projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 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() */ |