Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/frv/mm/extable.c | |
3 | */ | |
4 | ||
1da177e4 LT |
5 | #include <linux/module.h> |
6 | #include <linux/spinlock.h> | |
7 | #include <asm/uaccess.h> | |
8 | ||
9 | extern const struct exception_table_entry __attribute__((aligned(8))) __start___ex_table[]; | |
10 | extern const struct exception_table_entry __attribute__((aligned(8))) __stop___ex_table[]; | |
11 | extern const void __memset_end, __memset_user_error_lr, __memset_user_error_handler; | |
12 | extern const void __memcpy_end, __memcpy_user_error_lr, __memcpy_user_error_handler; | |
13 | extern spinlock_t modlist_lock; | |
14 | ||
15 | /*****************************************************************************/ | |
16 | /* | |
17 | * | |
18 | */ | |
19 | static inline unsigned long search_one_table(const struct exception_table_entry *first, | |
20 | const struct exception_table_entry *last, | |
21 | unsigned long value) | |
22 | { | |
23 | while (first <= last) { | |
24 | const struct exception_table_entry __attribute__((aligned(8))) *mid; | |
25 | long diff; | |
26 | ||
27 | mid = (last - first) / 2 + first; | |
28 | diff = mid->insn - value; | |
29 | if (diff == 0) | |
30 | return mid->fixup; | |
31 | else if (diff < 0) | |
32 | first = mid + 1; | |
33 | else | |
34 | last = mid - 1; | |
35 | } | |
36 | return 0; | |
37 | } /* end search_one_table() */ | |
38 | ||
39 | /*****************************************************************************/ | |
40 | /* | |
41 | * see if there's a fixup handler available to deal with a kernel fault | |
42 | */ | |
43 | unsigned long search_exception_table(unsigned long pc) | |
44 | { | |
018b8d12 | 45 | const struct exception_table_entry *extab; |
1da177e4 LT |
46 | |
47 | /* determine if the fault lay during a memcpy_user or a memset_user */ | |
48 | if (__frame->lr == (unsigned long) &__memset_user_error_lr && | |
49 | (unsigned long) &memset <= pc && pc < (unsigned long) &__memset_end | |
50 | ) { | |
51 | /* the fault occurred in a protected memset | |
52 | * - we search for the return address (in LR) instead of the program counter | |
53 | * - it was probably during a clear_user() | |
54 | */ | |
55 | return (unsigned long) &__memset_user_error_handler; | |
56 | } | |
018b8d12 DH |
57 | |
58 | if (__frame->lr == (unsigned long) &__memcpy_user_error_lr && | |
59 | (unsigned long) &memcpy <= pc && pc < (unsigned long) &__memcpy_end | |
60 | ) { | |
1da177e4 LT |
61 | /* the fault occurred in a protected memset |
62 | * - we search for the return address (in LR) instead of the program counter | |
63 | * - it was probably during a copy_to/from_user() | |
64 | */ | |
65 | return (unsigned long) &__memcpy_user_error_handler; | |
66 | } | |
67 | ||
018b8d12 DH |
68 | extab = search_exception_tables(pc); |
69 | if (extab) | |
70 | return extab->fixup; | |
1da177e4 | 71 | |
018b8d12 | 72 | return 0; |
1da177e4 | 73 | |
1da177e4 | 74 | } /* end search_exception_table() */ |