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 <asm/arcregs.h>
17 #include <asm/irqflags.h>
18
19 /*
20 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
21 * -Prints 3 regs per line and a CR.
22 * -To continue, callee regs right after scratch, special handling of CR
23 */
print_reg_file(long * reg_rev,int start_num)24 static noinline void print_reg_file(long *reg_rev, int start_num)
25 {
26 unsigned int i;
27 char buf[512];
28 int n = 0, len = sizeof(buf);
29
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 /* because pt_regs has regs reversed: r12..r0, r25..r13 */
38 if (is_isa_arcv2() && start_num == 0)
39 reg_rev++;
40 else
41 reg_rev--;
42 }
43
44 if (start_num != 0)
45 n += scnprintf(buf + n, len - n, "\n\n");
46
47 /* To continue printing callee regs on same line as scratch regs */
48 if (start_num == 0)
49 pr_info("%s", buf);
50 else
51 pr_cont("%s\n", buf);
52 }
53
show_callee_regs(struct callee_regs * cregs)54 static void show_callee_regs(struct callee_regs *cregs)
55 {
56 print_reg_file(&(cregs->r13), 13);
57 }
58
print_task_path_n_nm(struct task_struct * tsk,char * buf)59 static void print_task_path_n_nm(struct task_struct *tsk, char *buf)
60 {
61 char *path_nm = NULL;
62 struct mm_struct *mm;
63 struct file *exe_file;
64
65 mm = get_task_mm(tsk);
66 if (!mm)
67 goto done;
68
69 exe_file = get_mm_exe_file(mm);
70 mmput(mm);
71
72 if (exe_file) {
73 path_nm = file_path(exe_file, buf, 255);
74 fput(exe_file);
75 }
76
77 done:
78 pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
79 }
80
show_faulting_vma(unsigned long address,char * buf)81 static void show_faulting_vma(unsigned long address, char *buf)
82 {
83 struct vm_area_struct *vma;
84 struct inode *inode;
85 unsigned long ino = 0;
86 dev_t dev = 0;
87 char *nm = buf;
88 struct mm_struct *active_mm = current->active_mm;
89
90 /* can't use print_vma_addr() yet as it doesn't check for
91 * non-inclusive vma
92 */
93 down_read(&active_mm->mmap_sem);
94 vma = find_vma(active_mm, address);
95
96 /* check against the find_vma( ) behaviour which returns the next VMA
97 * if the container VMA is not found
98 */
99 if (vma && (vma->vm_start <= address)) {
100 struct file *file = vma->vm_file;
101 if (file) {
102 nm = file_path(file, buf, PAGE_SIZE - 1);
103 inode = file_inode(vma->vm_file);
104 dev = inode->i_sb->s_dev;
105 ino = inode->i_ino;
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("%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 pr_cont("Misaligned r/w from 0x%08lx\n", address);
148 else
149 pr_cont("%s access not allowed on page\n",
150 (cause_code == 0x01) ? "Read" :
151 ((cause_code == 0x02) ? "Write" : "EX"));
152 } else if (vec == ECR_V_INSN_ERR) {
153 pr_cont("Illegal Insn\n");
154 #ifdef CONFIG_ISA_ARCV2
155 } else if (vec == ECR_V_MEM_ERR) {
156 if (cause_code == 0x00)
157 pr_cont("Bus Error from Insn Mem\n");
158 else if (cause_code == 0x10)
159 pr_cont("Bus Error from Data Mem\n");
160 else
161 pr_cont("Bus Error, check PRM\n");
162 #endif
163 } else {
164 pr_cont("Check Programmer's Manual\n");
165 }
166 }
167
168 /************************************************************************
169 * API called by rest of kernel
170 ***********************************************************************/
171
show_regs(struct pt_regs * regs)172 void show_regs(struct pt_regs *regs)
173 {
174 struct task_struct *tsk = current;
175 struct callee_regs *cregs;
176 char *buf;
177
178 buf = (char *)__get_free_page(GFP_TEMPORARY);
179 if (!buf)
180 return;
181
182 print_task_path_n_nm(tsk, buf);
183 show_regs_print_info(KERN_INFO);
184
185 show_ecr_verbose(regs);
186
187 pr_info("[EFA ]: 0x%08lx\n[BLINK ]: %pS\n[ERET ]: %pS\n",
188 current->thread.fault_address,
189 (void *)regs->blink, (void *)regs->ret);
190
191 if (user_mode(regs))
192 show_faulting_vma(regs->ret, buf); /* faulting code, not data */
193
194 pr_info("[STAT32]: 0x%08lx", regs->status32);
195
196 #define STS_BIT(r, bit) r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
197
198 #ifdef CONFIG_ISA_ARCOMPACT
199 pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
200 (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
201 STS_BIT(regs, DE), STS_BIT(regs, AE),
202 STS_BIT(regs, A2), STS_BIT(regs, A1),
203 STS_BIT(regs, E2), STS_BIT(regs, E1));
204 #else
205 pr_cont(" : %2s%2s%2s%2s\n",
206 STS_BIT(regs, IE),
207 (regs->status32 & STATUS_U_MASK) ? "U " : "K ",
208 STS_BIT(regs, DE), STS_BIT(regs, AE));
