xref: /freebsd/libexec/rtld-elf/amd64/rtld_machdep.h (revision a3e8fd0b7f663db7eafff527d5c3ca3bcfa8a537)
1 /*-
2  * Copyright (c) 1999, 2000 John D. Polstra.
3  * All rights reserved.
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  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
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  * $FreeBSD$
27  */
28 
29 #ifndef RTLD_MACHDEP_H
30 #define RTLD_MACHDEP_H	1
31 
32 struct Struct_Obj_Entry;
33 
34 /* Return the address of the .dynamic section in the dynamic linker. */
35 #define rtld_dynamic(obj) \
36     ((const Elf_Dyn *)((obj)->relocbase + (Elf_Addr)&_DYNAMIC))
37 
38 /* Fixup the jump slot at "where" to transfer control to "target". */
39 static inline Elf_Addr
40 reloc_jmpslot(Elf_Addr *where, Elf_Addr target,
41 	      const struct Struct_Obj_Entry *obj)
42 {
43     dbg("reloc_jmpslot: *%p = %p", (void *)(where),
44 	(void *)(target));
45     (*(Elf_Addr *)(where) = (Elf_Addr)(target));
46     return target;
47 }
48 
49 #define make_function_pointer(def, defobj) \
50 	((defobj)->relocbase + (def)->st_value)
51 
52 #define call_initfini_pointer(obj, target) \
53 	(((InitFunc)(target))())
54 
55 static inline void
56 atomic_decr_int(volatile int *p)
57 {
58     __asm __volatile ("lock; decl %0" : "+m"(*p) : : "cc");
59 }
60 
61 static inline void
62 atomic_incr_int(volatile int *p)
63 {
64     __asm __volatile ("lock; incl %0" : "+m"(*p) : : "cc");
65 }
66 
67 static inline void
68 atomic_add_int(volatile int *p, int val)
69 {
70     __asm __volatile ("lock; addl %1, %0"
71 	: "+m"(*p)
72 	: "ri"(val)
73 	: "cc");
74 }
75 
76 #endif
77