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