
230
231         preempt_disable();
232 }
233
234 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
235                             unsigned long address)
236 {
237         current->thread.fault_address = address;
238
239         /* Show fault description */
240         pr_info("\n%s\n", str);
241
242         /* Caller and Callee regs */
243         show_regs(regs);
244
245         /* Show stack trace if this Fatality happened in kernel mode */
246         if (!user_mode(regs))
247                 show_stacktrace(current, regs);
248 }