1 /*
2 * Copyright (c) 1999-2000 Wichert Akkerman <wichert@cistron.nl>
3 * Copyright (c) 2002-2005 Roland McGrath <roland@redhat.com>
4 * Copyright (c) 2008 Jan Kratochvil <jan.kratochvil@redhat.com>
5 * Copyright (c) 2009-2013 Denys Vlasenko <dvlasenk@redhat.com>
6 * Copyright (c) 2006-2015 Dmitry V. Levin <ldv@altlinux.org>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "defs.h"
33
34 #include <sched.h>
35
36 #ifndef CSIGNAL
37 # define CSIGNAL 0x000000ff
38 #endif
39
40 #include "xlat/clone_flags.h"
41
42 #if defined IA64
43 # define ARG_FLAGS 0
44 # define ARG_STACK 1
45 # define ARG_STACKSIZE (tcp->scno == SYS_clone2 ? 2 : -1)
46 # define ARG_PTID (tcp->scno == SYS_clone2 ? 3 : 2)
47 # define ARG_CTID (tcp->scno == SYS_clone2 ? 4 : 3)
48 # define ARG_TLS (tcp->scno == SYS_clone2 ? 5 : 4)
49 #elif defined S390 || defined S390X || defined CRISV10 || defined CRISV32
50 # define ARG_STACK 0
51 # define ARG_FLAGS 1
52 # define ARG_PTID 2
53 # define ARG_CTID 3
54 # define ARG_TLS 4
55 #elif defined X86_64 || defined X32
56 /* x86 personality processes have the last two arguments flipped. */
57 # define ARG_FLAGS 0
58 # define ARG_STACK 1
59 # define ARG_PTID 2
60 # define ARG_CTID ((current_personality != 1) ? 3 : 4)
61 # define ARG_TLS ((current_personality != 1) ? 4 : 3)
62 #elif defined ALPHA || defined TILE || defined OR1K
63 # define ARG_FLAGS 0
64 # define ARG_STACK 1
65 # define ARG_PTID 2
66 # define ARG_CTID 3
67 # define ARG_TLS 4
68 #else
69 # define ARG_FLAGS 0
70 # define ARG_STACK 1
71 # define ARG_PTID 2
72 # define ARG_TLS 3
73 # define ARG_CTID 4
74 #endif
75
76 #if defined I386 || defined X86_64 || defined X32
77 extern void print_user_desc(struct tcb *, long);
78 #endif /* I386 || X86_64 || X32 */
79
SYS_FUNC(clone)80 SYS_FUNC(clone)
81 {
82 if (exiting(tcp)) {
83 const char *sep = "|";
84 unsigned long flags = tcp->u_arg[ARG_FLAGS];
85 tprintf("child_stack=%#lx, ", tcp->u_arg[ARG_STACK]);
86 #ifdef ARG_STACKSIZE
87 if (ARG_STACKSIZE != -1)
88 tprintf("stack_size=%#lx, ",
89 tcp->u_arg[ARG_STACKSIZE]);
90 #endif
91 tprints("flags=");
92 if (!printflags(clone_flags, flags &~ CSIGNAL, NULL))
93 sep = "";
94 if ((flags & CSIGNAL) != 0)
95 tprintf("%s%s", sep, signame(flags & CSIGNAL));
96 if ((flags & (CLONE_PARENT_SETTID|CLONE_CHILD_SETTID
97 |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
98 return 0;
99 if (flags & CLONE_PARENT_SETTID)
100 tprintf(", parent_tidptr=%#lx", tcp->u_arg[ARG_PTID]);
101 if (flags & CLONE_SETTLS) {
102 #if defined I386 || defined X86_64 || defined X32
103 # ifndef I386
104 if (current_personality == 1)
105 # endif
106 {
107 tprints(", tls=");
108 print_user_desc(tcp, tcp->u_arg[ARG_TLS]);
109 }
110 # ifndef I386
111 else
112 # endif
113 #endif /* I386 || X86_64 || X32 */
114 tprintf(", tls=%#lx", tcp->u_arg[ARG_TLS]);
115 }
116 if (flags & (CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID))
117 tprintf(", child_tidptr=%#lx", tcp->u_arg[ARG_CTID]);
118 }
119 /* TODO on syscall entry:
120 * We can clear CLONE_PTRACE here since it is an ancient hack
121 * to allow us to catch children, and we use another hack for that.
122 * But CLONE_PTRACE can conceivably be used by malicious programs
123 * to subvert us. By clearing this bit, we can defend against it:
124 * in untraced execution, CLONE_PTRACE should have no effect.
125 *
126 * We can also clear CLONE_UNTRACED, since it allows to start
127 * children outside of our control. At the moment
128 * I'm trying to figure out whether there is a *legitimate*
129 * use of this flag which we should respect.
130 */
131 return 0;
132 }
133
SYS_FUNC(setns)134 SYS_FUNC(setns)
135 {
136 printfd(tcp, tcp->u_arg[0]);
137 tprints(", ");
138 printflags(clone_flags, tcp->u_arg[1], "CLONE_???");
139
140 return RVAL_DECODED;
141 }
142
SYS_FUNC(unshare)143 SYS_FUNC(unshare)
144 {
145 printflags(clone_flags, tcp->u_arg[0], "CLONE_???");
146 return RVAL_DECODED;
147 }
148
SYS_FUNC(fork)149 SYS_FUNC(fork)
150 {
151 return RVAL_DECODED | RVAL_UDECIMAL;
152 }
153