1/*-
2 * SPDX-License-Identifier: MIT-CMU
3 *
4 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
5 * All rights reserved.
6 *
7 * Author: Chris G. Demetriou
8 *
9 * Permission to use, copy, modify and distribute this software and
10 * its documentation is hereby granted, provided that both the copyright
11 * notice and this permission notice appear in all copies of the
12 * software, derivative works or modified versions, and any portions
13 * thereof, and that both notices appear in supporting documentation.
14 *
15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
16 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
17 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18 *
19 * Carnegie Mellon requests users of this software to return to
20 *
21 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
22 * School of Computer Science
23 * Carnegie Mellon University
24 * Pittsburgh PA 15213-3890
25 *
26 * any improvements or extensions that they make and grant Carnegie the
27 * rights to redistribute these changes.
28 *
29 * from: NetBSD: profile.h,v 1.9 1997/04/06 08:47:37 cgd Exp
30 * from: FreeBSD: src/sys/alpha/include/profile.h,v 1.4 1999/12/29
31 */
32
33#ifdef __arm__
34#include <arm/profile.h>
35#else /* !__arm__ */
36
37#ifndef _MACHINE_PROFILE_H_
38#define _MACHINE_PROFILE_H_
39
40#define FUNCTION_ALIGNMENT 32
41
42typedef u_long fptrdiff_t;
43
44#ifndef _KERNEL
45
46#include <sys/cdefs.h>
47
48typedef __uintfptr_t uintfptr_t;
49
50#define _MCOUNT_DECL \
51static void _mcount(uintfptr_t frompc, uintfptr_t selfpc) __used; \
52static void _mcount
53
54/*
55 * Call into _mcount. On arm64 the .mcount is a function so callers will
56 * handle caller saved registers. As we don't directly touch any callee
57 * saved registers we can just load the two arguments and use a tail call
58 * into the MI _mcount function.
59 *
60 * When building with gcc frompc will be in x0, however this is not the
61 * case on clang. As such we need to load it from the stack. As long as
62 * the caller follows the ABI this will load the correct value.
63 */
64#define MCOUNT __asm( \
65" .text \n" \
66" .align 6 \n" \
67" .type .mcount,#function \n" \
68" .globl .mcount \n" \
69" .mcount: \n" \
70" .cfi_startproc \n" \
71 /* Allow this to work with BTI, see BTI_C in asm.h */ \
72" hint #34 \n" \
73 /* Load the caller return address as frompc */ \
74" ldr x0, [x29, #8] \n" \
75 /* Use our return address as selfpc */ \
76" mov x1, lr \n" \
77" b _mcount \n" \
78" .cfi_endproc \n" \
79" .size .mcount, . - .mcount \n" \
80 );
81#if 0
82/*
83 * If clang passed frompc correctly we could implement it like this, however
84 * all clang versions we care about would need to be fixed before we could
85 * make this change.
86 */
87void
88mcount(uintfptr_t frompc)
89{
90 _mcount(frompc, __builtin_return_address(0));
91}
92#endif
93
94#endif /* !_KERNEL */
95
96#endif /* !_MACHINE_PROFILE_H_ */
97
98#endif /* !__arm__ */