Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 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 | |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 6 | #include <signal.h> |
Mike Frysinger | b40895c | 2018-05-30 17:12:59 -0400 | [diff] [blame] | 7 | #include <stdlib.h> |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 8 | #include <string.h> |
Mike Frysinger | b40895c | 2018-05-30 17:12:59 -0400 | [diff] [blame] | 9 | #include <unistd.h> |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 10 | |
Jorge Lucangeli Obes | a21c8fc | 2015-07-15 16:22:34 -0700 | [diff] [blame] | 11 | #include "signal_handler.h" |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 12 | |
| 13 | #include "util.h" |
| 14 | |
Mike Frysinger | b40895c | 2018-05-30 17:12:59 -0400 | [diff] [blame] | 15 | /* |
| 16 | * si_syscall was added in glibc-2.17+, but Android still uses glibc-2.15 |
| 17 | * for its prebuilt binary host toolchains. Add a compat hack for it. |
| 18 | */ |
| 19 | static int get_si_syscall(const siginfo_t *info) |
| 20 | { |
| 21 | #if defined(si_syscall) |
| 22 | return info->si_syscall; |
| 23 | #endif |
| 24 | |
| 25 | typedef struct { |
| 26 | void *ip; |
| 27 | int nr; |
| 28 | unsigned int arch; |
| 29 | } local_siginfo_t; |
| 30 | |
| 31 | union { |
| 32 | const siginfo_t *info; |
| 33 | const local_siginfo_t *local_info; |
| 34 | } local_info = { |
| 35 | .info = info, |
| 36 | }; |
| 37 | return local_info.local_info->nr; |
| 38 | } |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 39 | |
Mike Frysinger | 33d051a | 2018-05-30 16:41:10 -0400 | [diff] [blame] | 40 | void log_sigsys_handler(int sig attribute_unused, siginfo_t *info, |
Mike Frysinger | d9ef07c | 2018-05-30 16:51:36 -0400 | [diff] [blame] | 41 | void *void_context attribute_unused) |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 42 | { |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 43 | const char *syscall_name; |
Mike Frysinger | b40895c | 2018-05-30 17:12:59 -0400 | [diff] [blame] | 44 | int nr = get_si_syscall(info); |
| 45 | syscall_name = lookup_syscall_name(nr); |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 46 | |
Jeff Vander Stoep | 00c5791 | 2016-02-03 15:48:06 -0800 | [diff] [blame] | 47 | if (syscall_name) |
| 48 | die("blocked syscall: %s", syscall_name); |
| 49 | else |
Mike Frysinger | b40895c | 2018-05-30 17:12:59 -0400 | [diff] [blame] | 50 | die("blocked syscall: %d", nr); |
Jeff Vander Stoep | 00c5791 | 2016-02-03 15:48:06 -0800 | [diff] [blame] | 51 | |
Jorge Lucangeli Obes | bda833c | 2012-07-31 16:25:56 -0700 | [diff] [blame] | 52 | /* |
| 53 | * We trapped on a syscall that should have killed the process. |
| 54 | * This should never ever return, but we're paranoid. |
| 55 | */ |
| 56 | for (;;) |
| 57 | _exit(1); |
| 58 | } |
| 59 | |
| 60 | int install_sigsys_handler() |
| 61 | { |
| 62 | int ret = 0; |
| 63 | struct sigaction act; |
| 64 | sigset_t mask; |
| 65 | |
| 66 | memset(&act, 0, sizeof(act)); |
| 67 | act.sa_sigaction = &log_sigsys_handler; |
| 68 | act.sa_flags = SA_SIGINFO; |
| 69 | |
| 70 | sigemptyset(&mask); |
| 71 | sigaddset(&mask, SIGSYS); |
| 72 | |
| 73 | ret = sigaction(SIGSYS, &act, NULL); |
| 74 | if (ret < 0) |
| 75 | return ret; |
| 76 | |
| 77 | ret = sigprocmask(SIG_UNBLOCK, &mask, NULL); |
| 78 | if (ret < 0) |
| 79 | return ret; |
| 80 | |
| 81 | return 0; |
| 82 | } |