xref: /freebsd/lib/libc/csu/aarch64/reloc.c (revision dafba19e42e78cd3d7c9264ece49ddd3d7d70da5)
1 /*-
2  * Copyright (c) 2019 Leandro Lupori
3  * Copyright (c) 2021 The FreeBSD Foundation
4  *
5  * Portions of this software were developed by Andrew Turner
6  * under sponsorship from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 #include <machine/ifunc.h>
29 
30 static __ifunc_arg_t ifunc_arg;
31 
32 static void
33 ifunc_init(const Elf_Auxinfo *aux)
34 {
35 	ifunc_arg._size = sizeof(ifunc_arg);
36 	ifunc_arg._hwcap = 0;
37 	ifunc_arg._hwcap2 = 0;
38 	ifunc_arg._hwcap3 = 0;
39 	ifunc_arg._hwcap4 = 0;
40 
41 	for (;  aux->a_type != AT_NULL; aux++) {
42 		switch (aux->a_type) {
43 		case AT_HWCAP:
44 			ifunc_arg._hwcap = aux->a_un.a_val | _IFUNC_ARG_HWCAP;
45 			break;
46 		case AT_HWCAP2:
47 			ifunc_arg._hwcap2 = aux->a_un.a_val;
48 			break;
49 		case AT_HWCAP3:
50 			ifunc_arg._hwcap3 = aux->a_un.a_val;
51 			break;
52 		case AT_HWCAP4:
53 			ifunc_arg._hwcap4 = aux->a_un.a_val;
54 			break;
55 		}
56 	}
57 }
58 
59 static void
60 crt1_handle_rela(const Elf_Rela *r)
61 {
62 	typedef Elf_Addr (*ifunc_resolver_t)(
63 	    uint64_t, const __ifunc_arg_t *, uint64_t, uint64_t,
64 	    uint64_t, uint64_t, uint64_t, uint64_t);
65 	Elf_Addr *ptr, *where, target;
66 
67 	switch (ELF_R_TYPE(r->r_info)) {
68 	case R_AARCH64_IRELATIVE:
69 		ptr = (Elf_Addr *)r->r_addend;
70 		where = (Elf_Addr *)r->r_offset;
71 		target = ((ifunc_resolver_t)ptr)(ifunc_arg._hwcap, &ifunc_arg, 0, 0, 0, 0, 0, 0);
72 		*where = target;
73 		break;
74 	}
75 }
76