1#define _GNU_SOURCE
2#include <link.h>
3#include <stdint.h>
4
5struct find_exidx_data {
6 uintptr_t pc, exidx_start;
7 int exidx_len;
8};
9
10static int find_exidx(struct dl_phdr_info *info, size_t size, void *ptr)
11{
12 struct find_exidx_data *data = ptr;
13 const ElfW(Phdr) *phdr = info->dlpi_phdr;
14 uintptr_t addr, exidx_start = 0;
15 int i, match = 0, exidx_len = 0;
16
17 for (i = info->dlpi_phnum; i > 0; i--, phdr++) {
18 addr = info->dlpi_addr + phdr->p_vaddr;
19 switch (phdr->p_type) {
20 case PT_LOAD:
21 match |= data->pc >= addr && data->pc < addr + phdr->p_memsz;
22 break;
23 case PT_ARM_EXIDX:
24 exidx_start = addr;
25 exidx_len = phdr->p_memsz;
26 break;
27 }
28 }
29 data->exidx_start = exidx_start;
30 data->exidx_len = exidx_len;
31 return match;
32}
33
34uintptr_t __gnu_Unwind_Find_exidx(uintptr_t pc, int *pcount)
35{
36 struct find_exidx_data data;
37 data.pc = pc;
38 if (dl_iterate_phdr(find_exidx, &data) <= 0)
39 return 0;
40 *pcount = data.exidx_len / 8;
41 return data.exidx_start;
42}