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}
43