1 // SPDX-License-Identifier: GPL-2.0 <<
2 /* 1 /*
3 * linux/arch/arm/mm/extable.c !! 2 * linux/arch/ppc/mm/extable.c
>> 3 *
>> 4 * from linux/arch/i386/mm/extable.c
4 */ 5 */
5 #include <linux/extable.h> <<
6 #include <linux/uaccess.h> <<
7 6
8 int fixup_exception(struct pt_regs *regs) !! 7 #include <linux/config.h>
>> 8 #include <linux/module.h>
>> 9 #include <asm/uaccess.h>
>> 10
>> 11 extern struct exception_table_entry __start___ex_table[];
>> 12 extern struct exception_table_entry __stop___ex_table[];
>> 13
>> 14 /*
>> 15 * The exception table needs to be sorted because we use the macros
>> 16 * which put things into the exception table in a variety of segments
>> 17 * such as the prep, pmac, chrp, etc. segments as well as the init
>> 18 * segment and the main kernel text segment.
>> 19 */
>> 20 static inline void
>> 21 sort_ex_table(struct exception_table_entry *start,
>> 22 struct exception_table_entry *finish)
9 { 23 {
10 const struct exception_table_entry *fi !! 24 struct exception_table_entry el, *p, *q;
11 25
12 fixup = search_exception_tables(instru !! 26 /* insertion sort */
13 if (fixup) { !! 27 for (p = start + 1; p < finish; ++p) {
14 regs->ARM_pc = fixup->fixup; !! 28 /* start .. p-1 is sorted */
15 #ifdef CONFIG_THUMB2_KERNEL !! 29 if (p[0].insn < p[-1].insn) {
16 /* Clear the IT state to avoid !! 30 /* move element p down to its right place */
17 regs->ARM_cpsr &= ~PSR_IT_MASK !! 31 el = *p;
18 #endif !! 32 q = p;
>> 33 do {
>> 34 /* el comes before q[-1], move q[-1] up one */
>> 35 q[0] = q[-1];
>> 36 --q;
>> 37 } while (q > start && el.insn < q[-1].insn);
>> 38 *q = el;
>> 39 }
19 } 40 }
>> 41 }
>> 42
>> 43 void
>> 44 sort_exception_table(void)
>> 45 {
>> 46 sort_ex_table(__start___ex_table, __stop___ex_table);
>> 47 }
>> 48
>> 49 static inline unsigned long
>> 50 search_one_table(const struct exception_table_entry *first,
>> 51 const struct exception_table_entry *last,
>> 52 unsigned long value)
>> 53 {
>> 54 while (first <= last) {
>> 55 const struct exception_table_entry *mid;
>> 56 long diff;
>> 57
>> 58 mid = (last - first) / 2 + first;
>> 59 diff = mid->insn - value;
>> 60 if (diff == 0)
>> 61 return mid->fixup;
>> 62 else if (diff < 0)
>> 63 first = mid+1;
>> 64 else
>> 65 last = mid-1;
>> 66 }
>> 67 return 0;
>> 68 }
>> 69
>> 70 unsigned long
>> 71 search_exception_table(unsigned long addr)
>> 72 {
>> 73 unsigned long ret;
>> 74
>> 75 #ifndef CONFIG_MODULES
>> 76 /* There is only the kernel to search. */
>> 77 ret = search_one_table(__start___ex_table, __stop___ex_table-1, addr);
>> 78 if (ret) return ret;
>> 79 #else
>> 80 /* The kernel is the last "module" -- no need to treat it special. */
>> 81 struct module *mp;
>> 82 for (mp = module_list; mp != NULL; mp = mp->next) {
>> 83 if (mp->ex_table_start == NULL)
>> 84 continue;
>> 85 ret = search_one_table(mp->ex_table_start,
>> 86 mp->ex_table_end - 1, addr);
>> 87 if (ret)
>> 88 return ret;
>> 89 }
>> 90 #endif
20 91
21 return fixup != NULL; !! 92 return 0;
22 } 93 }
23 94
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