xref: /freebsd-12.1/usr.bin/truss/amd64-linux.c (revision df57947f)
1 /*-
2  * SPDX-License-Identifier: BSD-4-Clause
3  *
4  * Copyright 1997 Sean Eric Fagan
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by Sean Eric Fagan
17  * 4. Neither the name of the author may be used to endorse or promote
18  *    products derived from this software without specific prior written
19  *    permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 /* Linux/x86_64-specific system call handling. */
38 
39 #include <sys/ptrace.h>
40 
41 #include <machine/reg.h>
42 #include <machine/psl.h>
43 
44 #include <stdbool.h>
45 #include <stdio.h>
46 #include <sysdecode.h>
47 
48 #include "truss.h"
49 
50 static int
amd64_linux_fetch_args(struct trussinfo * trussinfo,u_int narg)51 amd64_linux_fetch_args(struct trussinfo *trussinfo, u_int narg)
52 {
53 	struct reg regs;
54 	struct current_syscall *cs;
55 	lwpid_t tid;
56 
57 	tid = trussinfo->curthread->tid;
58 	cs = &trussinfo->curthread->cs;
59 	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
60 		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
61 		return (-1);
62 	}
63 
64 	switch (narg) {
65 	default:
66 		cs->args[5] = regs.r_r9;
67 	case 5:
68 		cs->args[4] = regs.r_r8;
69 	case 4:
70 		cs->args[3] = regs.r_rcx;
71 	case 3:
72 		cs->args[2] = regs.r_rdx;
73 	case 2:
74 		cs->args[1] = regs.r_rsi;
75 	case 1:
76 		cs->args[0] = regs.r_rdi;
77 	}
78 
79 	return (0);
80 }
81 
82 static int
amd64_linux_fetch_retval(struct trussinfo * trussinfo,long * retval,int * errorp)83 amd64_linux_fetch_retval(struct trussinfo *trussinfo, long *retval, int *errorp)
84 {
85 	struct reg regs;
86 	lwpid_t tid;
87 
88 	tid = trussinfo->curthread->tid;
89 	if (ptrace(PT_GETREGS, tid, (caddr_t)&regs, 0) < 0) {
90 		fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
91 		return (-1);
92 	}
93 
94 	retval[0] = regs.r_rax;
95 	retval[1] = regs.r_rdx;
96 	*errorp = !!(regs.r_rflags & PSL_C);
97 	return (0);
98 }
99 
100 static struct procabi amd64_linux = {
101 	"Linux ELF64",
102 	SYSDECODE_ABI_LINUX,
103 	amd64_linux_fetch_args,
104 	amd64_linux_fetch_retval,
105 	STAILQ_HEAD_INITIALIZER(amd64_linux.extra_syscalls),
106 	{ NULL }
107 };
108 
109 PROCABI(amd64_linux);
110