aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arc/kernel/troubleshoot.c
blob: 3393558876a9b154ef723b8c0e025ca1f96ab633 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
 */

#include <linux/ptrace.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/kdev_t.h>
#include <linux/proc_fs.h>
#include <linux/file.h>
#include <linux/sched/mm.h>
#include <linux/sched/debug.h>

#include <asm/arcregs.h>
#include <asm/irqflags.h>

#define ARC_PATH_MAX	256

/*
 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
 *   -Prints 3 regs per line and a CR.
 *   -To continue, callee regs right after scratch, special handling of CR
 */
static noinline void print_reg_file(long *reg_rev, int start_num)
{
	unsigned int i;
	char buf[512];
	int n = 0, len = sizeof(buf);

	for (i = start_num; i < start_num + 13; i++) {
		n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
			       i, (unsigned long)*reg_rev);

		if (((i + 1) % 3) == 0)
			n += scnprintf(buf + n, len - n, "\n");

		/* because pt_regs has regs reversed: r12..r0, r25..r13 */
		if (is_isa_arcv2() && start_num == 0)
			reg_rev++;
		else
			reg_rev--;
	}

	if (start_num != 0)
		n += scnprintf(buf + n, len - n, "\n\n");

	/* To continue printing callee regs on same line as scratch regs */
	if (start_num == 0)
		pr_info("%s", buf);
	else
		pr_cont("%s\n", buf);
}

static void show_callee_regs(struct callee_regs *cregs)
{
	print_reg_file(&(cregs->r13), 13);
}

static void print_task_path_n_nm(struct task_struct *tsk)
{
	char *path_nm = NULL;
	struct mm_struct *mm;
	struct file *exe_file;
	char buf[ARC_PATH_MAX];

	mm = get_task_mm(tsk);
	if (!mm)
		goto done;

	exe_file = get_mm_exe_file(mm);
	mmput(mm);

	if (exe_file) {
		path_nm = file_path(exe_file, buf, ARC_PATH_MAX-1);
		fput(exe_file);
	}

done:
	pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
}

static void show_faulting_vma(unsigned long address)
{
	struct vm_area_struct *vma;
	struct mm_struct *active_mm = current->active_mm;

	/* can't use print_vma_addr() yet as it doesn't check for
	 * non-inclusive vma
	 */
	down_read(&active_mm->mmap_sem);
	vma = find_vma(active_mm, address);

	/* check against the find_vma( ) behaviour which returns the next VMA
	 * if the container VMA is not found
	 */
	if (vma && (vma->vm_start <= address)) {
		char buf[ARC_PATH_MAX];
		char *nm = "?";

		if (vma->vm_file) {
			nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
			if (IS_ERR(nm))
				nm = "?";
		}
		pr_info("  @off 0x%lx in [%s]  VMA: 0x%08lx to 0x%08lx\n",
			vma->vm_start < TASK_UNMAPPED_BASE ?
				address : address - vma->vm_start,
			nm, vma->vm_start, vma->vm_end);
	} else
		pr_info("    @No matching VMA found\n");

	up_read(&active_mm->mmap_sem);
}

static void show_ecr_verbose(struct pt_regs *regs)
{
	unsigned int vec, cause_code;
	unsigned long address;

	/* For Data fault, this is data address not instruction addr */
	address = current->thread.fault_address;

	vec = regs->ecr_vec;
	cause_code = regs->ecr_cause;

	/* For DTLB Miss or ProtV, display the memory involved too */
	if (vec == ECR_V_DTLB_MISS) {
		pr_cont("Invalid %s @ 0x%08lx by insn @ %pS\n",
		       (cause_code == 0x01) ? "Read" :
		       ((cause_code == 0x02) ? "Write" : "EX"),
		       address, (void *)regs->ret);
	} else if (vec == ECR_V_ITLB_MISS) {
		pr_cont("Insn could not be fetched\n");
	} else if (vec == ECR_V_MACH_CHK) {
		pr_cont("Machine Check (%s)\n", (cause_code == 0x0) ?
					"Double Fault" : "Other Fatal Err");

