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
 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	for (i = start_num; i < start_num + 13; i++) {
 30		n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
 31			       i, (unsigned long)*reg_rev);
 32
 33		if (((i + 1) % 3) == 0)
 34			n += scnprintf(buf + n, len - n, "\n");
 35
 36		/* because pt_regs has regs reversed: r12..r0, r25..r13 */
 37		reg_rev--;
 38	}
 39
 40	if (start_num != 0)
 41		n += scnprintf(buf + n, len - n, "\n\n");
 42
 43	/* To continue printing callee regs on same line as scratch regs */
 44	if (start_num == 0)
 45		pr_info("%s", buf);
 46	else
 47		pr_cont("%s\n", buf);
 48}
 49
 50static void show_callee_regs(struct callee_regs *cregs)
 51{
 52	print_reg_file(&(cregs->r13), 13);
 53}
 54
 55void print_task_path_n_nm(struct task_struct *tsk, char *buf)
 56{
 57	struct path path;
 58	char *path_nm = NULL;
 59	struct mm_struct *mm;
 60	struct file *exe_file;
 61
 62	mm = get_task_mm(tsk);
 63	if (!mm)
 64		goto done;
 65
 66	exe_file = get_mm_exe_file(mm);
 67	mmput(mm);
 68
 69	if (exe_file) {
 70		path = exe_file->f_path;
 71		path_get(&exe_file->f_path);
 72		fput(exe_file);
 73		path_nm = d_path(&path, buf, 255);
 74		path_put(&path);
 75	}
 76
 77done:
 78	pr_info("Path: %s\n", path_nm);
 79}
 80EXPORT_SYMBOL(print_task_path_n_nm);
 81
 82static void show_faulting_vma(unsigned long address, char *buf)
 83{
 84	struct vm_area_struct *vma;
 85	struct inode *inode;
 86	unsigned long ino = 0;
 87	dev_t dev = 0;
 88	char *nm = buf;
 89
 90	/* can't use print_vma_addr() yet as it doesn't check for
 91	 * non-inclusive vma
 92	 */
 93
 94	vma = find_vma(current->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			struct path *path = &file->f_path;
103			nm = d_path(path, buf, PAGE_SIZE - 1);
104			inode = file_inode(vma->vm_file);
105			dev = inode->i_sb->s_dev;
106			ino = inode->i_ino;
107		}
108		pr_info("    @off 0x%lx in [%s]\n"
109			"    VMA: 0x%08lx to 0x%08lx\n",
110			vma->vm_start < TASK_UNMAPPED_BASE ?
111				address : address - vma->vm_start,
112			nm, vma->vm_start, vma->vm_end);
113	} else {
114		pr_info("    @No matching VMA found\n");
115	}
116}
117
118static 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	} else {
155		pr_cont("Check Programmer's Manual\n");
156	}
157}
158
159/************************************************************************
160 *  API called by rest of kernel
161 ***********************************************************************/
162
163void show_regs(struct pt_regs *regs)
164{
165	struct task_struct *tsk = current;
166	struct callee_regs *cregs;
167	char *buf;
168
169	buf = (char *)__get_free_page(GFP_TEMPORARY);
170	if (!buf)
171		return;
172
173	print_task_path_n_nm(tsk, buf);
174	show_regs_print_info(KERN_INFO);
175
176	show_ecr_verbose(regs);
177
178	pr_info("[EFA   ]: 0x%08lx\n[BLINK ]: %pS\n[ERET  ]: %pS\n",
179		current->thread.fault_address,
180		(void *)regs->blink, (void *)regs->ret);
181
182	if (user_mode(regs))
183		show_faulting_vma(regs->ret, buf); /* faulting code, not data */
184
185	pr_info("[STAT32]: 0x%08lx", regs->status32);
186
187#define STS_BIT(r, bit)	r->status32 & STATUS_##bit##_MASK ? #bit : ""
188	if (!user_mode(regs))
189		pr_cont(" : %2s %2s %2s %2s %2s\n",
190			STS_BIT(regs, AE), STS_BIT(regs, A2), STS_BIT(regs, A1),
191			STS_BIT(regs, E2), STS_BIT(regs, E1));
192
193	pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
194		regs->bta, regs->sp, regs->fp);
195	pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
196	       regs->lp_start, regs->lp_end, regs->lp_count);
197
198	/* print regs->r0 thru regs->r12
199	 * Sequential printing was generating horrible code
