Commit | Line | Data |
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5a4f7c66 PM |
1 | #include <linux/bug.h> |
2 | #include <linux/io.h> | |
3 | #include <linux/types.h> | |
4 | #include <linux/kdebug.h> | |
47a3eb95 PM |
5 | #include <linux/signal.h> |
6 | #include <linux/sched.h> | |
9a33fc21 | 7 | #include <linux/uaccess.h> |
1e1030dc | 8 | #include <linux/hardirq.h> |
5f857bce PM |
9 | #include <linux/kernel.h> |
10 | #include <linux/kexec.h> | |
11 | #include <linux/module.h> | |
e115f2c1 | 12 | #include <asm/unwinder.h> |
e839ca52 | 13 | #include <asm/traps.h> |
5a4f7c66 | 14 | |
5f857bce PM |
15 | static DEFINE_SPINLOCK(die_lock); |
16 | ||
17 | void 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); | |
373d4d09 | 41 | add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); |
5f857bce PM |
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 | ||
57 | void 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 | */ | |
69 | void 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 | ||
626ac8e1 PM |
83 | #ifdef CONFIG_GENERIC_BUG |
84 | static void handle_BUG(struct pt_regs *regs) | |
5a4f7c66 | 85 | { |
e115f2c1 PM |
86 | const struct bug_entry *bug; |
87 | unsigned long bugaddr = regs->pc; | |
5a4f7c66 | 88 | enum bug_trap_type tt; |
e115f2c1 PM |
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); | |
5a4f7c66 | 100 | if (tt == BUG_TRAP_TYPE_WARN) { |
e115f2c1 | 101 | regs->pc += instruction_size(bugaddr); |
5a4f7c66 PM |
102 | return; |
103 | } | |
104 | ||
e115f2c1 | 105 | invalid: |
5a4f7c66 PM |
106 | die("Kernel BUG", regs, TRAPA_BUG_OPCODE & 0xff); |
107 | } | |
108 | ||
109 | int is_valid_bugaddr(unsigned long addr) | |
110 | { | |
2bcfffa4 | 111 | insn_size_t opcode; |
9a33fc21 PM |
112 | |
113 | if (addr < PAGE_OFFSET) | |
114 | return 0; | |
2bcfffa4 | 115 | if (probe_kernel_address((insn_size_t *)addr, opcode)) |
9a33fc21 | 116 | return 0; |
e115f2c1 | 117 | if (opcode == TRAPA_BUG_OPCODE) |
b344e24a MF |
118 | return 1; |
119 | ||
120 | return 0; | |
5a4f7c66 PM |
121 | } |
122 | #endif | |
123 | ||
124 | /* | |
125 | * Generic trap handler. | |
126 | */ | |
127 | BUILD_TRAP_HANDLER(debug) | |
128 | { | |
129 | TRAP_HANDLER_DECL; | |
130 | ||
131 | /* Rewind */ | |
9d56dd3b | 132 | regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); |
5a4f7c66 PM |
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 | */ | |
144 | BUILD_TRAP_HANDLER(bug) | |
145 | { | |
146 | TRAP_HANDLER_DECL; | |
147 | ||
148 | /* Rewind */ | |
9d56dd3b | 149 | regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); |
5a4f7c66 PM |
150 | |
151 | if (notify_die(DIE_TRAP, "bug trap", regs, 0, TRAPA_BUG_OPCODE & 0xff, | |
152 | SIGTRAP) == NOTIFY_STOP) | |
153 | return; | |
154 | ||
626ac8e1 | 155 | #ifdef CONFIG_GENERIC_BUG |
5a4f7c66 | 156 | if (__kernel_text_address(instruction_pointer(regs))) { |
2bcfffa4 | 157 | insn_size_t insn = *(insn_size_t *)instruction_pointer(regs); |
5a4f7c66 PM |
158 | if (insn == TRAPA_BUG_OPCODE) |
159 | handle_BUG(regs); | |
0ec39885 | 160 | return; |
5a4f7c66 PM |
161 | } |
162 | #endif | |
163 | ||
164 | force_sig(SIGTRAP, current); | |
165 | } | |
1e1030dc PM |
166 | |
167 | BUILD_TRAP_HANDLER(nmi) | |
168 | { | |
731ba330 | 169 | unsigned int cpu = smp_processor_id(); |
1e1030dc PM |
170 | TRAP_HANDLER_DECL; |
171 | ||
172 | nmi_enter(); | |
731ba330 | 173 | nmi_count(cpu)++; |
1e1030dc PM |
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 | } |