forked from strace/strace
-
Notifications
You must be signed in to change notification settings - Fork 0
/
clone.c
165 lines (155 loc) · 5.09 KB
/
clone.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
/*
* Copyright (c) 1999-2000 Wichert Akkerman <[email protected]>
* Copyright (c) 2002-2005 Roland McGrath <[email protected]>
* Copyright (c) 2008 Jan Kratochvil <[email protected]>
* Copyright (c) 2009-2013 Denys Vlasenko <[email protected]>
* Copyright (c) 2006-2015 Dmitry V. Levin <[email protected]>
* Copyright (c) 2014-2017 The strace developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "defs.h"
#include <sched.h>
#include <asm/unistd.h>
#ifndef CSIGNAL
# define CSIGNAL 0x000000ff
#endif
#include "xlat/clone_flags.h"
#include "xlat/setns_types.h"
#include "xlat/unshare_flags.h"
#if defined IA64
# define ARG_FLAGS 0
# define ARG_STACK 1
# define ARG_STACKSIZE (tcp->scno == __NR_clone2 ? 2 : -1)
# define ARG_PTID (tcp->scno == __NR_clone2 ? 3 : 2)
# define ARG_CTID (tcp->scno == __NR_clone2 ? 4 : 3)
# define ARG_TLS (tcp->scno == __NR_clone2 ? 5 : 4)
#elif defined S390 || defined S390X
# define ARG_STACK 0
# define ARG_FLAGS 1
# define ARG_PTID 2
# define ARG_CTID 3
# define ARG_TLS 4
#elif defined X86_64 || defined X32
/* x86 personality processes have the last two arguments flipped. */
# define ARG_FLAGS 0
# define ARG_STACK 1
# define ARG_PTID 2
# define ARG_CTID ((current_personality != 1) ? 3 : 4)
# define ARG_TLS ((current_personality != 1) ? 4 : 3)
#elif defined ALPHA || defined TILE || defined OR1K || defined RISCV
# define ARG_FLAGS 0
# define ARG_STACK 1
# define ARG_PTID 2
# define ARG_CTID 3
# define ARG_TLS 4
#else
# define ARG_FLAGS 0
# define ARG_STACK 1
# define ARG_PTID 2
# define ARG_TLS 3
# define ARG_CTID 4
#endif
static void
print_tls_arg(struct tcb *const tcp, const kernel_ulong_t addr)
{
#ifdef HAVE_STRUCT_USER_DESC
# if SUPPORTED_PERSONALITIES > 1
if (current_personality == 1)
# endif
{
print_user_desc(tcp, tcp->u_arg[ARG_TLS], USER_DESC_BOTH);
}
# if SUPPORTED_PERSONALITIES > 1
else
# endif
#endif /* HAVE_STRUCT_USER_DESC */
{
printaddr(tcp->u_arg[ARG_TLS]);
}
}
SYS_FUNC(clone)
{
if (exiting(tcp)) {
const char *sep = "|";
kernel_ulong_t flags = tcp->u_arg[ARG_FLAGS];
tprints("child_stack=");
printaddr(tcp->u_arg[ARG_STACK]);
tprints(", ");
#ifdef ARG_STACKSIZE
if (ARG_STACKSIZE != -1)
tprintf("stack_size=%#" PRI_klx ", ",
tcp->u_arg[ARG_STACKSIZE]);
#endif
tprints("flags=");
if (!printflags64(clone_flags, flags & ~CSIGNAL, NULL))
sep = "";
if ((flags & CSIGNAL) != 0)
tprintf("%s%s", sep, signame(flags & CSIGNAL));
if ((flags & (CLONE_PARENT_SETTID|CLONE_CHILD_SETTID
|CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
return 0;
if (flags & CLONE_PARENT_SETTID) {
tprints(", parent_tidptr=");
printaddr(tcp->u_arg[ARG_PTID]);
}
if (flags & CLONE_SETTLS) {
tprints(", tls=");
print_tls_arg(tcp, tcp->u_arg[ARG_TLS]);
}
if (flags & (CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID)) {
tprints(", child_tidptr=");
printaddr(tcp->u_arg[ARG_CTID]);
}
}
/* TODO on syscall entry:
* We can clear CLONE_PTRACE here since it is an ancient hack
* to allow us to catch children, and we use another hack for that.
* But CLONE_PTRACE can conceivably be used by malicious programs
* to subvert us. By clearing this bit, we can defend against it:
* in untraced execution, CLONE_PTRACE should have no effect.
*
* We can also clear CLONE_UNTRACED, since it allows to start
* children outside of our control. At the moment
* I'm trying to figure out whether there is a *legitimate*
* use of this flag which we should respect.
*/
return 0;
}
SYS_FUNC(setns)
{
printfd(tcp, tcp->u_arg[0]);
tprints(", ");
printxval(setns_types, tcp->u_arg[1], "CLONE_NEW???");
return RVAL_DECODED;
}
SYS_FUNC(unshare)
{
printflags64(unshare_flags, tcp->u_arg[0], "CLONE_???");
return RVAL_DECODED;
}
SYS_FUNC(fork)
{
return RVAL_DECODED | RVAL_UDECIMAL;
}