xref: /openbmc/linux/arch/microblaze/kernel/traps.c (revision ae213c44)
1 /*
2  * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
3  * Copyright (C) 2007-2009 PetaLogix
4  * Copyright (C) 2006 Atmark Techno, Inc.
5  *
6  * This file is subject to the terms and conditions of the GNU General Public
7  * License. See the file "COPYING" in the main directory of this archive
8  * for more details.
9  */
10 
11 #include <linux/export.h>
12 #include <linux/kernel.h>
13 #include <linux/kallsyms.h>
14 #include <linux/sched.h>
15 #include <linux/sched/debug.h>
16 #include <linux/debug_locks.h>
17 
18 #include <asm/exceptions.h>
19 #include <asm/unwind.h>
20 
21 void trap_init(void)
22 {
23 	__enable_hw_exceptions();
24 }
25 
26 static unsigned long kstack_depth_to_print;	/* 0 == entire stack */
27 
28 static int __init kstack_setup(char *s)
29 {
30 	return !kstrtoul(s, 0, &kstack_depth_to_print);
31 }
32 __setup("kstack=", kstack_setup);
33 
34 void show_stack(struct task_struct *task, unsigned long *sp)
35 {
36 	unsigned long words_to_show;
37 	u32 fp = (u32) sp;
38 
39 	if (fp == 0) {
40 		if (task) {
41 			fp = ((struct thread_info *)
42 				(task->stack))->cpu_context.r1;
43 		} else {
44 			/* Pick up caller of dump_stack() */
45 			fp = (u32)&sp - 8;
46 		}
47 	}
48 
49 	words_to_show = (THREAD_SIZE - (fp & (THREAD_SIZE - 1))) >> 2;
50 	if (kstack_depth_to_print && (words_to_show > kstack_depth_to_print))
51 		words_to_show = kstack_depth_to_print;
52 
53 	pr_info("Kernel Stack:\n");
54 
55 	/*
56 	 * Make the first line an 'odd' size if necessary to get
57 	 * remaining lines to start at an address multiple of 0x10
58 	 */
59 	if (fp & 0xF) {
60 		unsigned long line1_words = (0x10 - (fp & 0xF)) >> 2;
61 		if (line1_words < words_to_show) {
62 			print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 32,
63 				       4, (void *)fp, line1_words << 2, 0);
64 			fp += line1_words << 2;
65 			words_to_show -= line1_words;
66 		}
67 	}
68 	print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 32, 4, (void *)fp,
69 		       words_to_show << 2, 0);
70 	pr_info("\n\nCall Trace:\n");
71 	microblaze_unwind(task, NULL);
72 	pr_info("\n");
73 
74 	if (!task)
75 		task = current;
76 
77 	debug_show_held_locks(task);
78 }
79