f9caf79186d42dac848e2ca4ed8bd728bb659279
[sfrench/cifs-2.6.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/fs_struct.h>
14 #include <linux/proc_fs.h>
15 #include <linux/file.h>
16 #include <linux/sched/mm.h>
17 #include <linux/sched/debug.h>
18
19 #include <asm/arcregs.h>
20 #include <asm/irqflags.h>
21
22 /*
23  * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
24  *   -Prints 3 regs per line and a CR.
25  *   -To continue, callee regs right after scratch, special handling of CR
26  */
27 static noinline void print_reg_file(long *reg_rev, int start_num)
28 {
29         unsigned int i;
30         char buf[512];
31         int n = 0, len = sizeof(buf);
32
33         for (i = start_num; i < start_num + 13; i++) {
34                 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
35                                i, (unsigned long)*reg_rev);
36
37                 if (((i + 1) % 3) == 0)
38                         n += scnprintf(buf + n, len - n, "\n");
39
40                 /* because pt_regs has regs reversed: r12..r0, r25..r13 */
41                 if (is_isa_arcv2() && start_num == 0)
42                         reg_rev++;
43                 else
44                         reg_rev--;
45         }
46
47         if (start_num != 0)
48                 n += scnprintf(buf + n, len - n, "\n\n");
49
50         /* To continue printing callee regs on same line as scratch regs */
51         if (start_num == 0)
52                 pr_info("%s", buf);
53         else
54                 pr_cont("%s\n", buf);
55 }
56
57 static void show_callee_regs(struct callee_regs *cregs)
58 {
59         print_reg_file(&(cregs->r13), 13);
60 }
61
62 static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
63 {
64         char *path_nm = NULL;
65         struct mm_struct *mm;
66         struct file *exe_file;
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, 255);
77                 fput(exe_file);
78         }
79
80 done:
81         pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
82 }
83
84 static void show_faulting_vma(unsigned long address, char *buf)
85 {
86         struct vm_area_struct *vma;
87         struct inode *inode;
88         unsigned long ino = 0;
89         dev_t dev = 0;
90         char *nm = buf;
91         struct mm_struct *active_mm = current->active_mm;
92
93         /* can't use print_vma_addr() yet as it doesn't check for
94          * non-inclusive vma
95          */
96         down_read(&active_mm->mmap_sem);
97         vma = find_vma(active_mm, address);
98
99         /* check against the find_vma( ) behaviour which returns the next VMA
100          * if the container VMA is not found
101          */
102         if (vma && (vma->vm_start <= address)) {
103                 struct file *file = vma->vm_file;
104                 if (file) {
105                         nm = file_path(file, buf, PAGE_SIZE - 1);
106                         inode = file_inode(vma->vm_file);
107                         dev = inode->i_sb->s_dev;
108                         ino = inode->i_ino;
109                 }
110                 pr_info("    @off 0x%lx in [%s]\n"
111                         "    VMA: 0x%08lx to 0x%08lx\n",
112                         vma->vm_start < TASK_UNMAPPED_BASE ?
113                                 address : address - vma->vm_start,
114                         nm, vma->vm_start, vma->vm_end);
115         } else
116                 pr_info("    @No matching VMA found\n");
117
118         up_read(&active_mm->mmap_sem);
119 }
120
121 static void show_ecr_verbose(struct pt_regs *regs)
122 {
123         unsigned int vec, cause_code;
124         unsigned long address;
125
126         pr_info("\n[ECR   ]: 0x%08lx => ", regs->event);
127
128         /* For Data fault, this is data address not instruction addr */
129         address = current->thread.fault_address;
130
131         vec = regs->ecr_vec;
132         cause_code = regs->ecr_cause;
133
134         /* For DTLB Miss or ProtV, display the memory involved too */
135         if (vec == ECR_V_DTLB_MISS) {
136                 pr_cont("Invalid %s @ 0x%08lx by insn @ 0x%08lx\n",
137                        (cause_code == 0x01) ? "Read" :
138                        ((cause_code == 0x02) ? "Write" : "EX"),
139                        address, regs->ret);
140         } else if (vec == ECR_V_ITLB_MISS) {
141                 pr_cont("Insn could not be fetched\n");
142         } else if (vec == ECR_V_MACH_CHK) {
143                 pr_cont("%s\n", (cause_code == 0x0) ?
