]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - kernel/seccomp.c
Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6
[mirror_ubuntu-artful-kernel.git] / kernel / seccomp.c
CommitLineData
1da177e4
LT
1/*
2 * linux/kernel/seccomp.c
3 *
4 * Copyright 2004-2005 Andrea Arcangeli <andrea@cpushare.com>
5 *
6 * This defines a simple but solid secure-computing mode.
7 */
8
9#include <linux/seccomp.h>
10#include <linux/sched.h>
5b101740 11#include <linux/compat.h>
1da177e4
LT
12
13/* #define SECCOMP_DEBUG 1 */
1d9d02fe 14#define NR_SECCOMP_MODES 1
1da177e4
LT
15
16/*
17 * Secure computing mode 1 allows only read/write/exit/sigreturn.
18 * To be fully secure this must be combined with rlimit
19 * to limit the stack allocations too.
20 */
21static int mode1_syscalls[] = {
22 __NR_seccomp_read, __NR_seccomp_write, __NR_seccomp_exit, __NR_seccomp_sigreturn,
23 0, /* null terminated */
24};
25
5b101740 26#ifdef CONFIG_COMPAT
1da177e4
LT
27static int mode1_syscalls_32[] = {
28 __NR_seccomp_read_32, __NR_seccomp_write_32, __NR_seccomp_exit_32, __NR_seccomp_sigreturn_32,
29 0, /* null terminated */
30};
31#endif
32
33void __secure_computing(int this_syscall)
34{
35 int mode = current->seccomp.mode;
36 int * syscall;
37
38 switch (mode) {
39 case 1:
40 syscall = mode1_syscalls;
5b101740
RM
41#ifdef CONFIG_COMPAT
42 if (is_compat_task())
1da177e4
LT
43 syscall = mode1_syscalls_32;
44#endif
45 do {
46 if (*syscall == this_syscall)
47 return;
48 } while (*++syscall);
49 break;
50 default:
51 BUG();
52 }
53
54#ifdef SECCOMP_DEBUG
55 dump_stack();
56#endif
57 do_exit(SIGKILL);
58}
1d9d02fe
AA
59
60long prctl_get_seccomp(void)
61{
62 return current->seccomp.mode;
63}
64
65long prctl_set_seccomp(unsigned long seccomp_mode)
66{
67 long ret;
68
69 /* can set it only once to be even more secure */
70 ret = -EPERM;
71 if (unlikely(current->seccomp.mode))
72 goto out;
73
74 ret = -EINVAL;
75 if (seccomp_mode && seccomp_mode <= NR_SECCOMP_MODES) {
76 current->seccomp.mode = seccomp_mode;
77 set_thread_flag(TIF_SECCOMP);
cf99abac
AA
78#ifdef TIF_NOTSC
79 disable_TSC();
80#endif
1d9d02fe
AA
81 ret = 0;
82 }
83
84 out:
85 return ret;
86}