1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
  4 */
  5
  6#include <linux/ptrace.h>
  7#include <linux/module.h>
  8#include <linux/mm.h>
  9#include <linux/fs.h>
 10#include <linux/kdev_t.h>
 11#include <linux/proc_fs.h>
 12#include <linux/file.h>
 13#include <linux/sched/mm.h>
 14#include <linux/sched/debug.h>
 15
 16#include <asm/arcregs.h>
 17#include <asm/irqflags.h>
 18
 19#define ARC_PATH_MAX	256
 20
 21/*
 22 * Common routine to print scratch regs (r0-r12) or callee regs (r13-r25)
 23 *   -Prints 3 regs per line and a CR.
 24 *   -To continue, callee regs right after scratch, special handling of CR
 25 */
 26static noinline void print_reg_file(long *reg_rev, int start_num)
 27{
 28	unsigned int i;
 29	char buf[512];
 30	int n = 0, len = sizeof(buf);
 31
 32	for (i = start_num; i < start_num + 13; i++) {
 33		n += scnprintf(buf + n, len - n, "r%02u: 0x%08lx\t",
 34			       i, (unsigned long)*reg_rev);
 35
 36		if (((i + 1) % 3) == 0)
 37			n += scnprintf(buf + n, len - n, "\n");
 38
 39		/* because pt_regs has regs reversed: r12..r0, r25..r13 */
 40		if (is_isa_arcv2() && start_num == 0)
 41			reg_rev++;
 42		else
 43			reg_rev--;
 44	}
 45
 46	if (start_num != 0)
 47		n += scnprintf(buf + n, len - n, "\n\n");
 48
 49	/* To continue printing callee regs on same line as scratch regs */
 50	if (start_num == 0)
 51		pr_info("%s", buf);
 52	else
 53		pr_cont("%s\n", buf);
 54}
 55
 56static void show_callee_regs(struct callee_regs *cregs)
 57{
 58	print_reg_file(&(cregs->r13), 13);
 59}
 60
 61static void print_task_path_n_nm(struct task_struct *tsk)
 62{
 63	char *path_nm = NULL;
 64	struct mm_struct *mm;
 65	struct file *exe_file;
 66	char buf[ARC_PATH_MAX];
 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, ARC_PATH_MAX-1);
 77		fput(exe_file);
 78	}
 79
 80done:
 81	pr_info("Path: %s\n", !IS_ERR(path_nm) ? path_nm : "?");
 82}
 83
 84static void show_faulting_vma(unsigned long address)
 85{
 86	struct vm_area_struct *vma;
 87	struct mm_struct *active_mm = current->active_mm;
 88
 89	/* can't use print_vma_addr() yet as it doesn't check for
 90	 * non-inclusive vma
 91	 */
 92	down_read(&active_mm->mmap_sem);
 93	vma = find_vma(active_mm, address);
 94
 95	/* check against the find_vma( ) behaviour which returns the next VMA
 96	 * if the container VMA is not found
 97	 */
 98	if (vma && (vma->vm_start <= address)) {
 99		char buf[ARC_PATH_MAX];
100		char *nm = "?";
101
102		if (vma->vm_file) {
103			nm = file_path(vma->vm_file, buf, ARC_PATH_MAX-1);
104			if (IS_ERR(nm))
105				nm = "?";
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
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("Machine Check (%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		         IS_ENABLED(CONFIG_ISA_ARCOMPACT))
148			pr_cont("Misaligned r/w from 0x%08lx\n", address);
149		else
150			pr_cont("%s access not allowed on page\n",
151				(cause_code == 0x01) ? "Read" :
152				((cause_code == 0x02) ? "Write" : "EX"));
153	} else if (vec == ECR_V_INSN_ERR) {
154		pr_cont("Illegal Insn\n");
155#ifdef CONFIG_ISA_ARCV2
156	} else if (vec == ECR_V_MEM_ERR) {
157		if (cause_code == 0x00)
158			pr_cont("Bus Error from Insn Mem\n");
159		else if (cause_code == 0x10)
160			pr_cont("Bus Error from Data Mem\n");
161		else
162			pr_cont("Bus Error, check PRM\n");
163	} else if (vec == ECR_V_MISALIGN) {
164		pr_cont("Misaligned r/w from 0x%08lx\n", address);
165#endif
166	} else if (vec == ECR_V_TRAP) {
167		if (regs->ecr_param == 5)
168			pr_cont("gcc generated __builtin_trap\n");
169	} else {
170		pr_cont("Check Programmer's Manual\n");
171	}
172}
173
174/************************************************************************
175 *  API called by rest of kernel
176 ***********************************************************************/
177
178void show_regs(struct pt_regs *regs)
179{
180	struct task_struct *tsk = current;
181	struct callee_regs *cregs;
182
183	/*
184	 * generic code calls us with preemption disabled, but some calls
185	 * here could sleep, so re-enable to avoid lockdep splat
186	 */
187	preempt_enable();
188
189	print_task_path_n_nm(tsk);
190	show_regs_print_info(KERN_INFO);
191
192	show_ecr_verbose(regs);
193
194	pr_info("[EFA   ]: 0x%08lx\n[BLINK ]: %pS\n[ERET  ]: %pS\n",
195		current->thread.fault_address,
196		(void *)regs->blink, (void *)regs->ret);
197
198	if (user_mode(regs))
199		show_faulting_vma(regs->ret); /* faulting code, not data */
200
201	pr_info("[STAT32]: 0x%08lx", regs->status32);
202
203#define STS_BIT(r, bit)	r->status32 & STATUS_##bit##_MASK ? #bit" " : ""
204
205#ifdef CONFIG_ISA_ARCOMPACT
206	pr_cont(" : %2s%2s%2s%2s%2s%2s%2s\n",
207			(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
208			STS_BIT(regs, DE), STS_BIT(regs, AE),
209			STS_BIT(regs, A2), STS_BIT(regs, A1),
210			STS_BIT(regs, E2), STS_BIT(regs, E1));
211#else
212	pr_cont(" : %2s%2s%2s%2s\n",
213			STS_BIT(regs, IE),
214			(regs->status32 & STATUS_U_MASK) ? "U " : "K ",
215			STS_BIT(regs, DE), STS_BIT(regs, AE));
216#endif
217	pr_info("BTA: 0x%08lx\t SP: 0x%08lx\t FP: 0x%08lx\n",
218		regs->bta, regs->sp, regs->fp);
219	pr_info("LPS: 0x%08lx\tLPE: 0x%08lx\tLPC: 0x%08lx\n",
220	       regs->lp_start, regs->lp_end, regs->lp_count);
221
222	/* print regs->r0 thru regs->r12
223	 * Sequential printing was generating horrible code
224	 */
225	print_reg_file(&(regs->r0), 0);
226
227	/* If Callee regs were saved, display them too */
228	cregs = (struct callee_regs *)current->thread.callee_reg;
229	if (cregs)
230		show_callee_regs(cregs);
231
232	preempt_disable();
233}
234
235void show_kernel_fault_diag(const char *str, struct pt_regs *regs,
236			    unsigned long address)
237{
238	current->thread.fault_address = address;
239
240	/* Show fault description */
241	pr_info("\n%s\n", str);
242
243	/* Caller and Callee regs */
244	show_regs(regs);
245
246	/* Show stack trace if this Fatality happened in kernel mode */
247	if (!user_mode(regs))
248		show_stacktrace(current, regs);
249}