144                                         "Double Fault" : "Other Fatal Err");
145
146         } else if (vec == ECR_V_PROTV) {
147                 if (cause_code == ECR_C_PROTV_INST_FETCH)
148                         pr_cont("Execute from Non-exec Page\n");
149                 else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
150                         pr_cont("Misaligned r/w from 0x%08lx\n", address);
151                 else
152                         pr_cont("%s access not allowed on page\n",
153                                 (cause_code == 0x01) ? "Read" :
154                                 ((cause_code == 0x02) ? "Write" : "EX"));
155         } else if (vec == ECR_V_INSN_ERR) {
156                 pr_cont("Illegal Insn\n");
157 #ifdef CONFIG_ISA_ARCV2
158         } else if (vec == ECR_V_MEM_ERR) {
159                 if (cause_code == 0x00)
160                         pr_cont("Bus Error from Insn Mem\n");
161                 else if (cause_code == 0x10)
162                         pr_cont("Bus Error from Data Mem\n");
163                 else
164                         pr_cont("Bus Error, check PRM\n");
165 #endif
166         } else {
167                 pr_cont("Check Programmer's Manual\n");
168         }
169 }
170
171 /************************************************************************
172  *  API called by rest of kernel
173  ***********************************************************************/
174
175 void show_regs(struct pt_regs *regs)
176 {
177         struct task_struct *tsk = current;
178         struct callee_regs *cregs;
179         char *buf;
180
181         buf = (char *)__get_free_page(GFP_TEMPORARY);
182         if (!buf)
183                 return;
184
185         print_task_path_n_nm(tsk, buf);
186         show_regs_print_info(KERN_INFO);
187
188         show_ecr_verbose(regs);
189
190         pr_info("[EFA   ]: 0x%08lx\n[BLINK ]: %pS\n[ERET  ]: %pS\n",
191                 current->thread.fault_address,
192                 (void *)regs->blink, (void *)regs->ret);
193
194         if (user_mode(regs))
195                 show_faulting_vma(regs->ret, buf); /* faulting code, not data */
196
197         pr_info("[STAT32]: 0x%08lx", regs->status32);
198
199 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
200
201 #ifdef CONFIG_ISA_ARCOMPACT
202         pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
203                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
204                         STS_BIT(regs, DE), STS_BIT(regs, AE),
205                         STS_BIT(regs, A2), STS_BIT(regs, A1),
206                         STS_BIT(regs, E2), STS_BIT(regs, E1));
207 #else
208         pr_cont(" : %2s%2s%2s%2s\n",
209                         STS_BIT(regs, IE),
210                         (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
211                         STS_BIT(regs, DE), STS_BIT(regs, AE));
212 #endif
213         pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
214                 regs->bta, regs->sp, regs->fp);
215         pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
216                regs->lp_start, regs->lp_end, regs->lp_count);
217
218         /* print regs->r0 thru regs->r12
219          * Sequential printing was generating horrible code
220          */
221         print_reg_file(&(regs->r0), 0);
222
223         /* If Callee regs were saved, display them too */
224         cregs = (struct callee_regs *)current->thread.callee_reg;
225         if (cregs)
226                 show_callee_regs(cregs);
227
228         free_page((unsigned long)buf);
229 }
230
231 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
232                             unsigned long address)
233 {
234         current->thread.fault_address = address;
235
236         /* Caller and Callee regs */
237         show_regs(regs);
238
239         /* Show stack trace if this Fatality happened in kernel mode */
240         if (!user_mode(regs))
241                 show_stacktrace(current, regs);
242 }