blob: a8396f36bd1485f0653ccdc31abdc98d323df01e [file] [log] [blame]
Paul Mundt5a4f7c62007-11-20 18:08:06 +09001#include <linux/bug.h>
2#include <linux/io.h>
3#include <linux/types.h>
4#include <linux/kdebug.h>
Paul Mundt47a3eb92007-11-26 18:17:51 +09005#include <linux/signal.h>
6#include <linux/sched.h>
Paul Mundt9a33fc22008-05-19 19:32:07 +09007#include <linux/uaccess.h>
Paul Mundt1e1030d2009-09-01 17:38:32 +09008#include <linux/hardirq.h>
Paul Mundte115f2c2009-08-22 05:28:25 +09009#include <asm/unwinder.h>
Paul Mundt5a4f7c62007-11-20 18:08:06 +090010#include <asm/system.h>
11
12#ifdef CONFIG_BUG
Matt Flemingb344e24a2009-08-16 21:54:48 +010013void handle_BUG(struct pt_regs *regs)
Paul Mundt5a4f7c62007-11-20 18:08:06 +090014{
Paul Mundte115f2c2009-08-22 05:28:25 +090015 const struct bug_entry *bug;
16 unsigned long bugaddr = regs->pc;
Paul Mundt5a4f7c62007-11-20 18:08:06 +090017 enum bug_trap_type tt;
Paul Mundte115f2c2009-08-22 05:28:25 +090018
19 if (!is_valid_bugaddr(bugaddr))
20 goto invalid;
21
22 bug = find_bug(bugaddr);
23
24 /* Switch unwinders when unwind_stack() is called */
25 if (bug->flags & BUGFLAG_UNWINDER)
26 unwinder_faulted = 1;
27
28 tt = report_bug(bugaddr, regs);
Paul Mundt5a4f7c62007-11-20 18:08:06 +090029 if (tt == BUG_TRAP_TYPE_WARN) {
Paul Mundte115f2c2009-08-22 05:28:25 +090030 regs->pc += instruction_size(bugaddr);
Paul Mundt5a4f7c62007-11-20 18:08:06 +090031 return;
32 }
33
Paul Mundte115f2c2009-08-22 05:28:25 +090034invalid:
Paul Mundt5a4f7c62007-11-20 18:08:06 +090035 die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
36}
37
38int is_valid_bugaddr(unsigned long addr)
39{
Paul Mundt2bcfffa2009-05-09 16:02:08 +090040 insn_size_t opcode;
Paul Mundt9a33fc22008-05-19 19:32:07 +090041
42 if (addr < PAGE_OFFSET)
43 return 0;
Paul Mundt2bcfffa2009-05-09 16:02:08 +090044 if (probe_kernel_address((insn_size_t *)addr, opcode))
Paul Mundt9a33fc22008-05-19 19:32:07 +090045 return 0;
Paul Mundte115f2c2009-08-22 05:28:25 +090046 if (opcode == TRAPA_BUG_OPCODE)
Matt Flemingb344e24a2009-08-16 21:54:48 +010047 return 1;
48
49 return 0;
Paul Mundt5a4f7c62007-11-20 18:08:06 +090050}
51#endif
52
53/*
54 * Generic trap handler.
55 */
56BUILD_TRAP_HANDLER(debug)
57{
58 TRAP_HANDLER_DECL;
59
60 /* Rewind */
61 regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
62
63 if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff,
64 SIGTRAP) == NOTIFY_STOP)
65 return;
66
67 force_sig(SIGTRAP, current);
68}
69
70/*
71 * Special handler for BUG() traps.
72 */
73BUILD_TRAP_HANDLER(bug)
74{
75 TRAP_HANDLER_DECL;
76
77 /* Rewind */
78 regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
79
80 if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
81 SIGTRAP) == NOTIFY_STOP)
82 return;
83
84#ifdef CONFIG_BUG
85 if (__kernel_text_address(instruction_pointer(regs))) {
Paul Mundt2bcfffa2009-05-09 16:02:08 +090086 insn_size_t insn = *(insn_size_t *)instruction_pointer(regs);
Paul Mundt5a4f7c62007-11-20 18:08:06 +090087 if (insn == TRAPA_BUG_OPCODE)
88 handle_BUG(regs);
Magnus Damm0ec39882009-06-17 04:48:20 +000089 return;
Paul Mundt5a4f7c62007-11-20 18:08:06 +090090 }
91#endif
92
93 force_sig(SIGTRAP, current);
94}
Paul Mundt1e1030d2009-09-01 17:38:32 +090095
96BUILD_TRAP_HANDLER(nmi)
97{
98 TRAP_HANDLER_DECL;
99
100 nmi_enter();
101
102 switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) {
103 case NOTIFY_OK:
104 case NOTIFY_STOP:
105 break;
106 case NOTIFY_BAD:
107 die("Fatal Non-Maskable Interrupt", regs, SIGINT);
108 default:
109 printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n");
110 break;
111 }
112
113 nmi_exit();
114}