xref: /freebsd/lib/libc/csu/powerpc64/reloc.c (revision 63f537551380d2dab29fa402ad1269feae17e594)
1 /*-
2  * Copyright (c) 2019 Leandro Lupori
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  *
10  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
11  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
12  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
13  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
14  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
15  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
16  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
17  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
18  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
19  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
20  * SUCH DAMAGE.
21  */
22 
23 #include <sys/cdefs.h>
24 static uint32_t cpu_features;
25 static uint32_t cpu_features2;
26 
27 static void
28 init_cpu_features(char **env)
29 {
30 	const Elf_Auxinfo *aux;
31 
32 	/* Find the auxiliary vector on the stack. */
33 	while (*env++ != 0)	/* Skip over environment, and NULL terminator */
34 		;
35 	aux = (const Elf_Auxinfo *)env;
36 
37 	/* Digest the auxiliary vector. */
38 	for (;  aux->a_type != AT_NULL; aux++) {
39 		switch (aux->a_type) {
40 		case AT_HWCAP:
41 			cpu_features = (uint32_t)aux->a_un.a_val;
42 			break;
43 		case AT_HWCAP2:
44 			cpu_features2 = (uint32_t)aux->a_un.a_val;
45 			break;
46 		}
47 	}
48 }
49 
50 static void
51 crt1_handle_rela(const Elf_Rela *r)
52 {
53 	typedef Elf_Addr (*ifunc_resolver_t)(
54 	    uint32_t, uint32_t, uint64_t, uint64_t,
55 	    uint64_t, uint64_t, uint64_t, uint64_t);
56 	Elf_Addr *ptr, *where, target;
57 
58 	switch (ELF_R_TYPE(r->r_info)) {
59 	case R_PPC_IRELATIVE:
60 		ptr = (Elf_Addr *)r->r_addend;
61 		where = (Elf_Addr *)r->r_offset;
62 		target = ((ifunc_resolver_t)ptr)(cpu_features, cpu_features2,
63 		    0, 0, 0, 0, 0, 0);
64 		*where = target;
65 		break;
66 	}
67 }
68