elfcorehdr_read
rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf64_Ehdr), &addr);
rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
rc = elfcorehdr_read((char *)&ehdr, sizeof(Elf32_Ehdr), &addr);
rc = elfcorehdr_read(elfcorebuf, elfcorebuf_sz_orig, &addr);
rc = elfcorehdr_read(e_ident, EI_NIDENT, &addr);
extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);