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 * $FreeBSD$ 32 */ 33 34 #ifndef _MACHINE_PROFILE_H_ 35 #define _MACHINE_PROFILE_H_ 36 37 #define FUNCTION_ALIGNMENT 32 38 39 typedef u_long fptrdiff_t; 40 41 #ifndef _KERNEL 42 43 #include <sys/cdefs.h> 44 45 typedef __uintfptr_t uintfptr_t; 46 47 #define _MCOUNT_DECL \ 48 static void _mcount(uintfptr_t frompc, uintfptr_t selfpc) __used; \ 49 static void _mcount 50 51 /* 52 * Call into _mcount. On arm64 the .mcount is a function so callers will 53 * handle caller saved registers. As we don't directly touch any callee 54 * saved registers we can just load the two arguments and use a tail call 55 * into the MI _mcount function. 56 * 57 * When building with gcc frompc will be in x0, however this is not the 58 * case on clang. As such we need to load it from the stack. As long as 59 * the caller follows the ABI this will load the correct value. 60 */ 61 #define MCOUNT __asm( \ 62 " .text \n" \ 63 " .align 6 \n" \ 64 " .type .mcount,#function \n" \ 65 " .globl .mcount \n" \ 66 " .mcount: \n" \ 67 " .cfi_startproc \n" \ 68 /* Load the caller return address as frompc */ \ 69 " ldr x0, [x29, #8] \n" \ 70 /* Use our return address as selfpc */ \ 71 " mov x1, lr \n" \ 72 " b _mcount \n" \ 73 " .cfi_endproc \n" \ 74 " .size .mcount, . - .mcount \n" \ 75 ); 76 #if 0 77 /* 78 * If clang passed frompc correctly we could implement it like this, however 79 * all clang versions we care about would need to be fixed before we could 80 * make this change. 81 */ 82 void 83 mcount(uintfptr_t frompc) 84 { 85 _mcount(frompc, __builtin_return_address(0)); 86 } 87 #endif 88 89 #endif /* !_KERNEL */ 90 91 #endif /* !_MACHINE_PROFILE_H_ */ 92