dump_stack: unify debug information printed by show_regs()
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arc / kernel / troubleshoot.c
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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>
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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 <asm/arcregs.h>
17
18/*
19 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
20 * -Prints 3 regs per line and a CR.
21 * -To continue, callee regs right after scratch, special handling of CR
22 */
23static noinline void print_reg_file(long *reg_rev, int start_num)
24{
25 unsigned int i;
26 char buf[512];
27 int n = 0, len = sizeof(buf);
28
29 /* weird loop because pt_regs regs rev r12..r0, r25..r13 */
30 for (i = start_num; i < start_num + 13; i++) {
31 n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
32 i, (unsigned long)*reg_rev);
33
34 if (((i + 1) % 3) == 0)
35 n += scnprintf(buf + n, len - n, "\n");
36
37 reg_rev--;
38 }
39
40 if (start_num != 0)
41 n += scnprintf(buf + n, len - n, "\n\n");
42
43 pr_info("%s", buf);
44}
45
46static void show_callee_regs(struct callee_regs *cregs)
47{
48 print_reg_file(&(cregs->r13), 13);
49}
50
51void print_task_path_n_nm(struct task_struct *tsk, char *buf)
52{
53 struct path path;
54 char *path_nm = NULL;
55 struct mm_struct *mm;
56 struct file *exe_file;
57
58 mm = get_task_mm(tsk);
59 if (!mm)
60 goto done;
61
62 exe_file = get_mm_exe_file(mm);
63 mmput(mm);
64
65 if (exe_file) {
66 path = exe_file->f_path;
67 path_get(&exe_file->f_path);
68 fput(exe_file);
69 path_nm = d_path(&path, buf, 255);
70 path_put(&path);
71 }
72
73done:
74 pr_info("%s, TGID %u\n", path_nm, tsk->tgid);
75}
76EXPORT_SYMBOL(print_task_path_n_nm);
77
78static void show_faulting_vma(unsigned long address, char *buf)
79{
80 struct vm_area_struct *vma;
81 struct inode *inode;
82 unsigned long ino = 0;
83 dev_t dev = 0;
84 char *nm = buf;
85
86 vma = find_vma(current->active_mm, address);
87
88 /* check against the find_vma( ) behaviour which returns the next VMA
89 * if the container VMA is not found
90 */
91 if (vma && (vma->vm_start <= address)) {
92 struct file *file = vma->vm_file;
93 if (file) {
94 struct path *path = &file->f_path;
95 nm = d_path(path, buf, PAGE_SIZE - 1);
96 inode = vma->vm_file->f_path.dentry->d_inode;
97 dev = inode->i_sb->s_dev;
98 ino = inode->i_ino;
99 }
100 pr_info(" @off 0x%lx in [%s]\n"
101 " VMA: 0x%08lx to 0x%08lx\n\n",
102 address - vma->vm_start, nm, vma->vm_start, vma->vm_end);
103 } else
104 pr_info(" @No matching VMA found\n");
105}
106
107static void show_ecr_verbose(struct pt_regs *regs)
108{
109 unsigned int vec, cause_code, cause_reg;
110 unsigned long address;
111
112 cause_reg = current->thread.cause_code;
113 pr_info("\n[ECR]: 0x%08x => ", cause_reg);
114
115 /* For Data fault, this is data address not instruction addr */
116 address = current->thread.fault_address;
117
118 vec = cause_reg >> 16;
119 cause_code = (cause_reg >> 8) & 0xFF;
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 @ 0x%08lx\n",
124 (cause_code == 0x01) ? "Read From" :
125 ((cause_code == 0x02) ? "Write to" : "EX"),
126 address, 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("%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_LOAD)
137 pr_cont("Read from Non-readable Page\n");
138 else if (cause_code == ECR_C_PROTV_STORE)
139 pr_cont("Write to Non-writable Page\n");
140 else if (cause_code == ECR_C_PROTV_XCHG)
141 pr_cont("Data exchange protection violation\n");
142 else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
143 pr_cont("Misaligned r/w from 0x%08lx\n", address);
144 } else if (vec == ECR_V_INSN_ERR) {
145 pr_cont("Illegal Insn\n");
146 } else {
147 pr_cont("Check Programmer's Manual\n");
148 }
149}
150
151/************************************************************************
152 * API called by rest of kernel
153 ***********************************************************************/
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154
155void show_regs(struct pt_regs *regs)
156{
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157 struct task_struct *tsk = current;
158 struct callee_regs *cregs;
159 char *buf;
160
161 buf = (char *)__get_free_page(GFP_TEMPORARY);
162 if (!buf)
163 return;
164
165 print_task_path_n_nm(tsk, buf);
a43cb95d 166 show_regs_print_info(KERN_INFO);
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167
168 if (current->thread.cause_code)
169 show_ecr_verbose(regs);
170
171 pr_info("[EFA]: 0x%08lx\n", current->thread.fault_address);
