1 #include "defs.h"
2
3 /* defines copied from linux/sched.h since we can't include that
4 * ourselves (it conflicts with *lots* of libc includes)
5 */
6 #define CSIGNAL 0x000000ff /* signal mask to be sent at exit */
7 #define CLONE_VM 0x00000100 /* set if VM shared between processes */
8 #define CLONE_FS 0x00000200 /* set if fs info shared between processes */
9 #define CLONE_FILES 0x00000400 /* set if open files shared between processes */
10 #define CLONE_SIGHAND 0x00000800 /* set if signal handlers shared */
11 #define CLONE_IDLETASK 0x00001000 /* kernel-only flag */
12 #define CLONE_PTRACE 0x00002000 /* set if we want to let tracing continue on the child too */
13 #define CLONE_VFORK 0x00004000 /* set if the parent wants the child to wake it up on mm_release */
14 #define CLONE_PARENT 0x00008000 /* set if we want to have the same parent as the cloner */
15 #define CLONE_THREAD 0x00010000 /* Same thread group? */
16 #define CLONE_NEWNS 0x00020000 /* New namespace group? */
17 #define CLONE_SYSVSEM 0x00040000 /* share system V SEM_UNDO semantics */
18 #define CLONE_SETTLS 0x00080000 /* create a new TLS for the child */
19 #define CLONE_PARENT_SETTID 0x00100000 /* set the TID in the parent */
20 #define CLONE_CHILD_CLEARTID 0x00200000 /* clear the TID in the child */
21 #define CLONE_UNTRACED 0x00800000 /* set if the tracing process can't force CLONE_PTRACE on this clone */
22 #define CLONE_CHILD_SETTID 0x01000000 /* set the TID in the child */
23 #define CLONE_STOPPED 0x02000000 /* Start in stopped state */
24 #define CLONE_NEWUTS 0x04000000 /* New utsname group? */
25 #define CLONE_NEWIPC 0x08000000 /* New ipcs */
26 #define CLONE_NEWUSER 0x10000000 /* New user namespace */
27 #define CLONE_NEWPID 0x20000000 /* New pid namespace */
28 #define CLONE_NEWNET 0x40000000 /* New network namespace */
29 #define CLONE_IO 0x80000000 /* Clone io context */
30
31 #include "xlat/clone_flags.h"
32
33 #if defined IA64
34 # define ARG_FLAGS 0
35 # define ARG_STACK 1
36 # define ARG_STACKSIZE (tcp->scno == SYS_clone2 ? 2 : -1)
37 # define ARG_PTID (tcp->scno == SYS_clone2 ? 3 : 2)
38 # define ARG_CTID (tcp->scno == SYS_clone2 ? 4 : 3)
39 # define ARG_TLS (tcp->scno == SYS_clone2 ? 5 : 4)
40 #elif defined S390 || defined S390X || defined CRISV10 || defined CRISV32
41 # define ARG_STACK 0
42 # define ARG_FLAGS 1
43 # define ARG_PTID 2
44 # define ARG_CTID 3
45 # define ARG_TLS 4
46 #elif defined X86_64 || defined X32
47 /* x86 personality processes have the last two arguments flipped. */
48 # define ARG_FLAGS 0
49 # define ARG_STACK 1
50 # define ARG_PTID 2
51 # define ARG_CTID ((current_personality != 1) ? 3 : 4)
52 # define ARG_TLS ((current_personality != 1) ? 4 : 3)
53 #elif defined ALPHA || defined TILE || defined OR1K
54 # define ARG_FLAGS 0
55 # define ARG_STACK 1
56 # define ARG_PTID 2
57 # define ARG_CTID 3
58 # define ARG_TLS 4
59 #else
60 # define ARG_FLAGS 0
61 # define ARG_STACK 1
62 # define ARG_PTID 2
63 # define ARG_TLS 3
64 # define ARG_CTID 4
65 #endif
66
67 #if defined I386 || defined X86_64 || defined X32
68 extern void print_user_desc(struct tcb *, long);
69 #endif /* I386 || X86_64 || X32 */
70
SYS_FUNC(clone)71 SYS_FUNC(clone)
72 {
73 if (exiting(tcp)) {
74 const char *sep = "|";
75 unsigned long flags = tcp->u_arg[ARG_FLAGS];
76 tprintf("child_stack=%#lx, ", tcp->u_arg[ARG_STACK]);
77 #ifdef ARG_STACKSIZE
78 if (ARG_STACKSIZE != -1)
79 tprintf("stack_size=%#lx, ",
80 tcp->u_arg[ARG_STACKSIZE]);
81 #endif
82 tprints("flags=");
83 if (!printflags(clone_flags, flags &~ CSIGNAL, NULL))
84 sep = "";
85 if ((flags & CSIGNAL) != 0)
86 tprintf("%s%s", sep, signame(flags & CSIGNAL));
87 if ((flags & (CLONE_PARENT_SETTID|CLONE_CHILD_SETTID
88 |CLONE_CHILD_CLEARTID|CLONE_SETTLS)) == 0)
89 return 0;
90 if (flags & CLONE_PARENT_SETTID)
91 tprintf(", parent_tidptr=%#lx", tcp->u_arg[ARG_PTID]);
92 if (flags & CLONE_SETTLS) {
93 #if defined I386 || defined X86_64 || defined X32
94 # ifndef I386
95 if (current_personality == 1)
96 # endif
97 {
98 tprints(", tls=");
99 print_user_desc(tcp, tcp->u_arg[ARG_TLS]);
100 }
101 # ifndef I386
102 else
103 # endif
104 #endif /* I386 || X86_64 || X32 */
105 tprintf(", tls=%#lx", tcp->u_arg[ARG_TLS]);
106 }
107 if (flags & (CLONE_CHILD_SETTID|CLONE_CHILD_CLEARTID))
108 tprintf(", child_tidptr=%#lx", tcp->u_arg[ARG_CTID]);
109 }
110 /* TODO on syscall entry:
111 * We can clear CLONE_PTRACE here since it is an ancient hack
112 * to allow us to catch children, and we use another hack for that.
113 * But CLONE_PTRACE can conceivably be used by malicious programs
114 * to subvert us. By clearing this bit, we can defend against it:
115 * in untraced execution, CLONE_PTRACE should have no effect.
116 *
117 * We can also clear CLONE_UNTRACED, since it allows to start
118 * children outside of our control. At the moment
119 * I'm trying to figure out whether there is a *legitimate*
120 * use of this flag which we should respect.
121 */
122 return 0;
123 }
124
SYS_FUNC(setns)125 SYS_FUNC(setns)
126 {
127 if (entering(tcp)) {
128 printfd(tcp, tcp->u_arg[0]);
129 tprints(", ");
130 printflags(clone_flags, tcp->u_arg[1], "CLONE_???");
131 }
132 return 0;
133 }
134
SYS_FUNC(unshare)135 SYS_FUNC(unshare)
136 {
137 if (entering(tcp))
138 printflags(clone_flags, tcp->u_arg[0], "CLONE_???");
139 return 0;
140 }
141
SYS_FUNC(fork)142 SYS_FUNC(fork)
143 {
144 if (exiting(tcp))
145 return RVAL_UDECIMAL;
146 return 0;
147 }
148