github.com/afumu/libc@v0.0.6/musl/src/ldso/arm/find_exidx.c (about)

     1  #define _GNU_SOURCE
     2  #include <link.h>
     3  #include <stdint.h>
     4  
     5  struct find_exidx_data {
     6  	uintptr_t pc, exidx_start;
     7  	int exidx_len;
     8  };
     9  
    10  static 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  
    34  uintptr_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  }