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 <linux/uaccess.h>
  8#include <linux/hardirq.h>
  9#include <linux/kernel.h>
 10#include <linux/kexec.h>
 11#include <linux/module.h>
 12#include <asm/unwinder.h>
 13#include <asm/traps.h>
 14
 15static DEFINE_SPINLOCK(die_lock);
 16
 17void die(const char *str, struct pt_regs *regs, long err)
 18{
 19	static int die_counter;
 20
 21	oops_enter();
 22
 23	spin_lock_irq(&die_lock);
 24	console_verbose();
 25	bust_spinlocks(1);
 26
 27	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 28	print_modules();
 29	show_regs(regs);
 30
 31	printk("Process: %s (pid: %d, stack limit = %p)\n", current->comm,
 32			task_pid_nr(current), task_stack_page(current) + 1);
 33
 34	if (!user_mode(regs) || in_interrupt())
 35		dump_mem("Stack: ", regs->regs[15], THREAD_SIZE +
 36			 (unsigned long)task_stack_page(current));
 37
 38	notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV);
 39
 40	bust_spinlocks(0);
 41	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 42	spin_unlock_irq(&die_lock);
 43	oops_exit();
 44
 45	if (kexec_should_crash(current))
 46		crash_kexec(regs);
 47
 48	if (in_interrupt())
 49		panic("Fatal exception in interrupt");
 50
 51	if (panic_on_oops)
 52		panic("Fatal exception");
 53
 54	do_exit(SIGSEGV);
 55}
 56
 57void die_if_kernel(const char *str, struct pt_regs *regs, long err)
 58{
 59	if (!user_mode(regs))
 60		die(str, regs, err);
 61}
 62
 63/*
 64 * try and fix up kernelspace address errors
 65 * - userspace errors just cause EFAULT to be returned, resulting in SEGV
 66 * - kernel/userspace interfaces cause a jump to an appropriate handler
 67 * - other kernel errors are bad
 68 */
 69void die_if_no_fixup(const char *str, struct pt_regs *regs, long err)
 70{
 71	if (!user_mode(regs)) {
 72		const struct exception_table_entry *fixup;
 73		fixup = search_exception_tables(regs->pc);
 74		if (fixup) {
 75			regs->pc = fixup->fixup;
 76			return;
 77		}
 78
 79		die(str, regs, err);
 80	}
 81}
 82
 83#ifdef CONFIG_GENERIC_BUG
 84static void handle_BUG(struct pt_regs *regs)
 85{
 86	const struct bug_entry *bug;
 87	unsigned long bugaddr = regs->pc;
 88	enum bug_trap_type tt;
 89
 90	if (!is_valid_bugaddr(bugaddr))
 91		goto invalid;
 92
 93	bug = find_bug(bugaddr);
 94
 95	/* Switch unwinders when unwind_stack() is called */
 96	if (bug->flags & BUGFLAG_UNWINDER)
 97		unwinder_faulted = 1;
 98
 99	tt = report_bug(bugaddr, regs);
100	if (tt == BUG_TRAP_TYPE_WARN) {
101		regs->pc += instruction_size(bugaddr);
102		return;
103	}
104
105invalid:
106	die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
107}
108
109int is_valid_bugaddr(unsigned long addr)
110{
111	insn_size_t opcode;
112
113	if (addr < PAGE_OFFSET)
114		return 0;
115	if (probe_kernel_address((insn_size_t *)addr, opcode))
116		return 0;
117	if (opcode == TRAPA_BUG_OPCODE)
118		return 1;
119
120	return 0;
121}
122#endif
123
124/*
125 * Generic trap handler.
126 */
127BUILD_TRAP_HANDLER(debug)
128{
129	TRAP_HANDLER_DECL;
130
131	/* Rewind */
132	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
133
134	if (notify_die(DIE_TRAP, "debug trap", regs, 0, vec & 0xff,
135		       SIGTRAP) == NOTIFY_STOP)
136		return;
137
138	force_sig(SIGTRAP, current);
139}
140
141/*
142 * Special handler for BUG() traps.
143 */
144BUILD_TRAP_HANDLER(bug)
145{
146	TRAP_HANDLER_DECL;
147
148	/* Rewind */
149	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
150
151	if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff,
152		       SIGTRAP) == NOTIFY_STOP)
153		return;
154
155#ifdef CONFIG_GENERIC_BUG
156	if (__kernel_text_address(instruction_pointer(regs))) {
157		insn_size_t insn = *(insn_size_t *)instruction_pointer(regs);
158		if (insn == TRAPA_BUG_OPCODE)
159			handle_BUG(regs);
160		return;
161	}
162#endif
163
164	force_sig(SIGTRAP, current);
165}
166
167BUILD_TRAP_HANDLER(nmi)
168{
169	unsigned int cpu = smp_processor_id();
170	TRAP_HANDLER_DECL;
171
172	nmi_enter();
173	nmi_count(cpu)++;
174
175	switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) {
176	case NOTIFY_OK:
177	case NOTIFY_STOP:
178		break;
179	case NOTIFY_BAD:
180		die("Fatal Non-Maskable Interrupt", regs, SIGINT);
181	default:
182		printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n");
183		break;
184	}
185
186	nmi_exit();
187}

  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 <linux/uaccess.h>
  8#include <linux/hardirq.h>
 
 
 
  9#include <asm/unwinder.h>
 10#include <asm/system.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 11
 12#ifdef CONFIG_GENERIC_BUG
 13static void handle_BUG(struct pt_regs *regs)
 14{
 15	const struct bug_entry *bug;
 16	unsigned long bugaddr = regs->pc;
 17	enum bug_trap_type tt;
 18
 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);
 29	if (tt == BUG_TRAP_TYPE_WARN) {
 30		regs->pc += instruction_size(bugaddr);
 31		return;
 32	}
 33
 34invalid:
 35	die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff);
 36}
 37
 38int is_valid_bugaddr(unsigned long addr)
 39{
 40	insn_size_t opcode;
 41
 42	if (addr < PAGE_OFFSET)
 43		return 0;
 44	if (probe_kernel_address((insn_size_t *)addr, opcode))
 45		return 0;
 46	if (opcode == TRAPA_BUG_OPCODE)
 47		return 1;
 48
 49	return 0;
 50}
 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(__raw_readw(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(__raw_readw(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_GENERIC_BUG
 85	if (__kernel_text_address(instruction_pointer(regs))) {
 86		insn_size_t insn = *(insn_size_t *)instruction_pointer(regs);
 87		if (insn == TRAPA_BUG_OPCODE)
 88			handle_BUG(regs);
 89		return;
 90	}
 91#endif
 92
 93	force_sig(SIGTRAP, current);
 94}
 95
 96BUILD_TRAP_HANDLER(nmi)
 97{
 98	unsigned int cpu = smp_processor_id();
 99	TRAP_HANDLER_DECL;
100
101	nmi_enter();
102	nmi_count(cpu)++;
103
104	switch (notify_die(DIE_NMI, "NMI", regs, 0, vec & 0xff, SIGINT)) {
105	case NOTIFY_OK:
106	case NOTIFY_STOP:
107		break;
108	case NOTIFY_BAD:
109		die("Fatal Non-Maskable Interrupt", regs, SIGINT);
110	default:
111		printk(KERN_ALERT "Got NMI, but nobody cared. Ignoring...\n");
112		break;
113	}
114
115	nmi_exit();
116}