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 #include <sched.h>
34 #include <asm/unistd.h>
35
36 #ifndef CSIGNAL
37 # define CSIGNAL 0x000000ff
38 #endif
39
40 #include "xlat/clone_flags.h"
41 #include "xlat/setns_types.h"
42 #include "xlat/unshare_flags.h"
43
44 #if defined IA64
45 # define ARG_FLAGS 0
46 # define ARG_STACK 1
47 # define ARG_STACKSIZE (tcp->scno == __NR_clone2 ? 2 : -1)
48 # define ARG_PTID (tcp->scno == __NR_clone2 ? 3 : 2)
49 # define ARG_CTID (tcp->scno == __NR_clone2 ? 4 : 3)
50 # define ARG_TLS (tcp->scno == __NR_clone2 ? 5 : 4)
51 #elif defined S390 || defined S390X || defined CRISV10 || defined CRISV32
52 # define ARG_STACK 0
53 # define ARG_FLAGS 1
54 # define ARG_PTID 2
55 # define ARG_CTID 3
56 # define ARG_TLS 4
57 #elif defined X86_64 || defined X32
58 /* x86 personality processes have the last two arguments flipped. */
59 # define ARG_FLAGS 0
60 # define ARG_STACK 1
61 # define ARG_PTID 2
62 # define ARG_CTID ((current_personality != 1) ? 3 : 4)
63 # define ARG_TLS ((current_personality != 1) ? 4 : 3)
64 #elif defined ALPHA || defined TILE || defined OR1K || defined RISCV
65 # define ARG_FLAGS 0
66 # define ARG_STACK 1
67 # define ARG_PTID 2
68 # define ARG_CTID 3
69 # define ARG_TLS 4
70 #else
71 # define ARG_FLAGS 0
72 # define ARG_STACK 1
73 # define ARG_PTID 2
74 # define ARG_TLS 3
75 # define ARG_CTID 4
76 #endif
77
78 static void
print_tls_arg(struct tcb * const tcp,const kernel_ulong_t addr)79 print_tls_arg(struct tcb *const tcp, const kernel_ulong_t addr)
80 {
81 #ifdef HAVE_STRUCT_USER_DESC
82 # if SUPPORTED_PERSONALITIES > 1
83 if (current_personality == 1)
84 # endif
85 {
86 print_user_desc(tcp, tcp->u_arg[ARG_TLS]);
87 }
88 # if SUPPORTED_PERSONALITIES > 1
89 else
90 # endif
91 #endif /* HAVE_STRUCT_USER_DESC */
92 {
93 printaddr(tcp->u_arg[ARG_TLS]);
94 }
95 }
96
SYS_FUNC(clone)97 SYS_FUNC(clone)
98 {
99 if (exiting(tcp)) {
100 const char *sep = "|";
101 kernel_ulong_t flags = tcp->u_arg[ARG_FLAGS];
102 tprints("child_stack=");
103 printaddr(tcp->u_arg[ARG_STACK]);
104 tprints(", ");
105 #ifdef ARG_STACKSIZE
106 if (ARG_STACKSIZE != -1)
107 tprintf("stack_size=%#" PRI_klx ", ",
108 tcp->u_arg[ARG_STACKSIZE]);
109 #endif
110 tprints("flags=");
111 if (!printflags64(clone_flags, flags &~ CSIGNAL, NULL))
112 sep = "";
113 if ((flags & CSIGNAL) != 0)
114 tprintf("%s%s", sep, signame(flags & CSIGNAL));
115 if ((flags & (CLONE_PARENT_SETTID|CLONE_CHILD_SETTID
116 |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
117 return 0;
118 if (flags & CLONE_PARENT_SETTID) {
119 tprints(", parent_tidptr=");
120 printaddr(tcp->u_arg[ARG_PTID]);
121 }
122 if (flags & CLONE_SETTLS) {
123 tprints(", tls=");
124 print_tls_arg(tcp, tcp->u_arg[ARG_TLS]);
125 }
126 if (flags & (CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID)) {
127 tprints(", child_tidptr=");
128 printaddr(tcp->u_arg[ARG_CTID]);
129 }
130 }
131 /* TODO on syscall entry:
132 * We can clear CLONE_PTRACE here since it is an ancient hack
133 * to allow us to catch children, and we use another hack for that.
134 * But CLONE_PTRACE can conceivably be used by malicious programs
135 * to subvert us. By clearing this bit, we can defend against it:
136 * in untraced execution, CLONE_PTRACE should have no effect.
137 *
138 * We can also clear CLONE_UNTRACED, since it allows to start
139 * children outside of our control. At the moment
140 * I'm trying to figure out whether there is a *legitimate*
141 * use of this flag which we should respect.
142 */
143 return 0;
144 }
145
SYS_FUNC(setns)146 SYS_FUNC(setns)
147 {
148 printfd(tcp, tcp->u_arg[0]);
149 tprints(", ");
150 printxval(setns_types, tcp->u_arg[1], "CLONE_NEW???");
151
152 return RVAL_DECODED;
153 }
154
SYS_FUNC(unshare)155 SYS_FUNC(unshare)
156 {
157 printflags64(unshare_flags, tcp->u_arg[0], "CLONE_???");
158 return RVAL_DECODED;
159 }
160
SYS_FUNC(fork)161 SYS_FUNC(fork)
162 {
163 return RVAL_DECODED | RVAL_UDECIMAL;
164 }
165