xref: /freebsd/sys/i386/include/profile.h (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef _MACHINE_PROFILE_H_
33 #define	_MACHINE_PROFILE_H_
34 
35 #ifndef _KERNEL
36 
37 #include <sys/cdefs.h>
38 
39 #define	FUNCTION_ALIGNMENT	4
40 
41 #define	_MCOUNT_DECL static __inline void _mcount
42 
43 #define	MCOUNT								\
44 void									\
45 mcount()								\
46 {									\
47 	uintfptr_t selfpc, frompc, ecx;					\
48 	/*								\
49 	 * In gcc 4.2, ecx might be used in the caller as the arg	\
50 	 * pointer if the stack realignment option is set (-mstackrealign) \
51 	 * or if the caller has the force_align_arg_pointer attribute	\
52 	 * (stack realignment is ALWAYS on for main).  Preserve ecx	\
53 	 * here.							\
54 	 */								\
55 	__asm("" : "=c" (ecx));						\
56 	/*								\
57 	 * Find the return address for mcount,				\
58 	 * and the return address for mcount's caller.			\
59 	 *								\
60 	 * selfpc = pc pushed by call to mcount				\
61 	 */								\
62 	__asm("movl 4(%%ebp),%0" : "=r" (selfpc));			\
63 	/*								\
64 	 * frompc = pc pushed by call to mcount's caller.		\
65 	 * The caller's stack frame has already been built, so %ebp is	\
66 	 * the caller's frame pointer.  The caller's raddr is in the	\
67 	 * caller's frame following the caller's caller's frame pointer.\
68 	 */								\
69 	__asm("movl (%%ebp),%0" : "=r" (frompc));			\
70 	frompc = ((uintfptr_t *)frompc)[1];				\
71 	_mcount(frompc, selfpc);					\
72 	__asm("" : : "c" (ecx));					\
73 }
74 
75 typedef	u_int	uintfptr_t;
76 
77 /*
78  * An unsigned integral type that can hold non-negative difference between
79  * function pointers.
80  */
81 typedef	u_int	fptrdiff_t;
82 
83 __BEGIN_DECLS
84 void	mcount(void) __asm(".mcount");
85 __END_DECLS
86 
87 #endif /* !_KERNEL */
88 
89 #endif /* !_MACHINE_PROFILE_H_ */
90