traps.c revision 47a3eb95560ea525a2dfbee1c4e7f03a45fd2207 
1#include <linux/bug.h>
2#include <linux/io.h>
3#include <linux/types.h>
4#include <linux/kdebug.h>
5#include <linux/signal.h>
6#include <linux/sched.h>
7#include <asm/system.h>
8
9#ifdef CONFIG_BUG
10static void handle_BUG(struct pt_regs *regs)
11{
12	enum bug_trap_type tt;
13	tt = report_bug(regs->pc, regs);
14	if (tt == BUG_TRAP_TYPE_WARN) {
15		regs->pc += instruction_size(regs->pc);
16		return;
17	}
18
19	die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
20}
21
22int is_valid_bugaddr(unsigned long addr)
23{
24	return addr >= PAGE_OFFSET;
25}
26#endif
27
28/*
29 * Generic trap handler.
30 */
31BUILD_TRAP_HANDLER(debug)
32{
33	TRAP_HANDLER_DECL;
34
35	/* Rewind */
36	regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
37
38	if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff,
39		       SIGTRAP) == NOTIFY_STOP)
40		return;
41
42	force_sig(SIGTRAP, current);
43}
44
45/*
46 * Special handler for BUG() traps.
47 */
48BUILD_TRAP_HANDLER(bug)
49{
50	TRAP_HANDLER_DECL;
51
52	/* Rewind */
53	regs->pc -= instruction_size(ctrl_inw(regs->pc - 4));
54
55	if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
56		       SIGTRAP) == NOTIFY_STOP)
57		return;
58
59#ifdef CONFIG_BUG
60	if (__kernel_text_address(instruction_pointer(regs))) {
61		opcode_t insn = *(opcode_t *)instruction_pointer(regs);
62		if (insn == TRAPA_BUG_OPCODE)
63			handle_BUG(regs);
64	}
65#endif
66
67	force_sig(SIGTRAP, current);
68}
69