1 /* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
2 * Use of this source code is governed by a BSD-style license that can be
3 * found in the LICENSE file.
4 */
5
6 /* These header files need to be included before asm/siginfo.h such that
7 * pid_t, timer_t, and clock_t are defined. */
8 #include <stdlib.h>
9 #include <unistd.h>
10
11 #include <asm/siginfo.h>
12 #define __have_siginfo_t 1
13 #define __have_sigval_t 1
14 #define __have_sigevent_t 1
15
16 #include <signal.h>
17 #include <string.h>
18
19 #include "signal_handler.h"
20
21 #include "util.h"
22
23 struct local_sigsys {
24 void *ip;
25 int nr;
26 unsigned int arch;
27 };
28
log_sigsys_handler(int nr,siginfo_t * info,void * void_context)29 void log_sigsys_handler(int nr, siginfo_t *info, void *void_context)
30 {
31 struct local_sigsys sigsys;
32 const char *syscall_name;
33 memcpy(&sigsys, &info->_sifields, sizeof(sigsys));
34 syscall_name = lookup_syscall_name(sigsys.nr);
35
36 (void) void_context;
37
38 if (syscall_name)
39 die("blocked syscall: %s", syscall_name);
40 else
41 die("blocked syscall: %d", nr);
42
43 /*
44 * We trapped on a syscall that should have killed the process.
45 * This should never ever return, but we're paranoid.
46 */
47 for (;;)
48 _exit(1);
49 }
50
install_sigsys_handler()51 int install_sigsys_handler()
52 {
53 int ret = 0;
54 struct sigaction act;
55 sigset_t mask;
56
57 memset(&act, 0, sizeof(act));
58 act.sa_sigaction = &log_sigsys_handler;
59 act.sa_flags = SA_SIGINFO;
60
61 sigemptyset(&mask);
62 sigaddset(&mask, SIGSYS);
63
64 ret = sigaction(SIGSYS, &act, NULL);
65 if (ret < 0)
66 return ret;
67
68 ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
69 if (ret < 0)
70 return ret;
71
72 return 0;
73 }
74