209 #endif
210 pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
211 regs->bta, regs->sp, regs->fp);
212 pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
213 regs->lp_start, regs->lp_end, regs->lp_count);
214
215 /* print regs->r0 thru regs->r12
216 * Sequential printing was generating horrible code
217 */
218 print_reg_file(&(regs->r0), 0);
219
220 /* If Callee regs were saved, display them too */
221 cregs = (struct callee_regs *)current->thread.callee_reg;
222 if (cregs)
223 show_callee_regs(cregs);
224
225 free_page((unsigned long)buf);
226 }
227
show_kernel_fault_diag(const char * str,struct pt_regs * regs,unsigned long address)228 void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
229 unsigned long address)
230 {
231 current->thread.fault_address = address;
232
233 /* Caller and Callee regs */
234 show_regs(regs);
235
236 /* Show stack trace if this Fatality happened in kernel mode */
237 if (!user_mode(regs))
238 show_stacktrace(current, regs);
239 }
240
241 #ifdef CONFIG_DEBUG_FS
242
243 #include <linux/module.h>
244 #include <linux/fs.h>
245 #include <linux/mount.h>
246 #include <linux/pagemap.h>
247 #include <linux/init.h>
248 #include <linux/namei.h>
249 #include <linux/debugfs.h>
250
251 static struct dentry *test_dentry;
252 static struct dentry *test_dir;
253 static struct dentry *test_u32_dentry;
254
255 static u32 clr_on_read = 1;
256
257 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
258 u32 numitlb, numdtlb, num_pte_not_present;
259
fill_display_data(char * kbuf)260 static int fill_display_data(char *kbuf)
261 {
262 size_t num = 0;
263 num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb);
264 num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb);
265 num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present);
266
267 if (clr_on_read)
268 numitlb = numdtlb = num_pte_not_present = 0;
269
270 return num;
271 }
272
tlb_stats_open(struct inode * inode,struct file * file)273 static int tlb_stats_open(struct inode *inode, struct file *file)
274 {
275 file->private_data = (void *)__get_free_page(GFP_KERNEL);
276 return 0;
277 }
278
279 /* called on user read(): display the couters */
tlb_stats_output(struct file * file,char __user * user_buf,size_t len,loff_t * offset)280 static ssize_t tlb_stats_output(struct file *file, /* file descriptor */
281 char __user *user_buf, /* user buffer */
282 size_t len, /* length of buffer */
283 loff_t *offset) /* offset in the file */
284 {
285 size_t num;
286 char *kbuf = (char *)file->private_data;
287
288 /* All of the data can he shoved in one iteration */
289 if (*offset != 0)
290 return 0;
291
292 num = fill_display_data(kbuf);
293
294 /* simple_read_from_buffer() is helper for copy to user space
295 It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset
296 @3 (offset) into the user space address starting at @1 (user_buf).
297 @5 (len) is max size of user buffer
298 */
299 return simple_read_from_buffer(user_buf, num, offset, kbuf, len);
300 }
301
302 /* called on user write : clears the counters */
tlb_stats_clear(struct file * file,const char __user * user_buf,size_t length,loff_t * offset)303 static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf,
304 size_t length, loff_t *offset)
305 {
306 numitlb = numdtlb = num_pte_not_present = 0;
307 return length;
308 }
309
tlb_stats_close(struct inode * inode,struct file * file)310 static int tlb_stats_close(struct inode *inode, struct file *file)
311 {
312 free_page((unsigned long)(file->private_data));
313 return 0;
314 }
315
316 static const struct file_operations tlb_stats_file_ops = {
317 .read = tlb_stats_output,
318 .write = tlb_stats_clear,
319 .open = tlb_stats_open,
320 .release = tlb_stats_close
321 };
322 #endif
323
arc_debugfs_init(void)324 static int __init arc_debugfs_init(void)
325 {
326 test_dir = debugfs_create_dir("arc", NULL);
327
328 #ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
329 test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL,
330 &tlb_stats_file_ops);
331 #endif
332
333 test_u32_dentry =
334 debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read);
335
336 return 0;
337 }
338
339 module_init(arc_debugfs_init);
340
arc_debugfs_exit(void)341 static void __exit arc_debugfs_exit(void)
342 {
343 debugfs_remove(test_u32_dentry);
344 debugfs_remove(test_dentry);
345 debugfs_remove(test_dir);
346 }
347 module_exit(arc_debugfs_exit);
348
349 #endif
350