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
68extern void print_user_desc(struct tcb *, long);
69#endif /* I386 || X86_64 || X32 */
70
71SYS_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
125SYS_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
135SYS_FUNC(unshare)
136{
137	if (entering(tcp))
138		printflags(clone_flags, tcp->u_arg[0], "CLONE_???");
139	return 0;
140}
141
142SYS_FUNC(fork)
143{
144	if (exiting(tcp))
145		return RVAL_UDECIMAL;
146	return 0;
147}
148