xref: /freebsd/lib/libc/csu/riscv/reloc.c (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
1 /*-
2  * Copyright (c) 2019 Leandro Lupori
3  * Copyright (c) 2024 Jessica Clarke <jrtc27@FreeBSD.org>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  *
11  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
12  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
13  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
14  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
15  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
16  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
17  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
18  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
19  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
20  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
21  * SUCH DAMAGE.
22  */
23 
24 static unsigned long elf_hwcap;
25 
26 static void
27 ifunc_init(const Elf_Auxinfo *aux)
28 {
29 	/* Digest the auxiliary vector. */
30 	for (; aux->a_type != AT_NULL; aux++) {
31 		switch (aux->a_type) {
32 		case AT_HWCAP:
33 			elf_hwcap = (uint32_t)aux->a_un.a_val;
34 			break;
35 		}
36 	}
37 }
38 
39 static void
40 crt1_handle_rela(const Elf_Rela *r)
41 {
42 	typedef Elf_Addr (*ifunc_resolver_t)(
43 	    unsigned long, unsigned long, unsigned long, unsigned long,
44 	    unsigned long, unsigned long, unsigned long, unsigned long);
45 	Elf_Addr *ptr, *where, target;
46 
47 	switch (ELF_R_TYPE(r->r_info)) {
48 	case R_RISCV_IRELATIVE:
49 		ptr = (Elf_Addr *)r->r_addend;
50 		where = (Elf_Addr *)r->r_offset;
51 		target = ((ifunc_resolver_t)ptr)(elf_hwcap,
52 		    0, 0, 0, 0, 0, 0, 0);
53 		*where = target;
54 		break;
55 	}
56 }
57