Commit | Line | Data |
---|---|---|
6d48583b | 1 | #include <linux/module.h> |
6d48583b | 2 | #include <asm/uaccess.h> |
0d0efc07 | 3 | #include <asm/traps.h> |
6d48583b | 4 | |
548acf19 TL |
5 | typedef bool (*ex_handler_t)(const struct exception_table_entry *, |
6 | struct pt_regs *, int); | |
7 | ||
70627654 PA |
8 | static inline unsigned long |
9 | ex_fixup_addr(const struct exception_table_entry *x) | |
10 | { | |
11 | return (unsigned long)&x->fixup + x->fixup; | |
12 | } | |
548acf19 TL |
13 | static inline ex_handler_t |
14 | ex_fixup_handler(const struct exception_table_entry *x) | |
15 | { | |
16 | return (ex_handler_t)((unsigned long)&x->handler + x->handler); | |
17 | } | |
6d48583b | 18 | |
548acf19 TL |
19 | bool ex_handler_default(const struct exception_table_entry *fixup, |
20 | struct pt_regs *regs, int trapnr) | |
6d48583b | 21 | { |
548acf19 TL |
22 | regs->ip = ex_fixup_addr(fixup); |
23 | return true; | |
24 | } | |
25 | EXPORT_SYMBOL(ex_handler_default); | |
26 | ||
27 | bool ex_handler_fault(const struct exception_table_entry *fixup, | |
28 | struct pt_regs *regs, int trapnr) | |
29 | { | |
30 | regs->ip = ex_fixup_addr(fixup); | |
31 | regs->ax = trapnr; | |
32 | return true; | |
33 | } | |
34 | EXPORT_SYMBOL_GPL(ex_handler_fault); | |
35 | ||
36 | bool ex_handler_ext(const struct exception_table_entry *fixup, | |
37 | struct pt_regs *regs, int trapnr) | |
38 | { | |
39 | /* Special hack for uaccess_err */ | |
40 | current_thread_info()->uaccess_err = 1; | |
41 | regs->ip = ex_fixup_addr(fixup); | |
42 | return true; | |
43 | } | |
44 | EXPORT_SYMBOL(ex_handler_ext); | |
45 | ||
46 | bool ex_has_fault_handler(unsigned long ip) | |
47 | { | |
48 | const struct exception_table_entry *e; | |
49 | ex_handler_t handler; | |
50 | ||
51 | e = search_exception_tables(ip); | |
52 | if (!e) | |
53 | return false; | |
54 | handler = ex_fixup_handler(e); | |
55 | ||
56 | return handler == ex_handler_fault; | |
57 | } | |
58 | ||
59 | int fixup_exception(struct pt_regs *regs, int trapnr) | |
60 | { | |
61 | const struct exception_table_entry *e; | |
62 | ex_handler_t handler; | |
6d48583b HH |
63 | |
64 | #ifdef CONFIG_PNPBIOS | |
65 | if (unlikely(SEGMENT_IS_PNP_CODE(regs->cs))) { | |
66 | extern u32 pnp_bios_fault_eip, pnp_bios_fault_esp; | |
67 | extern u32 pnp_bios_is_utter_crap; | |
68 | pnp_bios_is_utter_crap = 1; | |
69 | printk(KERN_CRIT "PNPBIOS fault.. attempting recovery.\n"); | |
70 | __asm__ volatile( | |
71 | "movl %0, %%esp\n\t" | |
72 | "jmp *%1\n\t" | |
73 | : : "g" (pnp_bios_fault_esp), "g" (pnp_bios_fault_eip)); | |
74 | panic("do_trap: can't hit this"); | |
75 | } | |
76 | #endif | |
77 | ||
548acf19 TL |
78 | e = search_exception_tables(regs->ip); |
79 | if (!e) | |
80 | return 0; | |
6d48583b | 81 | |
548acf19 TL |
82 | handler = ex_fixup_handler(e); |
83 | return handler(e, regs, trapnr); | |
6d48583b | 84 | } |
6a1ea279 PA |
85 | |
86 | /* Restricted version used during very early boot */ | |
7bbcdb1c | 87 | int __init early_fixup_exception(struct pt_regs *regs, int trapnr) |
6a1ea279 | 88 | { |
548acf19 | 89 | const struct exception_table_entry *e; |
70627654 | 90 | unsigned long new_ip; |
548acf19 | 91 | ex_handler_t handler; |
6a1ea279 | 92 | |
0d0efc07 AL |
93 | /* Ignore early NMIs. */ |
94 | if (trapnr == X86_TRAP_NMI) | |
95 | return 1; | |
96 | ||
7bbcdb1c | 97 | e = search_exception_tables(regs->ip); |
548acf19 TL |
98 | if (!e) |
99 | return 0; | |
70627654 | 100 | |
548acf19 TL |
101 | new_ip = ex_fixup_addr(e); |
102 | handler = ex_fixup_handler(e); | |
6a1ea279 | 103 | |
548acf19 TL |
104 | /* special handling not supported during early boot */ |
105 | if (handler != ex_handler_default) | |
106 | return 0; | |
6a1ea279 | 107 | |
7bbcdb1c | 108 | regs->ip = new_ip; |
548acf19 | 109 | return 1; |
6a1ea279 | 110 | } |