Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/sparc/mm/extable.c |
| 3 | */ |
| 4 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | #include <linux/module.h> |
| 6 | #include <asm/uaccess.h> |
| 7 | |
| 8 | void sort_extable(struct exception_table_entry *start, |
| 9 | struct exception_table_entry *finish) |
| 10 | { |
| 11 | } |
| 12 | |
| 13 | /* Caller knows they are in a range if ret->fixup == 0 */ |
| 14 | const struct exception_table_entry * |
| 15 | search_extable(const struct exception_table_entry *start, |
| 16 | const struct exception_table_entry *last, |
| 17 | unsigned long value) |
| 18 | { |
| 19 | const struct exception_table_entry *walk; |
| 20 | |
| 21 | /* Single insn entries are encoded as: |
| 22 | * word 1: insn address |
| 23 | * word 2: fixup code address |
| 24 | * |
| 25 | * Range entries are encoded as: |
| 26 | * word 1: first insn address |
| 27 | * word 2: 0 |
| 28 | * word 3: last insn address + 4 bytes |
| 29 | * word 4: fixup code address |
| 30 | * |
Rusty Russell | ad6561d | 2009-06-12 21:47:03 -0600 | [diff] [blame] | 31 | * Deleted entries are encoded as: |
| 32 | * word 1: unused |
| 33 | * word 2: -1 |
| 34 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | * See asm/uaccess.h for more details. |
| 36 | */ |
| 37 | |
| 38 | /* 1. Try to find an exact match. */ |
| 39 | for (walk = start; walk <= last; walk++) { |
| 40 | if (walk->fixup == 0) { |
| 41 | /* A range entry, skip both parts. */ |
| 42 | walk++; |
| 43 | continue; |
| 44 | } |
| 45 | |
Rusty Russell | ad6561d | 2009-06-12 21:47:03 -0600 | [diff] [blame] | 46 | /* A deleted entry; see trim_init_extable */ |
| 47 | if (walk->fixup == -1) |
| 48 | continue; |
| 49 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | if (walk->insn == value) |
| 51 | return walk; |
| 52 | } |
| 53 | |
| 54 | /* 2. Try to find a range match. */ |
| 55 | for (walk = start; walk <= (last - 1); walk++) { |
| 56 | if (walk->fixup) |
| 57 | continue; |
| 58 | |
| 59 | if (walk[0].insn <= value && walk[1].insn > value) |
| 60 | return walk; |
| 61 | |
| 62 | walk++; |
| 63 | } |
| 64 | |
| 65 | return NULL; |
| 66 | } |
| 67 | |
Rusty Russell | ad6561d | 2009-06-12 21:47:03 -0600 | [diff] [blame] | 68 | #ifdef CONFIG_MODULES |
| 69 | /* We could memmove them around; easier to mark the trimmed ones. */ |
| 70 | void trim_init_extable(struct module *m) |
| 71 | { |
| 72 | unsigned int i; |
| 73 | bool range; |
| 74 | |
| 75 | for (i = 0; i < m->num_exentries; i += range ? 2 : 1) { |
| 76 | range = m->extable[i].fixup == 0; |
| 77 | |
| 78 | if (within_module_init(m->extable[i].insn, m)) { |
| 79 | m->extable[i].fixup = -1; |
| 80 | if (range) |
| 81 | m->extable[i+1].fixup = -1; |
| 82 | } |
| 83 | if (range) |
| 84 | i++; |
| 85 | } |
| 86 | } |
| 87 | #endif /* CONFIG_MODULES */ |
| 88 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | /* Special extable search, which handles ranges. Returns fixup */ |
| 90 | unsigned long search_extables_range(unsigned long addr, unsigned long *g2) |
| 91 | { |
| 92 | const struct exception_table_entry *entry; |
| 93 | |
| 94 | entry = search_exception_tables(addr); |
| 95 | if (!entry) |
| 96 | return 0; |
| 97 | |
| 98 | /* Inside range? Fix g2 and return correct fixup */ |
| 99 | if (!entry->fixup) { |
| 100 | *g2 = (addr - entry->insn) / 4; |
| 101 | return (entry + 1)->fixup; |
| 102 | } |
| 103 | |
| 104 | return entry->fixup; |
| 105 | } |