/* Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include <signal.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "signal_handler.h"
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#include "util.h"
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/*
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* si_syscall was added in glibc-2.17+, but Android still uses glibc-2.15
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* for its prebuilt binary host toolchains. Add a compat hack for it.
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*/
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static int get_si_syscall(const siginfo_t *info)
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{
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#if defined(si_syscall)
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return info->si_syscall;
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#endif
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typedef struct {
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void *ip;
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int nr;
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unsigned int arch;
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} local_siginfo_t;
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union {
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const siginfo_t *info;
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const local_siginfo_t *local_info;
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} local_info = {
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.info = info,
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};
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return local_info.local_info->nr;
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}
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void log_sigsys_handler(int sig attribute_unused, siginfo_t *info,
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void *void_context attribute_unused)
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{
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const char *syscall_name;
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int nr = get_si_syscall(info);
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syscall_name = lookup_syscall_name(nr);
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if (syscall_name)
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die("blocked syscall: %s", syscall_name);
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else
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die("blocked syscall: %d", nr);
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/*
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* We trapped on a syscall that should have killed the process.
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* This should never ever return, but we're paranoid.
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*/
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for (;;)
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_exit(1);
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}
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int install_sigsys_handler()
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{
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int ret = 0;
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struct sigaction act;
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sigset_t mask;
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memset(&act, 0, sizeof(act));
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act.sa_sigaction = &log_sigsys_handler;
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act.sa_flags = SA_SIGINFO;
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sigemptyset(&mask);
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sigaddset(&mask, SIGSYS);
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ret = sigaction(SIGSYS, &act, NULL);
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if (ret < 0)
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return ret;
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ret = sigprocmask(SIG_UNBLOCK, &mask, NULL);
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if (ret < 0)
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return ret;
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return 0;
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}
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