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/* $OpenBSD: syscallwx.c,v 1.1 2019/09/23 08:34:07 bluhm Exp $ */
/*
* Copyright (c) 2018 Todd Mortimer <mortimer@openbsd.org>
* Copyright (c) 2019 Alexander Bluhm <bluhm@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/mman.h>
#include <err.h>
#include <signal.h>
#include <unistd.h>
void handler(int);
int
main(int argc, char *argv[])
{
pid_t pid;
pid = getpid();
if (pid == -1)
err(1, "getpid");
/* map kill system call in libc writeable */
if (mprotect(kill, 100, PROT_EXEC | PROT_WRITE | PROT_READ) == -1)
err(1, "mprotect");
if (signal(SIGSEGV, handler) == SIG_ERR)
err(1, "signal");
if (kill(pid, SIGABRT) == -1)
err(1, "kill");
return 3;
}
void
handler(int signum)
{
_exit(0);
}
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