172 pr_info("[ERET]: 0x%08lx (PC of Faulting Instr)\n", regs->ret);
173
174 show_faulting_vma(regs->ret, buf); /* faulting code, not data */
175
176 /* can't use print_vma_addr() yet as it doesn't check for
177 * non-inclusive vma
178 */
179
180 /* print special regs */
181 pr_info("status32: 0x%08lx\n", regs->status32);
182 pr_info(" SP: 0x%08lx\tFP: 0x%08lx\n", regs->sp, regs->fp);
183 pr_info("BTA: 0x%08lx\tBLINK: 0x%08lx\n",
184 regs->bta, regs->blink);
185 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
186 regs->lp_start, regs->lp_end, regs->lp_count);
187
188 /* print regs->r0 thru regs->r12
189 * Sequential printing was generating horrible code
190 */
191 print_reg_file(&(regs->r0), 0);
192
193 /* If Callee regs were saved, display them too */
194 cregs = (struct callee_regs *)current->thread.callee_reg;
195 if (cregs)
196 show_callee_regs(cregs);
197
198 free_page((unsigned long)buf);
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199}
200
201void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
202 unsigned long address, unsigned long cause_reg)
203{
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204 current->thread.fault_address = address;
205 current->thread.cause_code = cause_reg;
206
207 /* Caller and Callee regs */
208 show_regs(regs);
209
210 /* Show stack trace if this Fatality happened in kernel mode */
211 if (!user_mode(regs))
212 show_stacktrace(current, regs);
c08098f2 213}
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214
215#ifdef CONFIG_DEBUG_FS
216
217#include <linux/module.h>
218#include <linux/fs.h>
219#include <linux/mount.h>
220#include <linux/pagemap.h>
221#include <linux/init.h>
222#include <linux/namei.h>
223#include <linux/debugfs.h>
224
225static struct dentry *test_dentry;
226static struct dentry *test_dir;
227static struct dentry *test_u32_dentry;
228
229static u32 clr_on_read = 1;
230
231#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
232u32 numitlb, numdtlb, num_pte_not_present;
233
234static int fill_display_data(char *kbuf)
235{
236 size_t num = 0;
237 num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb);
238 num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb);
239 num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present);
240
241 if (clr_on_read)
242 numitlb = numdtlb = num_pte_not_present = 0;
243
244 return num;
245}
246
247static int tlb_stats_open(struct inode *inode, struct file *file)
248{
249 file->private_data = (void *)__get_free_page(GFP_KERNEL);
250 return 0;
251}
252
253/* called on user read(): display the couters */
254static ssize_t tlb_stats_output(struct file *file, /* file descriptor */
255 char __user *user_buf, /* user buffer */
256 size_t len, /* length of buffer */
257 loff_t *offset) /* offset in the file */
258{
259 size_t num;
260 char *kbuf = (char *)file->private_data;
261
262 /* All of the data can he shoved in one iteration */
263 if (*offset != 0)
264 return 0;
265
266 num = fill_display_data(kbuf);
267
268 /* simple_read_from_buffer() is helper for copy to user space
269 It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset
270 @3 (offset) into the user space address starting at @1 (user_buf).
271 @5 (len) is max size of user buffer
272 */
273 return simple_read_from_buffer(user_buf, num, offset, kbuf, len);
274}
275
276/* called on user write : clears the counters */
277static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf,
278 size_t length, loff_t *offset)
279{
280 numitlb = numdtlb = num_pte_not_present = 0;
281 return length;
282}
283
284static int tlb_stats_close(struct inode *inode, struct file *file)
285{
286 free_page((unsigned long)(file->private_data));
287 return 0;
288}
289
290static const struct file_operations tlb_stats_file_ops = {
291 .read = tlb_stats_output,
292 .write = tlb_stats_clear,
293 .open = tlb_stats_open,
294 .release = tlb_stats_close
295};
296#endif
297
298static int __init arc_debugfs_init(void)
299{
300 test_dir = debugfs_create_dir("arc", NULL);
301
302#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
303 test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL,
304 &tlb_stats_file_ops);
305#endif
306
307 test_u32_dentry =
308 debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read);
309
310 return 0;
311}
312
313module_init(arc_debugfs_init);
314
315static void __exit arc_debugfs_exit(void)
316{
317 debugfs_remove(test_u32_dentry);
318 debugfs_remove(test_dentry);
319 debugfs_remove(test_dir);
320}
321module_exit(arc_debugfs_exit);
322
323#endif