Commit | Line | Data |
---|---|---|
6d48583b | 1 | #include <linux/module.h> |
6d48583b HH |
2 | #include <asm/uaccess.h> |
3 | ||
548acf19 TL |
4 | typedef bool (*ex_handler_t)(const struct exception_table_entry *, |
5 | struct pt_regs *, int); | |
6 | ||
70627654 PA |
7 | static inline unsigned long |
8 | ex_fixup_addr(const struct exception_table_entry *x) | |
9 | { | |
10 | return (unsigned long)&x->fixup + x->fixup; | |
11 | } | |
548acf19 TL |
12 | static inline ex_handler_t |
13 | ex_fixup_handler(const struct exception_table_entry *x) | |
14 | { | |
15 | return (ex_handler_t)((unsigned long)&x->handler + x->handler); | |
16 | } | |
6d48583b | 17 | |
548acf19 TL |
18 | bool ex_handler_default(const struct exception_table_entry *fixup, |
19 | struct pt_regs *regs, int trapnr) | |
6d48583b | 20 | { |
548acf19 TL |
21 | regs->ip = ex_fixup_addr(fixup); |
22 | return true; | |
23 | } | |
24 | EXPORT_SYMBOL(ex_handler_default); | |
25 | ||
26 | bool ex_handler_fault(const struct exception_table_entry *fixup, | |
27 | struct pt_regs *regs, int trapnr) | |
28 | { | |
29 | regs->ip = ex_fixup_addr(fixup); | |
30 | regs->ax = trapnr; | |
31 | return true; | |
32 | } | |
33 | EXPORT_SYMBOL_GPL(ex_handler_fault); | |
34 | ||
35 | bool ex_handler_ext(const struct exception_table_entry *fixup, | |
36 | struct pt_regs *regs, int trapnr) | |
37 | { | |
38 | /* Special hack for uaccess_err */ | |
39 | current_thread_info()->uaccess_err = 1; | |
40 | regs->ip = ex_fixup_addr(fixup); | |
41 | return true; | |
42 | } | |
43 | EXPORT_SYMBOL(ex_handler_ext); | |
44 | ||
45 | bool ex_has_fault_handler(unsigned long ip) | |
46 | { | |
47 | const struct exception_table_entry *e; | |
48 | ex_handler_t handler; | |
49 | ||
50 | e = search_exception_tables(ip); | |
51 | if (!e) | |
52 | return false; | |
53 | handler = ex_fixup_handler(e); | |
54 | ||
55 | return handler == ex_handler_fault; | |
56 | } | |
57 | ||
58 | int fixup_exception(struct pt_regs *regs, int trapnr) | |
59 | { | |
60 | const struct exception_table_entry *e; | |
61 | ex_handler_t handler; | |
6d48583b HH |
62 | |
63 | #ifdef CONFIG_PNPBIOS | |
64 | if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs))) { | |
65 | extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp; | |
66 | extern u32 pnp_bios_is_utter_crap; | |
67 | pnp_bios_is_utter_crap = 1; | |
68 | printk(KERN_CRIT "PNPBIOS fault.. attempting recovery.\n"); | |
69 | __asm__ volatile( | |
70 | "movl %0, %%esp\n\t" | |
71 | "jmp *%1\n\t" | |
72 | : : "g" (pnp_bios_fault_esp), "g" (pnp_bios_fault_eip)); | |
73 | panic("do_trap: can't hit this"); | |
74 | } | |
75 | #endif | |
76 | ||
548acf19 TL |
77 | e = search_exception_tables(regs->ip); |
78 | if (!e) | |
79 | return 0; | |
6d48583b | 80 | |
548acf19 TL |
81 | handler = ex_fixup_handler(e); |
82 | return handler(e, regs, trapnr); | |
6d48583b | 83 | } |
6a1ea279 PA |
84 | |
85 | /* Restricted version used during very early boot */ | |
86 | int __init early_fixup_exception(unsigned long *ip) | |
87 | { | |
548acf19 | 88 | const struct exception_table_entry *e; |
70627654 | 89 | unsigned long new_ip; |
548acf19 | 90 | ex_handler_t handler; |
6a1ea279 | 91 | |
548acf19 TL |
92 | e = search_exception_tables(*ip); |
93 | if (!e) | |
94 | return 0; | |
70627654 | 95 | |
548acf19 TL |
96 | new_ip = ex_fixup_addr(e); |
97 | handler = ex_fixup_handler(e); | |
6a1ea279 | 98 | |
548acf19 TL |
99 | /* special handling not supported during early boot */ |
100 | if (handler != ex_handler_default) | |
101 | return 0; | |
6a1ea279 | 102 | |
548acf19 TL |
103 | *ip = new_ip; |
104 | return 1; | |
6a1ea279 | 105 | } |