	} else if (vec == ECR_V_PROTV) {
		if (cause_code == ECR_C_PROTV_INST_FETCH)
			pr_cont("Execute from Non-exec Page\n");
		else if (cause_code == ECR_C_PROTV_MISALIG_DATA &&
		         IS_ENABLED(CONFIG_ISA_ARCOMPACT))
			pr_cont("Misaligned r/w from 0x%08lx\n", address);
		else
			pr_cont("%s access not allowed on page\n",
				(cause_code == 0x01) ? "Read" :
				((cause_code == 0x02) ? "Write" : "EX"));
	} else if (vec == ECR_V_INSN_ERR) {
		pr_cont("Illegal Insn\n");
#ifdef CONFIG_ISA_ARCV2
	} else if (vec == ECR_V_MEM_ERR) {
		if (cause_code == 0x00)
			pr_cont("Bus Error from Insn Mem\n");
		else if (cause_code == 0x10)
			pr_cont("Bus Error from Data Mem\n");
		else
			pr_cont("Bus Error, check PRM\n");
	} else if (vec == ECR_V_MISALIGN) {
		pr_cont("Misaligned r/w from 0x%08lx\n", address);
#endif
	} else if (vec == ECR_V_TRAP) {
		if (regs->ecr_param == 5)
			pr_cont("gcc generated __builtin_trap\n");
	} else {
		pr_cont("Check Programmer's Manual\n");
	}
}

/************************************************************************
 *  API called by rest of kernel
 ***********************************************************************/

void show_regs(struct pt_regs *regs)
{
	struct task_struct *tsk = current;
	struct callee_regs *cregs;

	/*
	 * generic code calls us with preemption disabled, but some calls
	 * here could sleep, so re-enable to avoid lockdep splat
	 */
	preempt_enable();

	print_task_path_n_nm(tsk);
	show_regs_print_info(KERN_INFO);

	show_ecr_verbose(regs);

	if (user_mode(regs))
		show_faulting_vma(regs->ret); /* faulting code, not data */

	pr_info("ECR: 0x%08lx EFA: 0x%08lx ERET: 0x%08lx\nSTAT: 0x%08lx",
		regs->event, current->thread.fault_address, regs->ret,
		regs->status32);

#define STS_BIT(r, bit)	r->status32 & STATUS_##bit##_MASK ? #bit" " : ""

#ifdef CONFIG_ISA_ARCOMPACT
	pr_cont(" [%2s%2s%2s%2s%2s%2s%2s]",
			(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
			STS_BIT(regs, DE), STS_BIT(regs, AE),
			STS_BIT(regs, A2), STS_BIT(regs, A1),
			STS_BIT(regs, E2), STS_BIT(regs, E1));
#else
	pr_cont(" [%2s%2s%2s%2s]",
			STS_BIT(regs, IE),
			(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
			STS_BIT(regs, DE), STS_BIT(regs, AE));
#endif
	pr_cont("  BTA: 0x%08lx\n  SP: 0x%08lx  FP: 0x%08lx BLK: %pS\n",
		regs->bta, regs->sp, regs->fp, (void *)regs->blink);
	pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
		regs->lp_start, regs->lp_end, regs->lp_count);

	/* print regs->r0 thru regs->r12
	 * Sequential printing was generating horrible code
	 */
	print_reg_file(&(regs->r0), 0);

	/* If Callee regs were saved, display them too */
	cregs = (struct callee_regs *)current->thread.callee_reg;
	if (cregs)
		show_callee_regs(cregs);

	preempt_disable();
}

void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
			    unsigned long address)
{
	current->thread.fault_address = address;

	/* Show fault description */
	pr_info("\n%s\n", str);

	/* Caller and Callee regs */
	show_regs(regs);

	/* Show stack trace if this Fatality happened in kernel mode */
	if (!user_mode(regs))
		show_stacktrace(current, regs);
}