200	 */
201	print_reg_file(&(regs->r0), 0);
202
203	/* If Callee regs were saved, display them too */
204	cregs = (struct callee_regs *)current->thread.callee_reg;
205	if (cregs)
206		show_callee_regs(cregs);
207
208	free_page((unsigned long)buf);
209}
210
211void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
212			    unsigned long address)
213{
214	current->thread.fault_address = address;
215
216	/* Caller and Callee regs */
217	show_regs(regs);
218
219	/* Show stack trace if this Fatality happened in kernel mode */
220	if (!user_mode(regs))
221		show_stacktrace(current, regs);
222}
223
224#ifdef CONFIG_DEBUG_FS
225
226#include <linux/module.h>
227#include <linux/fs.h>
228#include <linux/mount.h>
229#include <linux/pagemap.h>
230#include <linux/init.h>
231#include <linux/namei.h>
232#include <linux/debugfs.h>
233
234static struct dentry *test_dentry;
235static struct dentry *test_dir;
236static struct dentry *test_u32_dentry;
237
238static u32 clr_on_read = 1;
239
240#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
241u32 numitlb, numdtlb, num_pte_not_present;
242
243static int fill_display_data(char *kbuf)
244{
245	size_t num = 0;
246	num += sprintf(kbuf + num, "I-TLB Miss %x\n", numitlb);
247	num += sprintf(kbuf + num, "D-TLB Miss %x\n", numdtlb);
248	num += sprintf(kbuf + num, "PTE not present %x\n", num_pte_not_present);
249
250	if (clr_on_read)
251		numitlb = numdtlb = num_pte_not_present = 0;
252
253	return num;
254}
255
256static int tlb_stats_open(struct inode *inode, struct file *file)
257{
258	file->private_data = (void *)__get_free_page(GFP_KERNEL);
259	return 0;
260}
261
262/* called on user read(): display the couters */
263static ssize_t tlb_stats_output(struct file *file,	/* file descriptor */
264				char __user *user_buf,	/* user buffer */
265				size_t len,		/* length of buffer */
266				loff_t *offset)		/* offset in the file */
267{
268	size_t num;
269	char *kbuf = (char *)file->private_data;
270
271	/* All of the data can he shoved in one iteration */
272	if (*offset != 0)
273		return 0;
274
275	num = fill_display_data(kbuf);
276
277	/* simple_read_from_buffer() is helper for copy to user space
278	   It copies up to @2 (num) bytes from kernel buffer @4 (kbuf) at offset
279	   @3 (offset) into the user space address starting at @1 (user_buf).
280	   @5 (len) is max size of user buffer
281	 */
282	return simple_read_from_buffer(user_buf, num, offset, kbuf, len);
283}
284
285/* called on user write : clears the counters */
286static ssize_t tlb_stats_clear(struct file *file, const char __user *user_buf,
287			       size_t length, loff_t *offset)
288{
289	numitlb = numdtlb = num_pte_not_present = 0;
290	return length;
291}
292
293static int tlb_stats_close(struct inode *inode, struct file *file)
294{
295	free_page((unsigned long)(file->private_data));
296	return 0;
297}
298
299static const struct file_operations tlb_stats_file_ops = {
300	.read = tlb_stats_output,
301	.write = tlb_stats_clear,
302	.open = tlb_stats_open,
303	.release = tlb_stats_close
304};
305#endif
306
307static int __init arc_debugfs_init(void)
308{
309	test_dir = debugfs_create_dir("arc", NULL);
310
311#ifdef CONFIG_ARC_DBG_TLB_MISS_COUNT
312	test_dentry = debugfs_create_file("tlb_stats", 0444, test_dir, NULL,
313					  &tlb_stats_file_ops);
314#endif
315
316	test_u32_dentry =
317	    debugfs_create_u32("clr_on_read", 0444, test_dir, &clr_on_read);
318
319	return 0;
320}
321
322module_init(arc_debugfs_init);
323
324static void __exit arc_debugfs_exit(void)
325{
326	debugfs_remove(test_u32_dentry);
327	debugfs_remove(test_dentry);
328	debugfs_remove(test_dir);
329}
330module_exit(arc_debugfs_exit);
331
332#endif