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/i386-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_linux32_fetch_args(struct trussinfo * trussinfo,u_int narg)51 amd64_linux32_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)®s, 0) < 0) {
60 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
61 return (-1);
62 }
63
64 /*
65 * Linux passes syscall arguments in registers, not
66 * on the stack. Fortunately, we've got access to the
67 * register set. Note that we don't bother checking the
68 * number of arguments. And what does linux do for syscalls
69 * that have more than five arguments?
70 */
71 switch (narg) {
72 default:
73 cs->args[5] = regs.r_rbp; /* Unconfirmed */
74 case 5:
75 cs->args[4] = regs.r_rdi;
76 case 4:
77 cs->args[3] = regs.r_rsi;
78 case 3:
79 cs->args[2] = regs.r_rdx;
80 case 2:
81 cs->args[1] = regs.r_rcx;
82 case 1:
83 cs->args[0] = regs.r_rbx;
84 }
85
86 return (0);
87 }
88
89 static int
amd64_linux32_fetch_retval(struct trussinfo * trussinfo,long * retval,int * errorp)90 amd64_linux32_fetch_retval(struct trussinfo *trussinfo, long *retval,
91 int *errorp)
92 {
93 struct reg regs;
94 lwpid_t tid;
95
96 tid = trussinfo->curthread->tid;
97 if (ptrace(PT_GETREGS, tid, (caddr_t)®s, 0) < 0) {
98 fprintf(trussinfo->outfile, "-- CANNOT READ REGISTERS --\n");
99 return (-1);
100 }
101
102 retval[0] = regs.r_rax & 0xffffffff;
103 retval[1] = regs.r_rdx & 0xffffffff;
104 *errorp = !!(regs.r_rflags & PSL_C);
105 if (*errorp)
106 retval[0] = (int)retval[0];
107 return (0);
108 }
109
110 static struct procabi amd64_linux32 = {
111 "Linux ELF32",
112 SYSDECODE_ABI_LINUX32,
113 amd64_linux32_fetch_args,
114 amd64_linux32_fetch_retval,
115 STAILQ_HEAD_INITIALIZER(amd64_linux32.extra_syscalls),
116 { NULL }
117 };
118
119 PROCABI(amd64_linux32);
120